1 # SPDX-License-Identifier: GPL-2.0 1 # SPDX-License-Identifier: GPL-2.0
2 %YAML 1.2 2 %YAML 1.2
3 --- 3 ---
4 $id: http://devicetree.org/schemas/display/pan 4 $id: http://devicetree.org/schemas/display/panel/panel-common.yaml#
5 $schema: http://devicetree.org/meta-schemas/co 5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6 6
7 title: Common Properties for Display Panels 7 title: Common Properties for Display Panels
8 8
9 maintainers: 9 maintainers:
10 - Thierry Reding <thierry.reding@gmail.com> 10 - Thierry Reding <thierry.reding@gmail.com>
11 - Laurent Pinchart <laurent.pinchart+renesas@ 11 - Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
12 12
13 description: | 13 description: |
14 This document defines device tree properties 14 This document defines device tree properties common to several classes of
15 display panels. It doesn't constitute a devi 15 display panels. It doesn't constitute a device tree binding specification by
16 itself but is meant to be referenced by devi 16 itself but is meant to be referenced by device tree bindings.
17 17
18 When referenced from panel device tree bindi 18 When referenced from panel device tree bindings the properties defined in this
19 document are defined as follows. The panel d 19 document are defined as follows. The panel device tree bindings are
20 responsible for defining whether each proper 20 responsible for defining whether each property is required or optional.
21 21
22 properties: 22 properties:
23 # Descriptive Properties 23 # Descriptive Properties
24 width-mm: 24 width-mm:
25 description: 25 description:
26 Specifies the width of the physical area 26 Specifies the width of the physical area where images are displayed. This
27 property is expressed in millimeters and 27 property is expressed in millimeters and rounded to the closest unit.
28 28
29 height-mm: 29 height-mm:
30 description: 30 description:
31 Specifies the height of the physical are 31 Specifies the height of the physical area where images are displayed. This
32 property is expressed in millimeters and 32 property is expressed in millimeters and rounded to the closest unit.
33 33
34 label: 34 label:
35 description: | 35 description: |
36 The label property specifies a symbolic 36 The label property specifies a symbolic name for the panel as a
37 string suitable for use by humans. It ty 37 string suitable for use by humans. It typically contains a name inscribed
38 on the system (e.g. as an affixed label) 38 on the system (e.g. as an affixed label) or specified in the system's
39 documentation (e.g. in the user's manual 39 documentation (e.g. in the user's manual).
40 40
41 If no such name exists, and unless the p 41 If no such name exists, and unless the property is mandatory according to
42 device tree bindings, it shall rather be 42 device tree bindings, it shall rather be omitted than constructed of
43 non-descriptive information. For instanc 43 non-descriptive information. For instance an LCD panel in a system that
44 contains a single panel shall not be lab 44 contains a single panel shall not be labelled "LCD" if that name is not
45 inscribed on the system or used in a des 45 inscribed on the system or used in a descriptive fashion in system
46 documentation. 46 documentation.
47 47
48 rotation: 48 rotation:
49 description: 49 description:
50 Display rotation in degrees counter cloc 50 Display rotation in degrees counter clockwise (0,90,180,270)
51 $ref: /schemas/types.yaml#/definitions/uin 51 $ref: /schemas/types.yaml#/definitions/uint32
52 enum: [0, 90, 180, 270] 52 enum: [0, 90, 180, 270]
53 53
54 # Display Timings 54 # Display Timings
55 panel-timing: 55 panel-timing:
56 description: 56 description:
57 Most display panels are restricted to a 57 Most display panels are restricted to a single resolution and
58 require specific display timings. The pa 58 require specific display timings. The panel-timing subnode expresses those
59 timings. 59 timings.
60 $ref: panel-timing.yaml# 60 $ref: panel-timing.yaml#
61 61
62 display-timings: 62 display-timings:
63 description: 63 description:
64 Some display panels support several reso 64 Some display panels support several resolutions with different timings.
65 The display-timings bindings supports sp 65 The display-timings bindings supports specifying several timings and
66 optionally specifying which is the nativ 66 optionally specifying which is the native mode.
67 $ref: display-timings.yaml# 67 $ref: display-timings.yaml#
68 68
69 # Connectivity 69 # Connectivity
70 port: 70 port:
71 $ref: /schemas/graph.yaml#/properties/port 71 $ref: /schemas/graph.yaml#/properties/port
72 72
73 ddc-i2c-bus: 73 ddc-i2c-bus:
74 $ref: /schemas/types.yaml#/definitions/pha 74 $ref: /schemas/types.yaml#/definitions/phandle
75 description: 75 description:
76 Some panels expose EDID information thro 76 Some panels expose EDID information through an I2C-compatible
77 bus such as DDC2 or E-DDC. For such pane 77 bus such as DDC2 or E-DDC. For such panels the ddc-i2c-bus contains a
78 phandle to the system I2C controller con 78 phandle to the system I2C controller connected to that bus.
