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linux-sg2042/drivers/tty/serial/mxs-auart.c

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/*
* Freescale STMP37XX/STMP378X Application UART driver
*
* Author: dmitry pervushin <dimka@embeddedalley.com>
*
* Copyright 2008-2010 Freescale Semiconductor, Inc.
* Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#if defined(CONFIG_SERIAL_MXS_AUART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/wait.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
#include <linux/platform_device.h>
#include <linux/device.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/of_device.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <asm/cacheflush.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/err.h>
#include <linux/irq.h>
#include "serial_mctrl_gpio.h"
#define MXS_AUART_PORTS 5
#define MXS_AUART_FIFO_SIZE 16
#define AUART_CTRL0 0x00000000
#define AUART_CTRL0_SET 0x00000004
#define AUART_CTRL0_CLR 0x00000008
#define AUART_CTRL0_TOG 0x0000000c
#define AUART_CTRL1 0x00000010
#define AUART_CTRL1_SET 0x00000014
#define AUART_CTRL1_CLR 0x00000018
#define AUART_CTRL1_TOG 0x0000001c
#define AUART_CTRL2 0x00000020
#define AUART_CTRL2_SET 0x00000024
#define AUART_CTRL2_CLR 0x00000028
#define AUART_CTRL2_TOG 0x0000002c
#define AUART_LINECTRL 0x00000030
#define AUART_LINECTRL_SET 0x00000034
#define AUART_LINECTRL_CLR 0x00000038
#define AUART_LINECTRL_TOG 0x0000003c
#define AUART_LINECTRL2 0x00000040
#define AUART_LINECTRL2_SET 0x00000044
#define AUART_LINECTRL2_CLR 0x00000048
#define AUART_LINECTRL2_TOG 0x0000004c
#define AUART_INTR 0x00000050
#define AUART_INTR_SET 0x00000054
#define AUART_INTR_CLR 0x00000058
#define AUART_INTR_TOG 0x0000005c
#define AUART_DATA 0x00000060
#define AUART_STAT 0x00000070
#define AUART_DEBUG 0x00000080
#define AUART_VERSION 0x00000090
#define AUART_AUTOBAUD 0x000000a0
#define AUART_CTRL0_SFTRST (1 << 31)
#define AUART_CTRL0_CLKGATE (1 << 30)
#define AUART_CTRL0_RXTO_ENABLE (1 << 27)
#define AUART_CTRL0_RXTIMEOUT(v) (((v) & 0x7ff) << 16)
#define AUART_CTRL0_XFER_COUNT(v) ((v) & 0xffff)
#define AUART_CTRL1_XFER_COUNT(v) ((v) & 0xffff)
#define AUART_CTRL2_DMAONERR (1 << 26)
#define AUART_CTRL2_TXDMAE (1 << 25)
#define AUART_CTRL2_RXDMAE (1 << 24)
#define AUART_CTRL2_CTSEN (1 << 15)
#define AUART_CTRL2_RTSEN (1 << 14)
#define AUART_CTRL2_RTS (1 << 11)
#define AUART_CTRL2_RXE (1 << 9)
#define AUART_CTRL2_TXE (1 << 8)
#define AUART_CTRL2_UARTEN (1 << 0)
#define AUART_LINECTRL_BAUD_DIVINT_SHIFT 16
#define AUART_LINECTRL_BAUD_DIVINT_MASK 0xffff0000
#define AUART_LINECTRL_BAUD_DIVINT(v) (((v) & 0xffff) << 16)
#define AUART_LINECTRL_BAUD_DIVFRAC_SHIFT 8
#define AUART_LINECTRL_BAUD_DIVFRAC_MASK 0x00003f00
#define AUART_LINECTRL_BAUD_DIVFRAC(v) (((v) & 0x3f) << 8)
#define AUART_LINECTRL_WLEN_MASK 0x00000060
#define AUART_LINECTRL_WLEN(v) (((v) & 0x3) << 5)
#define AUART_LINECTRL_FEN (1 << 4)
#define AUART_LINECTRL_STP2 (1 << 3)
#define AUART_LINECTRL_EPS (1 << 2)
#define AUART_LINECTRL_PEN (1 << 1)
#define AUART_LINECTRL_BRK (1 << 0)
#define AUART_INTR_RTIEN (1 << 22)
#define AUART_INTR_TXIEN (1 << 21)
#define AUART_INTR_RXIEN (1 << 20)
#define AUART_INTR_CTSMIEN (1 << 17)
#define AUART_INTR_RTIS (1 << 6)
#define AUART_INTR_TXIS (1 << 5)
#define AUART_INTR_RXIS (1 << 4)
#define AUART_INTR_CTSMIS (1 << 1)
#define AUART_STAT_BUSY (1 << 29)
#define AUART_STAT_CTS (1 << 28)
#define AUART_STAT_TXFE (1 << 27)
#define AUART_STAT_TXFF (1 << 25)
#define AUART_STAT_RXFE (1 << 24)
#define AUART_STAT_OERR (1 << 19)
#define AUART_STAT_BERR (1 << 18)
#define AUART_STAT_PERR (1 << 17)
#define AUART_STAT_FERR (1 << 16)
#define AUART_STAT_RXCOUNT_MASK 0xffff
static struct uart_driver auart_driver;
enum mxs_auart_type {
IMX23_AUART,
IMX28_AUART,
};
struct mxs_auart_port {
struct uart_port port;
#define MXS_AUART_DMA_ENABLED 0x2
#define MXS_AUART_DMA_TX_SYNC 2 /* bit 2 */
#define MXS_AUART_DMA_RX_READY 3 /* bit 3 */
#define MXS_AUART_RTSCTS 4 /* bit 4 */
unsigned long flags;
unsigned int mctrl_prev;
enum mxs_auart_type devtype;
struct clk *clk;
struct device *dev;
/* for DMA */
struct scatterlist tx_sgl;
struct dma_chan *tx_dma_chan;
void *tx_dma_buf;
struct scatterlist rx_sgl;
struct dma_chan *rx_dma_chan;
