The Netronix embedded controller as found in Kobo Aura and Tolino Shine supports one PWM channel, which is used to control the frontlight brightness on these devices.
Signed-off-by: Jonathan Neuschäfer <[email protected]> --- v2: - Add plaintext binding to patch description, for comparison - Fix pwm-cells property (should be 2, not 1) - Add dummy regulator to example, because the pwm-backlight binding requires a power supply For reference, here is the binding in text form: PWM functionality in Netronix Embedded Controller Required properties: - compatible: should be "netronix,ntxec-pwm" - #pwm-cells: should be 2. Available PWM channels: - 0: The PWM channel controlled by registers 0xa1-0xa7 Example: embedded-controller@43 { compatible = "netronix,ntxec"; ... ec_pwm: pwm { compatible = "netronix,ntxec-pwm"; #pwm-cells = <1>; }; }; ... backlight { compatible = "pwm-backlight"; pwms = <&ec_pwm 0 50000>; }; --- .../bindings/mfd/netronix,ntxec.yaml | 19 +++++++++++ .../bindings/pwm/netronix,ntxec-pwm.yaml | 33 +++++++++++++++++++ 2 files changed, 52 insertions(+) create mode 100644 Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml diff --git a/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml b/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml index 596df460f98eb..73c873dda3e70 100644 --- a/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml +++ b/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml @@ -31,6 +31,9 @@ properties: description: The EC can signal interrupts via a GPIO line + pwm: + $ref: ../pwm/netronix,ntxec-pwm.yaml + required: - compatible - reg @@ -53,5 +56,21 @@ examples: interrupts = <11 IRQ_TYPE_EDGE_FALLING>; interrupt-controller; #interrupt-cells = <1>; + + ec_pwm: pwm { + compatible = "netronix,ntxec-pwm"; + #pwm-cells = <2>; + }; }; }; + + backlight { + compatible = "pwm-backlight"; + pwms = <&ec_pwm 0 50000>; + power-supply = <&backlight_regulator>; + }; + + backlight_regulator: regulator-dummy { + compatible = "regulator-fixed"; + regulator-name = "backlight"; + }; diff --git a/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml b/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml new file mode 100644 index 0000000000000..0c9d2801b8de1 --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml @@ -0,0 +1,33 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/pwm/netronix,ntxec-pwm.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: PWM functionality in Netronix embedded controller + +maintainers: + - Jonathan Neuschäfer <[email protected]> + +description: | + See also Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml + + The Netronix EC contains PWM functionality, which is usually used to drive + the backlight LED. + + The following PWM channels are supported: + - 0: The PWM channel controlled by registers 0xa1-0xa7 + +allOf: + - $ref: pwm.yaml# + +properties: + compatible: + const: netronix,ntxec-pwm + + "#pwm-cells": + const: 2 + +required: + - compatible + - "#pwm-cells" -- 2.28.0
