From: ChiYuan Huang <[email protected]>
Add MT6370 backlight binding documentation.
Signed-off-by: ChiYuan Huang <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
---
.../leds/backlight/mediatek,mt6370-backlight.yaml | 92 ++++++++++++++++++++++
1 file changed, 92 insertions(+)
create mode 100644 Documentation/devicetree/bindings/leds/backlight/mediatek,mt6370-backlight.yaml
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 <[email protected]>
+
+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
--
2.7.4
On Fri, Jul 22, 2022 at 6:24 PM ChiaEn Wu <[email protected]> wrote:
>
> Signed-off-by: ChiYuan Huang <[email protected]>
> Reviewed-by: Rob Herring <[email protected]>
> ---
[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/[email protected]/),
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.
--
Best Regards,
ChiaEn Wu