void *rx_dma_buf;
struct mctrl_gpios *gpios;
int gpio_irq[UART_GPIO_MAX];
bool ms_irq_enabled;
};
static struct platform_device_id mxs_auart_devtype[] = {
{ .name = "mxs-auart-imx23", .driver_data = IMX23_AUART },
{ .name = "mxs-auart-imx28", .driver_data = IMX28_AUART },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, mxs_auart_devtype);
static struct of_device_id mxs_auart_dt_ids[] = {
{
.compatible = "fsl,imx28-auart",
.data = &mxs_auart_devtype[IMX28_AUART]
}, {
.compatible = "fsl,imx23-auart",
.data = &mxs_auart_devtype[IMX23_AUART]
}, { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mxs_auart_dt_ids);
static inline int is_imx28_auart(struct mxs_auart_port *s)
{
return s->devtype == IMX28_AUART;
}
static inline bool auart_dma_enabled(struct mxs_auart_port *s)
{
return s->flags & MXS_AUART_DMA_ENABLED;
}
static void mxs_auart_stop_tx(struct uart_port *u);
#define to_auart_port(u) container_of(u, struct mxs_auart_port, port)
static void mxs_auart_tx_chars(struct mxs_auart_port *s);
static void dma_tx_callback(void *param)
{
struct mxs_auart_port *s = param;
struct circ_buf *xmit = &s->port.state->xmit;
dma_unmap_sg(s->dev, &s->tx_sgl, 1, DMA_TO_DEVICE);
/* clear the bit used to serialize the DMA tx. */
clear_bit(MXS_AUART_DMA_TX_SYNC, &s->flags);
smp_mb__after_atomic();
/* wake up the possible processes. */
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&s->port);
mxs_auart_tx_chars(s);
}
static int mxs_auart_dma_tx(struct mxs_auart_port *s, int size)
{
struct dma_async_tx_descriptor *desc;
struct scatterlist *sgl = &s->tx_sgl;
struct dma_chan *channel = s->tx_dma_chan;
u32 pio;
/* [1] : send PIO. Note, the first pio word is CTRL1. */
pio = AUART_CTRL1_XFER_COUNT(size);
desc = dmaengine_prep_slave_sg(channel, (struct scatterlist *)&pio,
1, DMA_TRANS_NONE, 0);
if (!desc) {
dev_err(s->dev, "step 1 error\n");
return -EINVAL;
}
/* [2] : set DMA buffer. */
sg_init_one(sgl, s->tx_dma_buf, size);
dma_map_sg(s->dev, sgl, 1, DMA_TO_DEVICE);
desc = dmaengine_prep_slave_sg(channel, sgl,
1, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc) {
dev_err(s->dev, "step 2 error\n");
return -EINVAL;
}
/* [3] : submit the DMA */
desc->callback = dma_tx_callback;
desc->callback_param = s;
dmaengine_submit(desc);
dma_async_issue_pending(channel);
return 0;
}
static void mxs_auart_tx_chars(struct mxs_auart_port *s)
{
struct circ_buf *xmit = &s->port.state->xmit;
if (auart_dma_enabled(s)) {
u32 i = 0;
int size;
void *buffer = s->tx_dma_buf;
if (test_and_set_bit(MXS_AUART_DMA_TX_SYNC, &s->flags))
return;
while (!uart_circ_empty(xmit) && !uart_tx_stopped(&s->port)) {
size = min_t(u32, UART_XMIT_SIZE - i,
CIRC_CNT_TO_END(xmit->head,
xmit->tail,
UART_XMIT_SIZE));
memcpy(buffer + i, xmit->buf + xmit->tail, size);
xmit->tail = (xmit->tail + size) & (UART_XMIT_SIZE - 1);
i += size;
if (i >= UART_XMIT_SIZE)
break;
}
if (uart_tx_stopped(&s->port))
mxs_auart_stop_tx(&s->port);
if (i) {
mxs_auart_dma_tx(s, i);
} else {
clear_bit(MXS_AUART_DMA_TX_SYNC, &s->flags);
smp_mb__after_atomic();
}
return;
}
while (!(readl(s->port.membase + AUART_STAT) &
AUART_STAT_TXFF)) {
if (s->port.x_char) {
s->port.icount.tx++;
writel(s->port.x_char,
s->port.membase + AUART_DATA);
s->port.x_char = 0;
continue;
}
if (!uart_circ_empty(xmit) && !uart_tx_stopped(&s->port)) {
s->port.icount.tx++;
writel(xmit->buf[xmit->tail],
s->port.membase + AUART_DATA);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
} else
break;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&s->port);
if (uart_circ_empty(&(s->port.state->xmit)))
writel(AUART_INTR_TXIEN,
s->port.membase + AUART_INTR_CLR);
else
writel(AUART_INTR_TXIEN,
s->port.membase + AUART_INTR_SET);
if (uart_tx_stopped(&s->port))
mxs_auart_stop_tx(&s->port);
}
static void mxs_auart_rx_char(struct mxs_auart_port *s)
{
int flag;
u32 stat;
u8 c;
c = readl(s->port.membase + AUART_DATA);
stat = readl(s->port.membase + AUART_STAT);
flag = TTY_NORMAL;
s->port.icount.rx++;
if (stat & AUART_STAT_BERR) {
s->port.icount.brk++;
if (uart_handle_break(&s->port))
goto out;
} else if (stat & AUART_STAT_PERR) {
s->port.icount.parity++;
} else if (stat & AUART_STAT_FERR) {
s->port.icount.frame++;
}
/*
* Mask off conditions which should be ingored.
