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watchdog: Convert txx9wdt driver to watchdog framework
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This patch converts txx9wdt driver to watchdog framework.
Also use devm_* APIs to save a few error handling code.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
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Axel Lin authored and Wim Van Sebroeck committed Mar 27, 2012
1 parent dddbc6a commit d624584
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Showing 2 changed files with 38 additions and 118 deletions.
1 change: 1 addition & 0 deletions drivers/watchdog/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -1003,6 +1003,7 @@ config AR7_WDT
config TXX9_WDT
tristate "Toshiba TXx9 Watchdog Timer"
depends on CPU_TX39XX || CPU_TX49XX
select WATCHDOG_CORE
help
Hardware driver for the built-in watchdog timer on TXx9 MIPS SoCs.

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155 changes: 37 additions & 118 deletions drivers/watchdog/txx9wdt.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -15,9 +15,7 @@
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/uaccess.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/err.h>
Expand All @@ -43,20 +41,19 @@ MODULE_PARM_DESC(nowayout,
#define WD_TIMER_CLK (clk_get_rate(txx9_imclk) / (2 << WD_TIMER_CCD))
#define WD_MAX_TIMEOUT ((0xffffffff >> (32 - TXX9_TIMER_BITS)) / WD_TIMER_CLK)

static unsigned long txx9wdt_alive;
static int expect_close;
static struct txx9_tmr_reg __iomem *txx9wdt_reg;
static struct clk *txx9_imclk;
static DEFINE_SPINLOCK(txx9_lock);

static void txx9wdt_ping(void)
static int txx9wdt_ping(struct watchdog_device *wdt_dev)
{
spin_lock(&txx9_lock);
__raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr);
spin_unlock(&txx9_lock);
return 0;
}

static void txx9wdt_start(void)
static int txx9wdt_start(struct watchdog_device *wdt_dev)
{
spin_lock(&txx9_lock);
__raw_writel(WD_TIMER_CLK * timeout, &txx9wdt_reg->cpra);
Expand All @@ -66,120 +63,44 @@ static void txx9wdt_start(void)
&txx9wdt_reg->tcr);
__raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr);
spin_unlock(&txx9_lock);
return 0;
}

static void txx9wdt_stop(void)
static int txx9wdt_stop(struct watchdog_device *wdt_dev)
{
spin_lock(&txx9_lock);
__raw_writel(TXx9_TMWTMR_WDIS, &txx9wdt_reg->wtmr);
__raw_writel(__raw_readl(&txx9wdt_reg->tcr) & ~TXx9_TMTCR_TCE,
&txx9wdt_reg->tcr);
spin_unlock(&txx9_lock);
}

static int txx9wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &txx9wdt_alive))
return -EBUSY;

if (__raw_readl(&txx9wdt_reg->tcr) & TXx9_TMTCR_TCE) {
clear_bit(0, &txx9wdt_alive);
return -EBUSY;
}

if (nowayout)
__module_get(THIS_MODULE);

txx9wdt_start();
return nonseekable_open(inode, file);
}

static int txx9wdt_release(struct inode *inode, struct file *file)
{
if (expect_close)
txx9wdt_stop();
else {
pr_crit("Unexpected close, not stopping watchdog!\n");
txx9wdt_ping();
}
clear_bit(0, &txx9wdt_alive);
expect_close = 0;
return 0;
}

static ssize_t txx9wdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
static int txx9wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int new_timeout)
{
if (len) {
if (!nowayout) {
size_t i;

expect_close = 0;
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
expect_close = 1;
}
}
txx9wdt_ping();
}
return len;
timeout = new_timeout;
txx9wdt_stop(wdt_dev);
txx9wdt_start(wdt_dev);
return 0;
}

static long txx9wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
int new_timeout;
static const struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
.firmware_version = 0,
.identity = "Hardware Watchdog for TXx9",
};

switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_KEEPALIVE:
txx9wdt_ping();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_timeout, p))
return -EFAULT;
if (new_timeout < 1 || new_timeout > WD_MAX_TIMEOUT)
return -EINVAL;
timeout = new_timeout;
txx9wdt_stop();
txx9wdt_start();
/* Fall */
case WDIOC_GETTIMEOUT:
return put_user(timeout, p);
default:
return -ENOTTY;
}
}
static const struct watchdog_info txx9wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.identity = "Hardware Watchdog for TXx9",
};

static const struct file_operations txx9wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = txx9wdt_write,
.unlocked_ioctl = txx9wdt_ioctl,
.open = txx9wdt_open,
.release = txx9wdt_release,
static const struct watchdog_ops txx9wdt_ops = {
.owner = THIS_MODULE,
.start = txx9wdt_start,
.stop = txx9wdt_stop,
.ping = txx9wdt_ping,
.set_timeout = txx9wdt_set_timeout,
};

static struct miscdevice txx9wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &txx9wdt_fops,
static struct watchdog_device txx9wdt = {
.info = &txx9wdt_info,
.ops = &txx9wdt_ops,
};

static int __init txx9wdt_probe(struct platform_device *dev)
Expand All @@ -201,26 +122,24 @@ static int __init txx9wdt_probe(struct platform_device *dev)
}

res = platform_get_resource(dev, IORESOURCE_MEM, 0);
if (!res)
goto exit_busy;
if (!devm_request_mem_region(&dev->dev, res->start, resource_size(res),
"txx9wdt"))
goto exit_busy;
txx9wdt_reg = devm_ioremap(&dev->dev, res->start, resource_size(res));
if (!txx9wdt_reg)
goto exit_busy;

ret = misc_register(&txx9wdt_miscdev);
if (ret) {
txx9wdt_reg = devm_request_and_ioremap(&dev->dev, res);
if (!txx9wdt_reg) {
ret = -EBUSY;
goto exit;
}

txx9wdt.min_timeout = 1;
txx9wdt.max_timeout = WD_MAX_TIMEOUT;
watchdog_set_nowayout(&txx9wdt, nowayout);

ret = watchdog_register_device(&txx9wdt);
if (ret)
goto exit;

pr_info("Hardware Watchdog Timer: timeout=%d sec (max %ld) (nowayout= %d)\n",
timeout, WD_MAX_TIMEOUT, nowayout);

return 0;
exit_busy:
ret = -EBUSY;
exit:
if (txx9_imclk) {
clk_disable(txx9_imclk);
Expand All @@ -231,15 +150,15 @@ static int __init txx9wdt_probe(struct platform_device *dev)

static int __exit txx9wdt_remove(struct platform_device *dev)
{
misc_deregister(&txx9wdt_miscdev);
watchdog_unregister_device(&txx9wdt);
clk_disable(txx9_imclk);
clk_put(txx9_imclk);
return 0;
}

static void txx9wdt_shutdown(struct platform_device *dev)
{
txx9wdt_stop();
txx9wdt_stop(&txx9wdt);
}

static struct platform_driver txx9wdt_driver = {
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