1 # SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
2 %YAML 1.2
3 ---
4 $id: http://devicetree.org/schemas/leds/backlight/qcom-wled.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6
7 title: Qualcomm Technologies, Inc. WLED driver
8
9 maintainers:
10 - Bjorn Andersson <andersson@kernel.org>
11 - Kiran Gunda <quic_kgunda@quicinc.com>
12
13 description: |
14 WLED (White Light Emitting Diode) driver is used for controlling display
15 backlight that is part of PMIC on Qualcomm Technologies, Inc. reference
16 platforms. The PMIC is connected to the host processor via SPMI bus.
17
18 properties:
19 compatible:
20 enum:
21 - qcom,pm8941-wled
22 - qcom,pmi8950-wled
23 - qcom,pmi8994-wled
24 - qcom,pmi8998-wled
25 - qcom,pm660l-wled
26 - qcom,pm6150l-wled
27 - qcom,pm8150l-wled
28
29 reg:
30 minItems: 1
31 maxItems: 2
32
33 default-brightness:
34 description: |
35 brightness value on boot.
36
37 label: true
38
39 max-brightness:
40 description: |
41 Maximum brightness level.
42
43 qcom,cs-out:
44 description: |
45 enable current sink output.
46 This property is supported only for WLED3.
47 type: boolean
48
49 qcom,cabc:
50 description: |
51 enable content adaptive backlight control.
52 type: boolean
53
54 qcom,ext-gen:
55 description: |
56 use externally generated modulator signal to dim.
57 This property is supported only for WLED3.
58 type: boolean
59
60 qcom,current-limit:
61 description: |
62 mA; per-string current limit.
63 This property is supported only for WLED3.
64 $ref: /schemas/types.yaml#/definitions/uint32
65 default: 20
66 minimum: 0
67 maximum: 25
68
69 qcom,current-limit-microamp:
70 description: |
71 uA; per-string current limit.
72 default: 25
73 minimum: 0
74 maximum: 30000
75 multipleOf: 25
76
77 qcom,current-boost-limit:
78 description: |
79 mA; boost current limit.
80 $ref: /schemas/types.yaml#/definitions/uint32
81
82 qcom,switching-freq:
83 description: |
84 kHz; switching frequency.
85 $ref: /schemas/types.yaml#/definitions/uint32
86 enum: [ 600, 640, 685, 738, 800, 872, 960, 1066, 1200, 1371, 1600, 1920,
87 2400, 3200, 4800, 9600 ]
88
89 qcom,ovp:
90 description: |
91 V; Over-voltage protection limit.
92 This property is supported only for WLED3.
93 $ref: /schemas/types.yaml#/definitions/uint32
94 enum: [ 27, 29, 32, 35 ]
95 default: 29
96
97 qcom,ovp-millivolt:
98 description: |
99 Over-voltage protection limit. This property is for WLED4 only.
100 $ref: /schemas/types.yaml#/definitions/uint32
101 enum: [ 18100, 19600, 29600, 31100 ]
102 default: 29600
103
104 qcom,num-strings:
105 description: |
106 number of led strings attached.
107 $ref: /schemas/types.yaml#/definitions/uint32
108
109 qcom,enabled-strings:
110 description: |
111 Array of the WLED strings numbered from 0 to 3. Each
112 string of leds are operated individually. Specify the
113 list of strings used by the device. Any combination of
114 led strings can be used.
115 $ref: /schemas/types.yaml#/definitions/uint32-array
116 minItems: 1
117 maxItems: 4
118
119 qcom,external-pfet:
120 description: |
121 Specify if external PFET control for short circuit
122 protection is used. This property is supported only
123 for WLED4.
124 type: boolean
125
126 qcom,auto-string-detection:
127 description: |
128 Enables auto-detection of the WLED string configuration.
129 This feature is not supported for WLED3.
130 type: boolean
131
132 interrupts:
133 minItems: 1
134 items:
135 - description: over voltage protection interrupt.
136 - description: short circuit interrupt.
137
138 interrupt-names:
139 minItems: 1
140 items:
141 - const: ovp
142 - const: short
143
144 qcom,modulator-sel:
145 description: |
146 Selects the modulator used for brightness modulation.
147 Allowed values are,
148 0 - Modulator A
149 1 - Modulator B
150 This property is applicable only to WLED5 peripheral.
151 $ref: /schemas/types.yaml#/definitions/uint32
152 enum: [ 0, 1 ]
153 default: 0
154
155 qcom,cabc-sel:
156 description: |
157 Selects the CABC pin signal used for brightness modulation.
158 Allowed values are,
159 0 - CABC disabled
160 1 - CABC 1
161 2 - CABC 2
162 3 - External signal (e.g. LPG) is used for dimming
163 This property is applicable only to WLED5 peripheral.
164 $ref: /schemas/types.yaml#/definitions/uint32
165 enum: [ 0, 1, 2, 3 ]
166
167 allOf:
168 - if:
169 properties:
170 compatible:
171 contains:
172 const: qcom,pm8941-wled
173
174 then:
175 properties:
176 reg:
177 maxItems: 1
178
179 qcom,current-boost-limit:
180 enum: [ 105, 385, 525, 805, 980, 1260, 1400, 1680 ]
181 default: 805
182
183 qcom,switching-freq:
184 default: 1600
185
186 qcom,num-strings:
187 enum: [ 1, 2, 3 ]
188
189 interrupts:
190 maxItems: 1
191
192 interrupt-names:
193 maxItems: 1
194
195 else:
196 properties:
197 reg:
198 minItems: 2
199
200 qcom,current-boost-limit:
201 enum: [ 105, 280, 450, 620, 970, 1150, 1300, 1500 ]
202 default: 970
203
204 qcom,switching-freq:
205 default: 800
206
207 qcom,num-strings:
208 enum: [ 1, 2, 3, 4 ]
209
210 interrupts:
211 minItems: 2
212
213 interrupt-names:
214 minItems: 2
215 - if:
216 properties:
217 compatible:
218 contains:
219 enum:
220 - qcom,pm8150l-wled
221
222 then:
223 properties:
224 default-brightness:
225 minimum: 0
226 maximum: 32767
227
228 max-brightness:
229 minimum: 0
230 maximum: 32767
231
232 else:
233 properties:
234 default-brightness:
235 minimum: 0
236 maximum: 4095
237
238 max-brightness:
239 minimum: 0
240 maximum: 4095
241
242 required:
243 - compatible
244 - reg
245 - label
246
247 additionalProperties: false
248
249 examples:
250 - |
251 backlight@d800 {
252 compatible = "qcom,pm8941-wled";
253 reg = <0xd800 0x100>;
254 label = "backlight";
255
256 qcom,cs-out;
257 qcom,current-limit = <20>;
258 qcom,current-boost-limit = <805>;
259 qcom,switching-freq = <1600>;
260 qcom,ovp = <29>;
261 qcom,num-strings = <2>;
262 qcom,enabled-strings = <0 1>;
263 };
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