*/
stat &= s->port.read_status_mask;
if (stat & AUART_STAT_BERR) {
flag = TTY_BREAK;
} else if (stat & AUART_STAT_PERR)
flag = TTY_PARITY;
else if (stat & AUART_STAT_FERR)
flag = TTY_FRAME;
if (stat & AUART_STAT_OERR)
s->port.icount.overrun++;
if (uart_handle_sysrq_char(&s->port, c))
goto out;
uart_insert_char(&s->port, stat, AUART_STAT_OERR, c, flag);
out:
writel(stat, s->port.membase + AUART_STAT);
}
static void mxs_auart_rx_chars(struct mxs_auart_port *s)
{
u32 stat = 0;
for (;;) {
stat = readl(s->port.membase + AUART_STAT);
if (stat & AUART_STAT_RXFE)
break;
mxs_auart_rx_char(s);
}
writel(stat, s->port.membase + AUART_STAT);
tty_flip_buffer_push(&s->port.state->port);
}
static int mxs_auart_request_port(struct uart_port *u)
{
return 0;
}
static int mxs_auart_verify_port(struct uart_port *u,
struct serial_struct *ser)
{
if (u->type != PORT_UNKNOWN && u->type != PORT_IMX)
return -EINVAL;
return 0;
}
static void mxs_auart_config_port(struct uart_port *u, int flags)
{
}
static const char *mxs_auart_type(struct uart_port *u)
{
struct mxs_auart_port *s = to_auart_port(u);
return dev_name(s->dev);
}
static void mxs_auart_release_port(struct uart_port *u)
{
}
static void mxs_auart_set_mctrl(struct uart_port *u, unsigned mctrl)
{
struct mxs_auart_port *s = to_auart_port(u);
u32 ctrl = readl(u->membase + AUART_CTRL2);
ctrl &= ~(AUART_CTRL2_RTSEN | AUART_CTRL2_RTS);
if (mctrl & TIOCM_RTS) {
if (uart_cts_enabled(u))
ctrl |= AUART_CTRL2_RTSEN;
else
ctrl |= AUART_CTRL2_RTS;
}
writel(ctrl, u->membase + AUART_CTRL2);
mctrl_gpio_set(s->gpios, mctrl);
}
#define MCTRL_ANY_DELTA (TIOCM_RI | TIOCM_DSR | TIOCM_CD | TIOCM_CTS)
static u32 mxs_auart_modem_status(struct mxs_auart_port *s, u32 mctrl)
{
u32 mctrl_diff;
mctrl_diff = mctrl ^ s->mctrl_prev;
s->mctrl_prev = mctrl;
if (mctrl_diff & MCTRL_ANY_DELTA && s->ms_irq_enabled &&
s->port.state != NULL) {
if (mctrl_diff & TIOCM_RI)
s->port.icount.rng++;
if (mctrl_diff & TIOCM_DSR)
s->port.icount.dsr++;
if (mctrl_diff & TIOCM_CD)
uart_handle_dcd_change(&s->port, mctrl & TIOCM_CD);
if (mctrl_diff & TIOCM_CTS)
uart_handle_cts_change(&s->port, mctrl & TIOCM_CTS);
wake_up_interruptible(&s->port.state->port.delta_msr_wait);
}
return mctrl;
}
static u32 mxs_auart_get_mctrl(struct uart_port *u)
{
struct mxs_auart_port *s = to_auart_port(u);
u32 stat = readl(u->membase + AUART_STAT);
u32 mctrl = 0;
if (stat & AUART_STAT_CTS)
mctrl |= TIOCM_CTS;
return mctrl_gpio_get(s->gpios, &mctrl);
}
/*
* Enable modem status interrupts
*/
static void mxs_auart_enable_ms(struct uart_port *port)
{
struct mxs_auart_port *s = to_auart_port(port);
/*
* Interrupt should not be enabled twice
*/
if (s->ms_irq_enabled)
return;
s->ms_irq_enabled = true;
if (s->gpio_irq[UART_GPIO_CTS] >= 0)
enable_irq(s->gpio_irq[UART_GPIO_CTS]);
/* TODO: enable AUART_INTR_CTSMIEN otherwise */
if (s->gpio_irq[UART_GPIO_DSR] >= 0)
enable_irq(s->gpio_irq[UART_GPIO_DSR]);
if (s->gpio_irq[UART_GPIO_RI] >= 0)
enable_irq(s->gpio_irq[UART_GPIO_RI]);
if (s->gpio_irq[UART_GPIO_DCD] >= 0)
enable_irq(s->gpio_irq[UART_GPIO_DCD]);
}
/*
* Disable modem status interrupts
*/
static void mxs_auart_disable_ms(struct uart_port *port)
{
struct mxs_auart_port *s = to_auart_port(port);
/*
* Interrupt should not be disabled twice
*/
if (!s->ms_irq_enabled)
return;
s->ms_irq_enabled = false;
if (s->gpio_irq[UART_GPIO_CTS] >= 0)
disable_irq(s->gpio_irq[UART_GPIO_CTS]);
/* TODO: disable AUART_INTR_CTSMIEN otherwise */
if (s->gpio_irq[UART_GPIO_DSR] >= 0)
disable_irq(s->gpio_irq[UART_GPIO_DSR]);
