linux-kernel - Re: [PATCH v4 3/5] docs: ABI: Document LP5812 LED sysfs interfaces

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Message-ID: <707dc912-12d2-4b50-b934-0c1d1f5efe6b@kernel.org>
Date: Sun, 6 Apr 2025 14:08:14 +0200
From: Krzysztof Kozlowski <krzk@...nel.org>
To: Nam Tran <trannamatk@...il.com>, pavel@...nel.org, lee@...nel.org,
 krzk+dt@...nel.org, robh@...nel.org, conor+dt@...nel.org, corbet@....net
Cc: devicetree@...r.kernel.org, linux-leds@...r.kernel.org,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 3/5] docs: ABI: Document LP5812 LED sysfs interfaces

On 05/04/2025 20:32, Nam Tran wrote:
> The LP5812 is a 4 × 3 matrix RGB LED driver
> with autonomous animation engine control.
> 
> The driver provides interfaces to configure
> LED modes manual/autonomous, set PWM/DC values,
> and manage autonomous animation engines.
> 
> Signed-off-by: Nam Tran <trannamatk@...il.com>
> ---
>  .../ABI/testing/sysfs-bus-i2c-devices-lp5812  | 150 ++++++++++++++++++
>  MAINTAINERS                                   |   1 +
>  2 files changed, 151 insertions(+)
>  create mode 100644 Documentation/ABI/testing/sysfs-bus-i2c-devices-lp5812
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-i2c-devices-lp5812 b/Documentation/ABI/testing/sysfs-bus-i2c-devices-lp5812
> new file mode 100644
> index 000000000000..e745f0f936c5
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-i2c-devices-lp5812
> @@ -0,0 +1,150 @@
> +What:		/sys/bus/i2c/devices/.../lp5812_chip_setup/device_enable

I do not see reason for such ABI. If you want to disable, just unbind it.

> +Date:		April 2025

Not possible...

> +KernelVersion:	6.14

You cannot go to the past. 6.14 was released. This will be v6.16 or later.

> +Contact:	Nam Tran <trannamatk@...il.com>
> +Description:
> +        Enables or disables the LP5812 device. (RW)
> +        0 - Disable
> +        1 - Enable
> +
> +What:		/sys/bus/i2c/devices/.../lp5812_chip_setup/dev_config

Looks like wrong path here and everywhere else. I think other name it as
led driver, e.g.
Documentation/ABI/testing/sysfs-class-led-driver-lm3533

> +Date:		April 2025
> +KernelVersion:	6.14
> +Contact:	Nam Tran <trannamatk@...il.com>
> +Description:
> +        Configures drive mode and scan order. (RW)
> +        Some valid values: tcmscan:4:0:1:2:3 (default), tcmscan:3:0:1:2, mixscan:2:2:0:3, mixscan:3:0:1:2:3
> +
> +What:		/sys/bus/i2c/devices/.../lp5812_chip_setup/device_command
> +Date:		April 2025
> +KernelVersion:	6.14
> +Contact:	Nam Tran <trannamatk@...il.com>
> +Description:
> +        Issues device-level commands. (WO)
> +        Valid values: "update", "start", "stop", "pause", "continue"
> +
> +What:		/sys/bus/i2c/devices/.../lp5812_chip_setup/device_reset
> +Date:		April 2025
> +KernelVersion:	6.14
> +Contact:	Nam Tran <trannamatk@...il.com>
> +Description:
> +        Triggers a software reset of the device. (WO)
> +        1 - resets device
> +        0 - does not reset device

I do not see kernel exposing it for other devices, drop.


> +
> +What:		/sys/bus/i2c/devices/.../lp5812_chip_setup/fault_clear
> +Date:		April 2025
> +KernelVersion:	6.14
> +Contact:	Nam Tran <trannamatk@...il.com>
> +Description:
> +        Clears fault status. (WO)
> +        1 - clears fault status
> +        0 - does not clear fault status
> +
> +What:		/sys/bus/i2c/devices/.../lp5812_chip_setup/tsd_config_status
> +Date:		April 2025
> +KernelVersion:	6.14
> +Contact:	Nam Tran <trannamatk@...il.com>
> +Description:
> +        Report the current thermal shutdown config status. (RO)
> +
> +What:		/sys/bus/i2c/devices/.../led_<id>/enable
> +Date:		April 2025
> +KernelVersion:	6.14
> +Contact:	Nam Tran <trannamatk@...il.com>
> +Description:
> +        Enables or disables the specified LED channel. (RW)
> +        1 - Enable
> +        0 - Disable

No, you already have standard ABI for this. I also already told you that
you cannot duplicate existing kernel interface.

