OpenCloudOS-Kernel/drivers/tty/serial/imx.c

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tty: add SPDX identifiers to all remaining files in drivers/tty/ It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/tty files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Jiri Slaby <jslaby@suse.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: James Hogan <jhogan@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Eric Anholt <eric@anholt.net> Cc: Stefan Wahren <stefan.wahren@i2se.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ray Jui <rjui@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Joachim Eastwood <manabian@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: "Uwe Kleine-König" <kernel@pengutronix.de> Cc: Pat Gefre <pfg@sgi.com> Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Sylvain Lemieux <slemieux.tyco@gmail.com> Cc: Carlo Caione <carlo@caione.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Andy Gross <andy.gross@linaro.org> Cc: David Brown <david.brown@linaro.org> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Barry Song <baohua@kernel.org> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@tabi.org> Cc: Tony Prisk <linux@prisktech.co.nz> Cc: Michal Simek <michal.simek@xilinx.com> Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-07 01:11:51 +08:00
// SPDX-License-Identifier: GPL-2.0+
/*
* Driver for Motorola/Freescale IMX serial ports
*
* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
*
* Author: Sascha Hauer <sascha@saschahauer.de>
* Copyright (C) 2004 Pengutronix
*/
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/platform_device.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/ktime.h>
#include <linux/pinctrl/consumer.h>
#include <linux/rational.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/io.h>
#include <linux/dma-mapping.h>
#include <asm/irq.h>
#include <linux/platform_data/serial-imx.h>
#include <linux/platform_data/dma-imx.h>
#include "serial_mctrl_gpio.h"
/* Register definitions */
#define URXD0 0x0 /* Receiver Register */
#define URTX0 0x40 /* Transmitter Register */
#define UCR1 0x80 /* Control Register 1 */
#define UCR2 0x84 /* Control Register 2 */
#define UCR3 0x88 /* Control Register 3 */
#define UCR4 0x8c /* Control Register 4 */
#define UFCR 0x90 /* FIFO Control Register */
#define USR1 0x94 /* Status Register 1 */
#define USR2 0x98 /* Status Register 2 */
#define UESC 0x9c /* Escape Character Register */
#define UTIM 0xa0 /* Escape Timer Register */
#define UBIR 0xa4 /* BRM Incremental Register */
#define UBMR 0xa8 /* BRM Modulator Register */
#define UBRC 0xac /* Baud Rate Count Register */
#define IMX21_ONEMS 0xb0 /* One Millisecond register */
#define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
#define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
/* UART Control Register Bit Fields.*/
#define URXD_DUMMY_READ (1<<16)
#define URXD_CHARRDY (1<<15)
#define URXD_ERR (1<<14)
#define URXD_OVRRUN (1<<13)
#define URXD_FRMERR (1<<12)
#define URXD_BRK (1<<11)
#define URXD_PRERR (1<<10)
#define URXD_RX_DATA (0xFF<<0)
#define UCR1_ADEN (1<<15) /* Auto detect interrupt */
#define UCR1_ADBR (1<<14) /* Auto detect baud rate */
#define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */
#define UCR1_IDEN (1<<12) /* Idle condition interrupt */
#define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
#define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */
#define UCR1_RXDMAEN (1<<8) /* Recv ready DMA enable */
#define UCR1_IREN (1<<7) /* Infrared interface enable */
#define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */
#define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */
#define UCR1_SNDBRK (1<<4) /* Send break */
#define UCR1_TXDMAEN (1<<3) /* Transmitter ready DMA enable */
#define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
#define UCR1_ATDMAEN (1<<2) /* Aging DMA Timer Enable */
#define UCR1_DOZE (1<<1) /* Doze */
#define UCR1_UARTEN (1<<0) /* UART enabled */
#define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */
#define UCR2_IRTS (1<<14) /* Ignore RTS pin */
#define UCR2_CTSC (1<<13) /* CTS pin control */
#define UCR2_CTS (1<<12) /* Clear to send */
#define UCR2_ESCEN (1<<11) /* Escape enable */
#define UCR2_PREN (1<<8) /* Parity enable */
#define UCR2_PROE (1<<7) /* Parity odd/even */
#define UCR2_STPB (1<<6) /* Stop */
#define UCR2_WS (1<<5) /* Word size */
#define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */
#define UCR2_ATEN (1<<3) /* Aging Timer Enable */
#define UCR2_TXEN (1<<2) /* Transmitter enabled */
#define UCR2_RXEN (1<<1) /* Receiver enabled */
#define UCR2_SRST (1<<0) /* SW reset */
#define UCR3_DTREN (1<<13) /* DTR interrupt enable */
#define UCR3_PARERREN (1<<12) /* Parity enable */
#define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */
#define UCR3_DSR (1<<10) /* Data set ready */
#define UCR3_DCD (1<<9) /* Data carrier detect */
#define UCR3_RI (1<<8) /* Ring indicator */
#define UCR3_ADNIMP (1<<7) /* Autobaud Detection Not Improved */
#define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */
#define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */
#define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */
#define UCR3_DTRDEN (1<<3) /* Data Terminal Ready Delta Enable. */
#define IMX21_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select */
#define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
#define UCR3_BPEN (1<<0) /* Preset registers enable */
#define UCR4_CTSTL_SHF 10 /* CTS trigger level shift */
#define UCR4_CTSTL_MASK 0x3F /* CTS trigger is 6 bits wide */
#define UCR4_INVR (1<<9) /* Inverted infrared reception */
#define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */
#define UCR4_WKEN (1<<7) /* Wake interrupt enable */
#define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */
#define UCR4_IDDMAEN (1<<6) /* DMA IDLE Condition Detected */
#define UCR4_IRSC (1<<5) /* IR special case */
#define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */
#define UCR4_BKEN (1<<2) /* Break condition interrupt enable */
#define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */
#define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
#define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
#define UFCR_DCEDTE (1<<6) /* DCE/DTE mode select */
#define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
#define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7)
#define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
#define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
#define USR1_RTSS (1<<14) /* RTS pin status */
#define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */
#define USR1_RTSD (1<<12) /* RTS delta */
#define USR1_ESCF (1<<11) /* Escape seq interrupt flag */
#define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */
#define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */
#define USR1_AGTIM (1<<8) /* Ageing timer interrupt flag */
#define USR1_DTRD (1<<7) /* DTR Delta */
#define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */
#define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */
#define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */
#define USR2_ADET (1<<15) /* Auto baud rate detect complete */
#define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
#define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
#define USR2_IDLE (1<<12) /* Idle condition */
#define USR2_RIDELT (1<<10) /* Ring Interrupt Delta */
#define USR2_RIIN (1<<9) /* Ring Indicator Input */
#define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
#define USR2_WAKE (1<<7) /* Wake */
#define USR2_DCDIN (1<<5) /* Data Carrier Detect Input */
#define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
#define USR2_TXDC (1<<3) /* Transmitter complete */
#define USR2_BRCD (1<<2) /* Break condition */
#define USR2_ORE (1<<1) /* Overrun error */
#define USR2_RDR (1<<0) /* Recv data ready */
#define UTS_FRCPERR (1<<13) /* Force parity error */
#define UTS_LOOP (1<<12) /* Loop tx and rx */
#define UTS_TXEMPTY (1<<6) /* TxFIFO empty */
#define UTS_RXEMPTY (1<<5) /* RxFIFO empty */
#define UTS_TXFULL (1<<4) /* TxFIFO full */
#define UTS_RXFULL (1<<3) /* RxFIFO full */
#define UTS_SOFTRST (1<<0) /* Software reset */
/* We've been assigned a range on the "Low-density serial ports" major */
#define SERIAL_IMX_MAJOR 207
#define MINOR_START 16
#define DEV_NAME "ttymxc"
/*
* This determines how often we check the modem status signals
* for any change. They generally aren't connected to an IRQ
* so we have to poll them. We also check immediately before
* filling the TX fifo incase CTS has been dropped.
*/
#define MCTRL_TIMEOUT (250*HZ/1000)
#define DRIVER_NAME "IMX-uart"
#define UART_NR 8
/* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */
enum imx_uart_type {
IMX1_UART,
IMX21_UART,
IMX53_UART,
IMX6Q_UART,
};
/* device type dependent stuff */
struct imx_uart_data {
unsigned uts_reg;
enum imx_uart_type devtype;
};
enum imx_tx_state {
OFF,
WAIT_AFTER_RTS,
SEND,
WAIT_AFTER_SEND,
};
struct imx_port {
struct uart_port port;
struct timer_list timer;
unsigned int old_status;
unsigned int have_rtscts:1;
unsigned int have_rtsgpio:1;
unsigned int dte_mode:1;
unsigned int inverted_tx:1;
unsigned int inverted_rx:1;
struct clk *clk_ipg;
struct clk *clk_per;
const struct imx_uart_data *devdata;
struct mctrl_gpios *gpios;
/* shadow registers */
unsigned int ucr1;
unsigned int ucr2;
unsigned int ucr3;
unsigned int ucr4;
unsigned int ufcr;
/* DMA fields */
unsigned int dma_is_enabled:1;
unsigned int dma_is_rxing:1;
unsigned int dma_is_txing:1;
struct dma_chan *dma_chan_rx, *dma_chan_tx;
struct scatterlist rx_sgl, tx_sgl[2];
void *rx_buf;
serial: imx-serial - update UART IMX driver to use cyclic DMA The IMX UART has a 32 bytes HW buffer which can be filled up in 2777us at 115200 baud or 80us at 4Mbaud (supported by IMX53). Taking this in consideration there is a good probability to lose data because of the DMA startup latency. Our tests (explained below) indicates a latency up to 4400us when creating interrupt load and ~70us without. When creating interrupt load I was able to see continuous overrun errors by checking serial driver statistics using the command: `cat /proc/tty/driver/IMX-uart`. Replace manual restart of DMA with cyclic DMA to eliminate data loss due to DMA engine startup latency (similar approch to atmel_serial.c driver). As result the DMA engine will start on the first serial data transfer and stops only when serial port is closed. Tests environment: Using the m53evk board I have used a GPIO for profiling the IMX serial driver. - The RX line and GPIO were connected to oscilloscope. - Run a small test program on the m53evk board that will only open and read data from ttymxc2 port. - Connect the ttymxc2 port to my laptop using a USB serial converter where another test program is running, able to send configurable packet lengths and intervals. - Serial ports configured at 115200 8N1. - Interrupts load created by disconnecting/connecting (3s interval) a USB hub, using a digital switch, with 4 USB devices (USB-Serial converter, USB SD card, etc) connected. (around 160 interrupts/second generated) - The GPIO was toggled HI in the `imx_int` when USR1_RRDY or USR1_AGTIM events are received and toggled back, once the DMA configuration is finalized, at the end of `imx_dma_rxint`. Measurements: The measurements were done from the end of the last byte (RX line) until the GPIO was toggled back LOW. Note: The GPIO toggling was done using `gpiod_set_value` method. Tests performed: 1. Sending 9 bytes packets at 8ms interval. Having the 9 bytes packets will activate the RRDY threshold event and IMX serial interrupt called. Results: - DMA start latency (interrupt start latency + DMA configuration) consistently 70us when system not loaded. - DMA start latency up to 4400us when system loaded. 2. Sending 40 bytes packet at 8mS interval. Results with load: - Able to observe overruns by running: `watch -n1 cat /proc/tty/driver/IMX-uart` Tested-by: Peter Senna Tschudin <peter.senna@collabora.com> Acked-by: Peter Senna Tschudin <peter.senna@collabora.com> Signed-off-by: Nandor Han <nandor.han@ge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-08 20:38:27 +08:00
struct circ_buf rx_ring;
unsigned int rx_periods;
dma_cookie_t rx_cookie;
unsigned int tx_bytes;
unsigned int dma_tx_nents;
unsigned int saved_reg[10];
bool context_saved;
enum imx_tx_state tx_state;
struct hrtimer trigger_start_tx;
struct hrtimer trigger_stop_tx;
};
struct imx_port_ucrs {
unsigned int ucr1;
unsigned int ucr2;
unsigned int ucr3;
};
static struct imx_uart_data imx_uart_devdata[] = {
[IMX1_UART] = {
.uts_reg = IMX1_UTS,
.devtype = IMX1_UART,
},
[IMX21_UART] = {
.uts_reg = IMX21_UTS,
.devtype = IMX21_UART,
},
[IMX53_UART] = {
.uts_reg = IMX21_UTS,
.devtype = IMX53_UART,
},
[IMX6Q_UART] = {
.uts_reg = IMX21_UTS,
.devtype = IMX6Q_UART,
},
};
static const struct platform_device_id imx_uart_devtype[] = {
{
.name = "imx1-uart",
.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
}, {
.name = "imx21-uart",
.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
}, {
.name = "imx53-uart",
.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX53_UART],
}, {
.name = "imx6q-uart",
.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
}, {
/* sentinel */
}
};
MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
static const struct of_device_id imx_uart_dt_ids[] = {
{ .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
{ .compatible = "fsl,imx53-uart", .data = &imx_uart_devdata[IMX53_UART], },
{ .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
{ .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
static void imx_uart_writel(struct imx_port *sport, u32 val, u32 offset)
{
switch (offset) {
case UCR1:
sport->ucr1 = val;
break;
case UCR2:
sport->ucr2 = val;
break;
case UCR3:
sport->ucr3 = val;
break;
case UCR4:
sport->ucr4 = val;
break;
case UFCR:
sport->ufcr = val;
break;
default:
break;
}
writel(val, sport->port.membase + offset);
}
static u32 imx_uart_readl(struct imx_port *sport, u32 offset)
{
switch (offset) {
case UCR1:
return sport->ucr1;
break;
case UCR2:
/*
* UCR2_SRST is the only bit in the cached registers that might
* differ from the value that was last written. As it only
* automatically becomes one after being cleared, reread
* conditionally.
*/
if (!(sport->ucr2 & UCR2_SRST))
sport->ucr2 = readl(sport->port.membase + offset);
return sport->ucr2;
break;
case UCR3:
return sport->ucr3;
break;
case UCR4:
return sport->ucr4;
break;
case UFCR:
return sport->ufcr;
break;
default:
return readl(sport->port.membase + offset);
}
}
static inline unsigned imx_uart_uts_reg(struct imx_port *sport)
{
return sport->devdata->uts_reg;
}
static inline int imx_uart_is_imx1(struct imx_port *sport)
{
return sport->devdata->devtype == IMX1_UART;
}
static inline int imx_uart_is_imx21(struct imx_port *sport)
{
return sport->devdata->devtype == IMX21_UART;
}
static inline int imx_uart_is_imx53(struct imx_port *sport)
{
return sport->devdata->devtype == IMX53_UART;
}
static inline int imx_uart_is_imx6q(struct imx_port *sport)
{
return sport->devdata->devtype == IMX6Q_UART;
}
/*
* Save and restore functions for UCR1, UCR2 and UCR3 registers
*/
#if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE)
static void imx_uart_ucrs_save(struct imx_port *sport,
struct imx_port_ucrs *ucr)
{
/* save control registers */
ucr->ucr1 = imx_uart_readl(sport, UCR1);
ucr->ucr2 = imx_uart_readl(sport, UCR2);
ucr->ucr3 = imx_uart_readl(sport, UCR3);
}
static void imx_uart_ucrs_restore(struct imx_port *sport,
struct imx_port_ucrs *ucr)
{
/* restore control registers */
imx_uart_writel(sport, ucr->ucr1, UCR1);
imx_uart_writel(sport, ucr->ucr2, UCR2);
imx_uart_writel(sport, ucr->ucr3, UCR3);
}
#endif
/* called with port.lock taken and irqs caller dependent */
static void imx_uart_rts_active(struct imx_port *sport, u32 *ucr2)
{
*ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
sport->port.mctrl |= TIOCM_RTS;
mctrl_gpio_set(sport->gpios, sport->port.mctrl);
}
/* called with port.lock taken and irqs caller dependent */
static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2)
{
*ucr2 &= ~UCR2_CTSC;
*ucr2 |= UCR2_CTS;
sport->port.mctrl &= ~TIOCM_RTS;
mctrl_gpio_set(sport->gpios, sport->port.mctrl);
}
static void start_hrtimer_ms(struct hrtimer *hrt, unsigned long msec)
{
long sec = msec / MSEC_PER_SEC;
long nsec = (msec % MSEC_PER_SEC) * 1000000;
ktime_t t = ktime_set(sec, nsec);
hrtimer_start(hrt, t, HRTIMER_MODE_REL);
}
/* called with port.lock taken and irqs off */
static void imx_uart_start_rx(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned int ucr1, ucr2;
ucr1 = imx_uart_readl(sport, UCR1);
ucr2 = imx_uart_readl(sport, UCR2);
ucr2 |= UCR2_RXEN;
if (sport->dma_is_enabled) {
ucr1 |= UCR1_RXDMAEN | UCR1_ATDMAEN;
} else {
ucr1 |= UCR1_RRDYEN;
ucr2 |= UCR2_ATEN;
}
/* Write UCR2 first as it includes RXEN */
imx_uart_writel(sport, ucr2, UCR2);
imx_uart_writel(sport, ucr1, UCR1);
}
/* called with port.lock taken and irqs off */
static void imx_uart_stop_tx(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
u32 ucr1, ucr4, usr2;
if (sport->tx_state == OFF)
return;
/*
* We are maybe in the SMP context, so if the DMA TX thread is running
* on other cpu, we have to wait for it to finish.
*/
if (sport->dma_is_txing)
return;
ucr1 = imx_uart_readl(sport, UCR1);
imx_uart_writel(sport, ucr1 & ~UCR1_TRDYEN, UCR1);
usr2 = imx_uart_readl(sport, USR2);
if (!(usr2 & USR2_TXDC)) {
/* The shifter is still busy, so retry once TC triggers */
return;
}
ucr4 = imx_uart_readl(sport, UCR4);
ucr4 &= ~UCR4_TCEN;
imx_uart_writel(sport, ucr4, UCR4);
/* in rs485 mode disable transmitter */
if (port->rs485.flags & SER_RS485_ENABLED) {
if (sport->tx_state == SEND) {
sport->tx_state = WAIT_AFTER_SEND;
start_hrtimer_ms(&sport->trigger_stop_tx,
port->rs485.delay_rts_after_send);
return;
}
if (sport->tx_state == WAIT_AFTER_RTS ||
sport->tx_state == WAIT_AFTER_SEND) {
u32 ucr2;
hrtimer_try_to_cancel(&sport->trigger_start_tx);
ucr2 = imx_uart_readl(sport, UCR2);
if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
imx_uart_rts_active(sport, &ucr2);
else
imx_uart_rts_inactive(sport, &ucr2);
imx_uart_writel(sport, ucr2, UCR2);
imx_uart_start_rx(port);
sport->tx_state = OFF;
}
} else {
sport->tx_state = OFF;
}
}
/* called with port.lock taken and irqs off */
static void imx_uart_stop_rx(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
u32 ucr1, ucr2;
ucr1 = imx_uart_readl(sport, UCR1);
ucr2 = imx_uart_readl(sport, UCR2);
if (sport->dma_is_enabled) {
ucr1 &= ~(UCR1_RXDMAEN | UCR1_ATDMAEN);
} else {
ucr1 &= ~UCR1_RRDYEN;
ucr2 &= ~UCR2_ATEN;
}
imx_uart_writel(sport, ucr1, UCR1);
ucr2 &= ~UCR2_RXEN;
imx_uart_writel(sport, ucr2, UCR2);
}
/* called with port.lock taken and irqs off */
static void imx_uart_enable_ms(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
mod_timer(&sport->timer, jiffies);
mctrl_gpio_enable_ms(sport->gpios);
}
static void imx_uart_dma_tx(struct imx_port *sport);
/* called with port.lock taken and irqs off */
static inline void imx_uart_transmit_buffer(struct imx_port *sport)
{
struct circ_buf *xmit = &sport->port.state->xmit;
if (sport->port.x_char) {
/* Send next char */
imx_uart_writel(sport, sport->port.x_char, URTX0);
sport->port.icount.tx++;
sport->port.x_char = 0;
return;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
imx_uart_stop_tx(&sport->port);
return;
}
if (sport->dma_is_enabled) {
u32 ucr1;
/*
* We've just sent a X-char Ensure the TX DMA is enabled
* and the TX IRQ is disabled.