if (s->gpio_irq[UART_GPIO_RI] >= 0)
disable_irq(s->gpio_irq[UART_GPIO_RI]);
if (s->gpio_irq[UART_GPIO_DCD] >= 0)
disable_irq(s->gpio_irq[UART_GPIO_DCD]);
}
static int mxs_auart_dma_prep_rx(struct mxs_auart_port *s);
static void dma_rx_callback(void *arg)
{
struct mxs_auart_port *s = (struct mxs_auart_port *) arg;
struct tty_port *port = &s->port.state->port;
int count;
u32 stat;
dma_unmap_sg(s->dev, &s->rx_sgl, 1, DMA_FROM_DEVICE);
stat = readl(s->port.membase + AUART_STAT);
stat &= ~(AUART_STAT_OERR | AUART_STAT_BERR |
AUART_STAT_PERR | AUART_STAT_FERR);
count = stat & AUART_STAT_RXCOUNT_MASK;
tty_insert_flip_string(port, s->rx_dma_buf, count);
writel(stat, s->port.membase + AUART_STAT);
tty_flip_buffer_push(port);
/* start the next DMA for RX. */
mxs_auart_dma_prep_rx(s);
}
static int mxs_auart_dma_prep_rx(struct mxs_auart_port *s)
{
struct dma_async_tx_descriptor *desc;
struct scatterlist *sgl = &s->rx_sgl;
struct dma_chan *channel = s->rx_dma_chan;
u32 pio[1];
/* [1] : send PIO */
pio[0] = AUART_CTRL0_RXTO_ENABLE
| AUART_CTRL0_RXTIMEOUT(0x80)
| AUART_CTRL0_XFER_COUNT(UART_XMIT_SIZE);
desc = dmaengine_prep_slave_sg(channel, (struct scatterlist *)pio,
1, DMA_TRANS_NONE, 0);
if (!desc) {
dev_err(s->dev, "step 1 error\n");
return -EINVAL;
}
/* [2] : send DMA request */
sg_init_one(sgl, s->rx_dma_buf, UART_XMIT_SIZE);
dma_map_sg(s->dev, sgl, 1, DMA_FROM_DEVICE);
desc = dmaengine_prep_slave_sg(channel, sgl, 1, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc) {
dev_err(s->dev, "step 2 error\n");
return -1;
}
/* [3] : submit the DMA, but do not issue it. */
desc->callback = dma_rx_callback;
desc->callback_param = s;
dmaengine_submit(desc);
dma_async_issue_pending(channel);
return 0;
}
static void mxs_auart_dma_exit_channel(struct mxs_auart_port *s)
{
if (s->tx_dma_chan) {
dma_release_channel(s->tx_dma_chan);
s->tx_dma_chan = NULL;
}
if (s->rx_dma_chan) {
dma_release_channel(s->rx_dma_chan);
s->rx_dma_chan = NULL;
}
kfree(s->tx_dma_buf);
kfree(s->rx_dma_buf);
s->tx_dma_buf = NULL;
s->rx_dma_buf = NULL;
}
static void mxs_auart_dma_exit(struct mxs_auart_port *s)
{
writel(AUART_CTRL2_TXDMAE | AUART_CTRL2_RXDMAE | AUART_CTRL2_DMAONERR,
s->port.membase + AUART_CTRL2_CLR);
mxs_auart_dma_exit_channel(s);
s->flags &= ~MXS_AUART_DMA_ENABLED;
clear_bit(MXS_AUART_DMA_TX_SYNC, &s->flags);
clear_bit(MXS_AUART_DMA_RX_READY, &s->flags);
}
static int mxs_auart_dma_init(struct mxs_auart_port *s)
{
if (auart_dma_enabled(s))
return 0;
/* init for RX */
s->rx_dma_chan = dma_request_slave_channel(s->dev, "rx");
if (!s->rx_dma_chan)
goto err_out;
s->rx_dma_buf = kzalloc(UART_XMIT_SIZE, GFP_KERNEL | GFP_DMA);
if (!s->rx_dma_buf)
goto err_out;
/* init for TX */
s->tx_dma_chan = dma_request_slave_channel(s->dev, "tx");
if (!s->tx_dma_chan)
goto err_out;
s->tx_dma_buf = kzalloc(UART_XMIT_SIZE, GFP_KERNEL | GFP_DMA);
if (!s->tx_dma_buf)
goto err_out;
/* set the flags */
s->flags |= MXS_AUART_DMA_ENABLED;
dev_dbg(s->dev, "enabled the DMA support.");
/* The DMA buffer is now the FIFO the TTY subsystem can use */
s->port.fifosize = UART_XMIT_SIZE;
return 0;
err_out:
mxs_auart_dma_exit_channel(s);
return -EINVAL;
}
#define RTS_AT_AUART() IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(s->gpios, \
UART_GPIO_RTS))
#define CTS_AT_AUART() IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(s->gpios, \
UART_GPIO_CTS))
static void mxs_auart_settermios(struct uart_port *u,
struct ktermios *termios,
struct ktermios *old)
{
struct mxs_auart_port *s = to_auart_port(u);
u32 bm, ctrl, ctrl2, div;
