xref: /linux/Documentation/devicetree/bindings/display/panel/panel-timing.yaml (revision 0526b56cbc3c489642bd6a5fe4b718dea7ef0ee8) 
1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/display/panel/panel-timing.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: panel timing
8
9maintainers:
10  - Thierry Reding <thierry.reding@gmail.com>
11  - Sam Ravnborg <sam@ravnborg.org>
12
13description: |
14  There are different ways of describing the timing data of a panel. The
15  devicetree representation corresponds to the one commonly found in datasheets
16  for panels.
17
18  The parameters are defined as seen in the following illustration.
19
20  +-------+----------+-------------------------------------+----------+
21  |       |          |        ^                            |          |
22  |       |          |        |vsync_len                   |          |
23  |       |          |        v                            |          |
24  +-------+----------+-------------------------------------+----------+
25  |       |          |        ^                            |          |
26  |       |          |        |vback_porch                 |          |
27  |       |          |        v                            |          |
28  +-------+----------#######################################----------+
29  |       |          #        ^                            #          |
30  |       |          #        |                            #          |
31  | hsync |  hback   #        |                            #  hfront  |
32  |  len  |   porch  #        |       hactive              #  porch   |
33  |<----->|<-------->#<-------+--------------------------->#<-------->|
34  |       |          #        |                            #          |
35  |       |          #        |vactive                     #          |
36  |       |          #        |                            #          |
37  |       |          #        v                            #          |
38  +-------+----------#######################################----------+
39  |       |          |        ^                            |          |
40  |       |          |        |vfront_porch                |          |
41  |       |          |        v                            |          |
42  +-------+----------+-------------------------------------+----------+
43
44
45  The following is the panel timings shown with time on the x-axis.
46  This matches the timing diagrams often found in data sheets.
47
48              Active                 Front           Sync           Back
49              Region                 Porch                          Porch
50  <-----------------------><----------------><-------------><-------------->
51    //////////////////////|
52   ////////////////////// |
53  //////////////////////  |..................               ................
54                                             _______________
55
56  Timing can be specified either as a typical value or as a tuple
57  of min, typ, max values.
58
59properties:
60
61  clock-frequency:
62    description: Panel clock in Hz
63
64  hactive:
65    $ref: /schemas/types.yaml#/definitions/uint32
66    description: Horizontal panel resolution in pixels
67
68  vactive:
69    $ref: /schemas/types.yaml#/definitions/uint32
70    description: Vertical panel resolution in pixels
71
72  hfront-porch:
73    description: Horizontal front porch panel timing
74    $ref: /schemas/types.yaml#/definitions/uint32-array
75    oneOf:
76      - maxItems: 1
77        items:
78          description: typical number of pixels
79      - minItems: 3
80        maxItems: 3
81        items:
82          description: min, typ, max number of pixels
83
84  hback-porch:
85    description: Horizontal back porch timing
86    $ref: /schemas/types.yaml#/definitions/uint32-array
87    oneOf:
88      - maxItems: 1
89        items:
90          description: typical number of pixels
91      - minItems: 3
92        maxItems: 3
93        items:
94          description: min, typ, max number of pixels
95
96  hsync-len:
97    description: Horizontal sync length panel timing
98    $ref: /schemas/types.yaml#/definitions/uint32-array
99    oneOf:
100      - maxItems: 1
101        items:
102          description: typical number of pixels
103      - minItems: 3
104        maxItems: 3
105        items:
106          description: min, typ, max number of pixels
107
108  vfront-porch:
109    description: Vertical front porch panel timing
110    $ref: /schemas/types.yaml#/definitions/uint32-array
111    oneOf:
112      - maxItems: 1
113        items:
114          description: typical number of lines
115      - minItems: 3
116        maxItems: 3
117        items:
118          description: min, typ, max number of lines
119
120  vback-porch:
121    description: Vertical back porch panel timing
122    $ref: /schemas/types.yaml#/definitions/uint32-array
123    oneOf:
124      - maxItems: 1
125        items:
126          description: typical number of lines
127      - minItems: 3
128        maxItems: 3
129        items:
130          description: min, typ, max number of lines
131
132  vsync-len:
133    description: Vertical sync length panel timing
134    $ref: /schemas/types.yaml#/definitions/uint32-array
135    oneOf:
136      - maxItems: 1
137        items:
138          description: typical number of lines
139      - minItems: 3
140        maxItems: 3
141        items:
142          description: min, typ, max number of lines
143
144  hsync-active:
145    description: |
146      Horizontal sync pulse.
147      0 selects active low, 1 selects active high.
148      If omitted then it is not used by the hardware
149    $ref: /schemas/types.yaml#/definitions/uint32
150    enum: [0, 1]
151
152  vsync-active:
153    description: |
154      Vertical sync pulse.
155      0 selects active low, 1 selects active high.
156      If omitted then it is not used by the hardware
157    $ref: /schemas/types.yaml#/definitions/uint32
158    enum: [0, 1]
159
160  de-active:
161    description: |
162      Data enable.
163      0 selects active low, 1 selects active high.
164      If omitted then it is not used by the hardware
165    $ref: /schemas/types.yaml#/definitions/uint32
166    enum: [0, 1]
167
168  pixelclk-active:
169    description: |
170      Data driving on rising or falling edge.
171      Use 0 to drive pixel data on falling edge and
172      sample data on rising edge.
173      Use 1 to drive pixel data on rising edge and
174      sample data on falling edge
175    $ref: /schemas/types.yaml#/definitions/uint32
176    enum: [0, 1]
177
178  syncclk-active:
179    description: |
180      Drive sync on rising or sample sync on falling edge.
181      If not specified then the setup is as specified by pixelclk-active.
182      Use 0 to drive sync on falling edge and
183      sample sync on rising edge of pixel clock.
184      Use 1 to drive sync on rising edge and
185      sample sync on falling edge of pixel clock
186    $ref: /schemas/types.yaml#/definitions/uint32
187    enum: [0, 1]
188
189  interlaced:
190    type: boolean
191    description: Enable interlaced mode
192
193  doublescan:
194    type: boolean
195    description: Enable double scan mode
196
197  doubleclk:
198    type: boolean
199    description: Enable double clock mode
200
201required:
202  - clock-frequency
203  - hactive
204  - vactive
205  - hfront-porch
206  - hback-porch
207  - hsync-len
208  - vfront-porch
209  - vback-porch
210  - vsync-len
211
212additionalProperties: false
213
214...
215