**/
ucr1 = imx_uart_readl(sport, UCR1);
ucr1 &= ~UCR1_TRDYEN;
if (sport->dma_is_txing) {
ucr1 |= UCR1_TXDMAEN;
imx_uart_writel(sport, ucr1, UCR1);
} else {
imx_uart_writel(sport, ucr1, UCR1);
imx_uart_dma_tx(sport);
}
return;
}
while (!uart_circ_empty(xmit) &&
!(imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)) {
/* send xmit->buf[xmit->tail]
* out the port here */
imx_uart_writel(sport, xmit->buf[xmit->tail], URTX0);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
sport->port.icount.tx++;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&sport->port);
if (uart_circ_empty(xmit))
imx_uart_stop_tx(&sport->port);
}
static void imx_uart_dma_tx_callback(void *data)
{
struct imx_port *sport = data;
struct scatterlist *sgl = &sport->tx_sgl[0];
struct circ_buf *xmit = &sport->port.state->xmit;
unsigned long flags;
u32 ucr1;
spin_lock_irqsave(&sport->port.lock, flags);
dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
ucr1 = imx_uart_readl(sport, UCR1);
ucr1 &= ~UCR1_TXDMAEN;
imx_uart_writel(sport, ucr1, UCR1);
/* update the stat */
xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
sport->port.icount.tx += sport->tx_bytes;
dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
sport->dma_is_txing = 0;
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&sport->port);
if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
imx_uart_dma_tx(sport);
else if (sport->port.rs485.flags & SER_RS485_ENABLED) {
u32 ucr4 = imx_uart_readl(sport, UCR4);
ucr4 |= UCR4_TCEN;
imx_uart_writel(sport, ucr4, UCR4);
}
spin_unlock_irqrestore(&sport->port.lock, flags);
}
/* called with port.lock taken and irqs off */
static void imx_uart_dma_tx(struct imx_port *sport)
{
struct circ_buf *xmit = &sport->port.state->xmit;
struct scatterlist *sgl = sport->tx_sgl;
struct dma_async_tx_descriptor *desc;
struct dma_chan *chan = sport->dma_chan_tx;
struct device *dev = sport->port.dev;
u32 ucr1, ucr4;
int ret;
if (sport->dma_is_txing)
return;
ucr4 = imx_uart_readl(sport, UCR4);
ucr4 &= ~UCR4_TCEN;
imx_uart_writel(sport, ucr4, UCR4);
sport->tx_bytes = uart_circ_chars_pending(xmit);
tty: serial: imx: setup the correct sg entry for tx dma There has oops as below happen on i.MX8MP EVK platform that has 6G bytes DDR memory. when (xmit->tail < xmit->head) && (xmit->head == 0), it setups one sg entry with sg->length is zero: sg_set_buf(sgl + 1, xmit->buf, xmit->head); if xmit->buf is allocated from >4G address space, and SDMA only support <4G address space, then dma_map_sg() will call swiotlb_map() to do bounce buffer copying and mapping. But swiotlb_map() don't allow sg entry's length is zero, otherwise report BUG_ON(). So the patch is to correct the tx DMA scatter list. Oops: [ 287.675715] kernel BUG at kernel/dma/swiotlb.c:497! [ 287.680592] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP [ 287.686075] Modules linked in: [ 287.689133] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.3-00016-g3fdc4e0-dirty #10 [ 287.696872] Hardware name: FSL i.MX8MP EVK (DT) [ 287.701402] pstate: 80000085 (Nzcv daIf -PAN -UAO) [ 287.706199] pc : swiotlb_tbl_map_single+0x1fc/0x310 [ 287.711076] lr : swiotlb_map+0x60/0x148 [ 287.714909] sp : ffff800010003c00 [ 287.718221] x29: ffff800010003c00 x28: 0000000000000000 [ 287.723533] x27: 0000000000000040 x26: ffff800011ae0000 [ 287.728844] x25: ffff800011ae09f8 x24: 0000000000000000 [ 287.734155] x23: 00000001b7af9000 x22: 0000000000000000 [ 287.739465] x21: ffff000176409c10 x20: 00000000001f7ffe [ 287.744776] x19: ffff000176409c10 x18: 000000000000002e [ 287.750087] x17: 0000000000000000 x16: 0000000000000000 [ 287.755397] x15: 0000000000000000 x14: 0000000000000000 [ 287.760707] x13: ffff00017f334000 x12: 0000000000000001 [ 287.766018] x11: 00000000001fffff x10: 0000000000000000 [ 287.771328] x9 : 0000000000000003 x8 : 0000000000000000 [ 287.776638] x7 : 0000000000000000 x6 : 0000000000000000 [ 287.781949] x5 : 0000000000200000 x4 : 0000000000000000 [ 287.787259] x3 : 0000000000000001 x2 : 00000001b7af9000 [ 287.792570] x1 : 00000000fbfff000 x0 : 0000000000000000 [ 287.797881] Call trace: [ 287.800328] swiotlb_tbl_map_single+0x1fc/0x310 [ 287.804859] swiotlb_map+0x60/0x148 [ 287.808347] dma_direct_map_page+0xf0/0x130 [ 287.812530] dma_direct_map_sg+0x78/0xe0 [ 287.816453] imx_uart_dma_tx+0x134/0x2f8 [ 287.820374] imx_uart_dma_tx_callback+0xd8/0x168 [ 287.824992] vchan_complete+0x194/0x200 [ 287.828828] tasklet_action_common.isra.0+0x154/0x1a0 [ 287.833879] tasklet_action+0x24/0x30 [ 287.837540] __do_softirq+0x120/0x23c [ 287.841202] irq_exit+0xb8/0xd8 [ 287.844343] __handle_domain_irq+0x64/0xb8 [ 287.848438] gic_handle_irq+0x5c/0x148 [ 287.852185] el1_irq+0xb8/0x180 [ 287.855327] cpuidle_enter_state+0x84/0x360 [ 287.859508] cpuidle_enter+0x34/0x48 [ 287.863083] call_cpuidle+0x18/0x38 [ 287.866571] do_idle+0x1e0/0x280 [ 287.869798] cpu_startup_entry+0x20/0x40 [ 287.873721] rest_init+0xd4/0xe0 [ 287.876949] arch_call_rest_init+0xc/0x14 [ 287.880958] start_kernel+0x420/0x44c [ 287.884622] Code: 9124c021 9417aff8 a94363f7 17ffffd5 (d4210000) [ 287.890718] ---[ end trace 5bc44c4ab6b009ce ]--- [ 287.895334] Kernel panic - not syncing: Fatal exception in interrupt [ 287.901686] SMP: stopping secondary CPUs [ 288.905607] SMP: failed to stop secondary CPUs 0-1 [ 288.910395] Kernel Offset: disabled [ 288.913882] CPU features: 0x0002,2000200c [ 288.917888] Memory Limit: none [ 288.920944] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- Reported-by: Eagle Zhou <eagle.zhou@nxp.com> Tested-by: Eagle Zhou <eagle.zhou@nxp.com> Signed-off-by: Fugang Duan <fugang.duan@nxp.com> Cc: stable <stable@vger.kernel.org> Fixes: 7942f8577f2a ("serial: imx: TX DMA: clean up sg initialization") Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/1581401761-6378-1-git-send-email-fugang.duan@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 14:16:01 +08:00
if (xmit->tail < xmit->head || xmit->head == 0) {
sport->dma_tx_nents = 1;
sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
} else {
sport->dma_tx_nents = 2;
sg_init_table(sgl, 2);
sg_set_buf(sgl, xmit->buf + xmit->tail,
UART_XMIT_SIZE - xmit->tail);
sg_set_buf(sgl + 1, xmit->buf, xmit->head);
}
ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
if (ret == 0) {
dev_err(dev, "DMA mapping error for TX.\n");
return;
}
desc = dmaengine_prep_slave_sg(chan, sgl, ret,
DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
if (!desc) {
dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
DMA_TO_DEVICE);
dev_err(dev, "We cannot prepare for the TX slave dma!\n");
return;
}
desc->callback = imx_uart_dma_tx_callback;
desc->callback_param = sport;
dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
uart_circ_chars_pending(xmit));
ucr1 = imx_uart_readl(sport, UCR1);
ucr1 |= UCR1_TXDMAEN;
imx_uart_writel(sport, ucr1, UCR1);
/* fire it */
sport->dma_is_txing = 1;
dmaengine_submit(desc);
dma_async_issue_pending(chan);
return;
}
/* called with port.lock taken and irqs off */
static void imx_uart_start_tx(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
u32 ucr1;
if (!sport->port.x_char && uart_circ_empty(&port->state->xmit))
return;
/*
* We cannot simply do nothing here if sport->tx_state == SEND already
* because UCR1_TXMPTYEN might already have been cleared in
* imx_uart_stop_tx(), but tx_state is still SEND.
*/
if (port->rs485.flags & SER_RS485_ENABLED) {
if (sport->tx_state == OFF) {
u32 ucr2 = imx_uart_readl(sport, UCR2);
if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
imx_uart_rts_active(sport, &ucr2);
else
imx_uart_rts_inactive(sport, &ucr2);
imx_uart_writel(sport, ucr2, UCR2);
if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
imx_uart_stop_rx(port);
sport->tx_state = WAIT_AFTER_RTS;
start_hrtimer_ms(&sport->trigger_start_tx,
port->rs485.delay_rts_before_send);
return;
}
if (sport->tx_state == WAIT_AFTER_SEND
|| sport->tx_state == WAIT_AFTER_RTS) {
hrtimer_try_to_cancel(&sport->trigger_stop_tx);
/*
* Enable transmitter and shifter empty irq only if DMA
* is off. In the DMA case this is done in the
* tx-callback.
*/
if (!sport->dma_is_enabled) {
u32 ucr4 = imx_uart_readl(sport, UCR4);
ucr4 |= UCR4_TCEN;
imx_uart_writel(sport, ucr4, UCR4);
}
sport->tx_state = SEND;
}
} else {
sport->tx_state = SEND;
}
if (!sport->dma_is_enabled) {
ucr1 = imx_uart_readl(sport, UCR1);
imx_uart_writel(sport, ucr1 | UCR1_TRDYEN, UCR1);
}
if (sport->dma_is_enabled) {
if (sport->port.x_char) {
/* We have X-char to send, so enable TX IRQ and
* disable TX DMA to let TX interrupt to send X-char */
ucr1 = imx_uart_readl(sport, UCR1);
ucr1 &= ~UCR1_TXDMAEN;
ucr1 |= UCR1_TRDYEN;
imx_uart_writel(sport, ucr1, UCR1);
return;
}
if (!uart_circ_empty(&port->state->xmit) &&
!uart_tx_stopped(port))
imx_uart_dma_tx(sport);
return;
}
}
static irqreturn_t __imx_uart_rtsint(int irq, void *dev_id)
{
struct imx_port *sport = dev_id;
u32 usr1;
imx_uart_writel(sport, USR1_RTSD, USR1);
usr1 = imx_uart_readl(sport, USR1) & USR1_RTSS;
uart_handle_cts_change(&sport->port, !!usr1);
wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
return IRQ_HANDLED;
}
static irqreturn_t imx_uart_rtsint(int irq, void *dev_id)
{
struct imx_port *sport = dev_id;
irqreturn_t ret;
spin_lock(&sport->port.lock);
ret = __imx_uart_rtsint(irq, dev_id);
spin_unlock(&sport->port.lock);
return ret;
}
static irqreturn_t imx_uart_txint(int irq, void *dev_id)
{
struct imx_port *sport = dev_id;
spin_lock(&sport->port.lock);
imx_uart_transmit_buffer(sport);
spin_unlock(&sport->port.lock);
return IRQ_HANDLED;
}
static irqreturn_t __imx_uart_rxint(int irq, void *dev_id)
{
struct imx_port *sport = dev_id;
unsigned int rx, flg, ignored = 0;
struct tty_port *port = &sport->port.state->port;
while (imx_uart_readl(sport, USR2) & USR2_RDR) {
u32 usr2;
flg = TTY_NORMAL;
sport->port.icount.rx++;
rx = imx_uart_readl(sport, URXD0);
usr2 = imx_uart_readl(sport, USR2);
if (usr2 & USR2_BRCD) {
imx_uart_writel(sport, USR2_BRCD, USR2);
if (uart_handle_break(&sport->port))
continue;
}
if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
continue;
if (unlikely(rx & URXD_ERR)) {
if (rx & URXD_BRK)
sport->port.icount.brk++;
else if (rx & URXD_PRERR)
sport->port.icount.parity++;
else if (rx & URXD_FRMERR)
sport->port.icount.frame++;
if (rx & URXD_OVRRUN)
sport->port.icount.overrun++;
if (rx & sport->port.ignore_status_mask) {
if (++ignored > 100)
goto out;
continue;
}
rx &= (sport->port.read_status_mask | 0xFF);
if (rx & URXD_BRK)
flg = TTY_BREAK;
else if (rx & URXD_PRERR)
flg = TTY_PARITY;
else if (rx & URXD_FRMERR)
flg = TTY_FRAME;
if (rx & URXD_OVRRUN)
flg = TTY_OVERRUN;
sport->port.sysrq = 0;
}
if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
goto out;
if (tty_insert_flip_char(port, rx, flg) == 0)
sport->port.icount.buf_overrun++;
}
out:
tty_flip_buffer_push(port);
return IRQ_HANDLED;
}
static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
{
struct imx_port *sport = dev_id;
irqreturn_t ret;
spin_lock(&sport->port.lock);
ret = __imx_uart_rxint(irq, dev_id);
spin_unlock(&sport->port.lock);
return ret;
}
static void imx_uart_clear_rx_errors(struct imx_port *sport);
/*
* We have a modem side uart, so the meanings of RTS and CTS are inverted.
*/
static unsigned int imx_uart_get_hwmctrl(struct imx_port *sport)
{
unsigned int tmp = TIOCM_DSR;
unsigned usr1 = imx_uart_readl(sport, USR1);
unsigned usr2 = imx_uart_readl(sport, USR2);
if (usr1 & USR1_RTSS)
tmp |= TIOCM_CTS;
/* in DCE mode DCDIN is always 0 */
if (!(usr2 & USR2_DCDIN))
tmp |= TIOCM_CAR;
if (sport->dte_mode)
if (!(imx_uart_readl(sport, USR2) & USR2_RIIN))
tmp |= TIOCM_RI;
return tmp;
}
/*
* Handle any change of modem status signal since we were last called.
*/
static void imx_uart_mctrl_check(struct imx_port *sport)
{
unsigned int status, changed;
status = imx_uart_get_hwmctrl(sport);
changed = status ^ sport->old_status;
if (changed == 0)
return;
sport->old_status = status;
if (changed & TIOCM_RI && status & TIOCM_RI)
sport->port.icount.rng++;
if (changed & TIOCM_DSR)
sport->port.icount.dsr++;
if (changed & TIOCM_CAR)
uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
if (changed & TIOCM_CTS)
uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
}
static irqreturn_t imx_uart_int(int irq, void *dev_id)
{
struct imx_port *sport = dev_id;
unsigned int usr1, usr2, ucr1, ucr2, ucr3, ucr4;
irqreturn_t ret = IRQ_NONE;
spin_lock(&sport->port.lock);
usr1 = imx_uart_readl(sport, USR1);
usr2 = imx_uart_readl(sport, USR2);
ucr1 = imx_uart_readl(sport, UCR1);
ucr2 = imx_uart_readl(sport, UCR2);
ucr3 = imx_uart_readl(sport, UCR3);
ucr4 = imx_uart_readl(sport, UCR4);
/*
* Even if a condition is true that can trigger an irq only handle it if
* the respective irq source is enabled. This prevents some undesired
* actions, for example if a character that sits in the RX FIFO and that
* should be fetched via DMA is tried to be fetched using PIO. Or the
* receiver is currently off and so reading from URXD0 results in an
* exception. So just mask the (raw) status bits for disabled irqs.
*/
if ((ucr1 & UCR1_RRDYEN) == 0)
usr1 &= ~USR1_RRDY;
if ((ucr2 & UCR2_ATEN) == 0)
usr1 &= ~USR1_AGTIM;
if ((ucr1 & UCR1_TRDYEN) == 0)
usr1 &= ~USR1_TRDY;
if ((ucr4 & UCR4_TCEN) == 0)
usr2 &= ~USR2_TXDC;
if ((ucr3 & UCR3_DTRDEN) == 0)
usr1 &= ~USR1_DTRD;
if ((ucr1 & UCR1_RTSDEN) == 0)
usr1 &= ~USR1_RTSD;
if ((ucr3 & UCR3_AWAKEN) == 0)
usr1 &= ~USR1_AWAKE;
if ((ucr4 & UCR4_OREN) == 0)
usr2 &= ~USR2_ORE;
if (usr1 & (USR1_RRDY | USR1_AGTIM)) {
imx_uart_writel(sport, USR1_AGTIM, USR1);
__imx_uart_rxint(irq, dev_id);
ret = IRQ_HANDLED;
}
if ((usr1 & USR1_TRDY) || (usr2 & USR2_TXDC)) {
imx_uart_transmit_buffer(sport);
ret = IRQ_HANDLED;
}
if (usr1 & USR1_DTRD) {
imx_uart_writel(sport, USR1_DTRD, USR1);
imx_uart_mctrl_check(sport);
ret = IRQ_HANDLED;
}
if (usr1 & USR1_RTSD) {
__imx_uart_rtsint(irq, dev_id);
ret = IRQ_HANDLED;
}
if (usr1 & USR1_AWAKE) {
imx_uart_writel(sport, USR1_AWAKE, USR1);
ret = IRQ_HANDLED;
}
if (usr2 & USR2_ORE) {
sport->port.icount.overrun++;
imx_uart_writel(sport, USR2_ORE, USR2);
ret = IRQ_HANDLED;
}
spin_unlock(&sport->port.lock);
return ret;
}
/*
* Return TIOCSER_TEMT when transmitter is not busy.