unsigned int cflag, baud;
cflag = termios->c_cflag;
ctrl = AUART_LINECTRL_FEN;
ctrl2 = readl(u->membase + AUART_CTRL2);
/* byte size */
switch (cflag & CSIZE) {
case CS5:
bm = 0;
break;
case CS6:
bm = 1;
break;
case CS7:
bm = 2;
break;
case CS8:
bm = 3;
break;
default:
return;
}
ctrl |= AUART_LINECTRL_WLEN(bm);
/* parity */
if (cflag & PARENB) {
ctrl |= AUART_LINECTRL_PEN;
if ((cflag & PARODD) == 0)
ctrl |= AUART_LINECTRL_EPS;
}
u->read_status_mask = 0;
if (termios->c_iflag & INPCK)
u->read_status_mask |= AUART_STAT_PERR;
if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
u->read_status_mask |= AUART_STAT_BERR;
/*
* Characters to ignore
*/
u->ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
u->ignore_status_mask |= AUART_STAT_PERR;
if (termios->c_iflag & IGNBRK) {
u->ignore_status_mask |= AUART_STAT_BERR;
/*
* If we're ignoring parity and break indicators,
* ignore overruns too (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
u->ignore_status_mask |= AUART_STAT_OERR;
}
/*
* ignore all characters if CREAD is not set
*/
if (cflag & CREAD)
ctrl2 |= AUART_CTRL2_RXE;
else
ctrl2 &= ~AUART_CTRL2_RXE;
/* figure out the stop bits requested */
if (cflag & CSTOPB)
ctrl |= AUART_LINECTRL_STP2;
/* figure out the hardware flow control settings */
ctrl2 &= ~(AUART_CTRL2_CTSEN | AUART_CTRL2_RTSEN);
if (cflag & CRTSCTS) {
/*
* The DMA has a bug(see errata:2836) in mx23.
* So we can not implement the DMA for auart in mx23,
* we can only implement the DMA support for auart
* in mx28.
*/
if (is_imx28_auart(s)
&& test_bit(MXS_AUART_RTSCTS, &s->flags)) {
if (!mxs_auart_dma_init(s))
/* enable DMA tranfer */
ctrl2 |= AUART_CTRL2_TXDMAE | AUART_CTRL2_RXDMAE
| AUART_CTRL2_DMAONERR;
}
/* Even if RTS is GPIO line RTSEN can be enabled because
* the pinctrl configuration decides about RTS pin function */
ctrl2 |= AUART_CTRL2_RTSEN;
if (CTS_AT_AUART())
ctrl2 |= AUART_CTRL2_CTSEN;
}
/* set baud rate */
baud = uart_get_baud_rate(u, termios, old, 0, u->uartclk);
div = u->uartclk * 32 / baud;
ctrl |= AUART_LINECTRL_BAUD_DIVFRAC(div & 0x3F);
ctrl |= AUART_LINECTRL_BAUD_DIVINT(div >> 6);
writel(ctrl, u->membase + AUART_LINECTRL);
writel(ctrl2, u->membase + AUART_CTRL2);
uart_update_timeout(u, termios->c_cflag, baud);
/* prepare for the DMA RX. */
if (auart_dma_enabled(s) &&
!test_and_set_bit(MXS_AUART_DMA_RX_READY, &s->flags)) {
if (!mxs_auart_dma_prep_rx(s)) {
/* Disable the normal RX interrupt. */
writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN,
u->membase + AUART_INTR_CLR);
} else {
mxs_auart_dma_exit(s);
dev_err(s->dev, "We can not start up the DMA.\n");
}
}
/* CTS flow-control and modem-status interrupts */
if (UART_ENABLE_MS(u, termios->c_cflag))
mxs_auart_enable_ms(u);
else
mxs_auart_disable_ms(u);
}
static void mxs_auart_set_ldisc(struct uart_port *port,
struct ktermios *termios)
{
if (termios->c_line == N_PPS) {
port->flags |= UPF_HARDPPS_CD;
mxs_auart_enable_ms(port);
} else {
port->flags &= ~UPF_HARDPPS_CD;
}
}
static irqreturn_t mxs_auart_irq_handle(int irq, void *context)
{
u32 istat;
struct mxs_auart_port *s = context;
u32 mctrl_temp = s->mctrl_prev;
u32 stat = readl(s->port.membase + AUART_STAT);
istat = readl(s->port.membase + AUART_INTR);
/* ack irq */
writel(istat & (AUART_INTR_RTIS
| AUART_INTR_TXIS
| AUART_INTR_RXIS
| AUART_INTR_CTSMIS),
s->port.membase + AUART_INTR_CLR);
/*
* Dealing with GPIO interrupt
*/
if (irq == s->gpio_irq[UART_GPIO_CTS] ||
irq == s->gpio_irq[UART_GPIO_DCD] ||
irq == s->gpio_irq[UART_GPIO_DSR] ||
irq == s->gpio_irq[UART_GPIO_RI])
