Messages in this thread | | | Date | Tue, 25 Oct 2022 07:21:34 -0700 | From | Guenter Roeck <> | Subject | Re: [PATCH v2 1/3] watchdog: imx2_wdg: suspend watchdog in WAIT mode |
| |
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@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; }
> /* > * 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
| |