Linux kernel mirror (for testing)
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linux
1# SPDX-License-Identifier: GPL-2.0
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/display/simple-framebuffer.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: Simple Framebuffer Device Tree Bindings
8
9maintainers:
10 - Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
11 - Hans de Goede <hdegoede@redhat.com>
12
13description: |+
14 A simple frame-buffer describes a frame-buffer setup by firmware or
15 the bootloader, with the assumption that the display hardware has
16 already been set up to scan out from the memory pointed to by the
17 reg property.
18
19 Since simplefb nodes represent runtime information they must be
20 sub-nodes of the chosen node (*). Simplefb nodes must be named
21 framebuffer@<address>.
22
23 If the devicetree contains nodes for the display hardware used by a
24 simplefb, then the simplefb node must contain a property called
25 display, which contains a phandle pointing to the primary display
26 hw node, so that the OS knows which simplefb to disable when handing
27 over control to a driver for the real hardware. The bindings for the
28 hw nodes must specify which node is considered the primary node.
29
30 It is advised to add display# aliases to help the OS determine how
31 to number things. If display# aliases are used, then if the simplefb
32 node contains a display property then the /aliases/display# path
33 must point to the display hw node the display property points to,
34 otherwise it must point directly to the simplefb node.
35
36 If a simplefb node represents the preferred console for user
37 interaction, then the chosen node stdout-path property should point
38 to it, or to the primary display hw node, as with display#
39 aliases. If display aliases are used then it should be set to the
40 alias instead.
41
42 It is advised that devicetree files contain pre-filled, disabled
43 framebuffer nodes, so that the firmware only needs to update the
44 mode information and enable them. This way if e.g. later on support
45 for more display clocks get added, the simplefb nodes will already
46 contain this info and the firmware does not need to be updated.
47
48 If pre-filled framebuffer nodes are used, the firmware may need
49 extra information to find the right node. In that case an extra
50 platform specific compatible and platform specific properties should
51 be used and documented.
52
53properties:
54 compatible:
55 items:
56 - enum:
57 - apple,simple-framebuffer
58 - allwinner,simple-framebuffer
59 - amlogic,simple-framebuffer
60 - const: simple-framebuffer
61
62 reg:
63 description: Location and size of the framebuffer memory
64
65 clocks:
66 description: List of clocks used by the framebuffer.
67
68 power-domains:
69 description: List of power domains used by the framebuffer.
70
71 width:
72 $ref: /schemas/types.yaml#/definitions/uint32
73 description: Width of the framebuffer in pixels
74
75 height:
76 $ref: /schemas/types.yaml#/definitions/uint32
77 description: Height of the framebuffer in pixels
78
79 stride:
80 $ref: /schemas/types.yaml#/definitions/uint32
81 description: Number of bytes of a line in the framebuffer
82
83 format:
84 description: >
85 Format of the framebuffer:
86 * `a8b8g8r8` - 32-bit pixels, d[31:24]=a, d[23:16]=b, d[15:8]=g, d[7:0]=r
87 * `r5g6b5` - 16-bit pixels, d[15:11]=r, d[10:5]=g, d[4:0]=b
88 * `x2r10g10b10` - 32-bit pixels, d[29:20]=r, d[19:10]=g, d[9:0]=b
89 * `x8r8g8b8` - 32-bit pixels, d[23:16]=r, d[15:8]=g, d[7:0]=b
90 enum:
91 - a8b8g8r8
92 - r5g6b5
93 - x2r10g10b10
94 - x8r8g8b8
95
96 display:
97 $ref: /schemas/types.yaml#/definitions/phandle
98 description: Primary display hardware node
99
100 allwinner,pipeline:
101 description: Pipeline used by the framebuffer on Allwinner SoCs
102 enum:
103 - de_be0-lcd0
104 - de_be0-lcd0-hdmi
105 - de_be0-lcd0-tve0
106 - de_be1-lcd0
107 - de_be1-lcd1-hdmi
108 - de_fe0-de_be0-lcd0
109 - de_fe0-de_be0-lcd0-hdmi
110 - de_fe0-de_be0-lcd0-tve0
111 - mixer0-lcd0
112 - mixer0-lcd0-hdmi
113 - mixer1-lcd1-hdmi
114 - mixer1-lcd1-tve
115
116 amlogic,pipeline:
117 description: Pipeline used by the framebuffer on Amlogic SoCs
118 enum:
119 - vpu-cvbs
120 - vpu-hdmi
121
122patternProperties:
123 "^[a-zA-Z0-9-]+-supply$":
124 $ref: /schemas/types.yaml#/definitions/phandle
125 description:
126 Regulators used by the framebuffer. These should be named
127 according to the names in the device design.
128
129required:
130 # The binding requires also reg, width, height, stride and format,
131 # but usually they will be filled by the bootloader.
132 - compatible
133
134allOf:
135 - if:
136 properties:
137 compatible:
138 contains:
139 const: allwinner,simple-framebuffer
140
141 then:
142 required:
143 - allwinner,pipeline
144
145 - if:
146 properties:
147 compatible:
148 contains:
149 const: amlogic,simple-framebuffer
150
151 then:
152 required:
153 - amlogic,pipeline
154
155
156additionalProperties: false
157
158examples:
159 - |
160 / {
161 compatible = "foo";
162 model = "foo";
163 #address-cells = <1>;
164 #size-cells = <1>;
165
166 chosen {
167 #address-cells = <1>;
168 #size-cells = <1>;
169 framebuffer0: framebuffer@1d385000 {
170 compatible = "allwinner,simple-framebuffer", "simple-framebuffer";
171 allwinner,pipeline = "de_be0-lcd0";
172 reg = <0x1d385000 3840000>;
173 width = <1600>;
174 height = <1200>;
175 stride = <3200>;
176 format = "r5g6b5";
177 clocks = <&ahb_gates 36>, <&ahb_gates 43>, <&ahb_gates 44>;
178 lcd-supply = <®_dc1sw>;
179 display = <&lcdc0>;
180 };
181 };
182 };
183
184...