提交 ee9b4500 编写于 作者: F Feng Tang 提交者: Greg Kroah-Hartman

serial: mrst_max3110: some code cleanup

The cleanup for mrst_max3110 includes:
* remove unneeded head files
* make the spi_transfer dma safe, so that driver is more portable
* add more check for error return value
* use mutex_trylock for read thread
Signed-off-by: NFeng Tang <feng.tang@intel.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
上级 b670bde0
/*
* max3110.c - spi uart protocol driver for Maxim 3110 on Moorestown
* mrst_max3110.c - spi uart protocol driver for Maxim 3110
*
* Copyright (C) Intel 2008 Feng Tang <feng.tang@intel.com>
* Copyright (c) 2008-2010, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
......@@ -32,18 +32,13 @@
#include <linux/irq.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_reg.h>
#include <linux/kthread.h>
#include <linux/delay.h>
#include <asm/atomic.h>
#include <linux/spi/spi.h>
#include <linux/spi/dw_spi.h>
#include "mrst_max3110.h"
......@@ -56,7 +51,7 @@
struct uart_max3110 {
struct uart_port port;
struct spi_device *spi;
char *name;
char name[24];
wait_queue_head_t wq;
struct task_struct *main_thread;
......@@ -67,35 +62,30 @@ struct uart_max3110 {
u16 cur_conf;
u8 clock;
u8 parity, word_7bits;
u16 irq;
unsigned long uart_flags;
/* console related */
struct circ_buf con_xmit;
/* irq related */
u16 irq;
};
/* global data structure, may need be removed */
struct uart_max3110 *pmax;
static inline void receive_char(struct uart_max3110 *max, u8 ch);
static struct uart_max3110 *pmax;
static void receive_chars(struct uart_max3110 *max,
unsigned char *str, int len);
static int max3110_read_multi(struct uart_max3110 *max, int len, u8 *buf);
static void max3110_console_receive(struct uart_max3110 *max);
static int max3110_read_multi(struct uart_max3110 *max, u8 *buf);
static void max3110_con_receive(struct uart_max3110 *max);
int max3110_write_then_read(struct uart_max3110 *max,
const u8 *txbuf, u8 *rxbuf, unsigned len, int always_fast)
static int max3110_write_then_read(struct uart_max3110 *max,
const void *txbuf, void *rxbuf, unsigned len, int always_fast)
{
struct spi_device *spi = max->spi;
struct spi_message message;
struct spi_transfer x;
int ret;
if (!txbuf || !rxbuf)
return -EINVAL;
spi_message_init(&message);
memset(&x, 0, sizeof x);
x.len = len;
......@@ -104,7 +94,7 @@ int max3110_write_then_read(struct uart_max3110 *max,
spi_message_add_tail(&x, &message);
if (always_fast)
x.speed_hz = 3125000;
x.speed_hz = spi->max_speed_hz;
else if (max->baud)
x.speed_hz = max->baud;
......@@ -113,58 +103,80 @@ int max3110_write_then_read(struct uart_max3110 *max,
return ret;
}
/* Write a u16 to the device, and return one u16 read back */
int max3110_out(struct uart_max3110 *max, const u16 out)
/* Write a 16b word to the device */
static int max3110_out(struct uart_max3110 *max, const u16 out)
{
u16 tmp;
void *buf;
u16 *obuf, *ibuf;
u8 ch;
int ret;
ret = max3110_write_then_read(max, (u8 *)&out, (u8 *)&tmp, 2, 1);
if (ret)
return ret;
buf = kzalloc(8, GFP_KERNEL | GFP_DMA);
if (!buf)
return -ENOMEM;
obuf = buf;
ibuf = buf + 4;
*obuf = out;
ret = max3110_write_then_read(max, obuf, ibuf, 2, 1);
if (ret) {
pr_warning(PR_FMT "%s(): get err msg %d when sending 0x%x\n",
__func__, ret, out);
goto exit;
}
/* If some valid data is read back */
if (tmp & MAX3110_READ_DATA_AVAILABLE)
receive_char(max, (tmp & 0xff));
if (*ibuf & MAX3110_READ_DATA_AVAILABLE) {
ch = *ibuf & 0xff;
receive_chars(max, &ch, 1);
}
exit:
kfree(buf);
return ret;
}
#define MAX_READ_LEN 20
/*
* This is usually used to read data from SPIC RX FIFO, which doesn't
* need any delay like flushing character out. It returns how many
* valide bytes are read back
* need any delay like flushing character out.
