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To:     linux-kernel@vger.kernel.org
Cc:     Lee Jones <lee.jones@linaro.org>, Rob Herring <robh+dt@kernel.org>,
        =?UTF-8?q?Jonathan=20Neusch=C3=A4fer?= <j.neuschaefer@gmx.net>,
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        Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        Fabio Estevam <festevam@gmail.com>,
        NXP Linux Team <linux-imx@nxp.com>,
        Sam Ravnborg <sam@ravnborg.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        Heiko Stuebner <heiko.stuebner@theobroma-systems.com>,
        Stephan Gerhold <stephan@gerhold.net>,
        Lubomir Rintel <lkundrak@v3.sk>,
        Mark Brown <broonie@kernel.org>, allen <allen.chen@ite.com.tw>,
        Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        devicetree@vger.kernel.org, linux-pwm@vger.kernel.org,
        linux-rtc@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Heiko Stuebner <heiko@sntech.de>,
        Josua Mayer <josua.mayer@jm0.eu>,
        Andreas Kemnade <andreas@kemnade.info>
Subject: [RFC PATCH 05/10] dt-bindings: pwm: Add bindings for PWM function in Netronix EC
Date:   Sun, 21 Jun 2020 00:42:16 +0200
Message-Id: <20200620224222.1312520-4-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.

Known problems:
- `make dt_binding_check` shows the following warnings:
  Documentation/devicetree/bindings/mfd/netronix,ntxec.example.dts:49.17-4=
2:
  Warning (pwms_property): /example-0/backlight:pwms: cell 2 is not a
  phandle reference
  Documentation/devicetree/bindings/mfd/netronix,ntxec.example.dts:49.17-4=
2:
  Warning (pwms_property): /example-0/backlight:pwms: Could not get
  phandle node for (cell 2)

Signed-off-by: Jonathan Neusch=C3=A4fer <j.neuschaefer@gmx.net>
=2D--
 .../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-p=
wm.yaml

diff --git a/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml b/D=
ocumentation/devicetree/bindings/mfd/netronix,ntxec.yaml
index 596df460f98eb..6562c41c5a9a9 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:
+    $ref: ../pwm/netronix,ntxec-pwm.yaml
+
 required:
   - compatible
   - reg
@@ -53,5 +56,15 @@ examples:
                     interrupts =3D <11 IRQ_TYPE_EDGE_FALLING>;
                     interrupt-controller;
                     #interrupt-cells =3D <1>;
+
+                    ec_pwm: pwm {
+                            compatible =3D "netronix,ntxec-pwm";
+                            #pwm-cells =3D <1>;
+                    };
             };
     };
+
+    backlight {
+            compatible =3D "pwm-backlight";
+            pwms =3D <&ec_pwm 0 50000>;
+    };
diff --git a/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml=
 b/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml
new file mode 100644
index 0000000000000..1dc1b1aba081c
=2D-- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/netronix,ntxec-pwm.yaml
@@ -0,0 +1,33 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$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: 1
+
+required:
+  - compatible
+  - "#pwm-cells"
=2D-
2.27.0