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OpenCloudOS-Kernel/drivers/serial/msm_serial.c

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/*
* drivers/serial/msm_serial.c - driver for msm7k serial device and console
*
* Copyright (C) 2007 Google, Inc.
* Author: Robert Love <rlove@google.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#if defined(CONFIG_SERIAL_MSM_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
# define SUPPORT_SYSRQ
#endif
#include <linux/hrtimer.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/irq.h>
#include <linux/init.h>
#include <linux/console.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/platform_device.h>
#include "msm_serial.h"
struct msm_port {
struct uart_port uart;
char name[16];
struct clk *clk;
unsigned int imr;
};
#define UART_TO_MSM(uart_port) ((struct msm_port *) uart_port)
static inline void msm_write(struct uart_port *port, unsigned int val,
unsigned int off)
{
__raw_writel(val, port->membase + off);
}
static inline unsigned int msm_read(struct uart_port *port, unsigned int off)
{
return __raw_readl(port->membase + off);
}
static void msm_stop_tx(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
msm_port->imr &= ~UART_IMR_TXLEV;
msm_write(port, msm_port->imr, UART_IMR);
}
static void msm_start_tx(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
msm_port->imr |= UART_IMR_TXLEV;
msm_write(port, msm_port->imr, UART_IMR);
}
static void msm_stop_rx(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
msm_port->imr &= ~(UART_IMR_RXLEV | UART_IMR_RXSTALE);
msm_write(port, msm_port->imr, UART_IMR);
}
static void msm_enable_ms(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
msm_port->imr |= UART_IMR_DELTA_CTS;
msm_write(port, msm_port->imr, UART_IMR);
}
static void handle_rx(struct uart_port *port)
{
struct tty_struct *tty = port->state->port.tty;
unsigned int sr;
/*
* Handle overrun. My understanding of the hardware is that overrun
* is not tied to the RX buffer, so we handle the case out of band.
*/
if ((msm_read(port, UART_SR) & UART_SR_OVERRUN)) {
port->icount.overrun++;
tty_insert_flip_char(tty, 0, TTY_OVERRUN);
msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
}
/* and now the main RX loop */
while ((sr = msm_read(port, UART_SR)) & UART_SR_RX_READY) {
unsigned int c;
char flag = TTY_NORMAL;
c = msm_read(port, UART_RF);
if (sr & UART_SR_RX_BREAK) {
port->icount.brk++;
if (uart_handle_break(port))
continue;
} else if (sr & UART_SR_PAR_FRAME_ERR) {
port->icount.frame++;
} else {
port->icount.rx++;
}
/* Mask conditions we're ignorning. */
sr &= port->read_status_mask;
if (sr & UART_SR_RX_BREAK) {
flag = TTY_BREAK;
} else if (sr & UART_SR_PAR_FRAME_ERR) {
flag = TTY_FRAME;
}
if (!uart_handle_sysrq_char(port, c))
tty_insert_flip_char(tty, c, flag);
}
tty_flip_buffer_push(tty);
}
static void handle_tx(struct uart_port *port)
{
struct circ_buf *xmit = &port->state->xmit;
struct msm_port *msm_port = UART_TO_MSM(port);
int sent_tx;
if (port->x_char) {
msm_write(port, port->x_char, UART_TF);
port->icount.tx++;
port->x_char = 0;
}
while (msm_read(port, UART_SR) & UART_SR_TX_READY) {
if (uart_circ_empty(xmit)) {
/* disable tx interrupts */
msm_port->imr &= ~UART_IMR_TXLEV;
msm_write(port, msm_port->imr, UART_IMR);
break;
}
