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[WATCHDOG] at32ap700x_wdt.c - Add nowayout + MAGICCLOSE features

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Add nowayout + MAGICCLOSE features.

Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Cc: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Wim Van Sebroeck 2007-06-20 23:36:43 +02:00
parent 726c9f611a
commit 28401140a2
1 changed files with 53 additions and 11 deletions
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64
drivers/char/watchdog/at32ap700x_wdt.c
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@ -30,6 +30,11 @@ MODULE_PARM_DESC(timeout,
"Timeout value. Limited to be 1 or 2 seconds. (default="
__MODULE_STRING(TIMEOUT_DEFAULT) ")");
static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
/* Watchdog registers and write/read macro */
#define WDT_CTRL 0x00
#define WDT_CTRL_EN 0
@ -54,6 +59,7 @@ struct wdt_at32ap700x {
};
static struct wdt_at32ap700x *wdt;
static char expect_release;
/*
* Disable the watchdog.
@ -102,15 +108,19 @@ static int at32_wdt_open(struct inode *inode, struct file *file)
}
/*
* Close the watchdog device. If CONFIG_WATCHDOG_NOWAYOUT is _not_ defined then
* the watchdog is also disabled.
* Close the watchdog device.
*/
static int at32_wdt_close(struct inode *inode, struct file *file)
{
#ifndef CONFIG_WATCHDOG_NOWAYOUT
at32_wdt_stop();
#endif
if (expect_release == 42) {
at32_wdt_stop();
} else {
dev_dbg(wdt->miscdev.parent,
"Unexpected close, not stopping watchdog!\n");
at32_wdt_pat();
}
clear_bit(1, &wdt->users);
expect_release = 0;
return 0;
}
@ -136,7 +146,9 @@ static int at32_wdt_settimeout(int time)
static struct watchdog_info at32_wdt_info = {
.identity = "at32ap700x watchdog",
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.options = WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
};
/*
@ -191,10 +203,35 @@ static int at32_wdt_ioctl(struct inode *inode, struct file *file,
return ret;
}
static ssize_t at32_wdt_write(struct file *file, const char *data, size_t len,
loff_t *ppos)
static ssize_t at32_wdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
at32_wdt_pat();
/* See if we got the magic character 'V' and reload the timer */
if (len) {
if (!nowayout) {
size_t i;
/*
* note: just in case someone wrote the magic
* character five months ago...
*/
expect_release = 0;
/*
* scan to see whether or not we got the magic
* character
*/
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data+i))
return -EFAULT;
if (c == 'V')
expect_release = 42;
}
}
/* someone wrote to us, we should pat the watchdog */
at32_wdt_pat();
}
return len;
}
@ -255,8 +292,9 @@ static int __init at32_wdt_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, wdt);
wdt->miscdev.parent = &pdev->dev;
dev_info(&pdev->dev, "AT32AP700X WDT at 0x%p, timeout %d sec\n",
wdt->regs, wdt->timeout);
dev_info(&pdev->dev,
"AT32AP700X WDT at 0x%p, timeout %d sec (nowayout=%d)\n",
wdt->regs, wdt->timeout, nowayout);
return 0;
@ -271,6 +309,10 @@ err_free:
static int __exit at32_wdt_remove(struct platform_device *pdev)
{
if (wdt && platform_get_drvdata(pdev) == wdt) {
/* Stop the timer before we leave */
if (!nowayout)
at32_wdt_stop();
misc_deregister(&wdt->miscdev);
iounmap(wdt->regs);
kfree(wdt);