On 10/25/22 00:25, Andrej Picej wrote:
Putting device into the "Suspend-To-Idle" mode causes watchdog to
trigger and reset the board after set watchdog timeout period elapses.
s/reset/resets/
Introduce new device-tree property "fsl,suspend-in-wait" which suspends
watchdog in WAIT mode. This is done by setting WDW bit in WCR
(Watchdog Control Register) Watchdog operation is restored after exiting
'.' after ')' missing ?
WAIT mode as expected. WAIT mode coresponds with Linux's
s/coresponds/corresponds/
"Suspend-To-Idle".
Signed-off-by: Andrej Picej <andrej.picej@xxxxxxxxx>
Reviewed-by: Fabio Estevam <festevam@xxxxxxxxx>
---
Changes in v2:
- validate the property with compatible string, as this functionality
is not supported by all devices.
---
drivers/watchdog/imx2_wdt.c | 37 +++++++++++++++++++++++++++++++++++++
1 file changed, 37 insertions(+)
diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
index d0c5d47ddede..dd9866c6f1e5 100644
--- a/drivers/watchdog/imx2_wdt.c
+++ b/drivers/watchdog/imx2_wdt.c
@@ -35,6 +35,7 @@
#define IMX2_WDT_WCR 0x00 /* Control Register */
#define IMX2_WDT_WCR_WT (0xFF << 8) /* -> Watchdog Timeout Field */
+#define IMX2_WDT_WCR_WDW BIT(7) /* -> Watchdog disable for WAIT */
#define IMX2_WDT_WCR_WDA BIT(5) /* -> External Reset WDOG_B */
#define IMX2_WDT_WCR_SRS BIT(4) /* -> Software Reset Signal */
#define IMX2_WDT_WCR_WRE BIT(3) /* -> WDOG Reset Enable */
@@ -67,6 +68,27 @@ struct imx2_wdt_device {
bool ext_reset;
bool clk_is_on;
bool no_ping;
+ bool sleep_wait;
+};
+
+static const char * const wdw_boards[] __initconst = {
+ "fsl,imx25-wdt",
+ "fsl,imx35-wdt",
+ "fsl,imx50-wdt",
+ "fsl,imx51-wdt",
+ "fsl,imx53-wdt",
+ "fsl,imx6q-wdt",
+ "fsl,imx6sl-wdt",
+ "fsl,imx6sll-wdt",
+ "fsl,imx6sx-wdt",
+ "fsl,imx6ul-wdt",
+ "fsl,imx7d-wdt",
+ "fsl,imx8mm-wdt",
+ "fsl,imx8mn-wdt",
+ "fsl,imx8mp-wdt",
+ "fsl,imx8mq-wdt",
+ "fsl,vf610-wdt",
+ NULL
};
static bool nowayout = WATCHDOG_NOWAYOUT;
@@ -129,6 +151,9 @@ static inline void imx2_wdt_setup(struct watchdog_device *wdog)
/* Suspend timer in low power mode, write once-only */
val |= IMX2_WDT_WCR_WDZST;
+ /* Suspend timer in low power WAIT mode, write once-only */
+ if (wdev->sleep_wait)
+ val |= IMX2_WDT_WCR_WDW;
/* Strip the old watchdog Time-Out value */
val &= ~IMX2_WDT_WCR_WT;
/* Generate internal chip-level reset if WDOG times out */
@@ -313,6 +338,18 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
wdev->ext_reset = of_property_read_bool(dev->of_node,
"fsl,ext-reset-output");
+
+ if (of_property_read_bool(dev->of_node, "fsl,suspend-in-wait"))
+ if (of_device_compatible_match(dev->of_node, wdw_boards))
+ wdev->sleep_wait = 1;
Since sleep_wait is bool:
wdev->sleep_wait = true;
+ else {
+ dev_warn(dev, "Warning: Suspending watchdog during " \
+ "WAIT mode is not supported for this device.\n");
Do not split strings. "Warning:" is redundant. Please handle the error first.
+ wdev->sleep_wait = 0;
Unnecessary; false by default. Also, this should fail and return -EINVAL.
Devicetree files should be correct, and warning messages tend to be ignored.
+ }
All branches of if/else need to wither use {} or no {}.
+ else
+ wdev->sleep_wait = 0;
+
Unnecessary.
I would suggest to replace the above code with something like
if (of_property_read_bool(dev->of_node, "fsl,suspend-in-wait")) {
if (!of_device_compatible_match(dev->of_node, wdw_boards)) {
dev_err(dev, "Suspending watchdog in WAIT mode is not supported for this device\n");
return -EINVAL;
}
wdev->sleep_wait = true;
}
/*
* The i.MX7D doesn't support low power mode, so we need to ping the watchdog
* during suspend.
I still wonder how that interacts with fsl,suspend-in-wait, but since we have a
property for that we can leave that for someone else to find out. Maybe add a
comment explaining that interaction with "fsl,suspend-in-wait" is unknown.
Thanks,
Guenter