msm_write(port, xmit->buf[xmit->tail], UART_TF);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
sent_tx = 1;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
}
static void handle_delta_cts(struct uart_port *port)
{
msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR);
port->icount.cts++;
wake_up_interruptible(&port->state->port.delta_msr_wait);
}
static irqreturn_t msm_irq(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
struct msm_port *msm_port = UART_TO_MSM(port);
unsigned int misr;
spin_lock(&port->lock);
misr = msm_read(port, UART_MISR);
msm_write(port, 0, UART_IMR); /* disable interrupt */
if (misr & (UART_IMR_RXLEV | UART_IMR_RXSTALE))
handle_rx(port);
if (misr & UART_IMR_TXLEV)
handle_tx(port);
if (misr & UART_IMR_DELTA_CTS)
handle_delta_cts(port);
msm_write(port, msm_port->imr, UART_IMR); /* restore interrupt */
spin_unlock(&port->lock);
return IRQ_HANDLED;
}
static unsigned int msm_tx_empty(struct uart_port *port)
{
return (msm_read(port, UART_SR) & UART_SR_TX_EMPTY) ? TIOCSER_TEMT : 0;
}
static unsigned int msm_get_mctrl(struct uart_port *port)
{
return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR | TIOCM_RTS;
}
static void msm_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
unsigned int mr;
mr = msm_read(port, UART_MR1);
if (!(mctrl & TIOCM_RTS)) {
mr &= ~UART_MR1_RX_RDY_CTL;
msm_write(port, mr, UART_MR1);
msm_write(port, UART_CR_CMD_RESET_RFR, UART_CR);
} else {
mr |= UART_MR1_RX_RDY_CTL;
msm_write(port, mr, UART_MR1);
}
}
static void msm_break_ctl(struct uart_port *port, int break_ctl)
{
if (break_ctl)
msm_write(port, UART_CR_CMD_START_BREAK, UART_CR);
else
msm_write(port, UART_CR_CMD_STOP_BREAK, UART_CR);
}
static int msm_set_baud_rate(struct uart_port *port, unsigned int baud)
{
unsigned int baud_code, rxstale, watermark;
switch (baud) {
case 300:
baud_code = UART_CSR_300;
rxstale = 1;
break;
case 600:
baud_code = UART_CSR_600;
rxstale = 1;
break;
case 1200:
baud_code = UART_CSR_1200;
rxstale = 1;
break;
case 2400:
baud_code = UART_CSR_2400;
rxstale = 1;
break;
case 4800:
baud_code = UART_CSR_4800;
rxstale = 1;
break;
case 9600:
baud_code = UART_CSR_9600;
rxstale = 2;
break;
case 14400:
baud_code = UART_CSR_14400;
rxstale = 3;
break;
case 19200:
baud_code = UART_CSR_19200;
rxstale = 4;
break;
case 28800:
baud_code = UART_CSR_28800;
rxstale = 6;
break;
case 38400:
baud_code = UART_CSR_38400;
rxstale = 8;
break;
case 57600:
baud_code = UART_CSR_57600;
rxstale = 16;
break;
case 115200:
default:
baud_code = UART_CSR_115200;
baud = 115200;
rxstale = 31;
break;
}
msm_write(port, baud_code, UART_CSR);
/* RX stale watermark */
watermark = UART_IPR_STALE_LSB & rxstale;
watermark |= UART_IPR_RXSTALE_LAST;
watermark |= UART_IPR_STALE_TIMEOUT_MSB & (rxstale << 2);
msm_write(port, watermark, UART_IPR);
/* set RX watermark */
watermark = (port->fifosize * 3) / 4;
msm_write(port, watermark, UART_RFWR);
/* set TX watermark */
msm_write(port, 10, UART_TFWR);
return baud;
}
static void msm_reset(struct uart_port *port)
{
/* reset everything */
msm_write(port, UART_CR_CMD_RESET_RX, UART_CR);
msm_write(port, UART_CR_CMD_RESET_TX, UART_CR);
msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
msm_write(port, UART_CR_CMD_RESET_BREAK_INT, UART_CR);
msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR);