> +
> +What:		/sys/bus/i2c/devices/.../led_<id>/mode
> +Date:		April 2025
> +KernelVersion:	6.14
> +Contact:	Nam Tran <trannamatk@...il.com>
> +Description:
> +        Selects LED operation mode. (RW)
> +        Valid values: "manual", "autonomous"
> +
> +What:		/sys/bus/i2c/devices/.../led_<id>/manual_dc
> +Date:		April 2025
> +KernelVersion:	6.14
> +Contact:	Nam Tran <trannamatk@...il.com>
> +Description:
> +        DC current level in manual mode. (RW)
> +        Valid values: 0 - 255

NAK, duplicating existing brightness.

> +
> +What:		/sys/bus/i2c/devices/.../led_<id>/manual_pwm
> +Date:		April 2025
> +KernelVersion:	6.14
> +Contact:	Nam Tran <trannamatk@...il.com>
> +Description:
> +        PWM duty cycle in manual mode. (RW)
> +        Valid values: 0 - 255
> +> +What:		/sys/bus/i2c/devices/.../led_<id>/autonomous_dc
> +Date:		April 2025
> +KernelVersion:	6.14
> +Contact:	Nam Tran <trannamatk@...il.com>
> +Description:
> +        DC current level used in autonomous mode. (RW)
> +        Valid values: 0 - 255
> +
> +What:		/sys/bus/i2c/devices/.../led_<id>/autonomous_dc
> +Date:		April 2025
> +KernelVersion:	6.14
> +Contact:	Nam Tran <trannamatk@...il.com>
> +Description:
> +        DC current level used in autonomous mode. (RW)
> +        Valid values: 0 - 255

Also duplicating brigthness.

> +
> +What:		/sys/bus/i2c/devices/.../led_<id>/pwm_dimming_scale
> +Date:		April 2025
> +KernelVersion:	6.14
> +Contact:	Nam Tran <trannamatk@...il.com>
> +Description:
> +        PWM dimming scale type. (RW)
> +        Valid values: "linear", "exponential"
> +
> +What:		/sys/bus/i2c/devices/.../led_<id>/pwm_phase_align
> +Date:		April 2025
> +KernelVersion:	6.14
> +Contact:	Nam Tran <trannamatk@...il.com>
> +Description:
> +        Configures PWM phase alignment. (RW)
> +        Valid values: "forward", "middle", "backward"
> +
> +What:		/sys/bus/i2c/devices/.../led_<id>/autonomous_animation
> +Date:		April 2025
> +KernelVersion:	6.14
> +Contact:	Nam Tran <trannamatk@...il.com>
> +Description:
> +        Controls AEU configuration and playback. (RW)
> +        Format: (aeu number):(start pause time):(stop pause time):(playback time)
> +        with aeu number 1, 2, 3; playback time 0 - 15
> +
> +What:		/sys/bus/i2c/devices/.../led_<id>/aep_status
> +Date:		April 2025
> +KernelVersion:	6.14
> +Contact:	Nam Tran <trannamatk@...il.com>
> +Description:
> +        Shows current animation pattern status, value from 0 to 7. (RO)
> +
> +What:		/sys/bus/i2c/devices/.../led_<id>/auto_pwm_val
> +Date:		April 2025
> +KernelVersion:	6.14
> +Contact:	Nam Tran <trannamatk@...il.com>
> +Description:
> +        Shows the pwm value in autonomous mode when pause the animation, value from 0 to 255. (RO)
> +
> +What:		/sys/bus/i2c/devices/.../led_<id>/lod_lsd
> +Date:		April 2025
> +KernelVersion:	6.14
> +Contact:	Nam Tran <trannamatk@...il.com>
> +Description:
> +        0 0 mean no lod and lsd fault detected, 1 1 mean lod and lsd fault detected (RO)
> +
> +
> +
> +
> +
> +

Why so many blank lines? Drop


Best regards,
Krzysztof