*/
static unsigned int imx_uart_tx_empty(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned int ret;
ret = (imx_uart_readl(sport, USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
/* If the TX DMA is working, return 0. */
if (sport->dma_is_txing)
ret = 0;
return ret;
}
/* called with port.lock taken and irqs off */
static unsigned int imx_uart_get_mctrl(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned int ret = imx_uart_get_hwmctrl(sport);
mctrl_gpio_get(sport->gpios, &ret);
return ret;
}
/* called with port.lock taken and irqs off */
static void imx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
struct imx_port *sport = (struct imx_port *)port;
u32 ucr3, uts;
if (!(port->rs485.flags & SER_RS485_ENABLED)) {
u32 ucr2;
/*
* Turn off autoRTS if RTS is lowered and restore autoRTS
* setting if RTS is raised.
*/
ucr2 = imx_uart_readl(sport, UCR2);
ucr2 &= ~(UCR2_CTS | UCR2_CTSC);
if (mctrl & TIOCM_RTS) {
ucr2 |= UCR2_CTS;
/*
* UCR2_IRTS is unset if and only if the port is
* configured for CRTSCTS, so we use inverted UCR2_IRTS
* to get the state to restore to.
*/
if (!(ucr2 & UCR2_IRTS))
ucr2 |= UCR2_CTSC;
}
imx_uart_writel(sport, ucr2, UCR2);
}
ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_DSR;
if (!(mctrl & TIOCM_DTR))
ucr3 |= UCR3_DSR;
imx_uart_writel(sport, ucr3, UCR3);
uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)) & ~UTS_LOOP;
if (mctrl & TIOCM_LOOP)
uts |= UTS_LOOP;
imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
mctrl_gpio_set(sport->gpios, mctrl);
}
/*
* Interrupts always disabled.
*/
static void imx_uart_break_ctl(struct uart_port *port, int break_state)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned long flags;
u32 ucr1;
spin_lock_irqsave(&sport->port.lock, flags);
ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_SNDBRK;
if (break_state != 0)
ucr1 |= UCR1_SNDBRK;
imx_uart_writel(sport, ucr1, UCR1);
spin_unlock_irqrestore(&sport->port.lock, flags);
}
/*
* This is our per-port timeout handler, for checking the
* modem status signals.
*/
static void imx_uart_timeout(struct timer_list *t)
{
treewide: setup_timer() -> timer_setup() This converts all remaining cases of the old setup_timer() API into using timer_setup(), where the callback argument is the structure already holding the struct timer_list. These should have no behavioral changes, since they just change which pointer is passed into the callback with the same available pointers after conversion. It handles the following examples, in addition to some other variations. Casting from unsigned long: void my_callback(unsigned long data) { struct something *ptr = (struct something *)data; ... } ... setup_timer(&ptr->my_timer, my_callback, ptr); and forced object casts: void my_callback(struct something *ptr) { ... } ... setup_timer(&ptr->my_timer, my_callback, (unsigned long)ptr); become: void my_callback(struct timer_list *t) { struct something *ptr = from_timer(ptr, t, my_timer); ... } ... timer_setup(&ptr->my_timer, my_callback, 0); Direct function assignments: void my_callback(unsigned long data) { struct something *ptr = (struct something *)data; ... } ... ptr->my_timer.function = my_callback; have a temporary cast added, along with converting the args: void my_callback(struct timer_list *t) { struct something *ptr = from_timer(ptr, t, my_timer); ... } ... ptr->my_timer.function = (TIMER_FUNC_TYPE)my_callback; And finally, callbacks without a data assignment: void my_callback(unsigned long data) { ... } ... setup_timer(&ptr->my_timer, my_callback, 0); have their argument renamed to verify they're unused during conversion: void my_callback(struct timer_list *unused) { ... } ... timer_setup(&ptr->my_timer, my_callback, 0); The conversion is done with the following Coccinelle script: spatch --very-quiet --all-includes --include-headers \ -I ./arch/x86/include -I ./arch/x86/include/generated \ -I ./include -I ./arch/x86/include/uapi \ -I ./arch/x86/include/generated/uapi -I ./include/uapi \ -I ./include/generated/uapi --include ./include/linux/kconfig.h \ --dir . \ --cocci-file ~/src/data/timer_setup.cocci @fix_address_of@ expression e; @@ setup_timer( -&(e) +&e , ...) // Update any raw setup_timer() usages that have a NULL callback, but // would otherwise match change_timer_function_usage, since the latter // will update all function assignments done in the face of a NULL // function initialization in setup_timer(). @change_timer_function_usage_NULL@ expression _E; identifier _timer; type _cast_data; @@ ( -setup_timer(&_E->_timer, NULL, _E); +timer_setup(&_E->_timer, NULL, 0); | -setup_timer(&_E->_timer, NULL, (_cast_data)_E); +timer_setup(&_E->_timer, NULL, 0); | -setup_timer(&_E._timer, NULL, &_E); +timer_setup(&_E._timer, NULL, 0); | -setup_timer(&_E._timer, NULL, (_cast_data)&_E); +timer_setup(&_E._timer, NULL, 0); ) @change_timer_function_usage@ expression _E; identifier _timer; struct timer_list _stl; identifier _callback; type _cast_func, _cast_data; @@ ( -setup_timer(&_E->_timer, _callback, _E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, &_callback, _E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, _callback, (_cast_data)_E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, &_callback, (_cast_data)_E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, (_cast_func)_callback, _E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, (_cast_func)&_callback, _E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, (_cast_func)_callback, (_cast_data)_E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, (_cast_func)&_callback, (_cast_data)_E); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E._timer, _callback, (_cast_data)_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, _callback, (_cast_data)&_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, &_callback, (_cast_data)_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, &_callback, (_cast_data)&_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, (_cast_func)_callback, (_cast_data)_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, (_cast_func)_callback, (_cast_data)&_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, (_cast_func)&_callback, (_cast_data)_E); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, (_cast_func)&_callback, (_cast_data)&_E); +timer_setup(&_E._timer, _callback, 0); | _E->_timer@_stl.function = _callback; | _E->_timer@_stl.function = &_callback; | _E->_timer@_stl.function = (_cast_func)_callback; | _E->_timer@_stl.function = (_cast_func)&_callback; | _E._timer@_stl.function = _callback; | _E._timer@_stl.function = &_callback; | _E._timer@_stl.function = (_cast_func)_callback; | _E._timer@_stl.function = (_cast_func)&_callback; ) // callback(unsigned long arg) @change_callback_handle_cast depends on change_timer_function_usage@ identifier change_timer_function_usage._callback; identifier change_timer_function_usage._timer; type _origtype; identifier _origarg; type _handletype; identifier _handle; @@ void _callback( -_origtype _origarg +struct timer_list *t ) { ( ... when != _origarg _handletype *_handle = -(_handletype *)_origarg; +from_timer(_handle, t, _timer); ... when != _origarg | ... when != _origarg _handletype *_handle = -(void *)_origarg; +from_timer(_handle, t, _timer); ... when != _origarg | ... when != _origarg _handletype *_handle; ... when != _handle _handle = -(_handletype *)_origarg; +from_timer(_handle, t, _timer); ... when != _origarg | ... when != _origarg _handletype *_handle; ... when != _handle _handle = -(void *)_origarg; +from_timer(_handle, t, _timer); ... when != _origarg ) } // callback(unsigned long arg) without existing variable @change_callback_handle_cast_no_arg depends on change_timer_function_usage && !change_callback_handle_cast@ identifier change_timer_function_usage._callback; identifier change_timer_function_usage._timer; type _origtype; identifier _origarg; type _handletype; @@ void _callback( -_origtype _origarg +struct timer_list *t ) { + _handletype *_origarg = from_timer(_origarg, t, _timer); + ... when != _origarg - (_handletype *)_origarg + _origarg ... when != _origarg } // Avoid already converted callbacks. @match_callback_converted depends on change_timer_function_usage && !change_callback_handle_cast && !change_callback_handle_cast_no_arg@ identifier change_timer_function_usage._callback; identifier t; @@ void _callback(struct timer_list *t) { ... } // callback(struct something *handle) @change_callback_handle_arg depends on change_timer_function_usage && !match_callback_converted && !change_callback_handle_cast && !change_callback_handle_cast_no_arg@ identifier change_timer_function_usage._callback; identifier change_timer_function_usage._timer; type _handletype; identifier _handle; @@ void _callback( -_handletype *_handle +struct timer_list *t ) { + _handletype *_handle = from_timer(_handle, t, _timer); ... } // If change_callback_handle_arg ran on an empty function, remove // the added handler. @unchange_callback_handle_arg depends on change_timer_function_usage && change_callback_handle_arg@ identifier change_timer_function_usage._callback; identifier change_timer_function_usage._timer; type _handletype; identifier _handle; identifier t; @@ void _callback(struct timer_list *t) { - _handletype *_handle = from_timer(_handle, t, _timer); } // We only want to refactor the setup_timer() data argument if we've found // the matching callback. This undoes changes in change_timer_function_usage. @unchange_timer_function_usage depends on change_timer_function_usage && !change_callback_handle_cast && !change_callback_handle_cast_no_arg && !change_callback_handle_arg@ expression change_timer_function_usage._E; identifier change_timer_function_usage._timer; identifier change_timer_function_usage._callback; type change_timer_function_usage._cast_data; @@ ( -timer_setup(&_E->_timer, _callback, 0); +setup_timer(&_E->_timer, _callback, (_cast_data)_E); | -timer_setup(&_E._timer, _callback, 0); +setup_timer(&_E._timer, _callback, (_cast_data)&_E); ) // If we fixed a callback from a .function assignment, fix the // assignment cast now. @change_timer_function_assignment depends on change_timer_function_usage && (change_callback_handle_cast || change_callback_handle_cast_no_arg || change_callback_handle_arg)@ expression change_timer_function_usage._E; identifier change_timer_function_usage._timer; identifier change_timer_function_usage._callback; type _cast_func; typedef TIMER_FUNC_TYPE; @@ ( _E->_timer.function = -_callback +(TIMER_FUNC_TYPE)_callback ; | _E->_timer.function = -&_callback +(TIMER_FUNC_TYPE)_callback ; | _E->_timer.function = -(_cast_func)_callback; +(TIMER_FUNC_TYPE)_callback ; | _E->_timer.function = -(_cast_func)&_callback +(TIMER_FUNC_TYPE)_callback ; | _E._timer.function = -_callback +(TIMER_FUNC_TYPE)_callback ; | _E._timer.function = -&_callback; +(TIMER_FUNC_TYPE)_callback ; | _E._timer.function = -(_cast_func)_callback +(TIMER_FUNC_TYPE)_callback ; | _E._timer.function = -(_cast_func)&_callback +(TIMER_FUNC_TYPE)_callback ; ) // Sometimes timer functions are called directly. Replace matched args. @change_timer_function_calls depends on change_timer_function_usage && (change_callback_handle_cast || change_callback_handle_cast_no_arg || change_callback_handle_arg)@ expression _E; identifier change_timer_function_usage._timer; identifier change_timer_function_usage._callback; type _cast_data; @@ _callback( ( -(_cast_data)_E +&_E->_timer | -(_cast_data)&_E +&_E._timer | -_E +&_E->_timer ) ) // If a timer has been configured without a data argument, it can be // converted without regard to the callback argument, since it is unused. @match_timer_function_unused_data@ expression _E; identifier _timer; identifier _callback; @@ ( -setup_timer(&_E->_timer, _callback, 0); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, _callback, 0L); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E->_timer, _callback, 0UL); +timer_setup(&_E->_timer, _callback, 0); | -setup_timer(&_E._timer, _callback, 0); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, _callback, 0L); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_E._timer, _callback, 0UL); +timer_setup(&_E._timer, _callback, 0); | -setup_timer(&_timer, _callback, 0); +timer_setup(&_timer, _callback, 0); | -setup_timer(&_timer, _callback, 0L); +timer_setup(&_timer, _callback, 0); | -setup_timer(&_timer, _callback, 0UL); +timer_setup(&_timer, _callback, 0); | -setup_timer(_timer, _callback, 0); +timer_setup(_timer, _callback, 0); | -setup_timer(_timer, _callback, 0L); +timer_setup(_timer, _callback, 0); | -setup_timer(_timer, _callback, 0UL); +timer_setup(_timer, _callback, 0); ) @change_callback_unused_data depends on match_timer_function_unused_data@ identifier match_timer_function_unused_data._callback; type _origtype; identifier _origarg; @@ void _callback( -_origtype _origarg +struct timer_list *unused ) { ... when != _origarg } Signed-off-by: Kees Cook <keescook@chromium.org>
2017-10-17 05:43:17 +08:00
struct imx_port *sport = from_timer(sport, t, timer);
unsigned long flags;
if (sport->port.state) {
spin_lock_irqsave(&sport->port.lock, flags);
imx_uart_mctrl_check(sport);
spin_unlock_irqrestore(&sport->port.lock, flags);
mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
}
}
/*
* There are two kinds of RX DMA interrupts(such as in the MX6Q):
* [1] the RX DMA buffer is full.
* [2] the aging timer expires
*
* Condition [2] is triggered when a character has been sitting in the FIFO
* for at least 8 byte durations.
*/
static void imx_uart_dma_rx_callback(void *data)
{
struct imx_port *sport = data;
struct dma_chan *chan = sport->dma_chan_rx;
struct scatterlist *sgl = &sport->rx_sgl;
struct tty_port *port = &sport->port.state->port;
struct dma_tx_state state;
serial: imx-serial - update UART IMX driver to use cyclic DMA The IMX UART has a 32 bytes HW buffer which can be filled up in 2777us at 115200 baud or 80us at 4Mbaud (supported by IMX53). Taking this in consideration there is a good probability to lose data because of the DMA startup latency. Our tests (explained below) indicates a latency up to 4400us when creating interrupt load and ~70us without. When creating interrupt load I was able to see continuous overrun errors by checking serial driver statistics using the command: `cat /proc/tty/driver/IMX-uart`. Replace manual restart of DMA with cyclic DMA to eliminate data loss due to DMA engine startup latency (similar approch to atmel_serial.c driver). As result the DMA engine will start on the first serial data transfer and stops only when serial port is closed. Tests environment: Using the m53evk board I have used a GPIO for profiling the IMX serial driver. - The RX line and GPIO were connected to oscilloscope. - Run a small test program on the m53evk board that will only open and read data from ttymxc2 port. - Connect the ttymxc2 port to my laptop using a USB serial converter where another test program is running, able to send configurable packet lengths and intervals. - Serial ports configured at 115200 8N1. - Interrupts load created by disconnecting/connecting (3s interval) a USB hub, using a digital switch, with 4 USB devices (USB-Serial converter, USB SD card, etc) connected. (around 160 interrupts/second generated) - The GPIO was toggled HI in the `imx_int` when USR1_RRDY or USR1_AGTIM events are received and toggled back, once the DMA configuration is finalized, at the end of `imx_dma_rxint`. Measurements: The measurements were done from the end of the last byte (RX line) until the GPIO was toggled back LOW. Note: The GPIO toggling was done using `gpiod_set_value` method. Tests performed: 1. Sending 9 bytes packets at 8ms interval. Having the 9 bytes packets will activate the RRDY threshold event and IMX serial interrupt called. Results: - DMA start latency (interrupt start latency + DMA configuration) consistently 70us when system not loaded. - DMA start latency up to 4400us when system loaded. 2. Sending 40 bytes packet at 8mS interval. Results with load: - Able to observe overruns by running: `watch -n1 cat /proc/tty/driver/IMX-uart` Tested-by: Peter Senna Tschudin <peter.senna@collabora.com> Acked-by: Peter Senna Tschudin <peter.senna@collabora.com> Signed-off-by: Nandor Han <nandor.han@ge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-08 20:38:27 +08:00
struct circ_buf *rx_ring = &sport->rx_ring;
enum dma_status status;
serial: imx-serial - update UART IMX driver to use cyclic DMA The IMX UART has a 32 bytes HW buffer which can be filled up in 2777us at 115200 baud or 80us at 4Mbaud (supported by IMX53). Taking this in consideration there is a good probability to lose data because of the DMA startup latency. Our tests (explained below) indicates a latency up to 4400us when creating interrupt load and ~70us without. When creating interrupt load I was able to see continuous overrun errors by checking serial driver statistics using the command: `cat /proc/tty/driver/IMX-uart`. Replace manual restart of DMA with cyclic DMA to eliminate data loss due to DMA engine startup latency (similar approch to atmel_serial.c driver). As result the DMA engine will start on the first serial data transfer and stops only when serial port is closed. Tests environment: Using the m53evk board I have used a GPIO for profiling the IMX serial driver. - The RX line and GPIO were connected to oscilloscope. - Run a small test program on the m53evk board that will only open and read data from ttymxc2 port. - Connect the ttymxc2 port to my laptop using a USB serial converter where another test program is running, able to send configurable packet lengths and intervals. - Serial ports configured at 115200 8N1. - Interrupts load created by disconnecting/connecting (3s interval) a USB hub, using a digital switch, with 4 USB devices (USB-Serial converter, USB SD card, etc) connected. (around 160 interrupts/second generated) - The GPIO was toggled HI in the `imx_int` when USR1_RRDY or USR1_AGTIM events are received and toggled back, once the DMA configuration is finalized, at the end of `imx_dma_rxint`. Measurements: The measurements were done from the end of the last byte (RX line) until the GPIO was toggled back LOW. Note: The GPIO toggling was done using `gpiod_set_value` method. Tests performed: 1. Sending 9 bytes packets at 8ms interval. Having the 9 bytes packets will activate the RRDY threshold event and IMX serial interrupt called. Results: - DMA start latency (interrupt start latency + DMA configuration) consistently 70us when system not loaded. - DMA start latency up to 4400us when system loaded. 2. Sending 40 bytes packet at 8mS interval. Results with load: - Able to observe overruns by running: `watch -n1 cat /proc/tty/driver/IMX-uart` Tested-by: Peter Senna Tschudin <peter.senna@collabora.com> Acked-by: Peter Senna Tschudin <peter.senna@collabora.com> Signed-off-by: Nandor Han <nandor.han@ge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-08 20:38:27 +08:00
unsigned int w_bytes = 0;
unsigned int r_bytes;
unsigned int bd_size;
status = dmaengine_tx_status(chan, sport->rx_cookie, &state);