*
* Return how many valide bytes are read back
*/
static int max3110_read_multi(struct uart_max3110 *max, int len, u8 *buf)
static int max3110_read_multi(struct uart_max3110 *max, u8 *rxbuf)
{
u16 out[MAX_READ_LEN], in[MAX_READ_LEN];
u8 *pbuf, valid_str[MAX_READ_LEN];
int i, j, bytelen;
void *buf;
u16 *obuf, *ibuf;
u8 *pbuf, valid_str[M3110_RX_FIFO_DEPTH];
int i, j, blen;
if (len > MAX_READ_LEN) {
pr_err(PR_FMT "read len %d is too large\n", len);
blen = M3110_RX_FIFO_DEPTH * sizeof(u16);
buf = kzalloc(blen * 2, GFP_KERNEL | GFP_DMA);
if (!buf) {
pr_warning(PR_FMT "%s(): fail to alloc dma buffer\n", __func__);
return 0;
}
bytelen = len * 2;
memset(out, 0, bytelen);
memset(in, 0, bytelen);
/* tx/rx always have the same length */
obuf = buf;
ibuf = buf + blen;
if (max3110_write_then_read(max, (u8 *)out, (u8 *)in, bytelen, 1))
if (max3110_write_then_read(max, obuf, ibuf, blen, 1)) {
kfree(buf);
return 0;
}
/* If caller don't provide a buffer, then handle received char */
pbuf = buf ? buf : valid_str;
/* If caller doesn't provide a buffer, then handle received char */
pbuf = rxbuf ? rxbuf : valid_str;
for (i = 0, j = 0; i < len; i++) {
if (in[i] & MAX3110_READ_DATA_AVAILABLE)
pbuf[j++] = (u8)(in[i] & 0xff);
for (i = 0, j = 0; i < M3110_RX_FIFO_DEPTH; i++) {
if (ibuf[i] & MAX3110_READ_DATA_AVAILABLE)
pbuf[j++] = ibuf[i] & 0xff;
}
if (j && (pbuf == valid_str))
receive_chars(max, valid_str, j);
kfree(buf);
return j;
}
......@@ -178,10 +190,6 @@ static void serial_m3110_con_putchar(struct uart_port *port, int ch)
xmit->buf[xmit->head] = (char)ch;
xmit->head = (xmit->head + 1) & (PAGE_SIZE - 1);
}
if (!test_and_set_bit(CON_TX_NEEDED, &max->uart_flags))
wake_up_process(max->main_thread);
}
/*
......@@ -197,6 +205,9 @@ static void serial_m3110_con_write(struct console *co,
return;
uart_console_write(&pmax->port, s, count, serial_m3110_con_putchar);
if (!test_and_set_bit(CON_TX_NEEDED, &pmax->uart_flags))
wake_up_process(pmax->main_thread);
}
static int __init
......@@ -210,6 +221,9 @@ serial_m3110_con_setup(struct console *co, char *options)
pr_info(PR_FMT "setting up console\n");
if (co->index == -1)
co->index = 0;
if (!max) {
pr_err(PR_FMT "pmax is NULL, return");
return -ENODEV;
......@@ -240,8 +254,6 @@ static struct console serial_m3110_console = {
.data = &serial_m3110_reg,
};
#define MRST_CONSOLE (&serial_m3110_console)
static unsigned int serial_m3110_tx_empty(struct uart_port *port)
{
return 1;
......@@ -259,32 +271,44 @@ static void serial_m3110_stop_rx(struct uart_port *port)
}
#define WORDS_PER_XFER 128
static inline void send_circ_buf(struct uart_max3110 *max,
