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watchdog: s3c2410: convert to use the watchdog framework
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Make this driver a user of the watchdog framework and remove now
centrally handled parts. Tested on a mini2440.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
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Wolfram Sang authored and Wim Van Sebroeck committed Nov 5, 2011
1 parent 74cd4c6 commit 25dc46e
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Showing 2 changed files with 38 additions and 139 deletions.
1 change: 1 addition & 0 deletions drivers/watchdog/Kconfig
View file
Original file line number Diff line number Diff line change
Expand Up @@ -170,6 +170,7 @@ config HAVE_S3C2410_WATCHDOG
config S3C2410_WATCHDOG
tristate "S3C2410 Watchdog"
depends on ARCH_S3C2410 || HAVE_S3C2410_WATCHDOG
select WATCHDOG_CORE
help
Watchdog timer block in the Samsung SoCs. This will reboot
the system when the timer expires with the watchdog enabled.
Expand Down
176 changes: 37 additions & 139 deletions drivers/watchdog/s3c2410_wdt.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -27,9 +27,8 @@
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/miscdevice.h>
#include <linux/miscdevice.h> /* for MODULE_ALIAS_MISCDEV */
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
Expand All @@ -38,6 +37,7 @@
#include <linux/io.h>
#include <linux/cpufreq.h>
#include <linux/slab.h>
#include <linux/err.h>

#include <mach/map.h>

Expand Down Expand Up @@ -74,14 +74,12 @@ MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, "
"0 to reboot (default 0)");
MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug (default 0)");

static unsigned long open_lock;
static struct device *wdt_dev; /* platform device attached to */
static struct resource *wdt_mem;
static struct resource *wdt_irq;
static struct clk *wdt_clock;
static void __iomem *wdt_base;
static unsigned int wdt_count;
static char expect_close;
static DEFINE_SPINLOCK(wdt_lock);

/* watchdog control routines */
Expand All @@ -93,11 +91,13 @@ static DEFINE_SPINLOCK(wdt_lock);

/* functions */

static void s3c2410wdt_keepalive(void)
static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
{
spin_lock(&wdt_lock);
writel(wdt_count, wdt_base + S3C2410_WTCNT);
spin_unlock(&wdt_lock);

return 0;
}

static void __s3c2410wdt_stop(void)
Expand All @@ -109,14 +109,16 @@ static void __s3c2410wdt_stop(void)
writel(wtcon, wdt_base + S3C2410_WTCON);
}

static void s3c2410wdt_stop(void)
static int s3c2410wdt_stop(struct watchdog_device *wdd)
{
spin_lock(&wdt_lock);
__s3c2410wdt_stop();
spin_unlock(&wdt_lock);

return 0;
}

static void s3c2410wdt_start(void)
static int s3c2410wdt_start(struct watchdog_device *wdd)
{
unsigned long wtcon;

Expand All @@ -142,14 +144,16 @@ static void s3c2410wdt_start(void)
writel(wdt_count, wdt_base + S3C2410_WTCNT);
writel(wtcon, wdt_base + S3C2410_WTCON);
spin_unlock(&wdt_lock);

return 0;
}

static inline int s3c2410wdt_is_running(void)
{
return readl(wdt_base + S3C2410_WTCON) & S3C2410_WTCON_ENABLE;
}

static int s3c2410wdt_set_heartbeat(int timeout)
static int s3c2410wdt_set_heartbeat(struct watchdog_device *wdd, unsigned timeout)
{
unsigned long freq = clk_get_rate(wdt_clock);
unsigned int count;
Expand Down Expand Up @@ -182,8 +186,6 @@ static int s3c2410wdt_set_heartbeat(int timeout)
}
}

tmr_margin = timeout;

DBG("%s: timeout=%d, divisor=%d, count=%d (%08x)\n",
__func__, timeout, divisor, count, count/divisor);

Expand All @@ -201,70 +203,6 @@ static int s3c2410wdt_set_heartbeat(int timeout)
return 0;
}

/*
* /dev/watchdog handling
*/

static int s3c2410wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &open_lock))
return -EBUSY;

if (nowayout)
__module_get(THIS_MODULE);

expect_close = 0;

/* start the timer */
s3c2410wdt_start();
return nonseekable_open(inode, file);
}

static int s3c2410wdt_release(struct inode *inode, struct file *file)
{
/*
* Shut off the timer.
* Lock it in if it's a module and we set nowayout
*/

if (expect_close == 42)
s3c2410wdt_stop();
else {
dev_err(wdt_dev, "Unexpected close, not stopping watchdog\n");
s3c2410wdt_keepalive();
}
expect_close = 0;
clear_bit(0, &open_lock);
return 0;
}

static ssize_t s3c2410wdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
/*
* Refresh the timer.
*/
if (len) {
if (!nowayout) {
size_t i;

/* In case it was set long ago */
expect_close = 0;

for (i = 0; i != len; i++) {
char c;

if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
expect_close = 42;
}
}
s3c2410wdt_keepalive();
}
return len;
}

#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)

static const struct watchdog_info s3c2410_wdt_ident = {
Expand All @@ -273,53 +211,17 @@ static const struct watchdog_info s3c2410_wdt_ident = {
.identity = "S3C2410 Watchdog",
};


static long s3c2410wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
int new_margin;

switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user(argp, &s3c2410_wdt_ident,
sizeof(s3c2410_wdt_ident)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_KEEPALIVE:
s3c2410wdt_keepalive();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_margin, p))
return -EFAULT;
if (s3c2410wdt_set_heartbeat(new_margin))
return -EINVAL;
s3c2410wdt_keepalive();
return put_user(tmr_margin, p);
case WDIOC_GETTIMEOUT:
return put_user(tmr_margin, p);
default:
return -ENOTTY;
}
}

