Re: [PATCHv2] rtc: pcf2127: handle boot-enabled watchdog feature

[Guenter Roeck <linux@roeck-us.net>]

On 10/3/19 6:33 AM, Martin Hundebøll wrote:
> Linux should handle when the pcf2127 watchdog feature is enabled by the
> bootloader. This is done by checking the watchdog timer value during
> init, and set the WDOG_HW_RUNNING flag if the value differs from zero.
> 
> Signed-off-by: Martin Hundebøll <martin@geanix.com>

Acked-by: Guenter Roeck <linux@roeck-us.net>

> ---
> 
> Change since v1:
>   * remove setting of WDOG_HW_RUNNING in pcf2127_wdt_start()
> 
>   drivers/rtc/rtc-pcf2127.c | 12 +++++++++++-
>   1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
> index cb3472f..4229915 100644
> --- a/drivers/rtc/rtc-pcf2127.c
> +++ b/drivers/rtc/rtc-pcf2127.c
> @@ -420,6 +420,7 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
>   			const char *name, bool has_nvmem)
>   {
>   	struct pcf2127 *pcf2127;
> +	u32 wdd_timeout;
>   	int ret = 0;
>   
>   	dev_dbg(dev, "%s\n", __func__);
> @@ -462,7 +463,6 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
>   	/*
>   	 * Watchdog timer enabled and reset pin /RST activated when timed out.
>   	 * Select 1Hz clock source for watchdog timer.
> -	 * Timer is not started until WD_VAL is loaded with a valid value.
>   	 * Note: Countdown timer disabled and not available.
>   	 */
>   	ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_WD_CTL,
> @@ -478,6 +478,16 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
>   		return ret;
>   	}
>   
> +	/* Test if watchdog timer is started by bootloader */
> +	ret = regmap_read(pcf2127->regmap, PCF2127_REG_WD_VAL, &wdd_timeout);
> +	if (ret) {
> +		dev_err(dev, "%s: watchdog value (wd_wal) failed\n", __func__);
> +		return ret;
> +	}
> +
> +	if (wdd_timeout)
> +		set_bit(WDOG_HW_RUNNING, &pcf2127->wdd.status);
> +
>   	ret = devm_watchdog_register_device(dev, &pcf2127->wdd);
>   	if (ret)
>   		return ret;
>