static void send_circ_buf(struct uart_max3110 *max,
struct circ_buf *xmit)
{
int len, left = 0;
u16 obuf[WORDS_PER_XFER], ibuf[WORDS_PER_XFER];
void *buf;
u16 *obuf, *ibuf;
u8 valid_str[WORDS_PER_XFER];
int i, j;
int i, j, len, blen, dma_size, left, ret = 0;
dma_size = WORDS_PER_XFER * sizeof(u16) * 2;
buf = kzalloc(dma_size, GFP_KERNEL | GFP_DMA);
if (!buf)
return;
obuf = buf;
ibuf = buf + dma_size/2;
while (!uart_circ_empty(xmit)) {
left = uart_circ_chars_pending(xmit);
while (left) {
len = (left >= WORDS_PER_XFER) ? WORDS_PER_XFER : left;
len = min(left, WORDS_PER_XFER);
blen = len * sizeof(u16);
memset(ibuf, 0, blen);
memset(obuf, 0, len * 2);
memset(ibuf, 0, len * 2);
for (i = 0; i < len; i++) {
obuf[i] = (u8)xmit->buf[xmit->tail] | WD_TAG;
xmit->tail = (xmit->tail + 1) &
(UART_XMIT_SIZE - 1);
}
max3110_write_then_read(max, (u8 *)obuf,
(u8 *)ibuf, len * 2, 0);
/* Fail to send msg to console is not very critical */
ret = max3110_write_then_read(max, obuf, ibuf, blen, 0);
if (ret)
pr_warning(PR_FMT "%s(): get err msg %d\n",
__func__, ret);
for (i = 0, j = 0; i < len; i++) {
if (ibuf[i] & MAX3110_READ_DATA_AVAILABLE)
valid_str[j++] = (u8)(ibuf[i] & 0xff);
valid_str[j++] = ibuf[i] & 0xff;
}
if (j)
......@@ -294,6 +318,8 @@ static inline void send_circ_buf(struct uart_max3110 *max,
left -= len;
}
}
kfree(buf);
}
static void transmit_char(struct uart_max3110 *max)
......@@ -313,8 +339,10 @@ static void transmit_char(struct uart_max3110 *max)
serial_m3110_stop_tx(port);
}
/* This will be called by uart_write() and tty_write, can't
* go to sleep */
/*
* This will be called by uart_write() and tty_write, can't
* go to sleep
*/
static void serial_m3110_start_tx(struct uart_port *port)
{
struct uart_max3110 *max =
......@@ -336,7 +364,7 @@ static void receive_chars(struct uart_max3110 *max, unsigned char *str, int len)
tty = port->state->port.tty;
if (!tty)
return; /* receive some char before the tty is opened */
return;
while (len) {
usable = tty_buffer_request_room(tty, len);
......@@ -344,32 +372,37 @@ static void receive_chars(struct uart_max3110 *max, unsigned char *str, int len)
tty_insert_flip_string(tty, str, usable);
str += usable;
port->icount.rx += usable;
tty_flip_buffer_push(tty);
}
len -= usable;
}
tty_flip_buffer_push(tty);
}
static inline void receive_char(struct uart_max3110 *max, u8 ch)
{
receive_chars(max, &ch, 1);
}
static void max3110_console_receive(struct uart_max3110 *max)
/*
* This routine will be used in read_thread or RX IRQ handling,
* it will first do one round buffer read(8 words), if there is some
* valid RX data, will try to read 5 more rounds till all data
* is read out.
