On Wed, 29 Jun 2022 at 10:48, Stephan Gerhold
<stephan.gerhold@xxxxxxxxxxxxxxx> wrote:
>
> The PM8916 PMIC provides "power-off reason" (POFF_REASON) registers
> to allow detecting why the board was powered off or rebooted. This
> can be used to expose if a reset happened due to a watchdog timeout.
> The watchdog API also provides status bits for overtemperature and
> undervoltage which happen to be reported in the same PMIC register.
>
> Make this information available as part of the watchdog device
> so userspace can decide to handle the situation accordingly.
>
> Signed-off-by: Stephan Gerhold <stephan.gerhold@xxxxxxxxxxxxxxx>
Reviewed-by: Loic Poulain <loic.poulain@xxxxxxxxxx>
> ---
> Changes in v2: Improve error handling (suggested by Guenter)
> ---
> drivers/watchdog/pm8916_wdt.c | 26 +++++++++++++++++++++++++-
> 1 file changed, 25 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/watchdog/pm8916_wdt.c b/drivers/watchdog/pm8916_wdt.c
> index 670cd79f4cf9..49f1a5204526 100644
> --- a/drivers/watchdog/pm8916_wdt.c
> +++ b/drivers/watchdog/pm8916_wdt.c
> @@ -9,6 +9,12 @@
> #include <linux/regmap.h>
> #include <linux/watchdog.h>
>
> +#define PON_POFF_REASON1 0x0c
> +#define PON_POFF_REASON1_PMIC_WD BIT(2)
> +#define PON_POFF_REASON2 0x0d
> +#define PON_POFF_REASON2_UVLO BIT(5)
> +#define PON_POFF_REASON2_OTST3 BIT(6)
> +
> #define PON_INT_RT_STS 0x10
> #define PMIC_WD_BARK_STS_BIT BIT(6)
>
> @@ -110,12 +116,14 @@ static irqreturn_t pm8916_wdt_isr(int irq, void *arg)
> }
>
> static const struct watchdog_info pm8916_wdt_ident = {
> - .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
> + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE |
> + WDIOF_OVERHEAT | WDIOF_CARDRESET | WDIOF_POWERUNDER,
> .identity = "QCOM PM8916 PON WDT",
> };
>
> static const struct watchdog_info pm8916_wdt_pt_ident = {
> .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE |
> + WDIOF_OVERHEAT | WDIOF_CARDRESET | WDIOF_POWERUNDER |
> WDIOF_PRETIMEOUT,
> .identity = "QCOM PM8916 PON WDT",
> };
> @@ -135,6 +143,7 @@ static int pm8916_wdt_probe(struct platform_device *pdev)
> struct pm8916_wdt *wdt;
> struct device *parent;
> int err, irq;
> + u8 poff[2];
>
> wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
> if (!wdt)
> @@ -175,6 +184,21 @@ static int pm8916_wdt_probe(struct platform_device *pdev)
> wdt->wdev.info = &pm8916_wdt_ident;
> }
>
> + err = regmap_bulk_read(wdt->regmap, wdt->baseaddr + PON_POFF_REASON1,
> + &poff, ARRAY_SIZE(poff));
> + if (err) {
> + dev_err(dev, "failed to read POFF reason: %d\n", err);
> + return err;
> + }
> +
> + dev_dbg(dev, "POFF reason: %#x %#x\n", poff[0], poff[1]);
> + if (poff[0] & PON_POFF_REASON1_PMIC_WD)
> + wdt->wdev.bootstatus |= WDIOF_CARDRESET;
> + if (poff[1] & PON_POFF_REASON2_UVLO)
> + wdt->wdev.bootstatus |= WDIOF_POWERUNDER;
> + if (poff[1] & PON_POFF_REASON2_OTST3)
> + wdt->wdev.bootstatus |= WDIOF_OVERHEAT;
> +
> /* Configure watchdog to hard-reset mode */
> err = regmap_write(wdt->regmap,
> wdt->baseaddr + PON_PMIC_WD_RESET_S2_CTL,
> --
> 2.30.2
>