/* kernel interface */

static const struct file_operations s3c2410wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = s3c2410wdt_write,
.unlocked_ioctl = s3c2410wdt_ioctl,
.open = s3c2410wdt_open,
.release = s3c2410wdt_release,
static struct watchdog_ops s3c2410wdt_ops = {
.owner = THIS_MODULE,
.start = s3c2410wdt_start,
.stop = s3c2410wdt_stop,
.ping = s3c2410wdt_keepalive,
.set_timeout = s3c2410wdt_set_heartbeat,
};

static struct miscdevice s3c2410wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &s3c2410wdt_fops,
static struct watchdog_device s3c2410_wdd = {
.info = &s3c2410_wdt_ident,
.ops = &s3c2410wdt_ops,
};

/* interrupt handler code */
Expand All @@ -328,7 +230,7 @@ static irqreturn_t s3c2410wdt_irq(int irqno, void *param)
{
dev_info(wdt_dev, "watchdog timer expired (irq)\n");

s3c2410wdt_keepalive();
s3c2410wdt_keepalive(&s3c2410_wdd);
return IRQ_HANDLED;
}

Expand All @@ -349,14 +251,14 @@ static int s3c2410wdt_cpufreq_transition(struct notifier_block *nb,
* the watchdog is running.
*/

s3c2410wdt_keepalive();
s3c2410wdt_keepalive(&s3c2410_wdd);
} else if (val == CPUFREQ_POSTCHANGE) {
s3c2410wdt_stop();
s3c2410wdt_stop(&s3c2410_wdd);

ret = s3c2410wdt_set_heartbeat(tmr_margin);
ret = s3c2410wdt_set_heartbeat(&s3c2410_wdd, s3c2410_wdd.timeout);

if (ret >= 0)
s3c2410wdt_start();
s3c2410wdt_start(&s3c2410_wdd);
else
goto err;
}
Expand All @@ -365,7 +267,8 @@ static int s3c2410wdt_cpufreq_transition(struct notifier_block *nb,
return 0;

err:
dev_err(wdt_dev, "cannot set new value for timeout %d\n", tmr_margin);
dev_err(wdt_dev, "cannot set new value for timeout %d\n",
s3c2410_wdd.timeout);
return ret;
}

Expand Down Expand Up @@ -396,10 +299,6 @@ static inline void s3c2410wdt_cpufreq_deregister(void)
}
#endif



/* device interface */

static int __devinit s3c2410wdt_probe(struct platform_device *pdev)
{
struct device *dev;
Expand Down Expand Up @@ -466,8 +365,8 @@ static int __devinit s3c2410wdt_probe(struct platform_device *pdev)
/* see if we can actually set the requested timer margin, and if
* not, try the default value */

if (s3c2410wdt_set_heartbeat(tmr_margin)) {
started = s3c2410wdt_set_heartbeat(
if (s3c2410wdt_set_heartbeat(&s3c2410_wdd, tmr_margin)) {
started = s3c2410wdt_set_heartbeat(&s3c2410_wdd,
CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME);

if (started == 0)
Expand All @@ -479,22 +378,21 @@ static int __devinit s3c2410wdt_probe(struct platform_device *pdev)
"cannot start\n");
}

ret = misc_register(&s3c2410wdt_miscdev);
ret = watchdog_register_device(&s3c2410_wdd);
if (ret) {
dev_err(dev, "cannot register miscdev on minor=%d (%d)\n",
WATCHDOG_MINOR, ret);
dev_err(dev, "cannot register watchdog (%d)\n", ret);
goto err_cpufreq;
}

if (tmr_atboot && started == 0) {
dev_info(dev, "starting watchdog timer\n");
s3c2410wdt_start();
s3c2410wdt_start(&s3c2410_wdd);
} else if (!tmr_atboot) {
/* if we're not enabling the watchdog, then ensure it is
* disabled if it has been left running from the bootloader
* or other source */

s3c2410wdt_stop();
s3c2410wdt_stop(&s3c2410_wdd);
}

/* print out a statement of readiness */
Expand Down Expand Up @@ -530,7 +428,7 @@ static int __devinit s3c2410wdt_probe(struct platform_device *pdev)

static int __devexit s3c2410wdt_remove(struct platform_device *dev)
{
misc_deregister(&s3c2410wdt_miscdev);
watchdog_unregister_device(&s3c2410_wdd);

s3c2410wdt_cpufreq_deregister();

Expand All @@ -550,7 +448,7 @@ static int __devexit s3c2410wdt_remove(struct platform_device *dev)

static void s3c2410wdt_shutdown(struct platform_device *dev)
{
s3c2410wdt_stop();
s3c2410wdt_stop(&s3c2410_wdd);
}

#ifdef CONFIG_PM
Expand All @@ -565,7 +463,7 @@ static int s3c2410wdt_suspend(struct platform_device *dev, pm_message_t state)
wtdat_save = readl(wdt_base + S3C2410_WTDAT);

/* Note that WTCNT doesn't need to be saved. */
s3c2410wdt_stop();
s3c2410wdt_stop(&s3c2410_wdd);

return 0;
}
Expand Down

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