Re: [PATCH] extcon: Add EXTCON_BATTERY type for battery presence

From: Chanwoo Choi
Date: Tue Jan 10 2023 - 08:40:33 EST


On 23. 1. 10. 11:36, andrew lien/WHQ/Wistron wrote:
> This information can be useful to device that support battery swap,
> for example allowing them to indicate that a battery is present or not,
> so provide a standard way to report it to userspace.
>
> Signed-off-by: andrew lien/WHQ/Wistron <andrew_lien@xxxxxxxxxxx>
> ---
> drivers/extcon/extcon.c | 5 +++++
> include/linux/extcon.h | 3 ++-
> 2 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c
> index b4df4372f097..6c47d23244c3 100644
> --- a/drivers/extcon/extcon.c
> +++ b/drivers/extcon/extcon.c
> @@ -184,6 +184,11 @@ static const struct __extcon_info {
> .id = EXTCON_MECHANICAL,
> .name = "MECHANICAL",
> },
> + [EXTCON_BATTERY] = {
> + .type = EXTCON_TYPE_MISC,
> + .id = EXTCON_BATTERY,
> + .name = "BATTERY",
> + },
>
> { /* sentinel */ }
> };
> diff --git a/include/linux/extcon.h b/include/linux/extcon.h
> index b0b4abb018ee..88210b481b6c 100644
> --- a/include/linux/extcon.h
> +++ b/include/linux/extcon.h
> @@ -81,8 +81,9 @@
> #define EXTCON_DOCK 60
> #define EXTCON_JIG 61
> #define EXTCON_MECHANICAL 62
> +#define EXTCON_BATTERY 63
>
> -#define EXTCON_NUM 63
> +#define EXTCON_NUM 64
>
> /*
> * Define the properties of supported external connectors.

Actually, battery is not external connector. The power_supply
subsystem already provided the POWER_SUPPLY_PROP_PRESENT
for the battery present. You have to develop the power_supply device driver
and then use power_supply_changed() to send the uevent to user-space.

--
Best Regards,
Samsung Electronics
Chanwoo Choi