Re: [PATCH v3 13/14] rtc: pcf2127: add flag for watchdog register value read support

From: Bruno Thomsen
Date: Sat Jan 07 2023 - 13:47:55 EST


Den tor. 15. dec. 2022 kl. 16.19 skrev Hugo Villeneuve <hugo@xxxxxxxxxxx>:
>
> From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
>
> The watchdog value register cannot be read on the PCF2131 after being
> set.
>
> Add a new flag to identify which variant has read access to this
> register, and use this flag to selectively test if watchdog timer was
> started by bootloader.
>
> Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>

Reviewed-by: Bruno Thomsen <bruno.thomsen@xxxxxxxxx>

> ---
> drivers/rtc/rtc-pcf2127.c | 20 ++++++++++++++------
> 1 file changed, 14 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
> index 3fd2fee4978b..1d2b5c9e6757 100644
> --- a/drivers/rtc/rtc-pcf2127.c
> +++ b/drivers/rtc/rtc-pcf2127.c
> @@ -214,6 +214,7 @@ struct pcf21xx_config {
> int max_register;
> unsigned int has_nvmem:1;
> unsigned int has_bit_wd_ctl_cd0:1;
> + unsigned int wd_val_reg_readable:1; /* If watchdog value register can be read. */
> unsigned int has_int_a_b:1; /* PCF2131 supports two interrupt outputs. */
> unsigned int has_reset_reg:1; /* If variant has a reset register. */
> u8 regs_td_base; /* Time/data base registers. */
> @@ -511,7 +512,6 @@ static const struct watchdog_ops pcf2127_watchdog_ops = {
>
> static int pcf2127_watchdog_init(struct device *dev, struct pcf2127 *pcf2127)
> {
> - u32 wdd_timeout;
> int ret;
>
> if (!IS_ENABLED(CONFIG_WATCHDOG) ||
> @@ -539,12 +539,17 @@ static int pcf2127_watchdog_init(struct device *dev, struct pcf2127 *pcf2127)
> watchdog_set_drvdata(&pcf2127->wdd, pcf2127);
>
> /* Test if watchdog timer is started by bootloader */
> - ret = regmap_read(pcf2127->regmap, pcf2127->cfg->reg_wd_val, &wdd_timeout);
> - if (ret)
> - return ret;
> + if (pcf2127->cfg->wd_val_reg_readable) {
> + u32 wdd_timeout;
> +
> + ret = regmap_read(pcf2127->regmap, pcf2127->cfg->reg_wd_val,
> + &wdd_timeout);
> + if (ret)
> + return ret;
>
> - if (wdd_timeout)
> - set_bit(WDOG_HW_RUNNING, &pcf2127->wdd.status);
> + if (wdd_timeout)
> + set_bit(WDOG_HW_RUNNING, &pcf2127->wdd.status);
> + }
>
> return devm_watchdog_register_device(dev, &pcf2127->wdd);
> }
> @@ -953,6 +958,7 @@ static struct pcf21xx_config pcf21xx_cfg[] = {
> .max_register = 0x1d,
> .has_nvmem = 1,
> .has_bit_wd_ctl_cd0 = 1,
> + .wd_val_reg_readable = 1,
> .has_int_a_b = 0,
> .has_reset_reg = 0,
> .regs_td_base = PCF2127_REG_TIME_DATE_BASE,
> @@ -980,6 +986,7 @@ static struct pcf21xx_config pcf21xx_cfg[] = {
> .max_register = 0x19,
> .has_nvmem = 0,
> .has_bit_wd_ctl_cd0 = 0,
> + .wd_val_reg_readable = 1,
> .has_int_a_b = 0,
> .has_reset_reg = 0,
> .regs_td_base = PCF2127_REG_TIME_DATE_BASE,
> @@ -1007,6 +1014,7 @@ static struct pcf21xx_config pcf21xx_cfg[] = {
> .max_register = 0x36,
> .has_nvmem = 0,
> .has_bit_wd_ctl_cd0 = 0,
> + .wd_val_reg_readable = 0,
> .has_int_a_b = 1,
> .has_reset_reg = 1,
> .regs_td_base = PCF2131_REG_TIME_DATE_BASE,
> --
> 2.30.2
>