Documentation/devicetree/bindings/leds/backlight/lm3630a-backlight.yaml

   1 # SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
   2 %YAML 1.2
   3 ---
   4 $id: http://devicetree.org/schemas/leds/backlight/lm3630a-backlight.yaml#
   5 $schema: http://devicetree.org/meta-schemas/core.yaml#
   6
   7 title: TI LM3630A High-Efficiency Dual-String White LED
   8
   9 maintainers:
  10   - Lee Jones <lee.jones@linaro.org>
  11   - Daniel Thompson <daniel.thompson@linaro.org>
  12   - Jingoo Han <jingoohan1@gmail.com>
  13
  14 description: |
  15   The LM3630A is a current-mode boost converter which supplies the power and
  16   controls the current in up to two strings of 10 LEDs per string.
  17   https://www.ti.com/product/LM3630A
  18
  19 properties:
  20   compatible:
  21     const: ti,lm3630a
  22
  23   reg:
  24     maxItems: 1
  25
  26   '#address-cells':
  27     const: 1
  28
  29   '#size-cells':
  30     const: 0
  31
  32   enable-gpios:
  33     description: GPIO to use to enable/disable the backlight (HWEN pin).
  34     maxItems: 1
  35
  36 required:
  37   - compatible
  38   - reg
  39   - '#address-cells'
  40   - '#size-cells'
  41
  42 patternProperties:
  43   "^led@[01]$":
  44     type: object
  45     description: |
  46       Properties for a string of connected LEDs.
  47
  48     properties:
  49       reg:
  50         description: |
  51           The control bank that is used to program the two current sinks. The
  52           LM3630A has two control banks (A and B) and are represented as 0 or 1
  53           in this property. The two current sinks can be controlled
  54           independently with both banks, or bank A can be configured to control
  55           both sinks with the led-sources property.
  56         minimum: 0
  57         maximum: 1
  58
  59       label:
  60         maxItems: 1
  61
  62       led-sources:
  63         allOf:
  64           - minItems: 1
  65             maxItems: 2
  66             items:
  67               minimum: 0
  68               maximum: 1
  69
  70       default-brightness:
  71         description: Default brightness level on boot.
  72         minimum: 0
  73         maximum: 255
  74
  75       max-brightness:
  76         description: Maximum brightness that is allowed during runtime.
  77         minimum: 0
  78         maximum: 255
  79
  80       ti,linear-mapping-mode:
  81         description: |
  82           Enable linear mapping mode. If disabled, then it will use exponential
  83           mapping mode in which the ramp up/down appears to have a more uniform
  84           transition to the human eye.
  85         type: boolean
  86
  87     required:
  88       - reg
  89
  90     additionalProperties: false
  91
  92 additionalProperties: false
  93
  94 examples:
  95   - |
  96     #include <dt-bindings/gpio/gpio.h>
  97     i2c {
  98         #address-cells = <1>;
  99         #size-cells = <0>;
 100
 101         led-controller@38 {
 102                 compatible = "ti,lm3630a";
 103                 reg = <0x38>;
 104                 enable-gpios = <&gpio2 5 GPIO_ACTIVE_HIGH>;
 105
 106                 #address-cells = <1>;
 107                 #size-cells = <0>;
 108
 109                 led@0 {
 110                         reg = <0>;
 111                         led-sources = <0 1>;
 112                         label = "lcd-backlight";
 113                         default-brightness = <200>;
 114                         max-brightness = <255>;
 115                 };
 116         };
 117     };
 118   - |
 119     i2c {
 120         #address-cells = <1>;
 121         #size-cells = <0>;
 122
 123         led-controller@38 {
 124                 compatible = "ti,lm3630a";
 125                 reg = <0x38>;
 126
 127                 #address-cells = <1>;
 128                 #size-cells = <0>;
 129
 130                 led@0 {
 131                         reg = <0>;
 132                         default-brightness = <150>;
 133                         ti,linear-mapping-mode;
 134                 };
 135
 136                 led@1 {
 137                         reg = <1>;
 138                         default-brightness = <225>;
 139                         ti,linear-mapping-mode;
 140                 };
 141         };
 142     };