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Subject: [PATCH v2 04/10] dt-bindings: pwm: Add bindings for PWM function in Netronix EC
Date:   Sat,  5 Sep 2020 15:32:24 +0200
Message-Id: <20200905133230.1014581-5-j.neuschaefer@gmx.net>
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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 Neusch=C3=A4fer <j.neuschaefer@gmx.net>
=2D--

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 requir=
es 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 =3D "netronix,ntxec";
  		...

  		ec_pwm: pwm {
  			compatible =3D "netronix,ntxec-pwm";
  			#pwm-cells =3D <1>;
  		};
  	};

  	...

  	backlight {
  		compatible =3D "pwm-backlight";
  		pwms =3D <&ec_pwm 0 50000>;
  	};
=2D--
 .../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-p=
wm.yaml

diff --git a/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml b/D=
ocumentation/devicetree/bindings/mfd/netronix,ntxec.yaml
index 596df460f98eb..73c873dda3e70 100644
=2D-- 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:
+    $ref: ../pwm/netronix,ntxec-pwm.yaml
+
 required:
   - compatible
   - reg
@@ -53,5 +56,21 @@ examples:
                     interrupts =3D <11 IRQ_TYPE_EDGE_FALLING>;
                     interrupt-controller;
                     #interrupt-cells =3D <1>;
+
+                    ec_pwm: pwm {
+                            compatible =3D "netronix,ntxec-pwm";
+                            #pwm-cells =3D <2>;
+                    };
             };
     };
+
+    backlight {
+            compatible =3D "pwm-backlight";
+            pwms =3D <&ec_pwm 0 50000>;
+            power-supply =3D <&backlight_regulator>;
+    };
+
+    backlight_regulator: regulator-dummy {
+            compatible =3D "regulator-fixed";
+            regulator-name =3D "backlight";
+    };
diff --git a/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml=
 b/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml
new file mode 100644
index 0000000000000..0c9d2801b8de1
=2D-- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml
@@ -0,0 +1,33 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$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 Neusch=C3=A4fer <j.neuschaefer@gmx.net>
+
+description: |
+  See also Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
+
+  The Netronix EC contains PWM functionality, which is usually used to dr=
ive
+  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"
=2D-
2.28.0