simple-framebuffer.yaml

  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
  8
  9maintainers:
 10  - Hans de Goede <hdegoede@redhat.com>
 11
 12description: |+
 13  A simple frame-buffer describes a frame-buffer setup by firmware or
 14  the bootloader, with the assumption that the display hardware has
 15  already been set up to scan out from the memory pointed to by the
 16  reg property.
 17
 18  Since simplefb nodes represent runtime information they must be
 19  sub-nodes of the chosen node (*). Simplefb nodes must be named
 20  framebuffer@<address>.
 21
 22  If the devicetree contains nodes for the display hardware used by a
 23  simplefb, then the simplefb node must contain a property called
 24  display, which contains a phandle pointing to the primary display
 25  hw node, so that the OS knows which simplefb to disable when handing
 26  over control to a driver for the real hardware. The bindings for the
 27  hw nodes must specify which node is considered the primary node.
 28
 29  If a panel node is given, then the driver uses this to configure the
 30  physical width and height of the display. If no panel node is given,
 31  then the driver uses the width and height properties of the simplefb
 32  node to estimate it.
 33
 34  It is advised to add display# aliases to help the OS determine how
 35  to number things. If display# aliases are used, then if the simplefb
 36  node contains a display property then the /aliases/display# path
 37  must point to the display hw node the display property points to,
 38  otherwise it must point directly to the simplefb node.
 39
 40  If a simplefb node represents the preferred console for user
 41  interaction, then the chosen node stdout-path property should point
 42  to it, or to the primary display hw node, as with display#
 43  aliases. If display aliases are used then it should be set to the
 44  alias instead.
 45
 46  It is advised that devicetree files contain pre-filled, disabled
 47  framebuffer nodes, so that the firmware only needs to update the
 48  mode information and enable them. This way if e.g. later on support
 49  for more display clocks get added, the simplefb nodes will already
 50  contain this info and the firmware does not need to be updated.
 51
 52  If pre-filled framebuffer nodes are used, the firmware may need
 53  extra information to find the right node. In that case an extra
 54  platform specific compatible and platform specific properties should
 55  be used and documented.
 56
 57properties:
 58  compatible:
 59    oneOf:
 60      - items:
 61          - enum:
 62              - apple,simple-framebuffer
 63              - allwinner,simple-framebuffer
 64              - amlogic,simple-framebuffer
 65          - const: simple-framebuffer
 66      - const: simple-framebuffer
 67
 68  reg:
 69    description: Location and size of the framebuffer memory
 70
 71  memory-region:
 72    maxItems: 1
 73    description: Phandle to a node describing the memory to be used for the
 74      framebuffer. If present, overrides the "reg" property (if one exists).
 75
 76  clocks:
 77    description: List of clocks used by the framebuffer.
 78
 79  power-domains:
 80    description: List of power domains used by the framebuffer.
