Messages in this thread | | | Date | Wed, 26 Oct 2022 08:59:15 +0200 | Subject | Re: [PATCH v2 1/3] watchdog: imx2_wdg: suspend watchdog in WAIT mode | From | Andrej Picej <> |
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On 25. 10. 22 16:21, Guenter Roeck wrote: > 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/ > Will fix this in v3, thank you.
>> "Suspend-To-Idle". >> >> Signed-off-by: Andrej Picej <andrej.picej@norik.com> >> Reviewed-by: Fabio Estevam <festevam@gmail.com> >> --- >> 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; > }
OK, this look cleaner, will use this, thanks.
> >> /* >> * 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. I'm assuming that i.MX7D doesn't enter any of low-power modes including WAIT mode. If this is the case the watchdog wouldn't get disabled.
Anyway, I will add a short comment regarding the unknown behaviour of this property with i.MX7D device.
Best regards, Andrej
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