Re: [PATCH 3/4] rtc: add battery low voltage detection feature

[Stefan Kerkmann <s.kerkmann@pengutronix.de>]

On 3/11/26 21:02, Hugo Villeneuve wrote:
> From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> 
> Some RTCs have a battery low voltage detection function. Add new feature
> so that it can be enabled, disabled or queried at runtime.
> 
> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> ---
>   include/uapi/linux/rtc.h | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/include/uapi/linux/rtc.h b/include/uapi/linux/rtc.h
> index 97aca4503a6a3..596eec119bb3a 100644
> --- a/include/uapi/linux/rtc.h
> +++ b/include/uapi/linux/rtc.h
> @@ -134,18 +134,23 @@ struct rtc_param {
>   #define RTC_FEATURE_CORRECTION		5
>   #define RTC_FEATURE_BACKUP_SWITCH_MODE	6
>   #define RTC_FEATURE_ALARM_WAKEUP_ONLY	7
> -#define RTC_FEATURE_CNT			8
> +#define RTC_FEATURE_BATTERY_LOW_DETECT	8
> +#define RTC_FEATURE_CNT			9
>   
>   /* parameter list */
>   #define RTC_PARAM_FEATURES		0
>   #define RTC_PARAM_CORRECTION		1
>   #define RTC_PARAM_BACKUP_SWITCH_MODE	2
> +#define RTC_PARAM_BATTERY_LOW_DETECT	3
>   
>   #define RTC_BSM_DISABLED	0
>   #define RTC_BSM_DIRECT		1
>   #define RTC_BSM_LEVEL		2
>   #define RTC_BSM_STANDBY		3
>   
> +#define RTC_BATTERY_LOW_DETECT_DISABLED	0
> +#define RTC_BATTERY_LOW_DETECT_ENABLED	1
> +
>   #define RTC_MAX_FREQ	8192
>   
>   

I have opened a PR against util-linux to add support and tested the patchset 
with the extended hwclock binary.

See: https://github.com/util-linux/util-linux/pull/4513

Reviewed-by: Stefan Kerkmann <s.kerkmann@pengutronix.de>
Tested-by: Stefan Kerkmann <s.kerkmann@pengutronix.de>

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