[PATCH] dt-bindings: backlight: Convert common backlight bindings to DT schema
Sam Ravnborg
sam at ravnborg.org
Fri Jun 19 21:53:41 UTC 2020
Hi Rob.
Good to have these converted. A few comments in the following. One
comment is for the backlight people as you copied the original text.
Sam
On Thu, Jun 18, 2020 at 04:44:13PM -0600, Rob Herring wrote:
> Convert the common GPIO, LED, and PWM backlight bindings to DT schema
> format.
>
> Given there's only 2 common properties and the descriptions are slightly
> different, I opted to not create a common backlight schema.
>
> Cc: Lee Jones <lee.jones at linaro.org>
> Cc: Daniel Thompson <daniel.thompson at linaro.org>
> Cc: Jingoo Han <jingoohan1 at gmail.com>
> Signed-off-by: Rob Herring <robh at kernel.org>
> ---
> .../leds/backlight/gpio-backlight.txt | 16 ---
> .../leds/backlight/gpio-backlight.yaml | 41 ++++++++
> .../bindings/leds/backlight/led-backlight.txt | 28 ------
> .../leds/backlight/led-backlight.yaml | 58 +++++++++++
> .../bindings/leds/backlight/pwm-backlight.txt | 61 ------------
> .../leds/backlight/pwm-backlight.yaml | 98 +++++++++++++++++++
> 6 files changed, 197 insertions(+), 105 deletions(-)
> delete mode 100644 Documentation/devicetree/bindings/leds/backlight/gpio-backlight.txt
> create mode 100644 Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml
> delete mode 100644 Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
> create mode 100644 Documentation/devicetree/bindings/leds/backlight/led-backlight.yaml
> delete mode 100644 Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt
> create mode 100644 Documentation/devicetree/bindings/leds/backlight/pwm-backlight.yaml
>
> diff --git a/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.txt b/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.txt
> deleted file mode 100644
> index 321be6640533..000000000000
> --- a/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.txt
> +++ /dev/null
> @@ -1,16 +0,0 @@
> -gpio-backlight bindings
> -
> -Required properties:
> - - compatible: "gpio-backlight"
> - - gpios: describes the gpio that is used for enabling/disabling the backlight.
> - refer to bindings/gpio/gpio.txt for more details.
> -
> -Optional properties:
> - - default-on: enable the backlight at boot.
> -
> -Example:
> - backlight {
> - compatible = "gpio-backlight";
> - gpios = <&gpio3 4 GPIO_ACTIVE_HIGH>;
> - default-on;
> - };
> diff --git a/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml b/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml
> new file mode 100644
> index 000000000000..75cc569b9c55
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml
> @@ -0,0 +1,41 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/backlight/gpio-backlight.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: gpio-backlight bindings
> +
> +maintainers:
> + - Lee Jones <lee.jones at linaro.org>
> + - Daniel Thompson <daniel.thompson at linaro.org>
> + - Jingoo Han <jingoohan1 at gmail.com>
> +
> +properties:
> + compatible:
> + const: gpio-backlight
> +
> + gpios:
> + description: The gpio that is used for enabling/disabling the backlight.
> + maxItems: 1
> +
> + default-on:
> + description: enable the backlight at boot.
> + type: boolean
> +
> +required:
> + - compatible
> + - gpios
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/gpio/gpio.h>
> + backlight {
> + compatible = "gpio-backlight";
> + gpios = <&gpio3 4 GPIO_ACTIVE_HIGH>;
> + default-on;
> + };
> +
> +...
> diff --git a/Documentation/devicetree/bindings/leds/backlight/led-backlight.txt b/Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
> deleted file mode 100644
> index 4c7dfbe7f67a..000000000000
> --- a/Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
> +++ /dev/null
> @@ -1,28 +0,0 @@
> -led-backlight bindings
> -
> -This binding is used to describe a basic backlight device made of LEDs.
> -It can also be used to describe a backlight device controlled by the output of
> -a LED driver.
> -
> -Required properties:
> - - compatible: "led-backlight"
> - - leds: a list of LEDs
> -
> -Optional properties:
> - - brightness-levels: Array of distinct brightness levels. The levels must be
> - in the range accepted by the underlying LED devices.
> - This is used to translate a backlight brightness level
> - into a LED brightness level. If it is not provided, the
> - identity mapping is used.
