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