*
* Use stack space as data buffer to save some system load, and chose
* 504 Btyes as a threadhold to do a bulk push to upper tty layer when
* receiving bulk data, a much bigger buffer may cause stack overflow
*/
static void max3110_con_receive(struct uart_max3110 *max)
{
int loop = 1, num, total = 0;
u8 recv_buf[512], *pbuf;
pbuf = recv_buf;
do {
num = max3110_read_multi(max, 8, pbuf);
num = max3110_read_multi(max, pbuf);
if (num) {
loop = 10;
loop = 5;
pbuf += num;
total += num;
if (total >= 500) {
if (total >= 504) {
receive_chars(max, recv_buf, total);
pbuf = recv_buf;
total = 0;
......@@ -397,7 +430,7 @@ static int max3110_main_thread(void *_max)
mutex_lock(&max->thread_mutex);
if (test_and_clear_bit(BIT_IRQ_PENDING, &max->uart_flags))
max3110_console_receive(max);
max3110_con_receive(max);
/* first handle console output */
if (test_and_clear_bit(CON_TX_NEEDED, &max->uart_flags))
......@@ -434,9 +467,14 @@ static int max3110_read_thread(void *_max)
pr_info(PR_FMT "start read thread\n");
do {
mutex_lock(&max->thread_mutex);
max3110_console_receive(max);
mutex_unlock(&max->thread_mutex);
/*
* If can't acquire the mutex, it means the main thread
* is running which will also perform the rx job
*/
if (mutex_trylock(&max->thread_mutex)) {
max3110_con_receive(max);
mutex_unlock(&max->thread_mutex);
}
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(HZ / 20);
......@@ -453,15 +491,16 @@ static int serial_m3110_startup(struct uart_port *port)
u16 config = 0;
int ret = 0;
if (port->line != 0)
if (port->line != 0) {
pr_err(PR_FMT "uart port startup failed\n");
return -1;
}
/* firstly disable all IRQ and config it to 115200, 8n1 */
/* Disable all IRQ and config it to 115200, 8n1 */
config = WC_TAG | WC_FIFO_ENABLE
| WC_1_STOPBITS
| WC_8BIT_WORD
| WC_BAUD_DR2;
ret = max3110_out(max, config);
/* as we use thread to handle tx/rx, need set low latency */
port->state->port.tty->low_latency = 1;
......@@ -472,14 +511,30 @@ static int serial_m3110_startup(struct uart_port *port)
if (ret)
return ret;
/* enable RX IRQ only */
/* Enable RX IRQ only */
config |= WC_RXA_IRQ_ENABLE;
max3110_out(max, config);
#else
/* if IRQ is disabled, start a read thread for input data */
/* If IRQ is disabled, start a read thread for input data */
max->read_thread =
kthread_run(max3110_read_thread, max, "max3110_read");
if (IS_ERR(max->read_thread)) {
ret = PTR_ERR(max->read_thread);
max->read_thread = NULL;
pr_err(PR_FMT "Can't create read thread!");
return ret;
}
#endif
ret = max3110_out(max, config);
if (ret) {
#ifdef CONFIG_MRST_MAX3110_IRQ
free_irq(max->irq, max);
#else
kthread_stop(max->read_thread);
max->read_thread = NULL;
#endif
return ret;
}
max->cur_conf = config;
return 0;
......@@ -516,8 +571,7 @@ static int serial_m3110_request_port(struct uart_port *port)
static void serial_m3110_config_port(struct uart_port *port, int flags)
{
/* give it fake type */
port->type = PORT_PXA;
port->type = PORT_MAX3100;
}
static int
......@@ -552,6 +606,9 @@ serial_m3110_set_termios(struct uart_port *port, struct ktermios *termios,
new_conf |= WC_7BIT_WORD;
break;
default:
/* We only support CS7 & CS8 */
termios->c_cflag &= ~CSIZE;