mxs_auart_modem_status(s,
mctrl_gpio_get(s->gpios, &mctrl_temp));
if (istat & AUART_INTR_CTSMIS) {
if (CTS_AT_AUART() && s->ms_irq_enabled)
uart_handle_cts_change(&s->port,
stat & AUART_STAT_CTS);
writel(AUART_INTR_CTSMIS,
s->port.membase + AUART_INTR_CLR);
istat &= ~AUART_INTR_CTSMIS;
}
if (istat & (AUART_INTR_RTIS | AUART_INTR_RXIS)) {
if (!auart_dma_enabled(s))
mxs_auart_rx_chars(s);
istat &= ~(AUART_INTR_RTIS | AUART_INTR_RXIS);
}
if (istat & AUART_INTR_TXIS) {
mxs_auart_tx_chars(s);
istat &= ~AUART_INTR_TXIS;
}
return IRQ_HANDLED;
}
static void mxs_auart_reset(struct uart_port *u)
{
int i;
unsigned int reg;
writel(AUART_CTRL0_SFTRST, u->membase + AUART_CTRL0_CLR);
for (i = 0; i < 10000; i++) {
reg = readl(u->membase + AUART_CTRL0);
if (!(reg & AUART_CTRL0_SFTRST))
break;
udelay(3);
}
writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_CLR);
}
static int mxs_auart_startup(struct uart_port *u)
{
int ret;
struct mxs_auart_port *s = to_auart_port(u);
ret = clk_prepare_enable(s->clk);
if (ret)
return ret;
writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_CLR);
writel(AUART_CTRL2_UARTEN, u->membase + AUART_CTRL2_SET);
writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN,
u->membase + AUART_INTR);
/* Reset FIFO size (it could have changed if DMA was enabled) */
u->fifosize = MXS_AUART_FIFO_SIZE;
/*
* Enable fifo so all four bytes of a DMA word are written to
* output (otherwise, only the LSB is written, ie. 1 in 4 bytes)
*/
writel(AUART_LINECTRL_FEN, u->membase + AUART_LINECTRL_SET);
/* get initial status of modem lines */
mctrl_gpio_get(s->gpios, &s->mctrl_prev);
s->ms_irq_enabled = false;
return 0;
}
static void mxs_auart_shutdown(struct uart_port *u)
{
struct mxs_auart_port *s = to_auart_port(u);
mxs_auart_disable_ms(u);
if (auart_dma_enabled(s))
mxs_auart_dma_exit(s);
writel(AUART_CTRL2_UARTEN, u->membase + AUART_CTRL2_CLR);
writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN,
u->membase + AUART_INTR_CLR);
writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_SET);
clk_disable_unprepare(s->clk);
}
static unsigned int mxs_auart_tx_empty(struct uart_port *u)
{
if ((readl(u->membase + AUART_STAT) &
(AUART_STAT_TXFE | AUART_STAT_BUSY)) == AUART_STAT_TXFE)
return TIOCSER_TEMT;
return 0;
}
static void mxs_auart_start_tx(struct uart_port *u)
{
struct mxs_auart_port *s = to_auart_port(u);
/* enable transmitter */
writel(AUART_CTRL2_TXE, u->membase + AUART_CTRL2_SET);
mxs_auart_tx_chars(s);
}
static void mxs_auart_stop_tx(struct uart_port *u)
{
writel(AUART_CTRL2_TXE, u->membase + AUART_CTRL2_CLR);
}
static void mxs_auart_stop_rx(struct uart_port *u)
{
writel(AUART_CTRL2_RXE, u->membase + AUART_CTRL2_CLR);
}
static void mxs_auart_break_ctl(struct uart_port *u, int ctl)
{
if (ctl)
writel(AUART_LINECTRL_BRK,
u->membase + AUART_LINECTRL_SET);
else
writel(AUART_LINECTRL_BRK,
u->membase + AUART_LINECTRL_CLR);
}
static struct uart_ops mxs_auart_ops = {
.tx_empty = mxs_auart_tx_empty,
.start_tx = mxs_auart_start_tx,
.stop_tx = mxs_auart_stop_tx,
.stop_rx = mxs_auart_stop_rx,
.enable_ms = mxs_auart_enable_ms,
.break_ctl = mxs_auart_break_ctl,
.set_mctrl = mxs_auart_set_mctrl,
.get_mctrl = mxs_auart_get_mctrl,
.startup = mxs_auart_startup,
.shutdown = mxs_auart_shutdown,
.set_termios = mxs_auart_settermios,
.set_ldisc = mxs_auart_set_ldisc,
.type = mxs_auart_type,
.release_port = mxs_auart_release_port,
.request_port = mxs_auart_request_port,
.config_port = mxs_auart_config_port,
.verify_port = mxs_auart_verify_port,
};