msm_write(port, UART_CR_CMD_SET_RFR, UART_CR);
}
static void msm_init_clock(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
clk_enable(msm_port->clk);
msm_write(port, 0xC0, UART_MREG);
msm_write(port, 0xB2, UART_NREG);
msm_write(port, 0x7D, UART_DREG);
msm_write(port, 0x1C, UART_MNDREG);
}
static int msm_startup(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
unsigned int data, rfr_level;
int ret;
snprintf(msm_port->name, sizeof(msm_port->name),
"msm_serial%d", port->line);
ret = request_irq(port->irq, msm_irq, IRQF_TRIGGER_HIGH,
msm_port->name, port);
if (unlikely(ret))
return ret;
msm_init_clock(port);
if (likely(port->fifosize > 12))
rfr_level = port->fifosize - 12;
else
rfr_level = port->fifosize;
/* set automatic RFR level */
data = msm_read(port, UART_MR1);
data &= ~UART_MR1_AUTO_RFR_LEVEL1;
data &= ~UART_MR1_AUTO_RFR_LEVEL0;
data |= UART_MR1_AUTO_RFR_LEVEL1 & (rfr_level << 2);
data |= UART_MR1_AUTO_RFR_LEVEL0 & rfr_level;
msm_write(port, data, UART_MR1);
/* make sure that RXSTALE count is non-zero */
data = msm_read(port, UART_IPR);
if (unlikely(!data)) {
data |= UART_IPR_RXSTALE_LAST;
data |= UART_IPR_STALE_LSB;
msm_write(port, data, UART_IPR);
}
msm_reset(port);
msm_write(port, 0x05, UART_CR); /* enable TX & RX */
/* turn on RX and CTS interrupts */
msm_port->imr = UART_IMR_RXLEV | UART_IMR_RXSTALE |
UART_IMR_CURRENT_CTS;
msm_write(port, msm_port->imr, UART_IMR);
return 0;
}
static void msm_shutdown(struct uart_port *port)
{
struct msm_port *msm_port = UART_TO_MSM(port);
msm_port->imr = 0;
msm_write(port, 0, UART_IMR); /* disable interrupts */
clk_disable(msm_port->clk);
free_irq(port->irq, port);
}
static void msm_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
unsigned long flags;
unsigned int baud, mr;
spin_lock_irqsave(&port->lock, flags);
/* calculate and set baud rate */
baud = uart_get_baud_rate(port, termios, old, 300, 115200);
baud = msm_set_baud_rate(port, baud);
if (tty_termios_baud_rate(termios))
tty_termios_encode_baud_rate(termios, baud, baud);
/* calculate parity */
mr = msm_read(port, UART_MR2);
mr &= ~UART_MR2_PARITY_MODE;
if (termios->c_cflag & PARENB) {
if (termios->c_cflag & PARODD)
mr |= UART_MR2_PARITY_MODE_ODD;
else if (termios->c_cflag & CMSPAR)
mr |= UART_MR2_PARITY_MODE_SPACE;
else
mr |= UART_MR2_PARITY_MODE_EVEN;
}
/* calculate bits per char */
mr &= ~UART_MR2_BITS_PER_CHAR;
switch (termios->c_cflag & CSIZE) {
case CS5:
mr |= UART_MR2_BITS_PER_CHAR_5;
break;
case CS6:
mr |= UART_MR2_BITS_PER_CHAR_6;
break;
case CS7:
mr |= UART_MR2_BITS_PER_CHAR_7;
break;
case CS8:
default:
mr |= UART_MR2_BITS_PER_CHAR_8;
break;
}
/* calculate stop bits */
mr &= ~(UART_MR2_STOP_BIT_LEN_ONE | UART_MR2_STOP_BIT_LEN_TWO);
if (termios->c_cflag & CSTOPB)
mr |= UART_MR2_STOP_BIT_LEN_TWO;
else
mr |= UART_MR2_STOP_BIT_LEN_ONE;
/* set parity, bits per char, and stop bit */
msm_write(port, mr, UART_MR2);
/* calculate and set hardware flow control */
mr = msm_read(port, UART_MR1);
mr &= ~(UART_MR1_CTS_CTL | UART_MR1_RX_RDY_CTL);
if (termios->c_cflag & CRTSCTS) {
mr |= UART_MR1_CTS_CTL;
mr |= UART_MR1_RX_RDY_CTL;
}
msm_write(port, mr, UART_MR1);
/* Configure status bits to ignore based on termio flags. */
port->read_status_mask = 0;
if (termios->c_iflag & INPCK)
port->read_status_mask |= UART_SR_PAR_FRAME_ERR;