79 79
80 no-hpd: 80 no-hpd:
81 type: boolean 81 type: boolean
82 description: 82 description:
83 This panel is supposed to communicate th 83 This panel is supposed to communicate that it's ready via HPD
84 (hot plug detect) signal, but the signal 84 (hot plug detect) signal, but the signal isn't hooked up so we should
85 hardcode the max delay from the panel sp 85 hardcode the max delay from the panel spec when powering up the panel.
86 86
87 hpd-gpios: 87 hpd-gpios:
88 maxItems: 1 88 maxItems: 1
89 description: 89 description:
90 If Hot Plug Detect (HPD) is connected to 90 If Hot Plug Detect (HPD) is connected to a GPIO in the system rather
91 than a dedicated HPD pin the pin can be 91 than a dedicated HPD pin the pin can be specified here.
92 92
93 # Control I/Os 93 # Control I/Os
94 94
95 # Many display panels can be controlled thro 95 # Many display panels can be controlled through pins driven by GPIOs. The nature
96 # and timing of those control signals are de 96 # and timing of those control signals are device-specific and left for panel
97 # device tree bindings to specify. The follo 97 # device tree bindings to specify. The following GPIO specifiers can however be
98 # used for panels that implement compatible 98 # used for panels that implement compatible control signals.
99 99
100 enable-gpios: 100 enable-gpios:
101 maxItems: 1 101 maxItems: 1
102 description: | 102 description: |
103 Specifier for a GPIO connected to the pa 103 Specifier for a GPIO connected to the panel enable control signal. The
104 enable signal is active high and enables 104 enable signal is active high and enables operation of the panel. This
105 property can also be used for panels imp 105 property can also be used for panels implementing an active low power down
106 signal, which is a negated version of th 106 signal, which is a negated version of the enable signal. Active low enable
107 signals (or active high power down signa 107 signals (or active high power down signals) can be supported by inverting
108 the GPIO specifier polarity flag. 108 the GPIO specifier polarity flag.
109 109
110 Note that the enable signal control pane 110 Note that the enable signal control panel operation only and must not be
111 confused with a backlight enable signal. 111 confused with a backlight enable signal.
112 112
113 reset-gpios: 113 reset-gpios:
114 maxItems: 1 114 maxItems: 1
115 description: 115 description:
116 Specifier for a GPIO connected to the pa 116 Specifier for a GPIO connected to the panel reset control signal.
117 The reset signal is active low and reset 117 The reset signal is active low and resets the panel internal logic
118 while active. Active high reset signals 118 while active. Active high reset signals can be supported by inverting the
119 GPIO specifier polarity flag. 119 GPIO specifier polarity flag.
120 120
121 te-gpios: 121 te-gpios:
122 maxItems: 1 122 maxItems: 1
123 description: 123 description:
124 GPIO spec for the tearing effect synchro 124 GPIO spec for the tearing effect synchronization signal.
125 The tearing effect signal is active high 125 The tearing effect signal is active high. Active low signals can be
126 supported by inverting the GPIO specifie 126 supported by inverting the GPIO specifier polarity flag.
127 127
128 # Power 128 # Power
129 power-supply: 129 power-supply:
130 description: 130 description:
131 Display panels require power to be suppl 131 Display panels require power to be supplied. While several panels need
132 more than one power supply with panel-sp 132 more than one power supply with panel-specific constraints governing the
133 order and timings of the power supplies, 133 order and timings of the power supplies, in many cases a single power
134 supply is sufficient, either because the 134 supply is sufficient, either because the panel has a single power rail, or
135 because all its power rails can be drive 135 because all its power rails can be driven by the same supply. In that case
136 the power-supply property specifies the 136 the power-supply property specifies the supply powering the panel as a
137 phandle to a regulator. 137 phandle to a regulator.
138 138
139 # Backlight 139 # Backlight
140 140
141 # Most display panels include a backlight. S 141 # Most display panels include a backlight. Some of them also include a backlight
142 # controller exposed through a control bus s 142 # controller exposed through a control bus such as I2C or DSI. Others expose
143 # backlight control through GPIO, PWM or oth 143 # backlight control through GPIO, PWM or other signals connected to an external
144 # backlight controller. 144 # backlight controller.
145 145
146 backlight: 146 backlight:
147 $ref: /schemas/types.yaml#/definitions/pha 147 $ref: /schemas/types.yaml#/definitions/phandle
148 description: 148 description:
149 For panels whose backlight is controlled 149 For panels whose backlight is controlled by an external backlight
150 controller, this property contains a pha 150 controller, this property contains a phandle that references the
151 controller. 151 controller.
152 152
153 dependencies: 153 dependencies:
154 width-mm: [ height-mm ] 154 width-mm: [ height-mm ]
155 height-mm: [ width-mm ] 155 height-mm: [ width-mm ]
156 156
157 additionalProperties: true 157 additionalProperties: true
158 158
159 ... 159 ...
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