static struct mxs_auart_port *auart_port[MXS_AUART_PORTS];
#ifdef CONFIG_SERIAL_MXS_AUART_CONSOLE
static void mxs_auart_console_putchar(struct uart_port *port, int ch)
{
unsigned int to = 1000;
while (readl(port->membase + AUART_STAT) & AUART_STAT_TXFF) {
if (!to--)
break;
udelay(1);
}
writel(ch, port->membase + AUART_DATA);
}
static void
auart_console_write(struct console *co, const char *str, unsigned int count)
{
struct mxs_auart_port *s;
struct uart_port *port;
unsigned int old_ctrl0, old_ctrl2;
unsigned int to = 20000;
if (co->index >= MXS_AUART_PORTS || co->index < 0)
return;
s = auart_port[co->index];
port = &s->port;
clk_enable(s->clk);
/* First save the CR then disable the interrupts */
old_ctrl2 = readl(port->membase + AUART_CTRL2);
old_ctrl0 = readl(port->membase + AUART_CTRL0);
writel(AUART_CTRL0_CLKGATE,
port->membase + AUART_CTRL0_CLR);
writel(AUART_CTRL2_UARTEN | AUART_CTRL2_TXE,
port->membase + AUART_CTRL2_SET);
uart_console_write(port, str, count, mxs_auart_console_putchar);
/* Finally, wait for transmitter to become empty ... */
while (readl(port->membase + AUART_STAT) & AUART_STAT_BUSY) {
udelay(1);
if (!to--)
break;
}
/*
* ... and restore the TCR if we waited long enough for the transmitter
* to be idle. This might keep the transmitter enabled although it is
* unused, but that is better than to disable it while it is still
* transmitting.
*/
if (!(readl(port->membase + AUART_STAT) & AUART_STAT_BUSY)) {
writel(old_ctrl0, port->membase + AUART_CTRL0);
writel(old_ctrl2, port->membase + AUART_CTRL2);
}
clk_disable(s->clk);
}
static void __init
auart_console_get_options(struct uart_port *port, int *baud,
int *parity, int *bits)
{
unsigned int lcr_h, quot;
if (!(readl(port->membase + AUART_CTRL2) & AUART_CTRL2_UARTEN))
return;
lcr_h = readl(port->membase + AUART_LINECTRL);
*parity = 'n';
if (lcr_h & AUART_LINECTRL_PEN) {
if (lcr_h & AUART_LINECTRL_EPS)
*parity = 'e';
else
*parity = 'o';
}
if ((lcr_h & AUART_LINECTRL_WLEN_MASK) == AUART_LINECTRL_WLEN(2))
*bits = 7;
else
*bits = 8;
quot = ((readl(port->membase + AUART_LINECTRL)
& AUART_LINECTRL_BAUD_DIVINT_MASK))
>> (AUART_LINECTRL_BAUD_DIVINT_SHIFT - 6);
quot |= ((readl(port->membase + AUART_LINECTRL)
& AUART_LINECTRL_BAUD_DIVFRAC_MASK))
>> AUART_LINECTRL_BAUD_DIVFRAC_SHIFT;
if (quot == 0)
quot = 1;
*baud = (port->uartclk << 2) / quot;
}
static int __init
auart_console_setup(struct console *co, char *options)
{
struct mxs_auart_port *s;
int baud = 9600;
int bits = 8;
int parity = 'n';
int flow = 'n';
int ret;
/*
* 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(auart_port))
co->index = 0;
s = auart_port[co->index];
if (!s)
return -ENODEV;
ret = clk_prepare_enable(s->clk);
if (ret)
return ret;
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
else
auart_console_get_options(&s->port, &baud, &parity, &bits);
ret = uart_set_options(&s->port, co, baud, parity, bits, flow);
clk_disable_unprepare(s->clk);
return ret;
}
static struct console auart_console = {
.name = "ttyAPP",
.write = auart_console_write,
.device = uart_console_device,
.setup = auart_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &auart_driver,
};
#endif
static struct uart_driver auart_driver = {
.owner = THIS_MODULE,
.driver_name = "ttyAPP",
.dev_name = "ttyAPP",
.major = 0,
.minor = 0,
.nr = MXS_AUART_PORTS,
#ifdef CONFIG_SERIAL_MXS_AUART_CONSOLE
.cons = &auart_console,
#endif
};
/*
* This function returns 1 if pdev isn't a device instatiated by dt, 0 if it
* could successfully get all information from dt or a negative errno.