serial: imx-serial - update UART IMX driver to use cyclic DMA The IMX UART has a 32 bytes HW buffer which can be filled up in 2777us at 115200 baud or 80us at 4Mbaud (supported by IMX53). Taking this in consideration there is a good probability to lose data because of the DMA startup latency. Our tests (explained below) indicates a latency up to 4400us when creating interrupt load and ~70us without. When creating interrupt load I was able to see continuous overrun errors by checking serial driver statistics using the command: `cat /proc/tty/driver/IMX-uart`. Replace manual restart of DMA with cyclic DMA to eliminate data loss due to DMA engine startup latency (similar approch to atmel_serial.c driver). As result the DMA engine will start on the first serial data transfer and stops only when serial port is closed. Tests environment: Using the m53evk board I have used a GPIO for profiling the IMX serial driver. - The RX line and GPIO were connected to oscilloscope. - Run a small test program on the m53evk board that will only open and read data from ttymxc2 port. - Connect the ttymxc2 port to my laptop using a USB serial converter where another test program is running, able to send configurable packet lengths and intervals. - Serial ports configured at 115200 8N1. - Interrupts load created by disconnecting/connecting (3s interval) a USB hub, using a digital switch, with 4 USB devices (USB-Serial converter, USB SD card, etc) connected. (around 160 interrupts/second generated) - The GPIO was toggled HI in the `imx_int` when USR1_RRDY or USR1_AGTIM events are received and toggled back, once the DMA configuration is finalized, at the end of `imx_dma_rxint`. Measurements: The measurements were done from the end of the last byte (RX line) until the GPIO was toggled back LOW. Note: The GPIO toggling was done using `gpiod_set_value` method. Tests performed: 1. Sending 9 bytes packets at 8ms interval. Having the 9 bytes packets will activate the RRDY threshold event and IMX serial interrupt called. Results: - DMA start latency (interrupt start latency + DMA configuration) consistently 70us when system not loaded. - DMA start latency up to 4400us when system loaded. 2. Sending 40 bytes packet at 8mS interval. Results with load: - Able to observe overruns by running: `watch -n1 cat /proc/tty/driver/IMX-uart` Tested-by: Peter Senna Tschudin <peter.senna@collabora.com> Acked-by: Peter Senna Tschudin <peter.senna@collabora.com> Signed-off-by: Nandor Han <nandor.han@ge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-08 20:38:27 +08:00
if (status == DMA_ERROR) {
imx_uart_clear_rx_errors(sport);
serial: imx-serial - update UART IMX driver to use cyclic DMA The IMX UART has a 32 bytes HW buffer which can be filled up in 2777us at 115200 baud or 80us at 4Mbaud (supported by IMX53). Taking this in consideration there is a good probability to lose data because of the DMA startup latency. Our tests (explained below) indicates a latency up to 4400us when creating interrupt load and ~70us without. When creating interrupt load I was able to see continuous overrun errors by checking serial driver statistics using the command: `cat /proc/tty/driver/IMX-uart`. Replace manual restart of DMA with cyclic DMA to eliminate data loss due to DMA engine startup latency (similar approch to atmel_serial.c driver). As result the DMA engine will start on the first serial data transfer and stops only when serial port is closed. Tests environment: Using the m53evk board I have used a GPIO for profiling the IMX serial driver. - The RX line and GPIO were connected to oscilloscope. - Run a small test program on the m53evk board that will only open and read data from ttymxc2 port. - Connect the ttymxc2 port to my laptop using a USB serial converter where another test program is running, able to send configurable packet lengths and intervals. - Serial ports configured at 115200 8N1. - Interrupts load created by disconnecting/connecting (3s interval) a USB hub, using a digital switch, with 4 USB devices (USB-Serial converter, USB SD card, etc) connected. (around 160 interrupts/second generated) - The GPIO was toggled HI in the `imx_int` when USR1_RRDY or USR1_AGTIM events are received and toggled back, once the DMA configuration is finalized, at the end of `imx_dma_rxint`. Measurements: The measurements were done from the end of the last byte (RX line) until the GPIO was toggled back LOW. Note: The GPIO toggling was done using `gpiod_set_value` method. Tests performed: 1. Sending 9 bytes packets at 8ms interval. Having the 9 bytes packets will activate the RRDY threshold event and IMX serial interrupt called. Results: - DMA start latency (interrupt start latency + DMA configuration) consistently 70us when system not loaded. - DMA start latency up to 4400us when system loaded. 2. Sending 40 bytes packet at 8mS interval. Results with load: - Able to observe overruns by running: `watch -n1 cat /proc/tty/driver/IMX-uart` Tested-by: Peter Senna Tschudin <peter.senna@collabora.com> Acked-by: Peter Senna Tschudin <peter.senna@collabora.com> Signed-off-by: Nandor Han <nandor.han@ge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-08 20:38:27 +08:00
return;
}
if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
serial: imx-serial - update UART IMX driver to use cyclic DMA The IMX UART has a 32 bytes HW buffer which can be filled up in 2777us at 115200 baud or 80us at 4Mbaud (supported by IMX53). Taking this in consideration there is a good probability to lose data because of the DMA startup latency. Our tests (explained below) indicates a latency up to 4400us when creating interrupt load and ~70us without. When creating interrupt load I was able to see continuous overrun errors by checking serial driver statistics using the command: `cat /proc/tty/driver/IMX-uart`. Replace manual restart of DMA with cyclic DMA to eliminate data loss due to DMA engine startup latency (similar approch to atmel_serial.c driver). As result the DMA engine will start on the first serial data transfer and stops only when serial port is closed. Tests environment: Using the m53evk board I have used a GPIO for profiling the IMX serial driver. - The RX line and GPIO were connected to oscilloscope. - Run a small test program on the m53evk board that will only open and read data from ttymxc2 port. - Connect the ttymxc2 port to my laptop using a USB serial converter where another test program is running, able to send configurable packet lengths and intervals. - Serial ports configured at 115200 8N1. - Interrupts load created by disconnecting/connecting (3s interval) a USB hub, using a digital switch, with 4 USB devices (USB-Serial converter, USB SD card, etc) connected. (around 160 interrupts/second generated) - The GPIO was toggled HI in the `imx_int` when USR1_RRDY or USR1_AGTIM events are received and toggled back, once the DMA configuration is finalized, at the end of `imx_dma_rxint`. Measurements: The measurements were done from the end of the last byte (RX line) until the GPIO was toggled back LOW. Note: The GPIO toggling was done using `gpiod_set_value` method. Tests performed: 1. Sending 9 bytes packets at 8ms interval. Having the 9 bytes packets will activate the RRDY threshold event and IMX serial interrupt called. Results: - DMA start latency (interrupt start latency + DMA configuration) consistently 70us when system not loaded. - DMA start latency up to 4400us when system loaded. 2. Sending 40 bytes packet at 8mS interval. Results with load: - Able to observe overruns by running: `watch -n1 cat /proc/tty/driver/IMX-uart` Tested-by: Peter Senna Tschudin <peter.senna@collabora.com> Acked-by: Peter Senna Tschudin <peter.senna@collabora.com> Signed-off-by: Nandor Han <nandor.han@ge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-08 20:38:27 +08:00
/*
* The state-residue variable represents the empty space
* relative to the entire buffer. Taking this in consideration
* the head is always calculated base on the buffer total
* length - DMA transaction residue. The UART script from the
* SDMA firmware will jump to the next buffer descriptor,
* once a DMA transaction if finalized (IMX53 RM - A.4.1.2.4).
* Taking this in consideration the tail is always at the
* beginning of the buffer descriptor that contains the head.
*/
serial: imx-serial - update UART IMX driver to use cyclic DMA The IMX UART has a 32 bytes HW buffer which can be filled up in 2777us at 115200 baud or 80us at 4Mbaud (supported by IMX53). Taking this in consideration there is a good probability to lose data because of the DMA startup latency. Our tests (explained below) indicates a latency up to 4400us when creating interrupt load and ~70us without. When creating interrupt load I was able to see continuous overrun errors by checking serial driver statistics using the command: `cat /proc/tty/driver/IMX-uart`. Replace manual restart of DMA with cyclic DMA to eliminate data loss due to DMA engine startup latency (similar approch to atmel_serial.c driver). As result the DMA engine will start on the first serial data transfer and stops only when serial port is closed. Tests environment: Using the m53evk board I have used a GPIO for profiling the IMX serial driver. - The RX line and GPIO were connected to oscilloscope. - Run a small test program on the m53evk board that will only open and read data from ttymxc2 port. - Connect the ttymxc2 port to my laptop using a USB serial converter where another test program is running, able to send configurable packet lengths and intervals. - Serial ports configured at 115200 8N1. - Interrupts load created by disconnecting/connecting (3s interval) a USB hub, using a digital switch, with 4 USB devices (USB-Serial converter, USB SD card, etc) connected. (around 160 interrupts/second generated) - The GPIO was toggled HI in the `imx_int` when USR1_RRDY or USR1_AGTIM events are received and toggled back, once the DMA configuration is finalized, at the end of `imx_dma_rxint`. Measurements: The measurements were done from the end of the last byte (RX line) until the GPIO was toggled back LOW. Note: The GPIO toggling was done using `gpiod_set_value` method. Tests performed: 1. Sending 9 bytes packets at 8ms interval. Having the 9 bytes packets will activate the RRDY threshold event and IMX serial interrupt called. Results: - DMA start latency (interrupt start latency + DMA configuration) consistently 70us when system not loaded. - DMA start latency up to 4400us when system loaded. 2. Sending 40 bytes packet at 8mS interval. Results with load: - Able to observe overruns by running: `watch -n1 cat /proc/tty/driver/IMX-uart` Tested-by: Peter Senna Tschudin <peter.senna@collabora.com> Acked-by: Peter Senna Tschudin <peter.senna@collabora.com> Signed-off-by: Nandor Han <nandor.han@ge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-08 20:38:27 +08:00
/* Calculate the head */
rx_ring->head = sg_dma_len(sgl) - state.residue;
/* Calculate the tail. */
bd_size = sg_dma_len(sgl) / sport->rx_periods;
rx_ring->tail = ((rx_ring->head-1) / bd_size) * bd_size;
if (rx_ring->head <= sg_dma_len(sgl) &&
rx_ring->head > rx_ring->tail) {
/* Move data from tail to head */
r_bytes = rx_ring->head - rx_ring->tail;
/* CPU claims ownership of RX DMA buffer */
dma_sync_sg_for_cpu(sport->port.dev, sgl, 1,
DMA_FROM_DEVICE);
w_bytes = tty_insert_flip_string(port,
sport->rx_buf + rx_ring->tail, r_bytes);
/* UART retrieves ownership of RX DMA buffer */
dma_sync_sg_for_device(sport->port.dev, sgl, 1,
DMA_FROM_DEVICE);
if (w_bytes != r_bytes)
sport->port.icount.buf_overrun++;
serial: imx-serial - update UART IMX driver to use cyclic DMA The IMX UART has a 32 bytes HW buffer which can be filled up in 2777us at 115200 baud or 80us at 4Mbaud (supported by IMX53). Taking this in consideration there is a good probability to lose data because of the DMA startup latency. Our tests (explained below) indicates a latency up to 4400us when creating interrupt load and ~70us without. When creating interrupt load I was able to see continuous overrun errors by checking serial driver statistics using the command: `cat /proc/tty/driver/IMX-uart`. Replace manual restart of DMA with cyclic DMA to eliminate data loss due to DMA engine startup latency (similar approch to atmel_serial.c driver). As result the DMA engine will start on the first serial data transfer and stops only when serial port is closed. Tests environment: Using the m53evk board I have used a GPIO for profiling the IMX serial driver. - The RX line and GPIO were connected to oscilloscope. - Run a small test program on the m53evk board that will only open and read data from ttymxc2 port. - Connect the ttymxc2 port to my laptop using a USB serial converter where another test program is running, able to send configurable packet lengths and intervals. - Serial ports configured at 115200 8N1. - Interrupts load created by disconnecting/connecting (3s interval) a USB hub, using a digital switch, with 4 USB devices (USB-Serial converter, USB SD card, etc) connected. (around 160 interrupts/second generated) - The GPIO was toggled HI in the `imx_int` when USR1_RRDY or USR1_AGTIM events are received and toggled back, once the DMA configuration is finalized, at the end of `imx_dma_rxint`. Measurements: The measurements were done from the end of the last byte (RX line) until the GPIO was toggled back LOW. Note: The GPIO toggling was done using `gpiod_set_value` method. Tests performed: 1. Sending 9 bytes packets at 8ms interval. Having the 9 bytes packets will activate the RRDY threshold event and IMX serial interrupt called. Results: - DMA start latency (interrupt start latency + DMA configuration) consistently 70us when system not loaded. - DMA start latency up to 4400us when system loaded. 2. Sending 40 bytes packet at 8mS interval. Results with load: - Able to observe overruns by running: `watch -n1 cat /proc/tty/driver/IMX-uart` Tested-by: Peter Senna Tschudin <peter.senna@collabora.com> Acked-by: Peter Senna Tschudin <peter.senna@collabora.com> Signed-off-by: Nandor Han <nandor.han@ge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-08 20:38:27 +08:00
sport->port.icount.rx += w_bytes;
} else {
WARN_ON(rx_ring->head > sg_dma_len(sgl));
WARN_ON(rx_ring->head <= rx_ring->tail);
}
}
serial: imx-serial - update UART IMX driver to use cyclic DMA The IMX UART has a 32 bytes HW buffer which can be filled up in 2777us at 115200 baud or 80us at 4Mbaud (supported by IMX53). Taking this in consideration there is a good probability to lose data because of the DMA startup latency. Our tests (explained below) indicates a latency up to 4400us when creating interrupt load and ~70us without. When creating interrupt load I was able to see continuous overrun errors by checking serial driver statistics using the command: `cat /proc/tty/driver/IMX-uart`. Replace manual restart of DMA with cyclic DMA to eliminate data loss due to DMA engine startup latency (similar approch to atmel_serial.c driver). As result the DMA engine will start on the first serial data transfer and stops only when serial port is closed. Tests environment: Using the m53evk board I have used a GPIO for profiling the IMX serial driver. - The RX line and GPIO were connected to oscilloscope. - Run a small test program on the m53evk board that will only open and read data from ttymxc2 port. - Connect the ttymxc2 port to my laptop using a USB serial converter where another test program is running, able to send configurable packet lengths and intervals. - Serial ports configured at 115200 8N1. - Interrupts load created by disconnecting/connecting (3s interval) a USB hub, using a digital switch, with 4 USB devices (USB-Serial converter, USB SD card, etc) connected. (around 160 interrupts/second generated) - The GPIO was toggled HI in the `imx_int` when USR1_RRDY or USR1_AGTIM events are received and toggled back, once the DMA configuration is finalized, at the end of `imx_dma_rxint`. Measurements: The measurements were done from the end of the last byte (RX line) until the GPIO was toggled back LOW. Note: The GPIO toggling was done using `gpiod_set_value` method. Tests performed: 1. Sending 9 bytes packets at 8ms interval. Having the 9 bytes packets will activate the RRDY threshold event and IMX serial interrupt called. Results: - DMA start latency (interrupt start latency + DMA configuration) consistently 70us when system not loaded. - DMA start latency up to 4400us when system loaded. 2. Sending 40 bytes packet at 8mS interval. Results with load: - Able to observe overruns by running: `watch -n1 cat /proc/tty/driver/IMX-uart` Tested-by: Peter Senna Tschudin <peter.senna@collabora.com> Acked-by: Peter Senna Tschudin <peter.senna@collabora.com> Signed-off-by: Nandor Han <nandor.han@ge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-08 20:38:27 +08:00
if (w_bytes) {
tty_flip_buffer_push(port);
dev_dbg(sport->port.dev, "We get %d bytes.\n", w_bytes);
}
}
/* RX DMA buffer periods */
serial: imx: adapt rx buffer and dma periods Using only 4 DMA periods for UART RX is very few if we have a high frequency of small transfers - like in our case using Bluetooth with many small packets via UART - causing many dma transfers but in each only filling a fraction of a single buffer. Such a case may lead to the situation that DMA RX transfer is triggered but no free buffer is available. When this happens dma channel ist stopped - with the patch "dmaengine: imx-sdma: fix dma freezes" temporarily only - with the possible consequences that: with disabled hw flow control: If enough data is incoming on UART port the RX FIFO runs over and characters will be lost. What then happens depends on upper layer. with enabled hw flow control: If enough data is incoming on UART port the RX FIFO reaches a level where CTS is deasserted and remote device sending the data stops. If it fails to stop timely the i.MX' RX FIFO may run over and data get lost. Otherwise it's internal TX buffer may getting filled to a point where it runs over and data is again lost. It depends on the remote device how this case is handled and if it is recoverable. Obviously we want to avoid having no free buffers available. So we decrease the size of the buffers and increase their number and the total buffer size. Signed-off-by: Philipp Puschmann <philipp.puschmann@emlix.com> Reviewed-by: Lucas Stach <l.stach@pengutronix.de> Link: https://lore.kernel.org/r/20190923135916.1212-1-philipp.puschmann@emlix.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-23 21:59:16 +08:00
#define RX_DMA_PERIODS 16
#define RX_BUF_SIZE (RX_DMA_PERIODS * PAGE_SIZE / 4)
static int imx_uart_start_rx_dma(struct imx_port *sport)
{
struct scatterlist *sgl = &sport->rx_sgl;
struct dma_chan *chan = sport->dma_chan_rx;
struct device *dev = sport->port.dev;
struct dma_async_tx_descriptor *desc;
int ret;
serial: imx-serial - update UART IMX driver to use cyclic DMA The IMX UART has a 32 bytes HW buffer which can be filled up in 2777us at 115200 baud or 80us at 4Mbaud (supported by IMX53). Taking this in consideration there is a good probability to lose data because of the DMA startup latency. Our tests (explained below) indicates a latency up to 4400us when creating interrupt load and ~70us without. When creating interrupt load I was able to see continuous overrun errors by checking serial driver statistics using the command: `cat /proc/tty/driver/IMX-uart`. Replace manual restart of DMA with cyclic DMA to eliminate data loss due to DMA engine startup latency (similar approch to atmel_serial.c driver). As result the DMA engine will start on the first serial data transfer and stops only when serial port is closed. Tests environment: Using the m53evk board I have used a GPIO for profiling the IMX serial driver. - The RX line and GPIO were connected to oscilloscope. - Run a small test program on the m53evk board that will only open and read data from ttymxc2 port. - Connect the ttymxc2 port to my laptop using a USB serial converter where another test program is running, able to send configurable packet lengths and intervals. - Serial ports configured at 115200 8N1. - Interrupts load created by disconnecting/connecting (3s interval) a USB hub, using a digital switch, with 4 USB devices (USB-Serial converter, USB SD card, etc) connected. (around 160 interrupts/second generated) - The GPIO was toggled HI in the `imx_int` when USR1_RRDY or USR1_AGTIM events are received and toggled back, once the DMA configuration is finalized, at the end of `imx_dma_rxint`. Measurements: The measurements were done from the end of the last byte (RX line) until the GPIO was toggled back LOW. Note: The GPIO toggling was done using `gpiod_set_value` method. Tests performed: 1. Sending 9 bytes packets at 8ms interval. Having the 9 bytes packets will activate the RRDY threshold event and IMX serial interrupt called. Results: - DMA start latency (interrupt start latency + DMA configuration) consistently 70us when system not loaded. - DMA start latency up to 4400us when system loaded. 2. Sending 40 bytes packet at 8mS interval. Results with load: - Able to observe overruns by running: `watch -n1 cat /proc/tty/driver/IMX-uart` Tested-by: Peter Senna Tschudin <peter.senna@collabora.com> Acked-by: Peter Senna Tschudin <peter.senna@collabora.com> Signed-off-by: Nandor Han <nandor.han@ge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-08 20:38:27 +08:00
