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.
Known problems:
- `make dt_binding_check` shows the following warnings:
Documentation/devicetree/bindings/mfd/netronix,ntxec.example.dts:49.17-42:
Warning (pwms_property): /example-0/backlight:pwms: cell 2 is not a
phandle reference
Documentation/devicetree/bindings/mfd/netronix,ntxec.example.dts:49.17-42:
Warning (pwms_property): /example-0/backlight:pwms: Could not get
phandle node for (cell 2)
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@xxxxxxx>
---
.../bindings/mfd/netronix,ntxec.yaml | 13 ++++++++
.../bindings/pwm/netronix,ntxec-pwm.yaml | 33 +++++++++++++++++++
2 files changed, 46 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..6562c41c5a9a9 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:
+ $ref: ../pwm/netronix,ntxec-pwm.yaml
+
required:
- compatible
- reg
@@ -53,5 +56,15 @@ examples:
interrupts = <11 IRQ_TYPE_EDGE_FALLING>;
interrupt-controller;
#interrupt-cells = <1>;
+
+ ec_pwm: pwm {
+ compatible = "netronix,ntxec-pwm";
+ #pwm-cells = <1>;
+ };
};
};
+
+ backlight {
+ compatible = "pwm-backlight";
+ pwms = <&ec_pwm 0 50000>;
+ };
diff --git a/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml b/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml
new file mode 100644
index 0000000000000..1dc1b1aba081c
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml
@@ -0,0 +1,33 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$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 <j.neuschaefer@xxxxxxx>
+
+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: 1
+
+required:
+ - compatible
+ - "#pwm-cells"
--
2.27.0