*/
static int serial_mxs_probe_dt(struct mxs_auart_port *s,
struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
int ret;
if (!np)
/* 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: %d\n", ret);
return ret;
}
s->port.line = ret;
if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
set_bit(MXS_AUART_RTSCTS, &s->flags);
return 0;
}
static bool mxs_auart_init_gpios(struct mxs_auart_port *s, struct device *dev)
{
enum mctrl_gpio_idx i;
struct gpio_desc *gpiod;
s->gpios = mctrl_gpio_init(dev, 0);
if (IS_ERR_OR_NULL(s->gpios))
return false;
/* Block (enabled before) DMA option if RTS or CTS is GPIO line */
if (!RTS_AT_AUART() || !CTS_AT_AUART()) {
if (test_bit(MXS_AUART_RTSCTS, &s->flags))
dev_warn(dev,
"DMA and flow control via gpio may cause some problems. DMA disabled!\n");
clear_bit(MXS_AUART_RTSCTS, &s->flags);
}
for (i = 0; i < UART_GPIO_MAX; i++) {
gpiod = mctrl_gpio_to_gpiod(s->gpios, i);
if (gpiod && (gpiod_get_direction(gpiod) == GPIOF_DIR_IN))
s->gpio_irq[i] = gpiod_to_irq(gpiod);
else
s->gpio_irq[i] = -EINVAL;
}
return true;
}
static void mxs_auart_free_gpio_irq(struct mxs_auart_port *s)
{
enum mctrl_gpio_idx i;
for (i = 0; i < UART_GPIO_MAX; i++)
if (s->gpio_irq[i] >= 0)
free_irq(s->gpio_irq[i], s);
}
static int mxs_auart_request_gpio_irq(struct mxs_auart_port *s)
{
int *irq = s->gpio_irq;
enum mctrl_gpio_idx i;
int err = 0;
for (i = 0; (i < UART_GPIO_MAX) && !err; i++) {
if (irq[i] < 0)
continue;
irq_set_status_flags(irq[i], IRQ_NOAUTOEN);
err = request_irq(irq[i], mxs_auart_irq_handle,
IRQ_TYPE_EDGE_BOTH, dev_name(s->dev), s);
if (err)
dev_err(s->dev, "%s - Can't get %d irq\n",
__func__, irq[i]);
}
/*
* If something went wrong, rollback.
*/
while (err && (--i >= 0))
if (irq[i] >= 0)
free_irq(irq[i], s);
return err;
}
static int mxs_auart_probe(struct platform_device *pdev)
{
const struct of_device_id *of_id =
of_match_device(mxs_auart_dt_ids, &pdev->dev);
struct mxs_auart_port *s;
u32 version;
int ret, irq;
struct resource *r;
s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
if (!s)
return -ENOMEM;
ret = serial_mxs_probe_dt(s, pdev);
if (ret > 0)
s->port.line = pdev->id < 0 ? 0 : pdev->id;
else if (ret < 0)
return ret;
if (of_id) {
pdev->id_entry = of_id->data;
s->devtype = pdev->id_entry->driver_data;
}
s->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(s->clk))
return PTR_ERR(s->clk);
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!r)
return -ENXIO;
s->port.mapbase = r->start;
s->port.membase = ioremap(r->start, resource_size(r));
s->port.ops = &mxs_auart_ops;
s->port.iotype = UPIO_MEM;
s->port.fifosize = MXS_AUART_FIFO_SIZE;
s->port.uartclk = clk_get_rate(s->clk);
s->port.type = PORT_IMX;
s->port.dev = s->dev = &pdev->dev;
s->mctrl_prev = 0;
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
s->port.irq = irq;
ret = devm_request_irq(&pdev->dev, irq, mxs_auart_irq_handle, 0,
dev_name(&pdev->dev), s);
if (ret)
return ret;
platform_set_drvdata(pdev, s);
if (!mxs_auart_init_gpios(s, &pdev->dev))
dev_err(&pdev->dev,
"Failed to initialize GPIOs. The serial port may not work as expected\n");
/*
* Get the GPIO lines IRQ
*/
ret = mxs_auart_request_gpio_irq(s);
if (ret)
return ret;
auart_port[s->port.line] = s;
mxs_auart_reset(&s->port);
ret = uart_add_one_port(&auart_driver, &s->port);
if (ret)
goto out_free_gpio_irq;
version = readl(s->port.membase + AUART_VERSION);
dev_info(&pdev->dev, "Found APPUART %d.%d.%d\n",
(version >> 24) & 0xff,
(version >> 16) & 0xff, version & 0xffff);
return 0;
out_free_gpio_irq:
mxs_auart_free_gpio_irq(s);
auart_port[pdev->id] = NULL;
return ret;
}
static int mxs_auart_remove(struct platform_device *pdev)
{
struct mxs_auart_port *s = platform_get_drvdata(pdev);
uart_remove_one_port(&auart_driver, &s->port);
auart_port[pdev->id] = NULL;
mxs_auart_free_gpio_irq(s);
return 0;
}
static struct platform_driver mxs_auart_driver = {
.probe = mxs_auart_probe,
.remove = mxs_auart_remove,
.driver = {
.name = "mxs-auart",
.of_match_table = mxs_auart_dt_ids,
},
};
static int __init mxs_auart_init(void)
{
int r;
r = uart_register_driver(&auart_driver);
if (r)
goto out;
r = platform_driver_register(&mxs_auart_driver);
if (r)
goto out_err;
return 0;
out_err:
uart_unregister_driver(&auart_driver);
out:
return r;
}
static void __exit mxs_auart_exit(void)
{
platform_driver_unregister(&mxs_auart_driver);
uart_unregister_driver(&auart_driver);
}
module_init(mxs_auart_init);
module_exit(mxs_auart_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Freescale MXS application uart driver");
MODULE_ALIAS("platform:mxs-auart");
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