diff mbox series

[v6,05/13] dt-bindings: backlight: Add MediaTek MT6370 backlight

Message ID 20220722102407.2205-6-peterwu.pub@gmail.com
State New
Headers show
Series [v6,01/13] dt-bindings: usb: Add MediaTek MT6370 TCPC | expand

Commit Message

ChiaEn Wu July 22, 2022, 10:23 a.m. UTC
From: ChiYuan Huang <cy_huang@richtek.com>

Add MT6370 backlight binding documentation.

Signed-off-by: ChiYuan Huang <cy_huang@richtek.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../leds/backlight/mediatek,mt6370-backlight.yaml  | 92 ++++++++++++++++++++++
 1 file changed, 92 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/backlight/mediatek,mt6370-backlight.yaml

Comments

ChiaEn Wu Aug. 1, 2022, 6:47 a.m. UTC | #1
On Fri, Jul 22, 2022 at 6:24 PM ChiaEn Wu <peterwu.pub@gmail.com> wrote:
>
> Signed-off-by: ChiYuan Huang <cy_huang@richtek.com>
> Reviewed-by: Rob Herring <robh@kernel.org>
> ---

[snip]

> +  compatible:
> +    const: mediatek,mt6370-backlight
> +
> +  default-brightness:
> +    minimum: 0
> +    maximum: 2048
> +
> +  max-brightness:
> +    minimum: 0
> +    maximum: 2048
> +

Hi Rob, Krzysztof,

First, I'm so sorry for our SoB writing wrong, I'll fix it in the next patch.
Because of this mail thread
(https://lore.kernel.org/all/20220728113109.7gf3b36mqjxlhcq3@maple.lan/),
I would like to discuss with you that I may change the following in
this DT document, I am not sure whether you agree or not.

1. Add some descriptions about MT6372, which supports 16384 steps (14
bits) and is different from MT6370/MT6371 (2048 steps, 11 bits)
2. Modify the format of 'compatible' as follows to distinguish between
MT6370/MT6371 or MT6372
------------------------------------------
properties:
  compatible:
    enum:
      - mediatek,mt6370-backlight
      - mediatek,mt6372-backlight
------------------------------------------

3. Remove the 'maximum' value of 'default-brightness' and
'max-brightness', and add "if-else" to determine the "maximum" value
as follows
------------------------------------------
  default-brightness:
    minimum: 0

  max-brightness:
    minimum: 0

...

if:
  properties:
    compatible:
      contains:
        const: mediatek,mt6372-backlight

then:
  properties:
    default-brightness:
      maximum: 16384

    max-brightness:
      maximum: 16384

else:
  properties:
    default-brightness:
      maximum: 2048

    max-brightness:
      maximum: 2048
------------------------------------------

4. Add a new boolean property to allow the user to determine whether
to enable the exponential mode of backlight brightness or not. Like
this,
------------------------------------------
  mediatek,bled-exponential-mode-enable:
    description: |
      Enable the exponential mode of backlight brightness. If this property
      is not enabled, the default is to use linear mode.
    type: boolean
------------------------------------------

I hope these changes I have added will meet your expectations.
And I'm not sure if I should remove 'Reviewed-By' first until it
passes your review.
Thanks.
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/leds/backlight/mediatek,mt6370-backlight.yaml b/Documentation/devicetree/bindings/leds/backlight/mediatek,mt6370-backlight.yaml
new file mode 100644
index 0000000..d674212
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/backlight/mediatek,mt6370-backlight.yaml
@@ -0,0 +1,92 @@ 
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/backlight/mediatek,mt6370-backlight.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MediaTek MT6370 Backlight
+
+maintainers:
+  - ChiaEn Wu <chiaen_wu@richtek.com>
+
+description: |
+  This module is part of the MT6370 MFD device.
+  The MT6370 Backlight WLED driver supports up to a 29V output voltage for
+  4 channels of 8 series WLEDs. Each channel supports up to 30mA of current
+  capability with 2048 current steps (11 bits) in exponential or linear
+  mapping curves.
+
+allOf:
+  - $ref: common.yaml#
+
+properties:
+  compatible:
+    const: mediatek,mt6370-backlight
+
+  default-brightness:
+    minimum: 0
+    maximum: 2048
+
+  max-brightness:
+    minimum: 0
+    maximum: 2048
+
+  enable-gpios:
+    description: External backlight 'enable' pin
+    maxItems: 1
+
+  mediatek,bled-pwm-enable:
+    description: |
+      Enable external PWM input for backlight dimming
+    type: boolean
+
+  mediatek,bled-pwm-hys-enable:
+    description: |
+      Enable the backlight input-hysteresis for PWM mode
+    type: boolean
+
+  mediatek,bled-pwm-hys-input-th-steps:
+    $ref: /schemas/types.yaml#/definitions/uint8
+    enum: [1, 4, 16, 64]
+    description: |
+      The selection of the upper and lower bounds threshold of backlight
+      PWM resolution. If we choose selection 64, the variation of PWM
+      resolution needs more than 64 steps.
+
+  mediatek,bled-ovp-shutdown:
+    description: |
+      Enable the backlight shutdown when OVP level triggered
+    type: boolean
+
+  mediatek,bled-ovp-microvolt:
+    enum: [17000000, 21000000, 25000000, 29000000]
+    description: |
+      Backlight OVP level selection.
+
+  mediatek,bled-ocp-shutdown:
+    description: |
+      Enable the backlight shutdown when OCP level triggerred.
+    type: boolean
+
+  mediatek,bled-ocp-microamp:
+    enum: [900000, 1200000, 1500000, 1800000]
+    description: |
+      Backlight OC level selection.
+
+  mediatek,bled-channel-use:
+    $ref: /schemas/types.yaml#/definitions/uint8
+    description: |
+      Backlight LED channel to be used.
+      Each bit mapping to:
+        - 0: CH4
+        - 1: CH3
+        - 2: CH2
+        - 3: CH1
+    minimum: 1
+    maximum: 15
+
+required:
+  - compatible
+  - mediatek,bled-channel-use
+
+additionalProperties: false