termios->c_cflag |= CS8;
case CS8:
cval = UART_LCR_WLEN8;
new_conf |= WC_8BIT_WORD;
......@@ -560,7 +617,7 @@ serial_m3110_set_termios(struct uart_port *port, struct ktermios *termios,
baud = uart_get_baud_rate(port, termios, old, 0, 230400);
/* first calc the div for 1.8MHZ clock case */
/* First calc the div for 1.8MHZ clock case */
switch (baud) {
case 300:
clk_div = WC_BAUD_DR384;
......@@ -596,7 +653,7 @@ serial_m3110_set_termios(struct uart_port *port, struct ktermios *termios,
if (max->clock & MAX3110_HIGH_CLK)
break;
default:
/* pick the previous baud rate */
/* Pick the previous baud rate */
baud = max->baud;
clk_div = max->cur_conf & WC_BAUD_DIV_MASK;
tty_termios_encode_baud_rate(termios, baud, baud);
......@@ -604,15 +661,21 @@ serial_m3110_set_termios(struct uart_port *port, struct ktermios *termios,
if (max->clock & MAX3110_HIGH_CLK) {
clk_div += 1;
/* high clk version max3110 doesn't support B300 */
if (baud == 300)
/* High clk version max3110 doesn't support B300 */
if (baud == 300) {
baud = 600;
clk_div = WC_BAUD_DR384;
}
if (baud == 230400)
clk_div = WC_BAUD_DR1;
tty_termios_encode_baud_rate(termios, baud, baud);
}
new_conf = (new_conf & ~WC_BAUD_DIV_MASK) | clk_div;
if (unlikely(termios->c_cflag & CMSPAR))
termios->c_cflag &= ~CMSPAR;
if (termios->c_cflag & CSTOPB)
new_conf |= WC_2_STOPBITS;
else
......@@ -632,13 +695,14 @@ serial_m3110_set_termios(struct uart_port *port, struct ktermios *termios,
new_conf |= WC_TAG;
if (new_conf != max->cur_conf) {
max3110_out(max, new_conf);
max->cur_conf = new_conf;
max->baud = baud;
if (!max3110_out(max, new_conf)) {
max->cur_conf = new_conf;
max->baud = baud;
}
}
}
/* don't handle hw handshaking */
/* Don't handle hw handshaking */
static unsigned int serial_m3110_get_mctrl(struct uart_port *port)
{
return TIOCM_DSR | TIOCM_CAR | TIOCM_DSR;
......@@ -672,7 +736,7 @@ struct uart_ops serial_m3110_ops = {
.break_ctl = serial_m3110_break_ctl,
.startup = serial_m3110_startup,
.shutdown = serial_m3110_shutdown,
.set_termios = serial_m3110_set_termios, /* must have */
.set_termios = serial_m3110_set_termios,
.pm = serial_m3110_pm,
.type = serial_m3110_type,
.release_port = serial_m3110_release_port,
......@@ -688,52 +752,60 @@ static struct uart_driver serial_m3110_reg = {
.major = TTY_MAJOR,
.minor = 64,
.nr = 1,
.cons = MRST_CONSOLE,
.cons = &serial_m3110_console,
};
#ifdef CONFIG_PM
static int serial_m3110_suspend(struct spi_device *spi, pm_message_t state)
{
struct uart_max3110 *max = spi_get_drvdata(spi);
disable_irq(max->irq);
uart_suspend_port(&serial_m3110_reg, &max->port);
max3110_out(max, max->cur_conf | WC_SW_SHDI);
return 0;
}
static int serial_m3110_resume(struct spi_device *spi)
{
struct uart_max3110 *max = spi_get_drvdata(spi);
max3110_out(max, max->cur_conf);
uart_resume_port(&serial_m3110_reg, &max->port);
enable_irq(max->irq);
return 0;
}
#else
#define serial_m3110_suspend NULL
#define serial_m3110_resume NULL
#endif
static struct dw_spi_chip spi0_uart = {
.poll_mode = 1,
.enable_dma = 0,
.type = SPI_FRF_SPI,
};
static int serial_m3110_probe(struct spi_device *spi)
static int __devinit serial_m3110_probe(struct spi_device *spi)
{
struct uart_max3110 *max;
