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 oneOf:
56 - items:
57 - enum:
58 - apple,simple-framebuffer
59 - allwinner,simple-framebuffer
60 - amlogic,simple-framebuffer
61 - const: simple-framebuffer
62 - const: simple-framebuffer
63
64 reg:
65 description: Location and size of the framebuffer memory
66
67 clocks:
68 description: List of clocks used by the framebuffer.
69
70 power-domains:
71 description: List of power domains used by the framebuffer.
72
73 width:
74 $ref: /schemas/types.yaml#/definitions/uint32
75 description: Width of the framebuffer in pixels
76
77 height:
78 $ref: /schemas/types.yaml#/definitions/uint32
79 description: Height of the framebuffer in pixels
80
81 stride:
82 $ref: /schemas/types.yaml#/definitions/uint32
83 description: Number of bytes of a line in the framebuffer
84
85 format:
86 description: >
87 Format of the framebuffer:
88 * `a1r5g5b5` - 16-bit pixels, d[15]=a, d[14:10]=r, d[9:5]=g, d[4:0]=b
89 * `a2r10g10b10` - 32-bit pixels, d[31:30]=a, d[29:20]=r, d[19:10]=g, d[9:0]=b
90 * `a8b8g8r8` - 32-bit pixels, d[31:24]=a, d[23:16]=b, d[15:8]=g, d[7:0]=r
91 * `a8r8g8b8` - 32-bit pixels, d[31:24]=a, d[23:16]=r, d[15:8]=g, d[7:0]=b
92 * `r5g6b5` - 16-bit pixels, d[15:11]=r, d[10:5]=g, d[4:0]=b
93 * `r5g5b5a1` - 16-bit pixels, d[15:11]=r, d[10:6]=g, d[5:1]=b d[1:0]=a
94 * `r8g8b8` - 24-bit pixels, d[23:16]=r, d[15:8]=g, d[7:0]=b
95 * `x1r5g5b5` - 16-bit pixels, d[14:10]=r, d[9:5]=g, d[4:0]=b
96 * `x2r10g10b10` - 32-bit pixels, d[29:20]=r, d[19:10]=g, d[9:0]=b
97 * `x8r8g8b8` - 32-bit pixels, d[23:16]=r, d[15:8]=g, d[7:0]=b
98 enum:
99 - a1r5g5b5
100 - a2r10g10b10
101 - a8b8g8r8
102 - a8r8g8b8
103 - r5g6b5
104 - r5g5b5a1
105 - r8g8b8
106 - x1r5g5b5
107 - x2r10g10b10
108 - x8r8g8b8
109
110 display:
111 $ref: /schemas/types.yaml#/definitions/phandle
112 description: Primary display hardware node
113
114 allwinner,pipeline:
115 description: Pipeline used by the framebuffer on Allwinner SoCs
116 enum:
117 - de_be0-lcd0
118 - de_be0-lcd0-hdmi
119 - de_be0-lcd0-tve0
120 - de_be1-lcd0
121 - de_be1-lcd1-hdmi
122 - de_fe0-de_be0-lcd0
123 - de_fe0-de_be0-lcd0-hdmi
124 - de_fe0-de_be0-lcd0-tve0
125 - mixer0-lcd0
126 - mixer0-lcd0-hdmi
127 - mixer1-lcd1-hdmi
128 - mixer1-lcd1-tve
129
130 amlogic,pipeline:
131 description: Pipeline used by the framebuffer on Amlogic SoCs
132 enum:
133 - vpu-cvbs
134 - vpu-hdmi
135
136patternProperties:
137 "^[a-zA-Z0-9-]+-supply$":
138 $ref: /schemas/types.yaml#/definitions/phandle
139 description:
140 Regulators used by the framebuffer. These should be named
141 according to the names in the device design.
142
143required:
144 # The binding requires also reg, width, height, stride and format,
145 # but usually they will be filled by the bootloader.
146 - compatible
147
148allOf:
149 - if:
150 properties:
151 compatible:
152 contains:
153 const: allwinner,simple-framebuffer
154
155 then:
156 required:
157 - allwinner,pipeline
158
159 - if:
160 properties:
161 compatible:
162 contains:
163 const: amlogic,simple-framebuffer
164
165 then:
166 required:
167 - amlogic,pipeline
168
169
170additionalProperties: false
171
172examples:
173 - |
174 / {
175 compatible = "foo";
176 model = "foo";
177 #address-cells = <1>;
178 #size-cells = <1>;
179
180 chosen {
181 #address-cells = <1>;
182 #size-cells = <1>;
183 framebuffer0: framebuffer@1d385000 {
184 compatible = "allwinner,simple-framebuffer", "simple-framebuffer";
185 allwinner,pipeline = "de_be0-lcd0";
186 reg = <0x1d385000 3840000>;
187 width = <1600>;
188 height = <1200>;
189 stride = <3200>;
190 format = "r5g6b5";
191 clocks = <&ahb_gates 36>, <&ahb_gates 43>, <&ahb_gates 44>;
192 lcd-supply = <®_dc1sw>;
193 display = <&lcdc0>;
194 };
195 };
196 };
197
198...