 81
 82  width:
 83    $ref: /schemas/types.yaml#/definitions/uint32
 84    description: Width of the framebuffer in pixels
 85
 86  height:
 87    $ref: /schemas/types.yaml#/definitions/uint32
 88    description: Height of the framebuffer in pixels
 89
 90  stride:
 91    $ref: /schemas/types.yaml#/definitions/uint32
 92    description: Number of bytes of a line in the framebuffer
 93
 94  format:
 95    description: >
 96      Format of the framebuffer:
 97        * `a1r5g5b5` - 16-bit pixels, d[15]=a, d[14:10]=r, d[9:5]=g, d[4:0]=b
 98        * `a2r10g10b10` - 32-bit pixels, d[31:30]=a, d[29:20]=r, d[19:10]=g, d[9:0]=b
 99        * `a8b8g8r8` - 32-bit pixels, d[31:24]=a, d[23:16]=b, d[15:8]=g, d[7:0]=r
100        * `a8r8g8b8` - 32-bit pixels, d[31:24]=a, d[23:16]=r, d[15:8]=g, d[7:0]=b
101        * `r5g6b5` - 16-bit pixels, d[15:11]=r, d[10:5]=g, d[4:0]=b
102        * `r5g5b5a1` - 16-bit pixels, d[15:11]=r, d[10:6]=g, d[5:1]=b d[1:0]=a
103        * `r8g8b8` - 24-bit pixels, d[23:16]=r, d[15:8]=g, d[7:0]=b
104        * `x1r5g5b5` - 16-bit pixels, d[14:10]=r, d[9:5]=g, d[4:0]=b
105        * `x2r10g10b10` - 32-bit pixels, d[29:20]=r, d[19:10]=g, d[9:0]=b
106        * `x8r8g8b8` - 32-bit pixels, d[23:16]=r, d[15:8]=g, d[7:0]=b
107        * `x8b8g8r8` - 32-bit pixels, d[23:16]=b, d[15:8]=g, d[7:0]=r
108    enum:
109      - a1r5g5b5
110      - a2r10g10b10
111      - a8b8g8r8
112      - a8r8g8b8
113      - r5g6b5
114      - r5g5b5a1
115      - r8g8b8
116      - x1r5g5b5
117      - x2r10g10b10
118      - x8r8g8b8
119      - x8b8g8r8
120
121  display:
122    $ref: /schemas/types.yaml#/definitions/phandle
123    description: Primary display hardware node
124
125  panel:
126    $ref: /schemas/types.yaml#/definitions/phandle
127    description: Display panel node
128
129  allwinner,pipeline:
130    description: Pipeline used by the framebuffer on Allwinner SoCs
131    enum:
132      - de_be0-lcd0
133      - de_be0-lcd0-hdmi
134      - de_be0-lcd0-tve0
135      - de_be1-lcd0
136      - de_be1-lcd1-hdmi
137      - de_fe0-de_be0-lcd0
138      - de_fe0-de_be0-lcd0-hdmi
139      - de_fe0-de_be0-lcd0-tve0
140      - mixer0-lcd0
141      - mixer0-lcd0-hdmi
142      - mixer1-lcd1-hdmi
143      - mixer1-lcd1-tve
144
145  amlogic,pipeline:
146    description: Pipeline used by the framebuffer on Amlogic SoCs
147    enum:
148      - vpu-cvbs
149      - vpu-hdmi
150
151patternProperties:
152  "^[a-zA-Z0-9-]+-supply$":
153    $ref: /schemas/types.yaml#/definitions/phandle
154    description:
155      Regulators used by the framebuffer. These should be named
156      according to the names in the device design.
157
158required:
159  # The binding requires also reg, width, height, stride and format,
160  # but usually they will be filled by the bootloader.
161  - compatible
162
163allOf:
164  - if:
165      properties:
166        compatible:
167          contains:
168            const: allwinner,simple-framebuffer
169
170    then:
171      required:
172        - allwinner,pipeline
173
174  - if:
175      properties:
176        compatible:
177          contains:
178            const: amlogic,simple-framebuffer
179
180    then:
181      required:
182        - amlogic,pipeline
183
184additionalProperties: false
185
186examples:
187  - |
188    / {
189        compatible = "foo";
190        model = "foo";
191        #address-cells = <1>;
192        #size-cells = <1>;
193
194        chosen {
195            #address-cells = <1>;
196            #size-cells = <1>;
197            framebuffer0: framebuffer@1d385000 {
198                compatible = "allwinner,simple-framebuffer", "simple-framebuffer";
199                allwinner,pipeline = "de_be0-lcd0";
200                reg = <0x1d385000 3840000>;
201                width = <1600>;
202                height = <1200>;
203                stride = <3200>;
204                format = "r5g6b5";
205                clocks = <&ahb_gates 36>, <&ahb_gates 43>, <&ahb_gates 44>;
206                lcd-supply = <&reg_dc1sw>;
207                display = <&lcdc0>;
208            };
209        };
210    };
211
212...