if (termios->c_iflag & (BRKINT | PARMRK))
port->read_status_mask |= UART_SR_RX_BREAK;
uart_update_timeout(port, termios->c_cflag, baud);
spin_unlock_irqrestore(&port->lock, flags);
}
static const char *msm_type(struct uart_port *port)
{
return "MSM";
}
static void msm_release_port(struct uart_port *port)
{
struct platform_device *pdev = to_platform_device(port->dev);
struct resource *resource;
resource_size_t size;
resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (unlikely(!resource))
return;
size = resource->end - resource->start + 1;
release_mem_region(port->mapbase, size);
iounmap(port->membase);
port->membase = NULL;
}
static int msm_request_port(struct uart_port *port)
{
struct platform_device *pdev = to_platform_device(port->dev);
struct resource *resource;
resource_size_t size;
resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (unlikely(!resource))
return -ENXIO;
size = resource->end - resource->start + 1;
if (unlikely(!request_mem_region(port->mapbase, size, "msm_serial")))
return -EBUSY;
port->membase = ioremap(port->mapbase, size);
if (!port->membase) {
release_mem_region(port->mapbase, size);
return -EBUSY;
}
return 0;
}
static void msm_config_port(struct uart_port *port, int flags)
{
if (flags & UART_CONFIG_TYPE) {
port->type = PORT_MSM;
msm_request_port(port);
}
}
static int msm_verify_port(struct uart_port *port, struct serial_struct *ser)
{
if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_MSM))
return -EINVAL;
if (unlikely(port->irq != ser->irq))
return -EINVAL;
return 0;
}
static void msm_power(struct uart_port *port, unsigned int state,
unsigned int oldstate)
{
struct msm_port *msm_port = UART_TO_MSM(port);
switch (state) {
case 0:
clk_enable(msm_port->clk);
break;
case 3:
clk_disable(msm_port->clk);
break;
default:
printk(KERN_ERR "msm_serial: Unknown PM state %d\n", state);
}
}
static struct uart_ops msm_uart_pops = {
.tx_empty = msm_tx_empty,
.set_mctrl = msm_set_mctrl,
.get_mctrl = msm_get_mctrl,
.stop_tx = msm_stop_tx,
.start_tx = msm_start_tx,
.stop_rx = msm_stop_rx,
.enable_ms = msm_enable_ms,
.break_ctl = msm_break_ctl,
.startup = msm_startup,
.shutdown = msm_shutdown,
.set_termios = msm_set_termios,
.type = msm_type,
.release_port = msm_release_port,
.request_port = msm_request_port,
.config_port = msm_config_port,
.verify_port = msm_verify_port,
.pm = msm_power,
};
static struct msm_port msm_uart_ports[] = {
{
.uart = {
.iotype = UPIO_MEM,
.ops = &msm_uart_pops,
.flags = UPF_BOOT_AUTOCONF,
.fifosize = 512,
.line = 0,
},
},
{
.uart = {
.iotype = UPIO_MEM,
.ops = &msm_uart_pops,
.flags = UPF_BOOT_AUTOCONF,
.fifosize = 512,
.line = 1,
},
},
{
.uart = {
.iotype = UPIO_MEM,
.ops = &msm_uart_pops,
.flags = UPF_BOOT_AUTOCONF,
.fifosize = 64,
.line = 2,
},
},
};
#define UART_NR ARRAY_SIZE(msm_uart_ports)
static inline struct uart_port *get_port_from_line(unsigned int line)
{
return &msm_uart_ports[line].uart;
}
#ifdef CONFIG_SERIAL_MSM_CONSOLE
static void msm_console_putchar(struct uart_port *port, int c)
{
while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
;
msm_write(port, c, UART_TF);
}
static void msm_console_write(struct console *co, const char *s,
unsigned int count)
{
struct uart_port *port;
struct msm_port *msm_port;
BUG_ON(co->index < 0 || co->index >= UART_NR);
