0001 # SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
0002 %YAML 1.2
0003 ---
0004 $id: http://devicetree.org/schemas/leds/backlight/qcom-wled.yaml#
0005 $schema: http://devicetree.org/meta-schemas/core.yaml#
0006
0007 title: Binding for Qualcomm Technologies, Inc. WLED driver
0008
0009 maintainers:
0010 - Bjorn Andersson <bjorn.andersson@linaro.org>
0011 - Kiran Gunda <kgunda@codeaurora.org>
0012
0013 description: |
0014 WLED (White Light Emitting Diode) driver is used for controlling display
0015 backlight that is part of PMIC on Qualcomm Technologies, Inc. reference
0016 platforms. The PMIC is connected to the host processor via SPMI bus.
0017
0018 properties:
0019 compatible:
0020 enum:
0021 - qcom,pm8941-wled
0022 - qcom,pmi8994-wled
0023 - qcom,pmi8998-wled
0024 - qcom,pm660l-wled
0025 - qcom,pm6150l-wled
0026 - qcom,pm8150l-wled
0027
0028 reg:
0029 maxItems: 1
0030
0031 default-brightness:
0032 description: |
0033 brightness value on boot.
0034
0035 label: true
0036
0037 max-brightness:
0038 description: |
0039 Maximum brightness level.
0040
0041 qcom,cs-out:
0042 description: |
0043 enable current sink output.
0044 This property is supported only for WLED3.
0045 type: boolean
0046
0047 qcom,cabc:
0048 description: |
0049 enable content adaptive backlight control.
0050 type: boolean
0051
0052 qcom,ext-gen:
0053 description: |
0054 use externally generated modulator signal to dim.
0055 This property is supported only for WLED3.
0056 type: boolean
0057
0058 qcom,current-limit:
0059 description: |
0060 mA; per-string current limit.
0061 This property is supported only for WLED3.
0062 $ref: /schemas/types.yaml#/definitions/uint32
0063 default: 20
0064 minimum: 0
0065 maximum: 25
0066
0067 qcom,current-limit-microamp:
0068 description: |
0069 uA; per-string current limit.
0070 default: 25
0071 minimum: 0
0072 maximum: 30000
0073 multipleOf: 25
0074
0075 qcom,current-boost-limit:
0076 description: |
0077 mA; boost current limit.
0078 $ref: /schemas/types.yaml#/definitions/uint32
0079
0080 qcom,switching-freq:
0081 description: |
0082 kHz; switching frequency.
0083 $ref: /schemas/types.yaml#/definitions/uint32
0084 enum: [ 600, 640, 685, 738, 800, 872, 960, 1066, 1200, 1371, 1600, 1920,
0085 2400, 3200, 4800, 9600 ]
0086
0087 qcom,ovp:
0088 description: |
0089 V; Over-voltage protection limit.
0090 This property is supported only for WLED3.
0091 $ref: /schemas/types.yaml#/definitions/uint32
0092 enum: [ 27, 29, 32, 35 ]
0093 default: 29
0094
0095 qcom,ovp-millivolt:
0096 description: |
0097 Over-voltage protection limit. This property is for WLED4 only.
0098 $ref: /schemas/types.yaml#/definitions/uint32
0099 enum: [ 18100, 19600, 29600, 31100 ]
0100 default: 29600
0101
0102 qcom,num-strings:
0103 description: |
0104 number of led strings attached.
0105 $ref: /schemas/types.yaml#/definitions/uint32
0106
0107 qcom,enabled-strings:
0108 description: |
0109 Array of the WLED strings numbered from 0 to 3. Each
0110 string of leds are operated individually. Specify the
0111 list of strings used by the device. Any combination of
0112 led strings can be used.
0113 $ref: /schemas/types.yaml#/definitions/uint32-array
0114 minItems: 1
0115 maxItems: 4
0116
0117 qcom,external-pfet:
0118 description: |
0119 Specify if external PFET control for short circuit
0120 protection is used. This property is supported only
0121 for WLED4.
0122 type: boolean
0123
0124 qcom,auto-string-detection:
0125 description: |
0126 Enables auto-detection of the WLED string configuration.
0127 This feature is not supported for WLED3.
0128 type: boolean
0129
0130 interrupts:
0131 minItems: 1
0132 items:
0133 - description: over voltage protection interrupt.
0134 - description: short circuit interrupt.
0135
0136 interrupt-names:
0137 minItems: 1
0138 items:
0139 - const: ovp
0140 - const: short
0141
0142 qcom,modulator-sel:
0143 description: |
0144 Selects the modulator used for brightness modulation.
0145 Allowed values are,
0146 0 - Modulator A
0147 1 - Modulator B
0148 This property is applicable only to WLED5 peripheral.
0149 $ref: /schemas/types.yaml#/definitions/uint32
0150 enum: [ 0, 1 ]
0151 default: 0
0152
0153 qcom,cabc-sel:
0154 description: |
0155 Selects the CABC pin signal used for brightness modulation.
0156 Allowed values are,
0157 0 - CABC disabled
0158 1 - CABC 1
0159 2 - CABC 2
0160 3 - External signal (e.g. LPG) is used for dimming
0161 This property is applicable only to WLED5 peripheral.
0162 $ref: /schemas/types.yaml#/definitions/uint32
0163 enum: [ 0, 1, 2, 3 ]
0164
0165 allOf:
0166 - if:
0167 properties:
0168 compatible:
0169 contains:
0170 const: qcom,pm8941-wled
0171
0172 then:
0173 properties:
0174 qcom,current-boost-limit:
0175 enum: [ 105, 385, 525, 805, 980, 1260, 1400, 1680 ]
0176 default: 805
0177
0178 qcom,switching-freq:
0179 default: 1600
0180
0181 qcom,num-strings:
0182 enum: [ 1, 2, 3 ]
0183
0184 interrupts:
0185 maxItems: 1
0186
0187 interrupt-names:
0188 maxItems: 1
0189
0190 else:
0191 properties:
0192 qcom,current-boost-limit:
0193 enum: [ 105, 280, 450, 620, 970, 1150, 1300, 1500 ]
0194 default: 970
0195
0196 qcom,switching-freq:
0197 default: 800
0198
0199 qcom,num-strings:
0200 enum: [ 1, 2, 3, 4 ]
0201
0202 interrupts:
0203 minItems: 2
0204
0205 interrupt-names:
0206 minItems: 2
0207 - if:
0208 properties:
0209 compatible:
0210 contains:
0211 enum:
0212 - qcom,pm8150l-wled
0213
0214 then:
0215 properties:
0216 default-brightness:
0217 minimum: 0
0218 maximum: 32767
0219
0220 max-brightness:
0221 minimum: 0
0222 maximum: 32767
0223
0224 else:
0225 properties:
0226 default-brightness:
0227 minimum: 0
0228 maximum: 4095
0229
0230 max-brightness:
0231 minimum: 0
0232 maximum: 4095
0233
0234 required:
0235 - compatible
0236 - reg
0237 - label
0238
0239 additionalProperties: false
0240
0241 examples:
0242 - |
0243 backlight@d800 {
0244 compatible = "qcom,pm8941-wled";
0245 reg = <0xd800 0x100>;
0246 label = "backlight";
0247
0248 qcom,cs-out;
0249 qcom,current-limit = <20>;
0250 qcom,current-boost-limit = <805>;
0251 qcom,switching-freq = <1600>;
0252 qcom,ovp = <29>;
0253 qcom,num-strings = <2>;
0254 qcom,enabled-strings = <0 1>;
0255 };
