On Wed, Oct 19, 2022 at 01:17:12PM +0200, 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.
>
> 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
> WAIT mode as expected. WAIT mode coresponds with Linux's
> "Suspend-To-Idle".
>
Does that have any impact on suspend/resume handling in the driver,
specifically with the "no_ping" variable used for fsl,imx7d-wdt ?
Thanks,
Guenter
> Signed-off-by: Andrej Picej <andrej.picej@xxxxxxxxx>
> ---
> drivers/watchdog/imx2_wdt.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
> index d0c5d47ddede..150ba83ce176 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 +68,7 @@ struct imx2_wdt_device {
> bool ext_reset;
> bool clk_is_on;
> bool no_ping;
> + bool sleep_wait;
> };
>
> static bool nowayout = WATCHDOG_NOWAYOUT;
> @@ -129,6 +131,9 @@ 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 +318,8 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
>
> wdev->ext_reset = of_property_read_bool(dev->of_node,
> "fsl,ext-reset-output");
> + wdev->sleep_wait = of_property_read_bool(dev->of_node,
> + "fsl,suspend-in-wait");
> /*
> * The i.MX7D doesn't support low power mode, so we need to ping the watchdog
> * during suspend.
> --
> 2.25.1
>
