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 183 184 185additionalProperties: false 186 187examples: 188 - | 189 / { 190 compatible = "foo"; 191 model = "foo"; 192 #address-cells = <1>; 193 #size-cells = <1>; 194 195 chosen { 196 #address-cells = <1>; 197 #size-cells = <1>; 198 framebuffer0: framebuffer@1d385000 { 199 compatible = "allwinner,simple-framebuffer", "simple-framebuffer"; 200 allwinner,pipeline = "de_be0-lcd0"; 201 reg = <0x1d385000 3840000>; 202 width = <1600>; 203 height = <1200>; 204 stride = <3200>; 205 format = "r5g6b5"; 206 clocks = <&ahb_gates 36>, <&ahb_gates 43>, <&ahb_gates 44>; 207 lcd-supply = <®_dc1sw>; 208 display = <&lcdc0>; 209 }; 210 }; 211 }; 212 213... 214