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-mipi-dbi-spi.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6
7 title: MIPI DBI SPI Panel
8
9 maintainers:
10 - Noralf Trønnes <noralf@tronnes.org>
11
12 description: |
13 This binding is for display panels using a MIPI DBI compatible controller
14 in SPI mode.
15
16 The MIPI Alliance Standard for Display Bus Interface defines the electrical
17 and logical interfaces for display controllers historically used in mobile
18 phones. The standard defines 4 display architecture types and this binding is
19 for type 1 which has full frame memory. There are 3 interface types in the
20 standard and type C is the serial interface.
21
22 The standard defines the following interface signals for type C:
23 - Power:
24 - Vdd: Power supply for display module
25 Called power-supply in this binding.
26 - Vddi: Logic level supply for interface signals
27 Called io-supply in this binding.
28 - Interface:
29 - CSx: Chip select
30 - SCL: Serial clock
31 - Dout: Serial out
32 - Din: Serial in
33 - SDA: Bidrectional in/out
34 - D/CX: Data/command selection, high=data, low=command
35 Called dc-gpios in this binding.
36 - RESX: Reset when low
37 Called reset-gpios in this binding.
38
39 The type C interface has 3 options:
40
41 - Option 1: 9-bit mode and D/CX as the 9th bit
42 | Command | the next command or following data |
43 |<0><D7><D6><D5><D4><D3><D2><D1><D0>|<D/CX><D7><D6><D5><D4><D3><D2><D1><D0>|
44
45 - Option 2: 16-bit mode and D/CX as a 9th bit
46 | Command or data |
47 |<X><X><X><X><X><X><X><D/CX><D7><D6><D5><D4><D3><D2><D1><D0>|
48
49 - Option 3: 8-bit mode and D/CX as a separate interface line
50 | Command or data |
51 |<D7><D6><D5><D4><D3><D2><D1><D0>|
52
53 The standard defines one pixel format for type C: RGB111. The industry
54 however has decided to provide the type A/B interface pixel formats also on
55 the Type C interface and most common among these are RGB565 and RGB666.
56 The MIPI DCS command set_address_mode (36h) has one bit that controls RGB/BGR
57 order. This gives each supported RGB format a BGR variant.
58
59 The panel resolution is specified using the panel-timing node properties
60 hactive (width) and vactive (height). The other mandatory panel-timing
61 properties should be set to zero except clock-frequency which can be
62 optionally set to inform about the actual pixel clock frequency.
63
64 If the panel is wired to the controller at an offset specify this using
65 hback-porch (x-offset) and vback-porch (y-offset).
66
67 allOf:
68 - $ref: panel-common.yaml#
69 - $ref: /schemas/spi/spi-peripheral-props.yaml#
70
71 properties:
72 compatible:
73 items:
74 - enum:
75 - saef,sftc154b
76 - sainsmart18
77 - shineworld,lh133k
78 - const: panel-mipi-dbi-spi
79
80 reg:
81 maxItems: 1
82
83 write-only:
84 type: boolean
85 description:
86 Controller is not readable (ie. Din (MISO on the SPI interface) is not
87 wired up).
88
89 dc-gpios:
90 maxItems: 1
91 description: |
92 Controller data/command selection (D/CX) in 4-line SPI mode.
93 If not set, the controller is in 3-line SPI mode.
94
95 io-supply:
96 description: |
97 Logic level supply for interface signals (Vddi).
98 No need to set if this is the same as power-supply.
99
100 spi-3wire: true
101
102 format:
103 description: >
104 Pixel format in bit order as going on the wire:
105 * `x2r1g1b1r1g1b1` - RGB111, 2 pixels per byte
106 * `x2b1g1r1b1g1r1` - BGR111, 2 pixels per byte
107 * `x1r1g1b1x1r1g1b1` - RGB111, 2 pixels per byte
108 * `x1b1g1r1x1b1g1r1` - BGR111, 2 pixels per byte
109 * `r5g6b5` - RGB565, 2 bytes
110 * `b5g6r5` - BGR565, 2 bytes
111 * `r6x2g6x2b6x2` - RGB666, 3 bytes
112 * `b6x2g6x2r6x2` - BGR666, 3 bytes
113 enum:
114 - x2r1g1b1r1g1b1
115 - x2b1g1r1b1g1r1
116 - x1r1g1b1x1r1g1b1
117 - x1b1g1r1x1b1g1r1
118 - r5g6b5
119 - b5g6r5
120 - r6x2g6x2b6x2
121 - b6x2g6x2r6x2
122 default: r5g6b5
123
124 required:
125 - compatible
126 - reg
127 - width-mm
128 - height-mm
129 - panel-timing
130
131 unevaluatedProperties: false
132
133 examples:
134 - |
135 #include <dt-bindings/gpio/gpio.h>
136
137 spi {
138 #address-cells = <1>;
139 #size-cells = <0>;
140
141 display@0{
142 compatible = "sainsmart18", "panel-mipi-dbi-spi";
143 reg = <0>;
144 spi-max-frequency = <40000000>;
145
146 dc-gpios = <&gpio 24 GPIO_ACTIVE_HIGH>;
147 reset-gpios = <&gpio 25 GPIO_ACTIVE_HIGH>;
148 write-only;
149
150 format = "r5g6b5";
151
152 backlight = <&backlight>;
153
154 width-mm = <35>;
155 height-mm = <28>;
156
157 panel-timing {
158 hactive = <160>;
159 vactive = <128>;
160 hback-porch = <0>;
161 vback-porch = <0>;
162 clock-frequency = <0>;
163 hfront-porch = <0>;
164 hsync-len = <0>;
165 vfront-porch = <0>;
166 vsync-len = <0>;
167 };
168 };
169 };
170
171 ...
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