> -
> - - default-brightness-level: The default brightness level.
> -
> -Example:
> -
> - backlight {
> - compatible = "led-backlight";
> -
> - leds = <&led1>, <&led2>;
> - brightness-levels = <0 4 8 16 32 64 128 255>;
> - default-brightness-level = <6>;
> - };
> diff --git a/Documentation/devicetree/bindings/leds/backlight/led-backlight.yaml b/Documentation/devicetree/bindings/leds/backlight/led-backlight.yaml
> new file mode 100644
> index 000000000000..ae50945d2798
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/backlight/led-backlight.yaml
> @@ -0,0 +1,58 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/backlight/led-backlight.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: led-backlight bindings
> +
> +maintainers:
> + - Lee Jones <lee.jones at linaro.org>
> + - Daniel Thompson <daniel.thompson at linaro.org>
> + - Jingoo Han <jingoohan1 at gmail.com>
> +
> +description:
> + This binding is used to describe a basic backlight device made of LEDs. It
> + can also be used to describe a backlight device controlled by the output of
> + a LED driver.
> +
> +properties:
> + compatible:
> + const: led-backlight
> +
> + leds:
> + description: A list of LED nodes
> + $ref: /schemas/types.yaml#/definitions/phandle-array
> +
> + brightness-levels:
> + description: Array of distinct brightness levels. The levels must be
> + in the range accepted by the underlying LED devices. This is used
> + to translate a backlight brightness level into a LED brightness level.
> + If it is not provided, the identity mapping is used.
> + $ref: /schemas/types.yaml#/definitions/uint32-array
bike-shedding. To me it is a tad easier to read when multi-line
descriptions are on a separate line.
So "description:" on one line, and the text on following lines.
example-schema.yaml does both - so both are official acceptable.
> +
> + default-brightness-level:
> + description: The default brightness level (index into the array defined
> + by the "brightness-levels" property).
This description does not match my understading.
The description says "index into", but in reality this is a value that
matches somewhere in the range specified by brightness-levels.
So it is not an index.
Maybe I just read it wrong and the description is fine. But when I read
index the when it says 6 I would look for brightness-levels[6] equals
128 in the example below.
And this is not how it is coded.
> + $ref: /schemas/types.yaml#/definitions/uint32
> +
> +dependencies:
> + default-brightness-level: [brightness-levels]
So if we have efault-brightness-level then we must have
brightness-levels.
Sounds right.
> +
> +required:
> + - compatible
> + - leds
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + backlight {
> + compatible = "led-backlight";
> +
> + leds = <&led1>, <&led2>;
> + brightness-levels = <0 4 8 16 32 64 128 255>;
> + default-brightness-level = <6>;
> + };
> +
> +...
> diff --git a/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt b/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt
> deleted file mode 100644
> index 64fa2fbd98c9..000000000000
> --- a/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt
> +++ /dev/null
> @@ -1,61 +0,0 @@
> -pwm-backlight bindings
> -
> -Required properties:
> - - compatible: "pwm-backlight"
> - - pwms: OF device-tree PWM specification (see PWM binding[0])
> - - power-supply: regulator for supply voltage
> -
> -Optional properties:
> - - pwm-names: a list of names for the PWM devices specified in the
> - "pwms" property (see PWM binding[0])
> - - enable-gpios: contains a single GPIO specifier for the GPIO which enables
> - and disables the backlight (see GPIO binding[1])
> - - post-pwm-on-delay-ms: Delay in ms between setting an initial (non-zero) PWM
> - and enabling the backlight using GPIO.
> - - pwm-off-delay-ms: Delay in ms between disabling the backlight using GPIO
> - and setting PWM value to 0.
> - - brightness-levels: Array of distinct brightness levels. Typically these
> - are in the range from 0 to 255, but any range starting at
> - 0 will do. The actual brightness level (PWM duty cycle)
> - will be interpolated from these values. 0 means a 0% duty
> - cycle (darkest/off), while the last value in the array
> - represents a 100% duty cycle (brightest).
> - - default-brightness-level: The default brightness level (index into the
> - array defined by the "brightness-levels" property).
> - - num-interpolated-steps: Number of interpolated steps between each value
> - of brightness-levels table. This way a high
> - resolution pwm duty cycle can be used without
> - having to list out every possible value in the
> - brightness-level array.
