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watchdog: Convert wm8350_wdt driver to watchdog core
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This patch converts wm8350_wdt driver to use watchdog core APIs.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
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 85f6df1 commit 2e51d90
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Showing 2 changed files with 38 additions and 179 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 @@ -74,6 +74,7 @@ config WM831X_WATCHDOG
config WM8350_WATCHDOG
tristate "WM8350 watchdog"
depends on MFD_WM8350
select WATCHDOG_CORE
help
Support for the watchdog in the WM8350 AudioPlus PMIC. When
the watchdog triggers the system will be reset.
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216 changes: 37 additions & 179 deletions drivers/watchdog/wm8350_wdt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -14,8 +14,6 @@
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#include <linux/uaccess.h>
Expand All @@ -27,36 +25,36 @@ MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

static unsigned long wm8350_wdt_users;
static struct miscdevice wm8350_wdt_miscdev;
static int wm8350_wdt_expect_close;
static DEFINE_MUTEX(wdt_mutex);

static struct {
int time; /* Seconds */
u16 val; /* To be set in WM8350_SYSTEM_CONTROL_2 */
unsigned int time; /* Seconds */
u16 val; /* To be set in WM8350_SYSTEM_CONTROL_2 */
} wm8350_wdt_cfgs[] = {
{ 1, 0x02 },
{ 2, 0x04 },
{ 4, 0x05 },
};

static struct wm8350 *get_wm8350(void)
static int wm8350_wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
return dev_get_drvdata(wm8350_wdt_miscdev.parent);
}

static int wm8350_wdt_set_timeout(struct wm8350 *wm8350, u16 value)
{
int ret;
struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
int ret, i;
u16 reg;

for (i = 0; i < ARRAY_SIZE(wm8350_wdt_cfgs); i++)
if (wm8350_wdt_cfgs[i].time == timeout)
break;
if (i == ARRAY_SIZE(wm8350_wdt_cfgs))
return -EINVAL;

mutex_lock(&wdt_mutex);
wm8350_reg_unlock(wm8350);

reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
reg &= ~WM8350_WDOG_TO_MASK;
reg |= value;
reg |= wm8350_wdt_cfgs[i].val;
ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);

wm8350_reg_lock(wm8350);
Expand All @@ -65,8 +63,9 @@ static int wm8350_wdt_set_timeout(struct wm8350 *wm8350, u16 value)
return ret;
}

static int wm8350_wdt_start(struct wm8350 *wm8350)
static int wm8350_wdt_start(struct watchdog_device *wdt_dev)
{
struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
int ret;
u16 reg;

Expand All @@ -84,8 +83,9 @@ static int wm8350_wdt_start(struct wm8350 *wm8350)
return ret;
}

static int wm8350_wdt_stop(struct wm8350 *wm8350)
static int wm8350_wdt_stop(struct watchdog_device *wdt_dev)
{
struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
int ret;
u16 reg;

Expand All @@ -102,8 +102,9 @@ static int wm8350_wdt_stop(struct wm8350 *wm8350)
return ret;
}

static int wm8350_wdt_kick(struct wm8350 *wm8350)
static int wm8350_wdt_ping(struct watchdog_device *wdt_dev)
{
struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
int ret;
u16 reg;

Expand All @@ -117,168 +118,25 @@ static int wm8350_wdt_kick(struct wm8350 *wm8350)
return ret;
}

static int wm8350_wdt_open(struct inode *inode, struct file *file)
{
struct wm8350 *wm8350 = get_wm8350();
int ret;

if (!wm8350)
return -ENODEV;

if (test_and_set_bit(0, &wm8350_wdt_users))
return -EBUSY;

ret = wm8350_wdt_start(wm8350);
if (ret != 0)
return ret;

return nonseekable_open(inode, file);
}

static int wm8350_wdt_release(struct inode *inode, struct file *file)
{
struct wm8350 *wm8350 = get_wm8350();

if (wm8350_wdt_expect_close)
wm8350_wdt_stop(wm8350);
else {
dev_warn(wm8350->dev, "Watchdog device closed uncleanly\n");
wm8350_wdt_kick(wm8350);
}

clear_bit(0, &wm8350_wdt_users);

return 0;
}

static ssize_t wm8350_wdt_write(struct file *file,
const char __user *data, size_t count,
loff_t *ppos)
{
struct wm8350 *wm8350 = get_wm8350();
size_t i;

if (count) {
wm8350_wdt_kick(wm8350);

if (!nowayout) {
/* In case it was set long ago */
wm8350_wdt_expect_close = 0;

