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watchdog: shwdt: Conversion to watchdog core.
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Fairly straightforward conversion to utilize watchdog core support.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
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Paul Mundt committed May 10, 2012
1 parent 4096812 commit 1950f49
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Showing 2 changed files with 45 additions and 154 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 @@ -1138,6 +1138,7 @@ config ZVM_WATCHDOG
config SH_WDT
tristate "SuperH Watchdog"
depends on SUPERH && (CPU_SH3 || CPU_SH4)
select WATCHDOG_CORE
help
This driver adds watchdog support for the integrated watchdog in the
SuperH processors. If you have one of these processors and wish
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198 changes: 44 additions & 154 deletions drivers/watchdog/shwdt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -27,12 +27,10 @@
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/ioport.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <asm/watchdog.h>

#define DRV_NAME "sh-wdt"
Expand Down Expand Up @@ -67,8 +65,6 @@
static int clock_division_ratio = WTCSR_CKS_4096;
#define next_ping_period(cks) (jiffies + msecs_to_jiffies(cks - 4))

static const struct watchdog_info sh_wdt_info;
static struct platform_device *sh_wdt_dev;
static DEFINE_SPINLOCK(shwdt_lock);

#define WATCHDOG_HEARTBEAT 30 /* 30 sec default heartbeat */
Expand All @@ -86,8 +82,9 @@ struct sh_wdt {
char expect_close;
};

static void sh_wdt_start(struct sh_wdt *wdt)
static int sh_wdt_start(struct watchdog_device *wdt_dev)
{
struct sh_wdt *wdt = watchdog_get_drvdata(wdt_dev);
unsigned long flags;
u8 csr;

Expand Down Expand Up @@ -121,10 +118,13 @@ static void sh_wdt_start(struct sh_wdt *wdt)
sh_wdt_write_rstcsr(csr);
#endif
spin_unlock_irqrestore(&shwdt_lock, flags);

return 0;
}

static void sh_wdt_stop(struct sh_wdt *wdt)
static int sh_wdt_stop(struct watchdog_device *wdt_dev)
{
struct sh_wdt *wdt = watchdog_get_drvdata(wdt_dev);
unsigned long flags;
u8 csr;

Expand All @@ -137,18 +137,22 @@ static void sh_wdt_stop(struct sh_wdt *wdt)
sh_wdt_write_csr(csr);

spin_unlock_irqrestore(&shwdt_lock, flags);

return 0;
}

static inline void sh_wdt_keepalive(struct sh_wdt *wdt)
static int sh_wdt_keepalive(struct watchdog_device *wdt_dev)
{
unsigned long flags;

spin_lock_irqsave(&shwdt_lock, flags);
next_heartbeat = jiffies + (heartbeat * HZ);
spin_unlock_irqrestore(&shwdt_lock, flags);

return 0;
}

static int sh_wdt_set_heartbeat(int t)
static int sh_wdt_set_heartbeat(struct watchdog_device *wdt_dev, unsigned t)
{
unsigned long flags;

Expand All @@ -157,7 +161,9 @@ static int sh_wdt_set_heartbeat(int t)

spin_lock_irqsave(&shwdt_lock, flags);
heartbeat = t;
wdt_dev->timeout = t;
spin_unlock_irqrestore(&shwdt_lock, flags);

return 0;
}

Expand All @@ -183,134 +189,24 @@ static void sh_wdt_ping(unsigned long data)
spin_unlock_irqrestore(&shwdt_lock, flags);
}

static int sh_wdt_open(struct inode *inode, struct file *file)
{
struct sh_wdt *wdt = platform_get_drvdata(sh_wdt_dev);

if (test_and_set_bit(0, &wdt->enabled))
return -EBUSY;
if (nowayout)
__module_get(THIS_MODULE);

file->private_data = wdt;

sh_wdt_start(wdt);

return nonseekable_open(inode, file);
}

static int sh_wdt_close(struct inode *inode, struct file *file)
{
struct sh_wdt *wdt = file->private_data;

if (wdt->expect_close == 42) {
sh_wdt_stop(wdt);
} else {
dev_crit(wdt->dev, "Unexpected close, not "
"stopping watchdog!\n");
sh_wdt_keepalive(wdt);
}

clear_bit(0, &wdt->enabled);
wdt->expect_close = 0;

return 0;
}

static ssize_t sh_wdt_write(struct file *file, const char *buf,
size_t count, loff_t *ppos)
{
struct sh_wdt *wdt = file->private_data;

if (count) {
if (!nowayout) {
size_t i;

wdt->expect_close = 0;

for (i = 0; i != count; i++) {
char c;
if (get_user(c, buf + i))
return -EFAULT;
if (c == 'V')
wdt->expect_close = 42;
}
}
sh_wdt_keepalive(wdt);
}

return count;
}

static long sh_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct sh_wdt *wdt = file->private_data;
int new_heartbeat;
int options, retval = -EINVAL;

switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user((struct watchdog_info *)arg,
&sh_wdt_info, sizeof(sh_wdt_info)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, (int *)arg);
case WDIOC_SETOPTIONS:
if (get_user(options, (int *)arg))
return -EFAULT;

if (options & WDIOS_DISABLECARD) {
sh_wdt_stop(wdt);
retval = 0;
}

if (options & WDIOS_ENABLECARD) {
sh_wdt_start(wdt);
retval = 0;
}

return retval;
case WDIOC_KEEPALIVE:
sh_wdt_keepalive(wdt);
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_heartbeat, (int *)arg))
return -EFAULT;

if (sh_wdt_set_heartbeat(new_heartbeat))
return -EINVAL;

sh_wdt_keepalive(wdt);
/* Fall */
case WDIOC_GETTIMEOUT:
return put_user(heartbeat, (int *)arg);
default:
return -ENOTTY;
}
return 0;
}

static const struct file_operations sh_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = sh_wdt_write,
.unlocked_ioctl = sh_wdt_ioctl,
.open = sh_wdt_open,
.release = sh_wdt_close,
};

static const struct watchdog_info sh_wdt_info = {
.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = "SH WDT",
};

static struct miscdevice sh_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &sh_wdt_fops,
static const struct watchdog_ops sh_wdt_ops = {
.owner = THIS_MODULE,
.start = sh_wdt_start,
.stop = sh_wdt_stop,
.ping = sh_wdt_keepalive,
.set_timeout = sh_wdt_set_heartbeat,
};

static struct watchdog_device sh_wdt_dev = {
.info = &sh_wdt_info,
.ops = &sh_wdt_ops,
};

static int __devinit sh_wdt_probe(struct platform_device *pdev)
Expand Down Expand Up @@ -348,13 +244,25 @@ static int __devinit sh_wdt_probe(struct platform_device *pdev)
goto out_err;
}

sh_wdt_miscdev.parent = wdt->dev;
rc = sh_wdt_set_heartbeat(&sh_wdt_dev, heartbeat);
if (unlikely(rc)) {
/* Default timeout if invalid */
sh_wdt_set_heartbeat(&sh_wdt_dev, WATCHDOG_HEARTBEAT);

dev_warn(&pdev->dev,
"heartbeat value must be 1<=x<=3600, using %d\n",
sh_wdt_dev.timeout);
}

dev_info(&pdev->dev, "configured with heartbeat=%d sec (nowayout=%d)\n",
sh_wdt_dev.timeout, nowayout);

rc = misc_register(&sh_wdt_miscdev);
watchdog_set_nowayout(&sh_wdt_dev, nowayout);
watchdog_set_drvdata(&sh_wdt_dev, wdt);

rc = watchdog_register_device(&sh_wdt_dev);
if (unlikely(rc)) {
dev_err(&pdev->dev,
"Can't register miscdev on minor=%d (err=%d)\n",
sh_wdt_miscdev.minor, rc);
dev_err(&pdev->dev, "Can't register watchdog (err=%d)\n", rc);
goto out_unmap;
}

Expand All @@ -364,7 +272,6 @@ static int __devinit sh_wdt_probe(struct platform_device *pdev)
wdt->timer.expires = next_ping_period(clock_division_ratio);

platform_set_drvdata(pdev, wdt);
sh_wdt_dev = pdev;

dev_info(&pdev->dev, "initialized.\n");

Expand All @@ -387,9 +294,7 @@ static int __devexit sh_wdt_remove(struct platform_device *pdev)

platform_set_drvdata(pdev, NULL);

misc_deregister(&sh_wdt_miscdev);

sh_wdt_dev = NULL;
watchdog_unregister_device(&sh_wdt_dev);

devm_release_mem_region(&pdev->dev, res->start, resource_size(res));
devm_iounmap(&pdev->dev, wdt->base);
Expand All @@ -400,9 +305,7 @@ static int __devexit sh_wdt_remove(struct platform_device *pdev)

static void sh_wdt_shutdown(struct platform_device *pdev)
{
struct sh_wdt *wdt = platform_get_drvdata(pdev);

sh_wdt_stop(wdt);
sh_wdt_stop(&sh_wdt_dev);
}

static struct platform_driver sh_wdt_driver = {
Expand All @@ -418,8 +321,6 @@ static struct platform_driver sh_wdt_driver = {

static int __init sh_wdt_init(void)
{
int rc;

if (unlikely(clock_division_ratio < 0x5 ||
clock_division_ratio > 0x7)) {
clock_division_ratio = WTCSR_CKS_4096;
Expand All @@ -428,17 +329,6 @@ static int __init sh_wdt_init(void)
clock_division_ratio);
}

rc = sh_wdt_set_heartbeat(heartbeat);
if (unlikely(rc)) {
heartbeat = WATCHDOG_HEARTBEAT;

pr_info("heartbeat value must be 1<=x<=3600, using %d\n",
heartbeat);
}

pr_info("configured with heartbeat=%d sec (nowayout=%d)\n",
heartbeat, nowayout);

return platform_driver_register(&sh_wdt_driver);
}

Expand Down

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