[PATCH 2/3 v3] dt-bindings: backlight: Add Kinetic KTD253 bindings

[Linus Walleij]

This adds device tree bindings for the Kinetic KTD253
white LED backlight driver.

Cc: devicetree at vger.kernel.org
Cc: Sam Ravnborg <sam at ravnborg.org>
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
---
ChangeLog v2->v3:
- Drop the pointless cargo-culted "default-on" property that
  we were not using
- Correct the brightness in the example to something legal (13)
ChangeLog v1->v2:
- Create common.yaml for backlight as suggested by Sam and
  use that.
- Rename the GPIO line "enable-gpios"
---
 .../leds/backlight/kinetic,ktd253.yaml        | 46 +++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml

diff --git a/Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml b/Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml
new file mode 100644
index 000000000000..7a6ec1f8c0f3
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml
@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/backlight/kinetic,ktd253.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Kinetic Technologies KTD253 one-wire backlight
+
+maintainers:
+  - Linus Walleij <linus.walleij at linaro.org>
+
+description: |
+  The Kinetic Technologies KTD253 is a white LED backlight that is
+  controlled by a single GPIO line. If you just turn on the backlight
+  it goes to maximum backlight then you can set the level of backlight
+  using pulses on the enable wire. This is sometimes referred to as
+  "expresswire".
+
+allOf:
+  - $ref: common.yaml#
+
+properties:
+  compatible:
+    const: kinetic,ktd253
+
+  enable-gpios:
+    description: GPIO to use to enable/disable and dim the backlight.
+    maxItems: 1
+
+  default-brightness: true
+  max-brightness: true
+
+required:
+  - compatible
+  - enable-gpios
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    backlight {
+        compatible = "kinetic,ktd253";
+        enable-gpios = <&gpio2 5 GPIO_ACTIVE_HIGH>;
+        default-brightness = <13>;
+    };
-- 
2.26.2