[PATCH v3 1/2] watchdog: dw_wdt: add stop watchdog operation

From: Oleksij Rempel
Date: Mon Sep 25 2017 - 01:26:53 EST


From: Steffen Trumtrar <s.trumtrar@xxxxxxxxxxxxxx>

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.

Signed-off-by: Steffen Trumtrar <s.trumtrar@xxxxxxxxxxxxxx>
Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Cc: Wim Van Sebroeck <wim@xxxxxxxxx>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: linux-watchdog@xxxxxxxxxxxxxxx
---

changes v3:
- don't return error if rst is not present and set WDOG_HW_RUNNING bit
to notify watchdog core.

changes v2:
- test if dw_wdt->rst is NULL instead of IS_ERR

drivers/watchdog/dw_wdt.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
index 36be987ff9ef..6cc56b18ee52 100644
--- a/drivers/watchdog/dw_wdt.c
+++ b/drivers/watchdog/dw_wdt.c
@@ -135,6 +135,21 @@ static int dw_wdt_start(struct watchdog_device *wdd)
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,
unsigned long action, void *data)
{
@@ -173,6 +188,7 @@ static const struct watchdog_info dw_wdt_ident = {
static const struct watchdog_ops dw_wdt_ops = {
.owner = THIS_MODULE,
.start = dw_wdt_start,
+ .stop = dw_wdt_stop,
.ping = dw_wdt_ping,
.set_timeout = dw_wdt_set_timeout,
.get_timeleft = dw_wdt_get_timeleft,
--
2.11.0