watchdog: dw_wdt: add stop watchdog operation

The only way of stopping the watchdog is by resetting it.
Add the watchdog op for stopping the device and reset if
a reset line is provided.

At same time WDOG_HW_RUNNING should be remove from dw_wdt_start.
As commented by Guenter Roeck:
dw_wdt sets WDOG_HW_RUNNING in its open function. Result is
that the kref_get() in watchdog_open() won't be executed. But then
kref_put() in close will be called since the watchdog now does stop.
This causes the imbalance.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Cc: Wim Van Sebroeck <wim@iguana.be>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-watchdog@vger.kernel.org
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
This commit is contained in:
Oleksij Rempel 2017-09-26 08:11:22 +02:00 committed by Wim Van Sebroeck
parent d4238aa458
commit 1bfe888938
1 changed files with 16 additions and 2 deletions

View File

@ -127,14 +127,27 @@ static int dw_wdt_start(struct watchdog_device *wdd)
dw_wdt_set_timeout(wdd, wdd->timeout); dw_wdt_set_timeout(wdd, wdd->timeout);
set_bit(WDOG_HW_RUNNING, &wdd->status);
writel(WDOG_CONTROL_REG_WDT_EN_MASK, writel(WDOG_CONTROL_REG_WDT_EN_MASK,
dw_wdt->regs + WDOG_CONTROL_REG_OFFSET); dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
return 0; return 0;
} }
static int dw_wdt_stop(struct watchdog_device *wdd)
{
struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
if (!dw_wdt->rst) {
set_bit(WDOG_HW_RUNNING, &wdd->status);
return 0;
}
reset_control_assert(dw_wdt->rst);
reset_control_deassert(dw_wdt->rst);
return 0;
}
static int dw_wdt_restart(struct watchdog_device *wdd, static int dw_wdt_restart(struct watchdog_device *wdd,
unsigned long action, void *data) unsigned long action, void *data)
{ {
@ -173,6 +186,7 @@ static const struct watchdog_info dw_wdt_ident = {
static const struct watchdog_ops dw_wdt_ops = { static const struct watchdog_ops dw_wdt_ops = {
.owner = THIS_MODULE, .owner = THIS_MODULE,
.start = dw_wdt_start, .start = dw_wdt_start,
.stop = dw_wdt_stop,
.ping = dw_wdt_ping, .ping = dw_wdt_ping,
.set_timeout = dw_wdt_set_timeout, .set_timeout = dw_wdt_set_timeout,
.get_timeleft = dw_wdt_get_timeleft, .get_timeleft = dw_wdt_get_timeleft,