port = get_port_from_line(co->index);
msm_port = UART_TO_MSM(port);
spin_lock(&port->lock);
uart_console_write(port, s, count, msm_console_putchar);
spin_unlock(&port->lock);
}
static int __init msm_console_setup(struct console *co, char *options)
{
struct uart_port *port;
int baud, flow, bits, parity;
if (unlikely(co->index >= UART_NR || co->index < 0))
return -ENXIO;
port = get_port_from_line(co->index);
if (unlikely(!port->membase))
return -ENXIO;
port->cons = co;
msm_init_clock(port);
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
bits = 8;
parity = 'n';
flow = 'n';
msm_write(port, UART_MR2_BITS_PER_CHAR_8 | UART_MR2_STOP_BIT_LEN_ONE,
UART_MR2); /* 8N1 */
if (baud < 300 || baud > 115200)
baud = 115200;
msm_set_baud_rate(port, baud);
msm_reset(port);
printk(KERN_INFO "msm_serial: console setup on port #%d\n", port->line);
return uart_set_options(port, co, baud, parity, bits, flow);
}
static struct uart_driver msm_uart_driver;
static struct console msm_console = {
.name = "ttyMSM",
.write = msm_console_write,
.device = uart_console_device,
.setup = msm_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &msm_uart_driver,
};
#define MSM_CONSOLE (&msm_console)
#else
#define MSM_CONSOLE NULL
#endif
static struct uart_driver msm_uart_driver = {
.owner = THIS_MODULE,
.driver_name = "msm_serial",
.dev_name = "ttyMSM",
.nr = UART_NR,
.cons = MSM_CONSOLE,
};
static int __init msm_serial_probe(struct platform_device *pdev)
{
struct msm_port *msm_port;
struct resource *resource;
struct uart_port *port;
if (unlikely(pdev->id < 0 || pdev->id >= UART_NR))
return -ENXIO;
printk(KERN_INFO "msm_serial: detected port #%d\n", pdev->id);
port = get_port_from_line(pdev->id);
port->dev = &pdev->dev;
msm_port = UART_TO_MSM(port);
msm_port->clk = clk_get(&pdev->dev, "uart_clk");
if (unlikely(IS_ERR(msm_port->clk)))
return PTR_ERR(msm_port->clk);
port->uartclk = clk_get_rate(msm_port->clk);
resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (unlikely(!resource))
return -ENXIO;
port->mapbase = resource->start;
port->irq = platform_get_irq(pdev, 0);
if (unlikely(port->irq < 0))
return -ENXIO;
platform_set_drvdata(pdev, port);
return uart_add_one_port(&msm_uart_driver, port);
}
static int __devexit msm_serial_remove(struct platform_device *pdev)
{
struct msm_port *msm_port = platform_get_drvdata(pdev);
clk_put(msm_port->clk);
return 0;
}
static struct platform_driver msm_platform_driver = {
.remove = msm_serial_remove,
.driver = {
.name = "msm_serial",
.owner = THIS_MODULE,
},
};
static int __init msm_serial_init(void)
{
int ret;
ret = uart_register_driver(&msm_uart_driver);
if (unlikely(ret))
return ret;
ret = platform_driver_probe(&msm_platform_driver, msm_serial_probe);
if (unlikely(ret))
uart_unregister_driver(&msm_uart_driver);
printk(KERN_INFO "msm_serial: driver initialized\n");
return ret;
}
static void __exit msm_serial_exit(void)
{
#ifdef CONFIG_SERIAL_MSM_CONSOLE
unregister_console(&msm_console);
#endif
platform_driver_unregister(&msm_platform_driver);
uart_unregister_driver(&msm_uart_driver);
}
module_init(msm_serial_init);
module_exit(msm_serial_exit);
MODULE_AUTHOR("Robert Love <rlove@google.com>");
MODULE_DESCRIPTION("Driver for msm7x serial device");
MODULE_LICENSE("GPL");
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