int ret;
unsigned char *buffer;
void *buffer;
u16 res;
int ret = 0;
max = kzalloc(sizeof(*max), GFP_KERNEL);
if (!max)
return -ENOMEM;
/* set spi info */
spi->mode = SPI_MODE_0;
/* Set spi info */
spi->bits_per_word = 16;
max->clock = MAX3110_HIGH_CLK;
spi->controller_data = &spi0_uart;
spi_setup(spi);
max->port.type = PORT_PXA; /* need apply for a max3110 type */
max->port.fifosize = 2; /* only have 16b buffer */
max->port.type = PORT_MAX3100;
max->port.fifosize = 2; /* Only have 16b buffer */
max->port.ops = &serial_m3110_ops;
max->port.line = 0;
max->port.dev = &spi->dev;
max->port.uartclk = 115200;
max->spi = spi;
max->name = spi->modalias; /* use spi name as the name */
strcpy(max->name, spi->modalias);
max->irq = (u16)spi->irq;
mutex_init(&max->thread_mutex);
......@@ -755,13 +827,15 @@ static int serial_m3110_probe(struct spi_device *spi)
ret = -ENODEV;
goto err_get_page;
}
buffer = (unsigned char *)__get_free_page(GFP_KERNEL);
buffer = (void *)__get_free_page(GFP_KERNEL);
if (!buffer) {
ret = -ENOMEM;
goto err_get_page;
}
max->con_xmit.buf = (unsigned char *)buffer;
max->con_xmit.head = max->con_xmit.tail = 0;
max->con_xmit.buf = buffer;
max->con_xmit.head = 0;
max->con_xmit.tail = 0;
max->main_thread = kthread_run(max3110_main_thread,
max, "max3110_main");
......@@ -770,8 +844,10 @@ static int serial_m3110_probe(struct spi_device *spi)
goto err_kthread;
}
spi_set_drvdata(spi, max);
pmax = max;
/* give membase a psudo value to pass serial_core's check */
/* Give membase a psudo value to pass serial_core's check */
max->port.membase = (void *)0xff110000;
uart_add_one_port(&serial_m3110_reg, &max->port);
......@@ -780,19 +856,17 @@ static int serial_m3110_probe(struct spi_device *spi)
err_kthread:
free_page((unsigned long)buffer);
err_get_page:
pmax = NULL;
kfree(max);
return ret;
}
static int max3110_remove(struct spi_device *dev)
static int __devexit serial_m3110_remove(struct spi_device *dev)
{
struct uart_max3110 *max = pmax;
struct uart_max3110 *max = spi_get_drvdata(dev);
if (!pmax)
if (!max)
return 0;
pmax = NULL;
uart_remove_one_port(&serial_m3110_reg, &max->port);
free_page((unsigned long)max->con_xmit.buf);
......@@ -811,13 +885,12 @@ static struct spi_driver uart_max3110_driver = {
.owner = THIS_MODULE,
},
.probe = serial_m3110_probe,
.remove = __devexit_p(max3110_remove),
.remove = __devexit_p(serial_m3110_remove),
.suspend = serial_m3110_suspend,
.resume = serial_m3110_resume,
};
int __init serial_m3110_init(void)
static int __init serial_m3110_init(void)
{
int ret = 0;
......@@ -832,7 +905,7 @@ int __init serial_m3110_init(void)
return ret;
}
void __exit serial_m3110_exit(void)
static void __exit serial_m3110_exit(void)
{
spi_unregister_driver(&uart_max3110_driver);
uart_unregister_driver(&serial_m3110_reg);
......@@ -841,5 +914,5 @@ void __exit serial_m3110_exit(void)
module_init(serial_m3110_init);
module_exit(serial_m3110_exit);
MODULE_LICENSE("GPL");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("max3110-uart");
......@@ -56,4 +56,5 @@
#define WC_BAUD_DR192 (0xE)
#define WC_BAUD_DR384 (0xF)
#define M3110_RX_FIFO_DEPTH 8
#endif
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