[PATCH] watchdog: rzg2l_wdt: Issue a reset before we put the PM clocks

From: Prabhakar
Date: Mon Nov 14 2022 - 13:09:56 EST


From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>

On RZ/Five SoC it was observed that setting timeout (to say 1 sec)
wouldn't reset the system. To fix this we make sure we issue a reset
before putting the PM clocks to make sure the registers have been cleared.

While at it re-used rzg2l_wdt_stop() in rzg2l_wdt_set_timeout() as
we were calling the same functions here.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
---
Note,
- This patch has been tested on RZ/G2L, RZ/V2M and RZ/Five.
- My initial investigation showed adding the delay after pm_runtime_get_sync()
also fixed this issue.
- Do I need add the fixes tag ? what should be the operation PUT->RESET/RESET->PUT?
in case we need the tag is:
Fixes: 4055ee81009e6 ("watchdog: rzg2l_wdt: Add set_timeout callback")
---
drivers/watchdog/rzg2l_wdt.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
index 00438ceed17a..d1271cc7750f 100644
--- a/drivers/watchdog/rzg2l_wdt.c
+++ b/drivers/watchdog/rzg2l_wdt.c
@@ -115,16 +115,14 @@ static int rzg2l_wdt_stop(struct watchdog_device *wdev)
{
struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);

- pm_runtime_put(wdev->parent);
reset_control_reset(priv->rstc);
+ pm_runtime_put(wdev->parent);

return 0;
}

static int rzg2l_wdt_set_timeout(struct watchdog_device *wdev, unsigned int timeout)
{
- struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
-
wdev->timeout = timeout;

/*
@@ -132,8 +130,7 @@ static int rzg2l_wdt_set_timeout(struct watchdog_device *wdev, unsigned int time
* register so that it is updated with new timeout values.
*/
if (watchdog_active(wdev)) {
- pm_runtime_put(wdev->parent);
- reset_control_reset(priv->rstc);
+ rzg2l_wdt_stop(wdev);
rzg2l_wdt_start(wdev);
}

--
2.25.1