> -
> -[0]: Documentation/devicetree/bindings/pwm/pwm.txt
> -[1]: Documentation/devicetree/bindings/gpio/gpio.txt
> -
> -Example:
> -
> - backlight {
> - compatible = "pwm-backlight";
> - pwms = <&pwm 0 5000000>;
> -
> - brightness-levels = <0 4 8 16 32 64 128 255>;
> - default-brightness-level = <6>;
> -
> - power-supply = <&vdd_bl_reg>;
> - enable-gpios = <&gpio 58 0>;
> - post-pwm-on-delay-ms = <10>;
> - pwm-off-delay-ms = <10>;
> - };
> -
> -Example using num-interpolation-steps:
> -
> - backlight {
> - compatible = "pwm-backlight";
> - pwms = <&pwm 0 5000000>;
> -
> - brightness-levels = <0 2048 4096 8192 16384 65535>;
> - num-interpolated-steps = <2048>;
> - default-brightness-level = <4096>;
> -
> - power-supply = <&vdd_bl_reg>;
> - enable-gpios = <&gpio 58 0>;
> - };
> diff --git a/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.yaml b/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.yaml
> new file mode 100644
> index 000000000000..7e1f109a38a4
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.yaml
> @@ -0,0 +1,98 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/backlight/pwm-backlight.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: pwm-backlight bindings
> +
> +maintainers:
> + - Lee Jones <lee.jones at linaro.org>
> + - Daniel Thompson <daniel.thompson at linaro.org>
> + - Jingoo Han <jingoohan1 at gmail.com>
> +
> +properties:
> + compatible:
> + const: pwm-backlight
> +
> + pwms:
> + maxItems: 1
> +
> + pwm-names: true
> +
> + power-supply:
> + description: regulator for supply voltage
> +
> + enable-gpios:
> + description: Contains a single GPIO specifier for the GPIO which enables
> + and disables the backlight
> + maxItems: 1
> +
> + post-pwm-on-delay-ms:
> + description: Delay in ms between setting an initial (non-zero) PWM and
> + enabling the backlight using GPIO.
> +
> + pwm-off-delay-ms:
> + description: Delay in ms between disabling the backlight using GPIO
> + and setting PWM value to 0.
> +
> + brightness-levels:
> + description: Array of distinct brightness levels. Typically these are
> + in the range from 0 to 255, but any range starting at 0 will do. The
> + actual brightness level (PWM duty cycle) will be interpolated from
> + these values. 0 means a 0% duty cycle (darkest/off), while the last
> + value in the array represents a 100% duty cycle (brightest).
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> +
> + default-brightness-level:
> + description: The default brightness level (index into the array defined
> + by the "brightness-levels" property).
> + $ref: /schemas/types.yaml#/definitions/uint32
Same comment as before...
> +
> + num-interpolated-steps:
> + description: Number of interpolated steps between each value of brightness-levels
> + table. This way a high resolution pwm duty cycle can be used without
> + having to list out every possible value in the brightness-level array.
> + $ref: /schemas/types.yaml#/definitions/uint32
> +
> +dependencies:
> + default-brightness-level: [brightness-levels]
> + num-interpolated-steps: [brightness-levels]
> +
> +required:
> + - compatible
> + - pwms
> + - power-supply
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + backlight {
> + compatible = "pwm-backlight";
> + pwms = <&pwm 0 5000000>;
> +
> + brightness-levels = <0 4 8 16 32 64 128 255>;
> + default-brightness-level = <6>;
> +
> + power-supply = <&vdd_bl_reg>;
> + enable-gpios = <&gpio 58 0>;
> + post-pwm-on-delay-ms = <10>;
> + pwm-off-delay-ms = <10>;
> + };
> +
> + - |
> + // Example using num-interpolation-steps:
> + backlight {
> + compatible = "pwm-backlight";
> + pwms = <&pwm 0 5000000>;
> +
> + brightness-levels = <0 2048 4096 8192 16384 65535>;
> + num-interpolated-steps = <2048>;
> + default-brightness-level = <4096>;
> +
> + power-supply = <&vdd_bl_reg>;
> + enable-gpios = <&gpio 58 0>;
> + };
> +
> +...
> --
> 2.25.1
>
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