/* scan to see whether or not we got the magic
character */
for (i = 0; i != count; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
wm8350_wdt_expect_close = 42;
}
}
}
return count;
}

static const struct watchdog_info ident = {
static const struct watchdog_info wm8350_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.identity = "WM8350 Watchdog",
};

static long wm8350_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct wm8350 *wm8350 = get_wm8350();
int ret = -ENOTTY, time, i;
void __user *argp = (void __user *)arg;
int __user *p = argp;
u16 reg;

switch (cmd) {
case WDIOC_GETSUPPORT:
ret = copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
break;

case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
ret = put_user(0, p);
break;

case WDIOC_SETOPTIONS:
{
int options;

if (get_user(options, p))
return -EFAULT;

ret = -EINVAL;

/* Setting both simultaneously means at least one must fail */
if (options == WDIOS_DISABLECARD)
ret = wm8350_wdt_stop(wm8350);

if (options == WDIOS_ENABLECARD)
ret = wm8350_wdt_start(wm8350);
break;
}

case WDIOC_KEEPALIVE:
ret = wm8350_wdt_kick(wm8350);
break;

case WDIOC_SETTIMEOUT:
ret = get_user(time, p);
if (ret)
break;

if (time == 0) {
if (nowayout)
ret = -EINVAL;
else
wm8350_wdt_stop(wm8350);
break;
}

for (i = 0; i < ARRAY_SIZE(wm8350_wdt_cfgs); i++)
if (wm8350_wdt_cfgs[i].time == time)
break;
if (i == ARRAY_SIZE(wm8350_wdt_cfgs))
ret = -EINVAL;
else
ret = wm8350_wdt_set_timeout(wm8350,
wm8350_wdt_cfgs[i].val);
break;

case WDIOC_GETTIMEOUT:
reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
reg &= WM8350_WDOG_TO_MASK;
for (i = 0; i < ARRAY_SIZE(wm8350_wdt_cfgs); i++)
if (wm8350_wdt_cfgs[i].val == reg)
break;
if (i == ARRAY_SIZE(wm8350_wdt_cfgs)) {
dev_warn(wm8350->dev,
"Unknown watchdog configuration: %x\n", reg);
ret = -EINVAL;
} else
ret = put_user(wm8350_wdt_cfgs[i].time, p);

}

return ret;
}

static const struct file_operations wm8350_wdt_fops = {
static const struct watchdog_ops wm8350_wdt_ops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = wm8350_wdt_write,
.unlocked_ioctl = wm8350_wdt_ioctl,
.open = wm8350_wdt_open,
.release = wm8350_wdt_release,
.start = wm8350_wdt_start,
.stop = wm8350_wdt_stop,
.ping = wm8350_wdt_ping,
.set_timeout = wm8350_wdt_set_timeout,
};

static struct miscdevice wm8350_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &wm8350_wdt_fops,
static struct watchdog_device wm8350_wdt = {
.info = &wm8350_wdt_info,
.ops = &wm8350_wdt_ops,
.timeout = 4,
.min_timeout = 1,
.max_timeout = 4,
};

static int __devinit wm8350_wdt_probe(struct platform_device *pdev)
Expand All @@ -290,18 +148,18 @@ static int __devinit wm8350_wdt_probe(struct platform_device *pdev)
return -ENODEV;
}

/* Default to 4s timeout */
wm8350_wdt_set_timeout(wm8350, 0x05);
watchdog_set_nowayout(&wm8350_wdt, nowayout);
watchdog_set_drvdata(&wm8350_wdt, wm8350);

wm8350_wdt_miscdev.parent = &pdev->dev;
/* Default to 4s timeout */
wm8350_wdt_set_timeout(&wm8350_wdt, 4);

return misc_register(&wm8350_wdt_miscdev);
return watchdog_register_device(&wm8350_wdt);
}

static int __devexit wm8350_wdt_remove(struct platform_device *pdev)
{
misc_deregister(&wm8350_wdt_miscdev);

watchdog_unregister_device(&wm8350_wdt);
return 0;
}

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