sport->rx_ring.head = 0;
sport->rx_ring.tail = 0;
sport->rx_periods = RX_DMA_PERIODS;
serial: imx-serial - update UART IMX driver to use cyclic DMA The IMX UART has a 32 bytes HW buffer which can be filled up in 2777us at 115200 baud or 80us at 4Mbaud (supported by IMX53). Taking this in consideration there is a good probability to lose data because of the DMA startup latency. Our tests (explained below) indicates a latency up to 4400us when creating interrupt load and ~70us without. When creating interrupt load I was able to see continuous overrun errors by checking serial driver statistics using the command: `cat /proc/tty/driver/IMX-uart`. Replace manual restart of DMA with cyclic DMA to eliminate data loss due to DMA engine startup latency (similar approch to atmel_serial.c driver). As result the DMA engine will start on the first serial data transfer and stops only when serial port is closed. Tests environment: Using the m53evk board I have used a GPIO for profiling the IMX serial driver. - The RX line and GPIO were connected to oscilloscope. - Run a small test program on the m53evk board that will only open and read data from ttymxc2 port. - Connect the ttymxc2 port to my laptop using a USB serial converter where another test program is running, able to send configurable packet lengths and intervals. - Serial ports configured at 115200 8N1. - Interrupts load created by disconnecting/connecting (3s interval) a USB hub, using a digital switch, with 4 USB devices (USB-Serial converter, USB SD card, etc) connected. (around 160 interrupts/second generated) - The GPIO was toggled HI in the `imx_int` when USR1_RRDY or USR1_AGTIM events are received and toggled back, once the DMA configuration is finalized, at the end of `imx_dma_rxint`. Measurements: The measurements were done from the end of the last byte (RX line) until the GPIO was toggled back LOW. Note: The GPIO toggling was done using `gpiod_set_value` method. Tests performed: 1. Sending 9 bytes packets at 8ms interval. Having the 9 bytes packets will activate the RRDY threshold event and IMX serial interrupt called. Results: - DMA start latency (interrupt start latency + DMA configuration) consistently 70us when system not loaded. - DMA start latency up to 4400us when system loaded. 2. Sending 40 bytes packet at 8mS interval. Results with load: - Able to observe overruns by running: `watch -n1 cat /proc/tty/driver/IMX-uart` Tested-by: Peter Senna Tschudin <peter.senna@collabora.com> Acked-by: Peter Senna Tschudin <peter.senna@collabora.com> Signed-off-by: Nandor Han <nandor.han@ge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-08 20:38:27 +08:00
sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
if (ret == 0) {
dev_err(dev, "DMA mapping error for RX.\n");
return -EINVAL;
}
serial: imx-serial - update UART IMX driver to use cyclic DMA The IMX UART has a 32 bytes HW buffer which can be filled up in 2777us at 115200 baud or 80us at 4Mbaud (supported by IMX53). Taking this in consideration there is a good probability to lose data because of the DMA startup latency. Our tests (explained below) indicates a latency up to 4400us when creating interrupt load and ~70us without. When creating interrupt load I was able to see continuous overrun errors by checking serial driver statistics using the command: `cat /proc/tty/driver/IMX-uart`. Replace manual restart of DMA with cyclic DMA to eliminate data loss due to DMA engine startup latency (similar approch to atmel_serial.c driver). As result the DMA engine will start on the first serial data transfer and stops only when serial port is closed. Tests environment: Using the m53evk board I have used a GPIO for profiling the IMX serial driver. - The RX line and GPIO were connected to oscilloscope. - Run a small test program on the m53evk board that will only open and read data from ttymxc2 port. - Connect the ttymxc2 port to my laptop using a USB serial converter where another test program is running, able to send configurable packet lengths and intervals. - Serial ports configured at 115200 8N1. - Interrupts load created by disconnecting/connecting (3s interval) a USB hub, using a digital switch, with 4 USB devices (USB-Serial converter, USB SD card, etc) connected. (around 160 interrupts/second generated) - The GPIO was toggled HI in the `imx_int` when USR1_RRDY or USR1_AGTIM events are received and toggled back, once the DMA configuration is finalized, at the end of `imx_dma_rxint`. Measurements: The measurements were done from the end of the last byte (RX line) until the GPIO was toggled back LOW. Note: The GPIO toggling was done using `gpiod_set_value` method. Tests performed: 1. Sending 9 bytes packets at 8ms interval. Having the 9 bytes packets will activate the RRDY threshold event and IMX serial interrupt called. Results: - DMA start latency (interrupt start latency + DMA configuration) consistently 70us when system not loaded. - DMA start latency up to 4400us when system loaded. 2. Sending 40 bytes packet at 8mS interval. Results with load: - Able to observe overruns by running: `watch -n1 cat /proc/tty/driver/IMX-uart` Tested-by: Peter Senna Tschudin <peter.senna@collabora.com> Acked-by: Peter Senna Tschudin <peter.senna@collabora.com> Signed-off-by: Nandor Han <nandor.han@ge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-08 20:38:27 +08:00
desc = dmaengine_prep_dma_cyclic(chan, sg_dma_address(sgl),
sg_dma_len(sgl), sg_dma_len(sgl) / sport->rx_periods,
DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
if (!desc) {
dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE);
dev_err(dev, "We cannot prepare for the RX slave dma!\n");
return -EINVAL;
}
desc->callback = imx_uart_dma_rx_callback;
desc->callback_param = sport;
dev_dbg(dev, "RX: prepare for the DMA.\n");
sport->dma_is_rxing = 1;
serial: imx-serial - update UART IMX driver to use cyclic DMA The IMX UART has a 32 bytes HW buffer which can be filled up in 2777us at 115200 baud or 80us at 4Mbaud (supported by IMX53). Taking this in consideration there is a good probability to lose data because of the DMA startup latency. Our tests (explained below) indicates a latency up to 4400us when creating interrupt load and ~70us without. When creating interrupt load I was able to see continuous overrun errors by checking serial driver statistics using the command: `cat /proc/tty/driver/IMX-uart`. Replace manual restart of DMA with cyclic DMA to eliminate data loss due to DMA engine startup latency (similar approch to atmel_serial.c driver). As result the DMA engine will start on the first serial data transfer and stops only when serial port is closed. Tests environment: Using the m53evk board I have used a GPIO for profiling the IMX serial driver. - The RX line and GPIO were connected to oscilloscope. - Run a small test program on the m53evk board that will only open and read data from ttymxc2 port. - Connect the ttymxc2 port to my laptop using a USB serial converter where another test program is running, able to send configurable packet lengths and intervals. - Serial ports configured at 115200 8N1. - Interrupts load created by disconnecting/connecting (3s interval) a USB hub, using a digital switch, with 4 USB devices (USB-Serial converter, USB SD card, etc) connected. (around 160 interrupts/second generated) - The GPIO was toggled HI in the `imx_int` when USR1_RRDY or USR1_AGTIM events are received and toggled back, once the DMA configuration is finalized, at the end of `imx_dma_rxint`. Measurements: The measurements were done from the end of the last byte (RX line) until the GPIO was toggled back LOW. Note: The GPIO toggling was done using `gpiod_set_value` method. Tests performed: 1. Sending 9 bytes packets at 8ms interval. Having the 9 bytes packets will activate the RRDY threshold event and IMX serial interrupt called. Results: - DMA start latency (interrupt start latency + DMA configuration) consistently 70us when system not loaded. - DMA start latency up to 4400us when system loaded. 2. Sending 40 bytes packet at 8mS interval. Results with load: - Able to observe overruns by running: `watch -n1 cat /proc/tty/driver/IMX-uart` Tested-by: Peter Senna Tschudin <peter.senna@collabora.com> Acked-by: Peter Senna Tschudin <peter.senna@collabora.com> Signed-off-by: Nandor Han <nandor.han@ge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-08 20:38:27 +08:00
sport->rx_cookie = dmaengine_submit(desc);
dma_async_issue_pending(chan);
return 0;
}
static void imx_uart_clear_rx_errors(struct imx_port *sport)
{
struct tty_port *port = &sport->port.state->port;
u32 usr1, usr2;
usr1 = imx_uart_readl(sport, USR1);
usr2 = imx_uart_readl(sport, USR2);
if (usr2 & USR2_BRCD) {
sport->port.icount.brk++;
imx_uart_writel(sport, USR2_BRCD, USR2);
uart_handle_break(&sport->port);
if (tty_insert_flip_char(port, 0, TTY_BREAK) == 0)
sport->port.icount.buf_overrun++;
tty_flip_buffer_push(port);
} else {
if (usr1 & USR1_FRAMERR) {
sport->port.icount.frame++;
imx_uart_writel(sport, USR1_FRAMERR, USR1);
} else if (usr1 & USR1_PARITYERR) {
sport->port.icount.parity++;
imx_uart_writel(sport, USR1_PARITYERR, USR1);
}
}
if (usr2 & USR2_ORE) {
sport->port.icount.overrun++;
imx_uart_writel(sport, USR2_ORE, USR2);
}
}
#define TXTL_DEFAULT 2 /* reset default */
#define RXTL_DEFAULT 1 /* reset default */
#define TXTL_DMA 8 /* DMA burst setting */
#define RXTL_DMA 9 /* DMA burst setting */
static void imx_uart_setup_ufcr(struct imx_port *sport,
unsigned char txwl, unsigned char rxwl)
{
unsigned int val;
/* set receiver / transmitter trigger level */
val = imx_uart_readl(sport, UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
val |= txwl << UFCR_TXTL_SHF | rxwl;
imx_uart_writel(sport, val, UFCR);
}
static void imx_uart_dma_exit(struct imx_port *sport)
{
if (sport->dma_chan_rx) {
dmaengine_terminate_sync(sport->dma_chan_rx);
dma_release_channel(sport->dma_chan_rx);
sport->dma_chan_rx = NULL;
serial: imx-serial - update UART IMX driver to use cyclic DMA The IMX UART has a 32 bytes HW buffer which can be filled up in 2777us at 115200 baud or 80us at 4Mbaud (supported by IMX53). Taking this in consideration there is a good probability to lose data because of the DMA startup latency. Our tests (explained below) indicates a latency up to 4400us when creating interrupt load and ~70us without. When creating interrupt load I was able to see continuous overrun errors by checking serial driver statistics using the command: `cat /proc/tty/driver/IMX-uart`. Replace manual restart of DMA with cyclic DMA to eliminate data loss due to DMA engine startup latency (similar approch to atmel_serial.c driver). As result the DMA engine will start on the first serial data transfer and stops only when serial port is closed. Tests environment: Using the m53evk board I have used a GPIO for profiling the IMX serial driver. - The RX line and GPIO were connected to oscilloscope. - Run a small test program on the m53evk board that will only open and read data from ttymxc2 port. - Connect the ttymxc2 port to my laptop using a USB serial converter where another test program is running, able to send configurable packet lengths and intervals. - Serial ports configured at 115200 8N1. - Interrupts load created by disconnecting/connecting (3s interval) a USB hub, using a digital switch, with 4 USB devices (USB-Serial converter, USB SD card, etc) connected. (around 160 interrupts/second generated) - The GPIO was toggled HI in the `imx_int` when USR1_RRDY or USR1_AGTIM events are received and toggled back, once the DMA configuration is finalized, at the end of `imx_dma_rxint`. Measurements: The measurements were done from the end of the last byte (RX line) until the GPIO was toggled back LOW. Note: The GPIO toggling was done using `gpiod_set_value` method. Tests performed: 1. Sending 9 bytes packets at 8ms interval. Having the 9 bytes packets will activate the RRDY threshold event and IMX serial interrupt called. Results: - DMA start latency (interrupt start latency + DMA configuration) consistently 70us when system not loaded. - DMA start latency up to 4400us when system loaded. 2. Sending 40 bytes packet at 8mS interval. Results with load: - Able to observe overruns by running: `watch -n1 cat /proc/tty/driver/IMX-uart` Tested-by: Peter Senna Tschudin <peter.senna@collabora.com> Acked-by: Peter Senna Tschudin <peter.senna@collabora.com> Signed-off-by: Nandor Han <nandor.han@ge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-08 20:38:27 +08:00
sport->rx_cookie = -EINVAL;
kfree(sport->rx_buf);
sport->rx_buf = NULL;
}
if (sport->dma_chan_tx) {
dmaengine_terminate_sync(sport->dma_chan_tx);
dma_release_channel(sport->dma_chan_tx);
sport->dma_chan_tx = NULL;
}
}
static int imx_uart_dma_init(struct imx_port *sport)
{
struct dma_slave_config slave_config = {};
struct device *dev = sport->port.dev;
int ret;
/* Prepare for RX : */
sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
if (!sport->dma_chan_rx) {
dev_dbg(dev, "cannot get the DMA channel.\n");
ret = -EINVAL;
goto err;
}
slave_config.direction = DMA_DEV_TO_MEM;
slave_config.src_addr = sport->port.mapbase + URXD0;
slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
/* one byte less than the watermark level to enable the aging timer */
slave_config.src_maxburst = RXTL_DMA - 1;
ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
if (ret) {
dev_err(dev, "error in RX dma configuration.\n");
goto err;
}
sport->rx_buf = kzalloc(RX_BUF_SIZE, GFP_KERNEL);
if (!sport->rx_buf) {
ret = -ENOMEM;
goto err;
}
serial: imx-serial - update UART IMX driver to use cyclic DMA The IMX UART has a 32 bytes HW buffer which can be filled up in 2777us at 115200 baud or 80us at 4Mbaud (supported by IMX53). Taking this in consideration there is a good probability to lose data because of the DMA startup latency. Our tests (explained below) indicates a latency up to 4400us when creating interrupt load and ~70us without. When creating interrupt load I was able to see continuous overrun errors by checking serial driver statistics using the command: `cat /proc/tty/driver/IMX-uart`. Replace manual restart of DMA with cyclic DMA to eliminate data loss due to DMA engine startup latency (similar approch to atmel_serial.c driver). As result the DMA engine will start on the first serial data transfer and stops only when serial port is closed. Tests environment: Using the m53evk board I have used a GPIO for profiling the IMX serial driver. - The RX line and GPIO were connected to oscilloscope. - Run a small test program on the m53evk board that will only open and read data from ttymxc2 port. - Connect the ttymxc2 port to my laptop using a USB serial converter where another test program is running, able to send configurable packet lengths and intervals. - Serial ports configured at 115200 8N1. - Interrupts load created by disconnecting/connecting (3s interval) a USB hub, using a digital switch, with 4 USB devices (USB-Serial converter, USB SD card, etc) connected. (around 160 interrupts/second generated) - The GPIO was toggled HI in the `imx_int` when USR1_RRDY or USR1_AGTIM events are received and toggled back, once the DMA configuration is finalized, at the end of `imx_dma_rxint`. Measurements: The measurements were done from the end of the last byte (RX line) until the GPIO was toggled back LOW. Note: The GPIO toggling was done using `gpiod_set_value` method. Tests performed: 1. Sending 9 bytes packets at 8ms interval. Having the 9 bytes packets will activate the RRDY threshold event and IMX serial interrupt called. Results: - DMA start latency (interrupt start latency + DMA configuration) consistently 70us when system not loaded. - DMA start latency up to 4400us when system loaded. 2. Sending 40 bytes packet at 8mS interval. Results with load: - Able to observe overruns by running: `watch -n1 cat /proc/tty/driver/IMX-uart` Tested-by: Peter Senna Tschudin <peter.senna@collabora.com> Acked-by: Peter Senna Tschudin <peter.senna@collabora.com> Signed-off-by: Nandor Han <nandor.han@ge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-08 20:38:27 +08:00
sport->rx_ring.buf = sport->rx_buf;
/* Prepare for TX : */
sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
if (!sport->dma_chan_tx) {
dev_err(dev, "cannot get the TX DMA channel!\n");
ret = -EINVAL;
goto err;
}
slave_config.direction = DMA_MEM_TO_DEV;
slave_config.dst_addr = sport->port.mapbase + URTX0;
slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
slave_config.dst_maxburst = TXTL_DMA;
ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
if (ret) {
dev_err(dev, "error in TX dma configuration.");
goto err;
}
return 0;
err:
imx_uart_dma_exit(sport);
return ret;
}
static void imx_uart_enable_dma(struct imx_port *sport)
{
u32 ucr1;
imx_uart_setup_ufcr(sport, TXTL_DMA, RXTL_DMA);
/* set UCR1 */
ucr1 = imx_uart_readl(sport, UCR1);
ucr1 |= UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN;
imx_uart_writel(sport, ucr1, UCR1);
sport->dma_is_enabled = 1;
}
static void imx_uart_disable_dma(struct imx_port *sport)
{
u32 ucr1;
/* clear UCR1 */
ucr1 = imx_uart_readl(sport, UCR1);
ucr1 &= ~(UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN);
imx_uart_writel(sport, ucr1, UCR1);
imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
sport->dma_is_enabled = 0;
}
/* half the RX buffer size */
#define CTSTL 16
static int imx_uart_startup(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
int retval, i;
unsigned long flags;
int dma_is_inited = 0;
u32 ucr1, ucr2, ucr3, ucr4;
retval = clk_prepare_enable(sport->clk_per);
if (retval)
return retval;
retval = clk_prepare_enable(sport->clk_ipg);
if (retval) {
clk_disable_unprepare(sport->clk_per);
return retval;
}
imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
/* disable the DREN bit (Data Ready interrupt enable) before
* requesting IRQs
*/
ucr4 = imx_uart_readl(sport, UCR4);
/* set the trigger level for CTS */
ucr4 &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
ucr4 |= CTSTL << UCR4_CTSTL_SHF;
imx_uart_writel(sport, ucr4 & ~UCR4_DREN, UCR4);
/* Can we enable the DMA support? */
if (!uart_console(port) && imx_uart_dma_init(sport) == 0)
dma_is_inited = 1;
spin_lock_irqsave(&sport->port.lock, flags);
/* Reset fifo's and state machines */
i = 100;
ucr2 = imx_uart_readl(sport, UCR2);
ucr2 &= ~UCR2_SRST;
imx_uart_writel(sport, ucr2, UCR2);
while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
udelay(1);
/*
* Finally, clear and enable interrupts
*/
imx_uart_writel(sport, USR1_RTSD | USR1_DTRD, USR1);
imx_uart_writel(sport, USR2_ORE, USR2);
ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_RRDYEN;
ucr1 |= UCR1_UARTEN;
if (sport->have_rtscts)
ucr1 |= UCR1_RTSDEN;
imx_uart_writel(sport, ucr1, UCR1);
ucr4 = imx_uart_readl(sport, UCR4) & ~(UCR4_OREN | UCR4_INVR);
if (!sport->dma_is_enabled)
ucr4 |= UCR4_OREN;
if (sport->inverted_rx)
ucr4 |= UCR4_INVR;
imx_uart_writel(sport, ucr4, UCR4);
ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_INVT;
/*
* configure tx polarity before enabling tx
*/
if (sport->inverted_tx)
ucr3 |= UCR3_INVT;
if (!imx_uart_is_imx1(sport)) {
ucr3 |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD;
if (sport->dte_mode)
/* disable broken interrupts */
ucr3 &= ~(UCR3_RI | UCR3_DCD);
}
imx_uart_writel(sport, ucr3, UCR3);
ucr2 = imx_uart_readl(sport, UCR2) & ~UCR2_ATEN;
ucr2 |= (UCR2_RXEN | UCR2_TXEN);
if (!sport->have_rtscts)
ucr2 |= UCR2_IRTS;
/*
* make sure the edge sensitive RTS-irq is disabled,
* we're using RTSD instead.
