Re: [PATCH v1 1/6] dt-bindings: leds: Document TI LM3533 LED controller

[Svyatoslav Ryhel <clamor95@gmail.com>]

нд, 17 трав. 2026 р. о 16:45 Jonathan Cameron <jic23@kernel.org> пише:
>
> On Sun, 17 May 2026 10:43:01 +0300
> Svyatoslav Ryhel <clamor95@gmail.com> wrote:
>
> > Document the LM3533 - a complete power source for backlight, keypad and
> > indicator LEDs in smartphone handsets. The high-voltage inductive boost
> > converter provides the power for two series LED strings display backlight
> > and keypad functions.
> >
> > Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
> Hi Svyatoslav,
>
> I focused on the ALS part.. A few comments.
>
> > +# see ti,lm3533.yaml for an example
> > diff --git a/Documentation/devicetree/bindings/leds/ti,lm3533.yaml b/Documentation/devicetree/bindings/leds/ti,lm3533.yaml
> > new file mode 100644
> > index 000000000000..2e200f172400
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/leds/ti,lm3533.yaml
> > @@ -0,0 +1,190 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/leds/ti,lm3533.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: TI LM3533 Complete Lighting Power Solution
> > +
> > +description: >
> > +  The LM3533 is a complete power source for backlight, keypad, and indicator LEDs
> > +  in smartphone handsets. The high-voltage inductive boost converter provides the
> > +  power for two high voltage series LED strings for display backlight and four low
> > +  voltage control banks for individual LEDs. Additionally, LM3533 features an ALS
> > +  sensor support.
> Mention it is an interface for an external ALS.
>

Noted, thank you!

> > +  light-sensor:
> > +    type: object
> > +    additionalProperties: false
> > +
> > +    properties:
> > +      compatible:
> > +        const: ti,lm3533-als
> > +
> > +      interrupts:
> > +        maxItems: 1
> > +
> > +      ti,resistor-ohm:
> > +        $ref: /schemas/types.yaml#/definitions/uint32
> > +        description:
> > +          Internal configuration resister value when ALS is in Analog Sensor
> > +          mode and PWM mode is disabled.
>
> Good to note why this is a firmware thing rather than a userspace controlled
> thing. I looked it up, it's because expectation is the input is a current from
> the external analog ALS and these are used to convert it to a voltage with target
> range.
>

I will include your explanation.

> > +        minimum: 1575
> > +        maximum: 200000
> > +
> > +      ti,pwm-mode:
> > +        type: boolean
> > +        description:
> > +          Switch for mode in which ALS is running. If this property is set
> > +          then ALS is running in PWM mode, internal resistor value is set to
> > +          high-impedance (0) and ti,resistor-ohm property is ignored.
> I'd mention the ALS is an external device - so this is saying what interface thing
> thing connected is using.
>

Noted

> > +
> > +    required:
> > +      - compatible
> > +
> > +    anyOf:
> > +      - required:
> > +          - ti,resistor-ohm
> > +      - required:
> > +          - ti,pwm-mode
> > +
> > +patternProperties:
> > +  "^backlight@[01]$":
> > +    $ref: /schemas/leds/backlight/ti,lm3533-backlight.yaml#
> > +
> > +  "^led@[2-5]$":
> > +    $ref: /schemas/leds/ti,lm3533-leds.yaml#
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - light-sensor
> > +  - backlight@0
> > +  - backlight@1
>
> Similar for the led nodes.
>
> > +  - led@2
> > +  - led@3
> > +  - led@4
> > +  - led@5
>
> Curious - why are all the led nodes required?  What if some aren't wired to anything?
>

This is limitations of mfd devices. If it has subnodes, all subnodes
must be present to reflect mfd composition. Unused nodes should be
disabled.

However, I have asked Lee if he is fine if I will program dynamic mfd
composition based on the device tree. If he is fine, "required"
props/nodes list will be reduced.

> > +
> > +additionalProperties: false
>