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
7title: MIPI DBI SPI Panel
8
9maintainers:
10  - Noralf Trønnes <noralf@tronnes.org>
11
12description: |
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 panel resolution is specified using the panel-timing node properties
54  hactive (width) and vactive (height). The other mandatory panel-timing
55  properties should be set to zero except clock-frequency which can be
56  optionally set to inform about the actual pixel clock frequency.
57
58  If the panel is wired to the controller at an offset specify this using
59  hback-porch (x-offset) and vback-porch (y-offset).
60
61allOf:
62  - $ref: panel-common.yaml#
63  - $ref: /schemas/spi/spi-peripheral-props.yaml#
64
65properties:
66  compatible:
67    items:
68      - enum:
69          - saef,sftc154b
70          - sainsmart18
71          - shineworld,lh133k
72      - const: panel-mipi-dbi-spi
73
74  write-only:
75    type: boolean
76    description:
77      Controller is not readable (ie. Din (MISO on the SPI interface) is not
78      wired up).
79
80  dc-gpios:
81    maxItems: 1
82    description: |
83      Controller data/command selection (D/CX) in 4-line SPI mode.
84      If not set, the controller is in 3-line SPI mode.
85
86  io-supply:
87    description: |
88      Logic level supply for interface signals (Vddi).
89      No need to set if this is the same as power-supply.
90
91  spi-3wire: true
92
93required:
94  - compatible
95  - reg
96  - width-mm
97  - height-mm
98  - panel-timing
99
100unevaluatedProperties: false
101
102examples:
103  - |
104    #include <dt-bindings/gpio/gpio.h>
105
106    spi {
107        #address-cells = <1>;
108        #size-cells = <0>;
109
110        display@0{
111            compatible = "sainsmart18", "panel-mipi-dbi-spi";
112            reg = <0>;
113            spi-max-frequency = <40000000>;
114
115            dc-gpios = <&gpio 24 GPIO_ACTIVE_HIGH>;
116            reset-gpios = <&gpio 25 GPIO_ACTIVE_HIGH>;
117            write-only;
118
119            backlight = <&backlight>;
120
121            width-mm = <35>;
122            height-mm = <28>;
123
124            panel-timing {
125                hactive = <160>;
126                vactive = <128>;
127                hback-porch = <0>;
128                vback-porch = <0>;
129                clock-frequency = <0>;
130                hfront-porch = <0>;
131                hsync-len = <0>;
132                vfront-porch = <0>;
133                vsync-len = <0>;
134            };
135        };
136    };
137
138...
139