*/
if (!imx_uart_is_imx1(sport))
ucr2 &= ~UCR2_RTSEN;
imx_uart_writel(sport, ucr2, UCR2);
/*
* Enable modem status interrupts
*/
imx_uart_enable_ms(&sport->port);
if (dma_is_inited) {
imx_uart_enable_dma(sport);
imx_uart_start_rx_dma(sport);
} else {
ucr1 = imx_uart_readl(sport, UCR1);
ucr1 |= UCR1_RRDYEN;
imx_uart_writel(sport, ucr1, UCR1);
ucr2 = imx_uart_readl(sport, UCR2);
ucr2 |= UCR2_ATEN;
imx_uart_writel(sport, ucr2, UCR2);
}
spin_unlock_irqrestore(&sport->port.lock, flags);
return 0;
}
static void imx_uart_shutdown(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned long flags;
u32 ucr1, ucr2, ucr4;
if (sport->dma_is_enabled) {
dmaengine_terminate_sync(sport->dma_chan_tx);
if (sport->dma_is_txing) {
dma_unmap_sg(sport->port.dev, &sport->tx_sgl[0],
sport->dma_tx_nents, DMA_TO_DEVICE);
sport->dma_is_txing = 0;
}
dmaengine_terminate_sync(sport->dma_chan_rx);
if (sport->dma_is_rxing) {
dma_unmap_sg(sport->port.dev, &sport->rx_sgl,
1, DMA_FROM_DEVICE);
sport->dma_is_rxing = 0;
}
spin_lock_irqsave(&sport->port.lock, flags);
imx_uart_stop_tx(port);
imx_uart_stop_rx(port);
imx_uart_disable_dma(sport);
spin_unlock_irqrestore(&sport->port.lock, flags);
imx_uart_dma_exit(sport);
}
mctrl_gpio_disable_ms(sport->gpios);
spin_lock_irqsave(&sport->port.lock, flags);
ucr2 = imx_uart_readl(sport, UCR2);
ucr2 &= ~(UCR2_TXEN | UCR2_ATEN);
imx_uart_writel(sport, ucr2, UCR2);
ucr4 = imx_uart_readl(sport, UCR4);
ucr4 &= ~UCR4_OREN;
imx_uart_writel(sport, ucr4, UCR4);
spin_unlock_irqrestore(&sport->port.lock, flags);
/*
* Stop our timer.
*/
del_timer_sync(&sport->timer);
/*
* Disable all interrupts, port and break condition.
*/
spin_lock_irqsave(&sport->port.lock, flags);
ucr1 = imx_uart_readl(sport, UCR1);
ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN | UCR1_RXDMAEN | UCR1_ATDMAEN);
imx_uart_writel(sport, ucr1, UCR1);
spin_unlock_irqrestore(&sport->port.lock, flags);
clk_disable_unprepare(sport->clk_per);
clk_disable_unprepare(sport->clk_ipg);
}
/* called with port.lock taken and irqs off */
static void imx_uart_flush_buffer(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
struct scatterlist *sgl = &sport->tx_sgl[0];
u32 ucr2;
int i = 100, ubir, ubmr, uts;
if (!sport->dma_chan_tx)
return;
sport->tx_bytes = 0;
dmaengine_terminate_all(sport->dma_chan_tx);
if (sport->dma_is_txing) {
u32 ucr1;
dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,
DMA_TO_DEVICE);
ucr1 = imx_uart_readl(sport, UCR1);
ucr1 &= ~UCR1_TXDMAEN;
imx_uart_writel(sport, ucr1, UCR1);
sport->dma_is_txing = 0;
}
/*
* According to the Reference Manual description of the UART SRST bit:
*
* "Reset the transmit and receive state machines,
* all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
* and UTS[6-3]".
*
* We don't need to restore the old values from USR1, USR2, URXD and
* UTXD. UBRC is read only, so only save/restore the other three
* registers.
*/
ubir = imx_uart_readl(sport, UBIR);
ubmr = imx_uart_readl(sport, UBMR);
uts = imx_uart_readl(sport, IMX21_UTS);
ucr2 = imx_uart_readl(sport, UCR2);
ucr2 &= ~UCR2_SRST;
imx_uart_writel(sport, ucr2, UCR2);
while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
udelay(1);
/* Restore the registers */
imx_uart_writel(sport, ubir, UBIR);
imx_uart_writel(sport, ubmr, UBMR);
imx_uart_writel(sport, uts, IMX21_UTS);
}
static void
imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned long flags;
u32 ucr2, old_ucr2, ufcr;
unsigned int baud, quot;
unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
unsigned long div;
unsigned long num, denom, old_ubir, old_ubmr;
uint64_t tdiv64;
/*
* We only support CS7 and CS8.
*/
while ((termios->c_cflag & CSIZE) != CS7 &&
(termios->c_cflag & CSIZE) != CS8) {
termios->c_cflag &= ~CSIZE;
termios->c_cflag |= old_csize;
old_csize = CS8;
}
del_timer_sync(&sport->timer);
/*
* Ask the core to calculate the divisor for us.
*/
baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
quot = uart_get_divisor(port, baud);
spin_lock_irqsave(&sport->port.lock, flags);
/*
* Read current UCR2 and save it for future use, then clear all the bits
* except those we will or may need to preserve.
*/
old_ucr2 = imx_uart_readl(sport, UCR2);
ucr2 = old_ucr2 & (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN | UCR2_CTS);
ucr2 |= UCR2_SRST | UCR2_IRTS;
if ((termios->c_cflag & CSIZE) == CS8)
ucr2 |= UCR2_WS;
if (!sport->have_rtscts)
termios->c_cflag &= ~CRTSCTS;
if (port->rs485.flags & SER_RS485_ENABLED) {
/*
* RTS is mandatory for rs485 operation, so keep
* it under manual control and keep transmitter
* disabled.
*/
if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
imx_uart_rts_active(sport, &ucr2);
else
imx_uart_rts_inactive(sport, &ucr2);
} else if (termios->c_cflag & CRTSCTS) {
/*
* Only let receiver control RTS output if we were not requested
* to have RTS inactive (which then should take precedence).
*/
if (ucr2 & UCR2_CTS)
ucr2 |= UCR2_CTSC;
}
if (termios->c_cflag & CRTSCTS)
ucr2 &= ~UCR2_IRTS;
if (termios->c_cflag & CSTOPB)
ucr2 |= UCR2_STPB;
if (termios->c_cflag & PARENB) {
ucr2 |= UCR2_PREN;
if (termios->c_cflag & PARODD)
ucr2 |= UCR2_PROE;
}
sport->port.read_status_mask = 0;
if (termios->c_iflag & INPCK)
sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
if (termios->c_iflag & (BRKINT | PARMRK))
sport->port.read_status_mask |= URXD_BRK;
/*
* Characters to ignore
*/
sport->port.ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR;
if (termios->c_iflag & IGNBRK) {
sport->port.ignore_status_mask |= URXD_BRK;
/*
* If we're ignoring parity and break indicators,
* ignore overruns too (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
sport->port.ignore_status_mask |= URXD_OVRRUN;
}
if ((termios->c_cflag & CREAD) == 0)
sport->port.ignore_status_mask |= URXD_DUMMY_READ;
/*
* Update the per-port timeout.
*/
uart_update_timeout(port, termios->c_cflag, baud);
/* custom-baudrate handling */
div = sport->port.uartclk / (baud * 16);
if (baud == 38400 && quot != div)
baud = sport->port.uartclk / (quot * 16);
div = sport->port.uartclk / (baud * 16);
if (div > 7)
div = 7;
if (!div)
div = 1;
rational_best_approximation(16 * div * baud, sport->port.uartclk,
1 << 16, 1 << 16, &num, &denom);
tdiv64 = sport->port.uartclk;
tdiv64 *= num;
do_div(tdiv64, denom * 16 * div);
tty_termios_encode_baud_rate(termios,
(speed_t)tdiv64, (speed_t)tdiv64);
num -= 1;
denom -= 1;
ufcr = imx_uart_readl(sport, UFCR);
ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
imx_uart_writel(sport, ufcr, UFCR);
/*
* Two registers below should always be written both and in this
* particular order. One consequence is that we need to check if any of
* them changes and then update both. We do need the check for change
* as even writing the same values seem to "restart"
* transmission/receiving logic in the hardware, that leads to data
* breakage even when rate doesn't in fact change. E.g., user switches
* RTS/CTS handshake and suddenly gets broken bytes.
*/
old_ubir = imx_uart_readl(sport, UBIR);
old_ubmr = imx_uart_readl(sport, UBMR);
if (old_ubir != num || old_ubmr != denom) {
imx_uart_writel(sport, num, UBIR);
imx_uart_writel(sport, denom, UBMR);
}
if (!imx_uart_is_imx1(sport))
imx_uart_writel(sport, sport->port.uartclk / div / 1000,
IMX21_ONEMS);
imx_uart_writel(sport, ucr2, UCR2);
if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
imx_uart_enable_ms(&sport->port);
spin_unlock_irqrestore(&sport->port.lock, flags);
}
static const char *imx_uart_type(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
return sport->port.type == PORT_IMX ? "IMX" : NULL;
}
/*
* Configure/autoconfigure the port.
*/
static void imx_uart_config_port(struct uart_port *port, int flags)
{
struct imx_port *sport = (struct imx_port *)port;
if (flags & UART_CONFIG_TYPE)
sport->port.type = PORT_IMX;
}
/*
* Verify the new serial_struct (for TIOCSSERIAL).
* The only change we allow are to the flags and type, and
* even then only between PORT_IMX and PORT_UNKNOWN
*/
static int
imx_uart_verify_port(struct uart_port *port, struct serial_struct *ser)
{
struct imx_port *sport = (struct imx_port *)port;
int ret = 0;
if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
ret = -EINVAL;
if (sport->port.irq != ser->irq)
ret = -EINVAL;
if (ser->io_type != UPIO_MEM)
ret = -EINVAL;
if (sport->port.uartclk / 16 != ser->baud_base)
ret = -EINVAL;
if (sport->port.mapbase != (unsigned long)ser->iomem_base)
ret = -EINVAL;
if (sport->port.iobase != ser->port)
ret = -EINVAL;
if (ser->hub6 != 0)
ret = -EINVAL;
return ret;
}
#if defined(CONFIG_CONSOLE_POLL)
static int imx_uart_poll_init(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned long flags;
u32 ucr1, ucr2;
int retval;
retval = clk_prepare_enable(sport->clk_ipg);
if (retval)
return retval;
retval = clk_prepare_enable(sport->clk_per);
if (retval)
clk_disable_unprepare(sport->clk_ipg);
imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
spin_lock_irqsave(&sport->port.lock, flags);
/*
* Be careful about the order of enabling bits here. First enable the
* receiver (UARTEN + RXEN) and only then the corresponding irqs.
* This prevents that a character that already sits in the RX fifo is
* triggering an irq but the try to fetch it from there results in an
* exception because UARTEN or RXEN is still off.
*/
ucr1 = imx_uart_readl(sport, UCR1);
ucr2 = imx_uart_readl(sport, UCR2);
if (imx_uart_is_imx1(sport))
ucr1 |= IMX1_UCR1_UARTCLKEN;
ucr1 |= UCR1_UARTEN;
ucr1 &= ~(UCR1_TRDYEN | UCR1_RTSDEN | UCR1_RRDYEN);
ucr2 |= UCR2_RXEN;
ucr2 &= ~UCR2_ATEN;
imx_uart_writel(sport, ucr1, UCR1);
imx_uart_writel(sport, ucr2, UCR2);
/* now enable irqs */
imx_uart_writel(sport, ucr1 | UCR1_RRDYEN, UCR1);
imx_uart_writel(sport, ucr2 | UCR2_ATEN, UCR2);
spin_unlock_irqrestore(&sport->port.lock, flags);
return 0;
}
static int imx_uart_poll_get_char(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
if (!(imx_uart_readl(sport, USR2) & USR2_RDR))
return NO_POLL_CHAR;
return imx_uart_readl(sport, URXD0) & URXD_RX_DATA;
}
static void imx_uart_poll_put_char(struct uart_port *port, unsigned char c)
{
struct imx_port *sport = (struct imx_port *)port;
unsigned int status;
/* drain */
do {
status = imx_uart_readl(sport, USR1);
} while (~status & USR1_TRDY);
/* write */
imx_uart_writel(sport, c, URTX0);
/* flush */
do {
status = imx_uart_readl(sport, USR2);
} while (~status & USR2_TXDC);
}
#endif
/* called with port.lock taken and irqs off or from .probe without locking */
static int imx_uart_rs485_config(struct uart_port *port,
struct serial_rs485 *rs485conf)
{
struct imx_port *sport = (struct imx_port *)port;
u32 ucr2;
/* RTS is required to control the transmitter */
if (!sport->have_rtscts && !sport->have_rtsgpio)
rs485conf->flags &= ~SER_RS485_ENABLED;
if (rs485conf->flags & SER_RS485_ENABLED) {
/* Enable receiver if low-active RTS signal is requested */
if (sport->have_rtscts && !sport->have_rtsgpio &&
!(rs485conf->flags & SER_RS485_RTS_ON_SEND))
rs485conf->flags |= SER_RS485_RX_DURING_TX;
/* disable transmitter */
ucr2 = imx_uart_readl(sport, UCR2);
if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
imx_uart_rts_active(sport, &ucr2);
else
imx_uart_rts_inactive(sport, &ucr2);
imx_uart_writel(sport, ucr2, UCR2);
}
/* Make sure Rx is enabled in case Tx is active with Rx disabled */
if (!(rs485conf->flags & SER_RS485_ENABLED) ||
rs485conf->flags & SER_RS485_RX_DURING_TX)
imx_uart_start_rx(port);
port->rs485 = *rs485conf;
return 0;
}
static const struct uart_ops imx_uart_pops = {
.tx_empty = imx_uart_tx_empty,
.set_mctrl = imx_uart_set_mctrl,
.get_mctrl = imx_uart_get_mctrl,
.stop_tx = imx_uart_stop_tx,
.start_tx = imx_uart_start_tx,
.stop_rx = imx_uart_stop_rx,
.enable_ms = imx_uart_enable_ms,
.break_ctl = imx_uart_break_ctl,
.startup = imx_uart_startup,
.shutdown = imx_uart_shutdown,
.flush_buffer = imx_uart_flush_buffer,
.set_termios = imx_uart_set_termios,
.type = imx_uart_type,
.config_port = imx_uart_config_port,
.verify_port = imx_uart_verify_port,
#if defined(CONFIG_CONSOLE_POLL)
.poll_init = imx_uart_poll_init,
.poll_get_char = imx_uart_poll_get_char,
.poll_put_char = imx_uart_poll_put_char,
#endif
};
static struct imx_port *imx_uart_ports[UART_NR];
#if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE)
static void imx_uart_console_putchar(struct uart_port *port, int ch)
{
struct imx_port *sport = (struct imx_port *)port;
while (imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)
barrier();
imx_uart_writel(sport, ch, URTX0);
}
/*
* Interrupts are disabled on entering
*/
static void
imx_uart_console_write(struct console *co, const char *s, unsigned int count)
{
struct imx_port *sport = imx_uart_ports[co->index];
struct imx_port_ucrs old_ucr;
unsigned int ucr1;
unsigned long flags = 0;
serial: imx: Fix recursive locking bug commit 9ec1882df2 (tty: serial: imx: console write routing is unsafe on SMP) introduced a recursive locking bug in imx_console_write(). The callchain is: imx_rxint() spin_lock_irqsave(&sport->port.lock,flags); ... uart_handle_sysrq_char(); sysrq_function(); printk(); imx_console_write(); spin_lock_irqsave(&sport->port.lock,flags); <--- DEAD The bad news is that the kernel debugging facilities can dectect the problem, but the printks never surface on the serial console for obvious reasons. There is a similar issue with oops_in_progress. If the kernel crashes we really don't want to be stuck on the lock and unable to tell what happened. In general most UP originated drivers miss these checks and nobody ever notices because CONFIG_PROVE_LOCKING seems to be still ignored by a large number of developers. The solution is to avoid locking in the sysrq case and trylock in the oops_in_progress case. This scheme is used in other drivers as well and it would be nice if we could move this to a common place, so the usual copy/paste/modify bugs can be avoided. Now there is another issue with this scheme: CPU0 CPU1 printk() rxint() sysrq_detection() -> sets port->sysrq return from interrupt console_write() if (port->sysrq) avoid locking port->sysrq is reset with the next receive character. So as long as the port->sysrq is not reset and this can take an endless amount of time if after the break no futher receive character follows, all console writes happen unlocked. While the current writer is protected against other console writers by the console sem, it's unprotected against open/close or other operations which fiddle with the port. That's what the above mentioned commit tried to solve. That's an issue in all drivers which use that scheme and unfortunately there is no easy workaround. The only solution is to have a separate indicator port->sysrq_cpu. uart_handle_sysrq_char() then sets it to smp_processor_id() before calling into handle_sysrq() and resets it to -1 after that. Then change the locking check to: if (port->sysrq_cpu == smp_processor_id()) locked = 0; else if (oops_in_progress) locked = spin_trylock_irqsave(port->lock, flags); else spin_lock_irqsave(port->lock, flags); That would force all other cpus into the spin_lock path. Problem solved, but that's way beyond the scope of this fix and really wants to be implemented in a common function which calls the uart specific write function to avoid another gazillion of hard to debug copy/paste/modify bugs. Reported-and-tested-by: Tim Sander <tim@krieglstein.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable <stable@vger.kernel.org> # 3.6+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-15 04:01:06 +08:00
int locked = 1;
int retval;
Revert "serial: imx: remove unbalanced clk_prepare" This reverts commit 9e7b399d6528eac33a6fbfceb2b92af209c3454d. Commit ("9e7b399d6528ea") causes the following warning and sometimes also hangs the system: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/locking/mutex.c:868 mutex_trylock+0x20c/0x22c() DEBUG_LOCKS_WARN_ON(in_interrupt()) Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.2.0-rc7-next-20150818-00001-g14418a6 #4 Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) Backtrace: [<80012f08>] (dump_backtrace) from [<800130a4>] (show_stack+0x18/0x1c) r6:00000364 r5:00000000 r4:00000000 r3:00000000 [<8001308c>] (show_stack) from [<807902b8>] (dump_stack+0x88/0xa4) [<80790230>] (dump_stack) from [<8002a604>] (warn_slowpath_common+0x80/0xbc) r5:807945c4 r4:80ab3b50 [<8002a584>] (warn_slowpath_common) from [<8002a6e4>] (warn_slowpath_fmt+0x38/0x40) r8:00000000 r7:8131100c r6:8054c3cc r5:8131300c r4:80b0a570 [<8002a6b0>] (warn_slowpath_fmt) from [<807945c4>] (mutex_trylock+0x20c/0x22c) r3:8095d0d8 r2:8095ab28 [<807943b8>] (mutex_trylock) from [<8054c3cc>] (clk_prepare_lock+0x14/0xf4) r7:8131100c r6:be3f0c80 r5:00000037 r4:be3f0c80 [<8054c3b8>] (clk_prepare_lock) from [<8054dbfc>] (clk_prepare+0x18/0x30) r5:00000037 r4:be3f0c80 [<8054dbe4>] (clk_prepare) from [<8036a600>] (imx_console_write+0x30/0x244) r4:812d0bc8 r3:8132b9a4 To reproduce the problem we only need to let the board idle for something like 30 seconds. Tested on a imx6q-sabresd. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Reviewed-by: Eduardo Valentin <edubezval@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-18 23:43:12 +08:00
