Re: [PATCH v6 1/2] dt-bindings: leds: Add IS32FL3207 controller

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The `minimum: 149` constraint on `led-max-microamp` incorrectly rejects valid, lower-current configurations.
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--- Patch [1]: [PATCH v6 1/2] dt-bindings: leds: Add IS32FL3207 controller ---
commit 4fc20b49cd66c5af5de8db1465fd9c2b64f3c2ad
Author: Ahmad Byagowi <ahmadexp@gmail.com>

dt-bindings: leds: Add IS32FL3207 controller

The IS32FL3207 is an 18-channel constant-current LED controller with
per-output PWM and current scaling.

> diff --git a/Documentation/devicetree/bindings/leds/issi,is32fl3207.yaml b/Documentation/devicetree/bindings/leds/issi,is32fl3207.yaml
> new file mode 100644
> index 0000000000000..32eaf14ca7cf3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/issi,is32fl3207.yaml
> @@ -0,0 +1,285 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/issi,is32fl3207.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Lumissil IS32FL3207 18-channel LED controller

[ ... ]

> +patternProperties:
> +  "^led@[0-9a-f]+$":
> +    type: object
> +    $ref: common.yaml#
> +    unevaluatedProperties: false
> +
> +    properties:
> +      reg:
> +        minimum: 0
> +        maximum: 17
> +        description: |
> +          Zero-based LED output number. Values 0 through 17 correspond to
> +          OUT1 through OUT18.
> +
> +      led-max-microamp:
> +        minimum: 149
> +        maximum: 38250

[Severity: Medium]
Does this minimum constraint inadvertently reject valid lower-current limits
for single LEDs?

When a board designer uses a larger issi,riset-ohms (e.g., 100 kOhm) to
achieve a lower full-scale current, they may need to limit a specific LED to
a peak current well below 149 uA (e.g., 50 uA).

Since the hardware can represent much smaller currents with a large RISET,
could this prevent developers from enforcing valid safety limits below 149 uA,
forcing them to over-specify the limit?

> +        description: |
> +          Board-safe peak current for this output. The value must not exceed
> +          the full-scale current derived from issi,riset-ohms. The minimum is
> +          the smallest nonzero current representable at the maximum permitted
> +          full-scale current.

[ ... ]

> +  "^multi-led(@[0-9a-f]|-[0-9]+)?$":
> +    type: object
> +    $ref: leds-class-multicolor.yaml#
> +    unevaluatedProperties: false

[ ... ]

> +    patternProperties:
> +      "^led@[0-9a-f]+$":
> +        type: object
> +        $ref: common.yaml#
> +        unevaluatedProperties: false
> +
> +        properties:
> +          reg:
> +            minimum: 0
> +            maximum: 17
> +            description: |
> +              Zero-based LED output number. Values 0 through 17 correspond to
> +              OUT1 through OUT18.
> +
> +          led-max-microamp:
> +            minimum: 149
> +            maximum: 38250

[Severity: Medium]
Does this also incorrectly restrict nested LEDs inside multi-led groups from
having valid maximum current limits below 149 uA?

> +            description: |
> +              Board-safe peak current for this output. The value must not
> +              exceed the full-scale current derived from issi,riset-ohms. The
> +              minimum is the smallest nonzero current representable at the
> +              maximum permitted full-scale current.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/cover.1787247467.git.ahmadexp@gmail.com?part=1