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