retval = clk_enable(sport->clk_per);
if (retval)
return;
Revert "serial: imx: remove unbalanced clk_prepare" This reverts commit 9e7b399d6528eac33a6fbfceb2b92af209c3454d. Commit ("9e7b399d6528ea") causes the following warning and sometimes also hangs the system: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/locking/mutex.c:868 mutex_trylock+0x20c/0x22c() DEBUG_LOCKS_WARN_ON(in_interrupt()) Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.2.0-rc7-next-20150818-00001-g14418a6 #4 Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) Backtrace: [<80012f08>] (dump_backtrace) from [<800130a4>] (show_stack+0x18/0x1c) r6:00000364 r5:00000000 r4:00000000 r3:00000000 [<8001308c>] (show_stack) from [<807902b8>] (dump_stack+0x88/0xa4) [<80790230>] (dump_stack) from [<8002a604>] (warn_slowpath_common+0x80/0xbc) r5:807945c4 r4:80ab3b50 [<8002a584>] (warn_slowpath_common) from [<8002a6e4>] (warn_slowpath_fmt+0x38/0x40) r8:00000000 r7:8131100c r6:8054c3cc r5:8131300c r4:80b0a570 [<8002a6b0>] (warn_slowpath_fmt) from [<807945c4>] (mutex_trylock+0x20c/0x22c) r3:8095d0d8 r2:8095ab28 [<807943b8>] (mutex_trylock) from [<8054c3cc>] (clk_prepare_lock+0x14/0xf4) r7:8131100c r6:be3f0c80 r5:00000037 r4:be3f0c80 [<8054c3b8>] (clk_prepare_lock) from [<8054dbfc>] (clk_prepare+0x18/0x30) r5:00000037 r4:be3f0c80 [<8054dbe4>] (clk_prepare) from [<8036a600>] (imx_console_write+0x30/0x244) r4:812d0bc8 r3:8132b9a4 To reproduce the problem we only need to let the board idle for something like 30 seconds. Tested on a imx6q-sabresd. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Reviewed-by: Eduardo Valentin <edubezval@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-18 23:43:12 +08:00
retval = clk_enable(sport->clk_ipg);
if (retval) {
Revert "serial: imx: remove unbalanced clk_prepare" This reverts commit 9e7b399d6528eac33a6fbfceb2b92af209c3454d. Commit ("9e7b399d6528ea") causes the following warning and sometimes also hangs the system: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/locking/mutex.c:868 mutex_trylock+0x20c/0x22c() DEBUG_LOCKS_WARN_ON(in_interrupt()) Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.2.0-rc7-next-20150818-00001-g14418a6 #4 Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) Backtrace: [<80012f08>] (dump_backtrace) from [<800130a4>] (show_stack+0x18/0x1c) r6:00000364 r5:00000000 r4:00000000 r3:00000000 [<8001308c>] (show_stack) from [<807902b8>] (dump_stack+0x88/0xa4) [<80790230>] (dump_stack) from [<8002a604>] (warn_slowpath_common+0x80/0xbc) r5:807945c4 r4:80ab3b50 [<8002a584>] (warn_slowpath_common) from [<8002a6e4>] (warn_slowpath_fmt+0x38/0x40) r8:00000000 r7:8131100c r6:8054c3cc r5:8131300c r4:80b0a570 [<8002a6b0>] (warn_slowpath_fmt) from [<807945c4>] (mutex_trylock+0x20c/0x22c) r3:8095d0d8 r2:8095ab28 [<807943b8>] (mutex_trylock) from [<8054c3cc>] (clk_prepare_lock+0x14/0xf4) r7:8131100c r6:be3f0c80 r5:00000037 r4:be3f0c80 [<8054c3b8>] (clk_prepare_lock) from [<8054dbfc>] (clk_prepare+0x18/0x30) r5:00000037 r4:be3f0c80 [<8054dbe4>] (clk_prepare) from [<8036a600>] (imx_console_write+0x30/0x244) r4:812d0bc8 r3:8132b9a4 To reproduce the problem we only need to let the board idle for something like 30 seconds. Tested on a imx6q-sabresd. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Reviewed-by: Eduardo Valentin <edubezval@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-18 23:43:12 +08:00
clk_disable(sport->clk_per);
return;
}
serial: imx: Fix recursive locking bug commit 9ec1882df2 (tty: serial: imx: console write routing is unsafe on SMP) introduced a recursive locking bug in imx_console_write(). The callchain is: imx_rxint() spin_lock_irqsave(&sport->port.lock,flags); ... uart_handle_sysrq_char(); sysrq_function(); printk(); imx_console_write(); spin_lock_irqsave(&sport->port.lock,flags); <--- DEAD The bad news is that the kernel debugging facilities can dectect the problem, but the printks never surface on the serial console for obvious reasons. There is a similar issue with oops_in_progress. If the kernel crashes we really don't want to be stuck on the lock and unable to tell what happened. In general most UP originated drivers miss these checks and nobody ever notices because CONFIG_PROVE_LOCKING seems to be still ignored by a large number of developers. The solution is to avoid locking in the sysrq case and trylock in the oops_in_progress case. This scheme is used in other drivers as well and it would be nice if we could move this to a common place, so the usual copy/paste/modify bugs can be avoided. Now there is another issue with this scheme: CPU0 CPU1 printk() rxint() sysrq_detection() -> sets port->sysrq return from interrupt console_write() if (port->sysrq) avoid locking port->sysrq is reset with the next receive character. So as long as the port->sysrq is not reset and this can take an endless amount of time if after the break no futher receive character follows, all console writes happen unlocked. While the current writer is protected against other console writers by the console sem, it's unprotected against open/close or other operations which fiddle with the port. That's what the above mentioned commit tried to solve. That's an issue in all drivers which use that scheme and unfortunately there is no easy workaround. The only solution is to have a separate indicator port->sysrq_cpu. uart_handle_sysrq_char() then sets it to smp_processor_id() before calling into handle_sysrq() and resets it to -1 after that. Then change the locking check to: if (port->sysrq_cpu == smp_processor_id()) locked = 0; else if (oops_in_progress) locked = spin_trylock_irqsave(port->lock, flags); else spin_lock_irqsave(port->lock, flags); That would force all other cpus into the spin_lock path. Problem solved, but that's way beyond the scope of this fix and really wants to be implemented in a common function which calls the uart specific write function to avoid another gazillion of hard to debug copy/paste/modify bugs. Reported-and-tested-by: Tim Sander <tim@krieglstein.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable <stable@vger.kernel.org> # 3.6+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-15 04:01:06 +08:00
if (sport->port.sysrq)
locked = 0;
else if (oops_in_progress)
locked = spin_trylock_irqsave(&sport->port.lock, flags);
else
spin_lock_irqsave(&sport->port.lock, flags);
/*
* First, save UCR1/2/3 and then disable interrupts
*/
imx_uart_ucrs_save(sport, &old_ucr);
ucr1 = old_ucr.ucr1;
if (imx_uart_is_imx1(sport))
ucr1 |= IMX1_UCR1_UARTCLKEN;
ucr1 |= UCR1_UARTEN;
ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN);
imx_uart_writel(sport, ucr1, UCR1);
imx_uart_writel(sport, old_ucr.ucr2 | UCR2_TXEN, UCR2);
uart_console_write(&sport->port, s, count, imx_uart_console_putchar);
/*
* Finally, wait for transmitter to become empty
* and restore UCR1/2/3
*/
while (!(imx_uart_readl(sport, USR2) & USR2_TXDC));
imx_uart_ucrs_restore(sport, &old_ucr);
serial: imx: Fix recursive locking bug commit 9ec1882df2 (tty: serial: imx: console write routing is unsafe on SMP) introduced a recursive locking bug in imx_console_write(). The callchain is: imx_rxint() spin_lock_irqsave(&sport->port.lock,flags); ... uart_handle_sysrq_char(); sysrq_function(); printk(); imx_console_write(); spin_lock_irqsave(&sport->port.lock,flags); <--- DEAD The bad news is that the kernel debugging facilities can dectect the problem, but the printks never surface on the serial console for obvious reasons. There is a similar issue with oops_in_progress. If the kernel crashes we really don't want to be stuck on the lock and unable to tell what happened. In general most UP originated drivers miss these checks and nobody ever notices because CONFIG_PROVE_LOCKING seems to be still ignored by a large number of developers. The solution is to avoid locking in the sysrq case and trylock in the oops_in_progress case. This scheme is used in other drivers as well and it would be nice if we could move this to a common place, so the usual copy/paste/modify bugs can be avoided. Now there is another issue with this scheme: CPU0 CPU1 printk() rxint() sysrq_detection() -> sets port->sysrq return from interrupt console_write() if (port->sysrq) avoid locking port->sysrq is reset with the next receive character. So as long as the port->sysrq is not reset and this can take an endless amount of time if after the break no futher receive character follows, all console writes happen unlocked. While the current writer is protected against other console writers by the console sem, it's unprotected against open/close or other operations which fiddle with the port. That's what the above mentioned commit tried to solve. That's an issue in all drivers which use that scheme and unfortunately there is no easy workaround. The only solution is to have a separate indicator port->sysrq_cpu. uart_handle_sysrq_char() then sets it to smp_processor_id() before calling into handle_sysrq() and resets it to -1 after that. Then change the locking check to: if (port->sysrq_cpu == smp_processor_id()) locked = 0; else if (oops_in_progress) locked = spin_trylock_irqsave(port->lock, flags); else spin_lock_irqsave(port->lock, flags); That would force all other cpus into the spin_lock path. Problem solved, but that's way beyond the scope of this fix and really wants to be implemented in a common function which calls the uart specific write function to avoid another gazillion of hard to debug copy/paste/modify bugs. Reported-and-tested-by: Tim Sander <tim@krieglstein.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable <stable@vger.kernel.org> # 3.6+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-15 04:01:06 +08:00
if (locked)
spin_unlock_irqrestore(&sport->port.lock, flags);
Revert "serial: imx: remove unbalanced clk_prepare" This reverts commit 9e7b399d6528eac33a6fbfceb2b92af209c3454d. Commit ("9e7b399d6528ea") causes the following warning and sometimes also hangs the system: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/locking/mutex.c:868 mutex_trylock+0x20c/0x22c() DEBUG_LOCKS_WARN_ON(in_interrupt()) Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.2.0-rc7-next-20150818-00001-g14418a6 #4 Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) Backtrace: [<80012f08>] (dump_backtrace) from [<800130a4>] (show_stack+0x18/0x1c) r6:00000364 r5:00000000 r4:00000000 r3:00000000 [<8001308c>] (show_stack) from [<807902b8>] (dump_stack+0x88/0xa4) [<80790230>] (dump_stack) from [<8002a604>] (warn_slowpath_common+0x80/0xbc) r5:807945c4 r4:80ab3b50 [<8002a584>] (warn_slowpath_common) from [<8002a6e4>] (warn_slowpath_fmt+0x38/0x40) r8:00000000 r7:8131100c r6:8054c3cc r5:8131300c r4:80b0a570 [<8002a6b0>] (warn_slowpath_fmt) from [<807945c4>] (mutex_trylock+0x20c/0x22c) r3:8095d0d8 r2:8095ab28 [<807943b8>] (mutex_trylock) from [<8054c3cc>] (clk_prepare_lock+0x14/0xf4) r7:8131100c r6:be3f0c80 r5:00000037 r4:be3f0c80 [<8054c3b8>] (clk_prepare_lock) from [<8054dbfc>] (clk_prepare+0x18/0x30) r5:00000037 r4:be3f0c80 [<8054dbe4>] (clk_prepare) from [<8036a600>] (imx_console_write+0x30/0x244) r4:812d0bc8 r3:8132b9a4 To reproduce the problem we only need to let the board idle for something like 30 seconds. Tested on a imx6q-sabresd. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Reviewed-by: Eduardo Valentin <edubezval@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-18 23:43:12 +08:00
clk_disable(sport->clk_ipg);
clk_disable(sport->clk_per);
}
/*
* If the port was already initialised (eg, by a boot loader),
* try to determine the current setup.
*/
static void __init
imx_uart_console_get_options(struct imx_port *sport, int *baud,
int *parity, int *bits)
{
if (imx_uart_readl(sport, UCR1) & UCR1_UARTEN) {
/* ok, the port was enabled */
unsigned int ucr2, ubir, ubmr, uartclk;
unsigned int baud_raw;
unsigned int ucfr_rfdiv;
ucr2 = imx_uart_readl(sport, UCR2);
*parity = 'n';
if (ucr2 & UCR2_PREN) {
if (ucr2 & UCR2_PROE)
*parity = 'o';
else
*parity = 'e';
}
if (ucr2 & UCR2_WS)
*bits = 8;
else
*bits = 7;
ubir = imx_uart_readl(sport, UBIR) & 0xffff;
ubmr = imx_uart_readl(sport, UBMR) & 0xffff;
ucfr_rfdiv = (imx_uart_readl(sport, UFCR) & UFCR_RFDIV) >> 7;
if (ucfr_rfdiv == 6)
ucfr_rfdiv = 7;
else
ucfr_rfdiv = 6 - ucfr_rfdiv;
uartclk = clk_get_rate(sport->clk_per);
uartclk /= ucfr_rfdiv;
{ /*
* The next code provides exact computation of
* baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
* without need of float support or long long division,
* which would be required to prevent 32bit arithmetic overflow
*/
unsigned int mul = ubir + 1;
unsigned int div = 16 * (ubmr + 1);
unsigned int rem = uartclk % div;
baud_raw = (uartclk / div) * mul;
baud_raw += (rem * mul + div / 2) / div;
*baud = (baud_raw + 50) / 100 * 100;
}
if (*baud != baud_raw)
dev_info(sport->port.dev, "Console IMX rounded baud rate from %d to %d\n",
baud_raw, *baud);
}
}
static int __init
imx_uart_console_setup(struct console *co, char *options)
{
struct imx_port *sport;
int baud = 9600;
int bits = 8;
int parity = 'n';
int flow = 'n';
int retval;
/*
* Check whether an invalid uart number has been specified, and
* if so, search for the first available port that does have
* console support.
*/
if (co->index == -1 || co->index >= ARRAY_SIZE(imx_uart_ports))
co->index = 0;
sport = imx_uart_ports[co->index];
if (sport == NULL)
return -ENODEV;
/* For setting the registers, we only need to enable the ipg clock. */
retval = clk_prepare_enable(sport->clk_ipg);
if (retval)
goto error_console;
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
else
imx_uart_console_get_options(sport, &baud, &parity, &bits);
imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
Revert "serial: imx: remove unbalanced clk_prepare" This reverts commit 9e7b399d6528eac33a6fbfceb2b92af209c3454d. Commit ("9e7b399d6528ea") causes the following warning and sometimes also hangs the system: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/locking/mutex.c:868 mutex_trylock+0x20c/0x22c() DEBUG_LOCKS_WARN_ON(in_interrupt()) Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.2.0-rc7-next-20150818-00001-g14418a6 #4 Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) Backtrace: [<80012f08>] (dump_backtrace) from [<800130a4>] (show_stack+0x18/0x1c) r6:00000364 r5:00000000 r4:00000000 r3:00000000 [<8001308c>] (show_stack) from [<807902b8>] (dump_stack+0x88/0xa4) [<80790230>] (dump_stack) from [<8002a604>] (warn_slowpath_common+0x80/0xbc) r5:807945c4 r4:80ab3b50 [<8002a584>] (warn_slowpath_common) from [<8002a6e4>] (warn_slowpath_fmt+0x38/0x40) r8:00000000 r7:8131100c r6:8054c3cc r5:8131300c r4:80b0a570 [<8002a6b0>] (warn_slowpath_fmt) from [<807945c4>] (mutex_trylock+0x20c/0x22c) r3:8095d0d8 r2:8095ab28 [<807943b8>] (mutex_trylock) from [<8054c3cc>] (clk_prepare_lock+0x14/0xf4) r7:8131100c r6:be3f0c80 r5:00000037 r4:be3f0c80 [<8054c3b8>] (clk_prepare_lock) from [<8054dbfc>] (clk_prepare+0x18/0x30) r5:00000037 r4:be3f0c80 [<8054dbe4>] (clk_prepare) from [<8036a600>] (imx_console_write+0x30/0x244) r4:812d0bc8 r3:8132b9a4 To reproduce the problem we only need to let the board idle for something like 30 seconds. Tested on a imx6q-sabresd. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Reviewed-by: Eduardo Valentin <edubezval@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-18 23:43:12 +08:00
clk_disable(sport->clk_ipg);
if (retval) {
clk_unprepare(sport->clk_ipg);
goto error_console;
}
retval = clk_prepare(sport->clk_per);
if (retval)
clk_unprepare(sport->clk_ipg);
error_console:
return retval;
}
static struct uart_driver imx_uart_uart_driver;
static struct console imx_uart_console = {
.name = DEV_NAME,
.write = imx_uart_console_write,
.device = uart_console_device,
.setup = imx_uart_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &imx_uart_uart_driver,
};
#define IMX_CONSOLE &imx_uart_console
#else
#define IMX_CONSOLE NULL
#endif
static struct uart_driver imx_uart_uart_driver = {
.owner = THIS_MODULE,
.driver_name = DRIVER_NAME,
.dev_name = DEV_NAME,
.major = SERIAL_IMX_MAJOR,
.minor = MINOR_START,
.nr = ARRAY_SIZE(imx_uart_ports),
.cons = IMX_CONSOLE,
};
#ifdef CONFIG_OF
/*
* This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
* could successfully get all information from dt or a negative errno.
