[PATCH v4 1/2] dt-bindings: backlight: Add Texas Instruments LM3509

[Patrick Gansterer]

Add Device Tree bindings for Texas Instruments LM3509 - a
High Efficiency Boost for White LED's and/or OLED Displays

Signed-off-by: Patrick Gansterer <paroga at paroga.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski at linaro.org>
---
Changes in v4:
  Use backlight_*() to access backlight_device
  Do not set backlight_properties.power

v3: https://lore.kernel.org/all/20240309132521.1290173-1-paroga@paroga.com/

Changes in v3:
  Improved device tree bindings documentation

v2: https://lore.kernel.org/all/20240308215617.1729664-1-paroga@paroga.com/

Changes in v2:
  Add device tree nodes for each output
  Addressed multiple smaller review comments

v1: https://lore.kernel.org/all/20240302212757.1871164-1-paroga@paroga.com/

 .../bindings/leds/backlight/ti,lm3509.yaml    | 139 ++++++++++++++++++
 1 file changed, 139 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/backlight/ti,lm3509.yaml

diff --git a/Documentation/devicetree/bindings/leds/backlight/ti,lm3509.yaml b/Documentation/devicetree/bindings/leds/backlight/ti,lm3509.yaml
new file mode 100644
index 000000000000..b67f67648852
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/backlight/ti,lm3509.yaml
@@ -0,0 +1,139 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/backlight/ti,lm3509.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TI LM3509 High Efficiency Boost for White LED's and/or OLED Displays
+
+maintainers:
+  - Patrick Gansterer <paroga at paroga.com>
+
+description:
+  The LM3509 current mode boost converter offers two separate outputs.
+  https://www.ti.com/product/LM3509
+
+properties:
+  compatible:
+    const: ti,lm3509
+
+  reg:
+    maxItems: 1
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  reset-gpios:
+    maxItems: 1
+
+  ti,brightness-rate-of-change-us:
+    description: Brightness Rate of Change in microseconds.
+    enum: [51, 13000, 26000, 52000]
+
+  ti,oled-mode:
+    description: Enable OLED mode.
+    type: boolean
+
+patternProperties:
+  "^led@[01]$":
+    type: object
+    description: Properties for a string of connected LEDs.
+
+    allOf:
+      - $ref: common.yaml#
+
+    properties:
+      reg:
+        description:
+          The control register that is used to program the two current sinks.
+          The LM3509 has two registers (BMAIN and BSUB) and are represented
+          as 0 or 1 in this property. The two current sinks can be controlled
+          independently with both registers, or register BMAIN can be
+          configured to control both sinks with the led-sources property.
+        minimum: 0
+        maximum: 1
+
+      label: true
+
+      led-sources:
+        allOf:
+          - minItems: 1
+            maxItems: 2
+            items:
+              minimum: 0
+              maximum: 1
+
+      default-brightness:
+        minimum: 0
+        maximum: 31
+        default: 18
+
+      max-brightness:
+        minimum: 0
+        maximum: 31
+        default: 31
+
+    required:
+      - reg
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        backlight at 36 {
+            compatible = "ti,lm3509";
+            reg = <0x36>;
+            reset-gpios = <&gpio2 5 GPIO_ACTIVE_LOW>;
+
+            ti,oled-mode;
+            ti,brightness-rate-of-change-us = <52000>;
+
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            led at 0 {
+                reg = <0>;
+                led-sources = <0 1>;
+                label = "lcd-backlight";
+                default-brightness = <12>;
+                max-brightness = <31>;
+            };
+        };
+    };
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        backlight at 36 {
+            compatible = "ti,lm3509";
+            reg = <0x36>;
+
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            led at 0 {
+                reg = <0>;
+                default-brightness = <12>;
+            };
+
+            led at 1 {
+                reg = <1>;
+                default-brightness = <15>;
+            };
+        };
+    };
-- 
2.44.0