0001 # SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
0002 %YAML 1.2
0003 ---
0004 $id: http://devicetree.org/schemas/display/panel/panel-mipi-dbi-spi.yaml#
0005 $schema: http://devicetree.org/meta-schemas/core.yaml#
0006
0007 title: MIPI DBI SPI Panel
0008
0009 maintainers:
0010 - Noralf Trønnes <noralf@tronnes.org>
0011
0012 description: |
0013 This binding is for display panels using a MIPI DBI compatible controller
0014 in SPI mode.
0015
0016 The MIPI Alliance Standard for Display Bus Interface defines the electrical
0017 and logical interfaces for display controllers historically used in mobile
0018 phones. The standard defines 4 display architecture types and this binding is
0019 for type 1 which has full frame memory. There are 3 interface types in the
0020 standard and type C is the serial interface.
0021
0022 The standard defines the following interface signals for type C:
0023 - Power:
0024 - Vdd: Power supply for display module
0025 - Vddi: Logic level supply for interface signals
0026 Combined into one in this binding called: power-supply
0027 - Interface:
0028 - CSx: Chip select
0029 - SCL: Serial clock
0030 - Dout: Serial out
0031 - Din: Serial in
0032 - SDA: Bidrectional in/out
0033 - D/CX: Data/command selection, high=data, low=command
0034 Called dc-gpios in this binding.
0035 - RESX: Reset when low
0036 Called reset-gpios in this binding.
0037
0038 The type C interface has 3 options:
0039
0040 - Option 1: 9-bit mode and D/CX as the 9th bit
0041 | Command | the next command or following data |
0042 |<0><D7><D6><D5><D4><D3><D2><D1><D0>|<D/CX><D7><D6><D5><D4><D3><D2><D1><D0>|
0043
0044 - Option 2: 16-bit mode and D/CX as a 9th bit
0045 | Command or data |
0046 |<X><X><X><X><X><X><X><D/CX><D7><D6><D5><D4><D3><D2><D1><D0>|
0047
0048 - Option 3: 8-bit mode and D/CX as a separate interface line
0049 | Command or data |
0050 |<D7><D6><D5><D4><D3><D2><D1><D0>|
0051
0052 The panel resolution is specified using the panel-timing node properties
0053 hactive (width) and vactive (height). The other mandatory panel-timing
0054 properties should be set to zero except clock-frequency which can be
0055 optionally set to inform about the actual pixel clock frequency.
0056
0057 If the panel is wired to the controller at an offset specify this using
0058 hback-porch (x-offset) and vback-porch (y-offset).
0059
0060 allOf:
0061 - $ref: panel-common.yaml#
0062 - $ref: /schemas/spi/spi-peripheral-props.yaml#
0063
0064 properties:
0065 compatible:
0066 items:
0067 - enum:
0068 - sainsmart18
0069 - const: panel-mipi-dbi-spi
0070
0071 write-only:
0072 type: boolean
0073 description:
0074 Controller is not readable (ie. Din (MISO on the SPI interface) is not
0075 wired up).
0076
0077 dc-gpios:
0078 maxItems: 1
0079 description: |
0080 Controller data/command selection (D/CX) in 4-line SPI mode.
0081 If not set, the controller is in 3-line SPI mode.
0082
0083 required:
0084 - compatible
0085 - reg
0086 - width-mm
0087 - height-mm
0088 - panel-timing
0089
0090 unevaluatedProperties: false
0091
0092 examples:
0093 - |
0094 #include <dt-bindings/gpio/gpio.h>
0095
0096 spi {
0097 #address-cells = <1>;
0098 #size-cells = <0>;
0099
0100 display@0{
0101 compatible = "sainsmart18", "panel-mipi-dbi-spi";
0102 reg = <0>;
0103 spi-max-frequency = <40000000>;
0104
0105 dc-gpios = <&gpio 24 GPIO_ACTIVE_HIGH>;
0106 reset-gpios = <&gpio 25 GPIO_ACTIVE_HIGH>;
0107 write-only;
0108
0109 backlight = <&backlight>;
0110
0111 width-mm = <35>;
0112 height-mm = <28>;
0113
0114 panel-timing {
0115 hactive = <160>;
0116 vactive = <128>;
0117 hback-porch = <0>;
0118 vback-porch = <0>;
0119 clock-frequency = <0>;
0120 hfront-porch = <0>;
0121 hsync-len = <0>;
0122 vfront-porch = <0>;
0123 vsync-len = <0>;
0124 };
0125 };
0126 };
0127
0128 ...