*/
static int imx_uart_probe_dt(struct imx_port *sport,
struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
int ret;
sport->devdata = of_device_get_match_data(&pdev->dev);
if (!sport->devdata)
/* no device tree device */
return 1;
ret = of_alias_get_id(np, "serial");
if (ret < 0) {
dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
return ret;
}
sport->port.line = ret;
if (of_get_property(np, "uart-has-rtscts", NULL) ||
of_get_property(np, "fsl,uart-has-rtscts", NULL) /* deprecated */)
sport->have_rtscts = 1;
if (of_get_property(np, "fsl,dte-mode", NULL))
sport->dte_mode = 1;
if (of_get_property(np, "rts-gpios", NULL))
sport->have_rtsgpio = 1;
if (of_get_property(np, "fsl,inverted-tx", NULL))
sport->inverted_tx = 1;
if (of_get_property(np, "fsl,inverted-rx", NULL))
sport->inverted_rx = 1;
return 0;
}
#else
static inline int imx_uart_probe_dt(struct imx_port *sport,
struct platform_device *pdev)
{
return 1;
}
#endif
static void imx_uart_probe_pdata(struct imx_port *sport,
struct platform_device *pdev)
{
struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
sport->port.line = pdev->id;
sport->devdata = (struct imx_uart_data *) pdev->id_entry->driver_data;
if (!pdata)
return;
if (pdata->flags & IMXUART_HAVE_RTSCTS)
sport->have_rtscts = 1;
}
static enum hrtimer_restart imx_trigger_start_tx(struct hrtimer *t)
{
struct imx_port *sport = container_of(t, struct imx_port, trigger_start_tx);
unsigned long flags;
spin_lock_irqsave(&sport->port.lock, flags);
if (sport->tx_state == WAIT_AFTER_RTS)
imx_uart_start_tx(&sport->port);
spin_unlock_irqrestore(&sport->port.lock, flags);
return HRTIMER_NORESTART;
}
static enum hrtimer_restart imx_trigger_stop_tx(struct hrtimer *t)
{
struct imx_port *sport = container_of(t, struct imx_port, trigger_stop_tx);
unsigned long flags;
spin_lock_irqsave(&sport->port.lock, flags);
if (sport->tx_state == WAIT_AFTER_SEND)
imx_uart_stop_tx(&sport->port);
spin_unlock_irqrestore(&sport->port.lock, flags);
return HRTIMER_NORESTART;
}
static int imx_uart_probe(struct platform_device *pdev)
{
struct imx_port *sport;
void __iomem *base;
int ret = 0;
u32 ucr1;
struct resource *res;
int txirq, rxirq, rtsirq;
sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
if (!sport)
return -ENOMEM;
ret = imx_uart_probe_dt(sport, pdev);
if (ret > 0)
imx_uart_probe_pdata(sport, pdev);
else if (ret < 0)
return ret;
if (sport->port.line >= ARRAY_SIZE(imx_uart_ports)) {
dev_err(&pdev->dev, "serial%d out of range\n",
sport->port.line);
return -EINVAL;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(base))
return PTR_ERR(base);
rxirq = platform_get_irq(pdev, 0);
if (rxirq < 0)
return rxirq;
txirq = platform_get_irq_optional(pdev, 1);
rtsirq = platform_get_irq_optional(pdev, 2);
sport->port.dev = &pdev->dev;
sport->port.mapbase = res->start;
sport->port.membase = base;
sport->port.type = PORT_IMX,
sport->port.iotype = UPIO_MEM;
sport->port.irq = rxirq;
sport->port.fifosize = 32;
sport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE);
sport->port.ops = &imx_uart_pops;
sport->port.rs485_config = imx_uart_rs485_config;
sport->port.flags = UPF_BOOT_AUTOCONF;
timer_setup(&sport->timer, imx_uart_timeout, 0);
sport->gpios = mctrl_gpio_init(&sport->port, 0);
if (IS_ERR(sport->gpios))
return PTR_ERR(sport->gpios);
sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
if (IS_ERR(sport->clk_ipg)) {
ret = PTR_ERR(sport->clk_ipg);
dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
return ret;
}
sport->clk_per = devm_clk_get(&pdev->dev, "per");
if (IS_ERR(sport->clk_per)) {
ret = PTR_ERR(sport->clk_per);
dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
return ret;
}
sport->port.uartclk = clk_get_rate(sport->clk_per);
/* For register access, we only need to enable the ipg clock. */
ret = clk_prepare_enable(sport->clk_ipg);
if (ret) {
dev_err(&pdev->dev, "failed to enable per clk: %d\n", ret);
return ret;
}
/* initialize shadow register values */
sport->ucr1 = readl(sport->port.membase + UCR1);
sport->ucr2 = readl(sport->port.membase + UCR2);
sport->ucr3 = readl(sport->port.membase + UCR3);
sport->ucr4 = readl(sport->port.membase + UCR4);
sport->ufcr = readl(sport->port.membase + UFCR);
ret = uart_get_rs485_mode(&sport->port);
if (ret) {
clk_disable_unprepare(sport->clk_ipg);
return ret;
}
serial: Make retrieval of rs485 properties platform-agnostic Commit ef838a81dd4d ("serial: Add common rs485 device tree parsing function") consolidated retrieval of rs485 OF properties in a common helper function but did not #ifdef it to CONFIG_OF. The function is therefore included on ACPI platforms as well even though it's not used. On the other hand ACPI platforms with rs485 do exist (e.g. Siemens IOT2040) and they may leverage _DSD to store rs485 properties. Likewise, UART platform devices instantiated from an MFD should be able to specify rs485 properties. In fact, the tty subsystem maintainer had asked for a "generic" function during review of commit ef838a81dd4d: https://marc.info/?l=linux-serial&m=150143441725194&w=4 Thus, instead of constraining the helper to OF platforms, make it platform-agnostic by converting it to device_property_*() functions and renaming it accordingly. In imx.c, move the invocation of uart_get_rs485_mode() from serial_imx_probe_dt() to serial_imx_probe() so that it also gets called for non-OF devices. In omap-serial.c, move its invocation further up within serial_omap_probe_rs485() so that the RTS polarity can be overridden with the driver-specific "rs485-rts-active-high" property once we introduce a generic "rs485-rts-active-low" property. Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Lukas Wunner <lukas@wunner.de> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-25 06:26:40 +08:00
if (sport->port.rs485.flags & SER_RS485_ENABLED &&
(!sport->have_rtscts && !sport->have_rtsgpio))
dev_err(&pdev->dev, "no RTS control, disabling rs485\n");
/*
* If using the i.MX UART RTS/CTS control then the RTS (CTS_B)
* signal cannot be set low during transmission in case the
* receiver is off (limitation of the i.MX UART IP).
*/
if (sport->port.rs485.flags & SER_RS485_ENABLED &&
sport->have_rtscts && !sport->have_rtsgpio &&
(!(sport->port.rs485.flags & SER_RS485_RTS_ON_SEND) &&
!(sport->port.rs485.flags & SER_RS485_RX_DURING_TX)))
dev_err(&pdev->dev,
"low-active RTS not possible when receiver is off, enabling receiver\n");
imx_uart_rs485_config(&sport->port, &sport->port.rs485);
/* Disable interrupts before requesting them */
ucr1 = imx_uart_readl(sport, UCR1);
ucr1 &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN | UCR1_RTSDEN);
imx_uart_writel(sport, ucr1, UCR1);
if (!imx_uart_is_imx1(sport) && sport->dte_mode) {
/*
* The DCEDTE bit changes the direction of DSR, DCD, DTR and RI
* and influences if UCR3_RI and UCR3_DCD changes the level of RI
* and DCD (when they are outputs) or enables the respective
* irqs. So set this bit early, i.e. before requesting irqs.
*/
u32 ufcr = imx_uart_readl(sport, UFCR);
if (!(ufcr & UFCR_DCEDTE))
imx_uart_writel(sport, ufcr | UFCR_DCEDTE, UFCR);
/*
* Disable UCR3_RI and UCR3_DCD irqs. They are also not
* enabled later because they cannot be cleared
* (confirmed on i.MX25) which makes them unusable.
*/
imx_uart_writel(sport,
IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP | UCR3_DSR,
UCR3);
} else {
u32 ucr3 = UCR3_DSR;
u32 ufcr = imx_uart_readl(sport, UFCR);
if (ufcr & UFCR_DCEDTE)
imx_uart_writel(sport, ufcr & ~UFCR_DCEDTE, UFCR);
if (!imx_uart_is_imx1(sport))
ucr3 |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
imx_uart_writel(sport, ucr3, UCR3);
}
clk_disable_unprepare(sport->clk_ipg);
hrtimer_init(&sport->trigger_start_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hrtimer_init(&sport->trigger_stop_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
sport->trigger_start_tx.function = imx_trigger_start_tx;
sport->trigger_stop_tx.function = imx_trigger_stop_tx;
/*
* Allocate the IRQ(s) i.MX1 has three interrupts whereas later
* chips only have one interrupt.
*/
if (txirq > 0) {
ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_rxint, 0,
dev_name(&pdev->dev), sport);
if (ret) {
dev_err(&pdev->dev, "failed to request rx irq: %d\n",
ret);
return ret;
}
ret = devm_request_irq(&pdev->dev, txirq, imx_uart_txint, 0,
dev_name(&pdev->dev), sport);
if (ret) {
dev_err(&pdev->dev, "failed to request tx irq: %d\n",
ret);
return ret;
}
ret = devm_request_irq(&pdev->dev, rtsirq, imx_uart_rtsint, 0,
dev_name(&pdev->dev), sport);
if (ret) {
dev_err(&pdev->dev, "failed to request rts irq: %d\n",
ret);
return ret;
}
} else {
ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_int, 0,
dev_name(&pdev->dev), sport);
if (ret) {
dev_err(&pdev->dev, "failed to request irq: %d\n", ret);
return ret;
}
}
imx_uart_ports[sport->port.line] = sport;
platform_set_drvdata(pdev, sport);
return uart_add_one_port(&imx_uart_uart_driver, &sport->port);
}
static int imx_uart_remove(struct platform_device *pdev)
{
struct imx_port *sport = platform_get_drvdata(pdev);
return uart_remove_one_port(&imx_uart_uart_driver, &sport->port);
}
static void imx_uart_restore_context(struct imx_port *sport)
{
unsigned long flags;
spin_lock_irqsave(&sport->port.lock, flags);
if (!sport->context_saved) {
spin_unlock_irqrestore(&sport->port.lock, flags);
return;
}
imx_uart_writel(sport, sport->saved_reg[4], UFCR);
imx_uart_writel(sport, sport->saved_reg[5], UESC);
imx_uart_writel(sport, sport->saved_reg[6], UTIM);
imx_uart_writel(sport, sport->saved_reg[7], UBIR);
imx_uart_writel(sport, sport->saved_reg[8], UBMR);
imx_uart_writel(sport, sport->saved_reg[9], IMX21_UTS);
imx_uart_writel(sport, sport->saved_reg[0], UCR1);
imx_uart_writel(sport, sport->saved_reg[1] | UCR2_SRST, UCR2);
imx_uart_writel(sport, sport->saved_reg[2], UCR3);
imx_uart_writel(sport, sport->saved_reg[3], UCR4);
sport->context_saved = false;
spin_unlock_irqrestore(&sport->port.lock, flags);
}
static void imx_uart_save_context(struct imx_port *sport)
{
unsigned long flags;
/* Save necessary regs */
spin_lock_irqsave(&sport->port.lock, flags);
sport->saved_reg[0] = imx_uart_readl(sport, UCR1);
sport->saved_reg[1] = imx_uart_readl(sport, UCR2);
sport->saved_reg[2] = imx_uart_readl(sport, UCR3);
sport->saved_reg[3] = imx_uart_readl(sport, UCR4);
sport->saved_reg[4] = imx_uart_readl(sport, UFCR);
sport->saved_reg[5] = imx_uart_readl(sport, UESC);
sport->saved_reg[6] = imx_uart_readl(sport, UTIM);
sport->saved_reg[7] = imx_uart_readl(sport, UBIR);
sport->saved_reg[8] = imx_uart_readl(sport, UBMR);
sport->saved_reg[9] = imx_uart_readl(sport, IMX21_UTS);
sport->context_saved = true;
spin_unlock_irqrestore(&sport->port.lock, flags);
}
static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
{
u32 ucr3;
ucr3 = imx_uart_readl(sport, UCR3);
if (on) {
imx_uart_writel(sport, USR1_AWAKE, USR1);
ucr3 |= UCR3_AWAKEN;
} else {
ucr3 &= ~UCR3_AWAKEN;
}
imx_uart_writel(sport, ucr3, UCR3);
if (sport->have_rtscts) {
u32 ucr1 = imx_uart_readl(sport, UCR1);
if (on)
ucr1 |= UCR1_RTSDEN;
else
ucr1 &= ~UCR1_RTSDEN;
imx_uart_writel(sport, ucr1, UCR1);
}
}
static int imx_uart_suspend_noirq(struct device *dev)
{
struct imx_port *sport = dev_get_drvdata(dev);
imx_uart_save_context(sport);
clk_disable(sport->clk_ipg);
pinctrl_pm_select_sleep_state(dev);
return 0;
}
static int imx_uart_resume_noirq(struct device *dev)
{
struct imx_port *sport = dev_get_drvdata(dev);
int ret;
pinctrl_pm_select_default_state(dev);
ret = clk_enable(sport->clk_ipg);
if (ret)
return ret;
imx_uart_restore_context(sport);
return 0;
}
static int imx_uart_suspend(struct device *dev)
{
struct imx_port *sport = dev_get_drvdata(dev);
int ret;
uart_suspend_port(&imx_uart_uart_driver, &sport->port);
disable_irq(sport->port.irq);
ret = clk_prepare_enable(sport->clk_ipg);
if (ret)
return ret;
/* enable wakeup from i.MX UART */
imx_uart_enable_wakeup(sport, true);
return 0;
}
static int imx_uart_resume(struct device *dev)
{
struct imx_port *sport = dev_get_drvdata(dev);
/* disable wakeup from i.MX UART */
imx_uart_enable_wakeup(sport, false);
uart_resume_port(&imx_uart_uart_driver, &sport->port);
enable_irq(sport->port.irq);
clk_disable_unprepare(sport->clk_ipg);
serial: imx: Fix suspend / resume. When a non console i.MX UART is enabled in the device tree, system suspend fails due to an unprepared clock: [ 638.794563] PM: Syncing filesystems ... done. [ 638.878902] Freezing user space processes ... (elapsed 0.002 seconds) done. [ 638.888454] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done. [ 638.996697] PM: suspend of devices complete after 97.200 msecs [ 639.002611] PM: suspend devices took 0.100 seconds [ 639.013020] PM: late suspend of devices complete after 2.288 msecs [ 639.021486] ------------[ cut here ]------------ [ 639.026147] WARNING: CPU: 0 PID: 488 at drivers/clk/clk.c:732 clk_core_enable+0xc0/0x12c() [ 639.034413] Modules linked in: [ 639.037490] CPU: 0 PID: 488 Comm: system_server Tainted: G W 4.4.0-rc5-pknbsp-svn2214-atag-v4.4-rc5-121-gebfd9cb #1304 [ 639.049312] Hardware name: Freescale i.MX53 (Device Tree Support) [ 639.055444] [<c0016d54>] (unwind_backtrace) from [<c00140f8>] (show_stack+0x20/0x24) [ 639.063199] [<c00140f8>] (show_stack) from [<c02c99a0>] (dump_stack+0x20/0x28) [ 639.070442] [<c02c99a0>] (dump_stack) from [<c0024ca8>] (warn_slowpath_common+0x88/0xc0) [ 639.078541] [<c0024ca8>] (warn_slowpath_common) from [<c0024d0c>] (warn_slowpath_null+0x2c/0x34) [ 639.087332] [<c0024d0c>] (warn_slowpath_null) from [<c05171e8>] (clk_core_enable+0xc0/0x12c) [ 639.095777] [<c05171e8>] (clk_core_enable) from [<c05172f8>] (clk_enable+0x2c/0x40) [ 639.103441] [<c05172f8>] (clk_enable) from [<c0349880>] (imx_serial_port_suspend_noirq+0x20/0xe0) [ 639.112336] [<c0349880>] (imx_serial_port_suspend_noirq) from [<c03a26a0>] (dpm_run_callback+0x68/0x16c) [ 639.121825] [<c03a26a0>] (dpm_run_callback) from [<c03a2898>] (__device_suspend_noirq+0xf4/0x22c) [ 639.130705] [<c03a2898>] (__device_suspend_noirq) from [<c03a4b0c>] (dpm_suspend_noirq+0x148/0x30c) [ 639.139764] [<c03a4b0c>] (dpm_suspend_noirq) from [<c00511d4>] (suspend_devices_and_enter+0x2e8/0x6a4) [ 639.149078] [<c00511d4>] (suspend_devices_and_enter) from [<c00518a0>] (pm_suspend+0x310/0x4b8) [ 639.157782] [<c00518a0>] (pm_suspend) from [<c00500ec>] (state_store+0x7c/0xcc) [ 639.165099] [<c00500ec>] (state_store) from [<c02cb6dc>] (kobj_attr_store+0x1c/0x28) [ 639.172858] [<c02cb6dc>] (kobj_attr_store) from [<c01633d4>] (sysfs_kf_write+0x54/0x58) [ 639.180871] [<c01633d4>] (sysfs_kf_write) from [<c01629b4>] (kernfs_fop_write+0x100/0x1c8) [ 639.189152] [<c01629b4>] (kernfs_fop_write) from [<c00fb8b8>] (__vfs_write+0x3c/0xe8) [ 639.196991] [<c00fb8b8>] (__vfs_write) from [<c00fc810>] (vfs_write+0xa4/0x160) [ 639.204307] [<c00fc810>] (vfs_write) from [<c00fcac4>] (SyS_write+0x4c/0x98) [ 639.211363] [<c00fcac4>] (SyS_write) from [<c0010760>] (ret_fast_syscall+0x0/0x3c) This does not happen for the common case of a single UART used as a console (since imx_console_setup() already does a prepare) Signed-off-by: Martin Fuzzey <mfuzzey@parkeon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-05 23:53:31 +08:00
return 0;
}
static int imx_uart_freeze(struct device *dev)
{
struct imx_port *sport = dev_get_drvdata(dev);
uart_suspend_port(&imx_uart_uart_driver, &sport->port);
return clk_prepare_enable(sport->clk_ipg);
}
static int imx_uart_thaw(struct device *dev)
{
struct imx_port *sport = dev_get_drvdata(dev);
uart_resume_port(&imx_uart_uart_driver, &sport->port);
clk_disable_unprepare(sport->clk_ipg);
return 0;
}
static const struct dev_pm_ops imx_uart_pm_ops = {
.suspend_noirq = imx_uart_suspend_noirq,
.resume_noirq = imx_uart_resume_noirq,
.freeze_noirq = imx_uart_suspend_noirq,
.restore_noirq = imx_uart_resume_noirq,
.suspend = imx_uart_suspend,
.resume = imx_uart_resume,
.freeze = imx_uart_freeze,
.thaw = imx_uart_thaw,
.restore = imx_uart_thaw,
};
static struct platform_driver imx_uart_platform_driver = {
.probe = imx_uart_probe,
.remove = imx_uart_remove,
.id_table = imx_uart_devtype,
.driver = {
.name = "imx-uart",
.of_match_table = imx_uart_dt_ids,
.pm = &imx_uart_pm_ops,
},
};
static int __init imx_uart_init(void)
{
int ret = uart_register_driver(&imx_uart_uart_driver);
if (ret)
return ret;
ret = platform_driver_register(&imx_uart_platform_driver);
if (ret != 0)
uart_unregister_driver(&imx_uart_uart_driver);
return ret;
}
static void __exit imx_uart_exit(void)
{
platform_driver_unregister(&imx_uart_platform_driver);
uart_unregister_driver(&imx_uart_uart_driver);
}
module_init(imx_uart_init);
module_exit(imx_uart_exit);
MODULE_AUTHOR("Sascha Hauer");
MODULE_DESCRIPTION("IMX generic serial port driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:imx-uart");