Re: [PATCH v13 RESEND 3/4] docs: ABI: Document LP5812 LED sysfs interfaces

From: Randy Dunlap
Date: Sun Aug 17 2025 - 22:07:45 EST


Hi--

On 8/17/25 6:26 PM, Nam Tran wrote:
> The LP5812 is a 4x3 matrix RGB LED driver with autonomous animation
> engine control.
>
> This patch documents the basic sysfs interfaces provided by the driver,
> including LED activation, current control, fault status, and simple
> chip-level operations such as software reset and fault clearing.
>
> Signed-off-by: Nam Tran <trannamatk@xxxxxxxxx>
> ---
> .../ABI/testing/sysfs-bus-i2c-devices-lp5812 | 32 +++++++++++++++++++
> .../ABI/testing/sysfs-class-led-lp5812 | 32 +++++++++++++++++++
> MAINTAINERS | 2 ++
> 3 files changed, 66 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-bus-i2c-devices-lp5812
> create mode 100644 Documentation/ABI/testing/sysfs-class-led-lp5812
>


> diff --git a/Documentation/ABI/testing/sysfs-class-led-lp5812 b/Documentation/ABI/testing/sysfs-class-led-lp5812
> new file mode 100644
> index 000000000000..93eeecc60864
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-class-led-lp5812
> @@ -0,0 +1,32 @@
> +What: /sys/class/leds/led_<id>/activate
> +Date: July 2025
> +KernelVersion: 6.17
> +Contact: Nam Tran <trannamatk@xxxxxxxxx>
> +Description:
> + Activate or deactivate the specified LED channel. (WO)
> + 1 - Activate
> + 0 - Deactivate
> +
> +What: /sys/class/leds/led_<id>/led_current
> +Date: July 2025
> +KernelVersion: 6.17
> +Contact: Nam Tran <trannamatk@xxxxxxxxx>
> +Description:
> + DC current level. (WO)
> + Valid values: 0 - 255
> +
> +What: /sys/class/leds/led_<id>/max_current
> +Date: July 2025
> +KernelVersion: 6.17
> +Contact: Nam Tran <trannamatk@xxxxxxxxx>
> +Description:
> + Shows maximum DC current bit setting. (RO)
> + 0 (default) means the LED maximum current is set to 25.5 mA.
> + 1 means the LED maximum current is set to 51 mA.
> +
> +What: /sys/class/leds/led_<id>/lod_lsd
> +Date: July 2025
> +KernelVersion: 6.17
> +Contact: Nam Tran <trannamatk@xxxxxxxxx>
> +Description:
> + 0 0 mean no lod and lsd fault detected, 1 1 mean lod and lsd fault detected (RO)

At first the "0 0" and "1 1" confused me (thought it was a typo),
but I think what you are showing here is a sysfs file with 2 values, right?
That used to be discouraged (or even nacked), although I don't know the
current policy on that.

@Greg, any comment?


--
~Randy