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 It is advised to add display# aliases to help the OS determine how 30 to number things. If display# aliases are used, then if the simplefb 31 node contains a display property then the /aliases/display# path 32 must point to the display hw node the display property points to, 33 otherwise it must point directly to the simplefb node. 34 35 If a simplefb node represents the preferred console for user 36 interaction, then the chosen node stdout-path property should point 37 to it, or to the primary display hw node, as with display# 38 aliases. If display aliases are used then it should be set to the 39 alias instead. 40 41 It is advised that devicetree files contain pre-filled, disabled 42 framebuffer nodes, so that the firmware only needs to update the 43 mode information and enable them. This way if e.g. later on support 44 for more display clocks get added, the simplefb nodes will already 45 contain this info and the firmware does not need to be updated. 46 47 If pre-filled framebuffer nodes are used, the firmware may need 48 extra information to find the right node. In that case an extra 49 platform specific compatible and platform specific properties should 50 be used and documented. 51 52properties: 53 compatible: 54 oneOf: 55 - items: 56 - enum: 57 - apple,simple-framebuffer 58 - allwinner,simple-framebuffer 59 - amlogic,simple-framebuffer 60 - const: simple-framebuffer 61 - const: simple-framebuffer 62 63 reg: 64 description: Location and size of the framebuffer memory 65 66 clocks: 67 description: List of clocks used by the framebuffer. 68 69 power-domains: 70 description: List of power domains used by the framebuffer. 71 72 width: 73 $ref: /schemas/types.yaml#/definitions/uint32 74 description: Width of the framebuffer in pixels 75 76 height: 77 $ref: /schemas/types.yaml#/definitions/uint32 78 description: Height of the framebuffer in pixels 79 80 stride: 81 $ref: /schemas/types.yaml#/definitions/uint32 82 description: Number of bytes of a line in the framebuffer 83 84 format: 85 description: > 86 Format of the framebuffer: 87 * `a1r5g5b5` - 16-bit pixels, d[15]=a, d[14:10]=r, d[9:5]=g, d[4:0]=b 88 * `a2r10g10b10` - 32-bit pixels, d[31:30]=a, d[29:20]=r, d[19:10]=g, d[9:0]=b 89 * `a8b8g8r8` - 32-bit pixels, d[31:24]=a, d[23:16]=b, d[15:8]=g, d[7:0]=r 90 * `a8r8g8b8` - 32-bit pixels, d[31:24]=a, d[23:16]=r, d[15:8]=g, d[7:0]=b 91 * `r5g6b5` - 16-bit pixels, d[15:11]=r, d[10:5]=g, d[4:0]=b 92 * `r5g5b5a1` - 16-bit pixels, d[15:11]=r, d[10:6]=g, d[5:1]=b d[1:0]=a 93 * `r8g8b8` - 24-bit pixels, d[23:16]=r, d[15:8]=g, d[7:0]=b 94 * `x1r5g5b5` - 16-bit pixels, d[14:10]=r, d[9:5]=g, d[4:0]=b 95 * `x2r10g10b10` - 32-bit pixels, d[29:20]=r, d[19:10]=g, d[9:0]=b 96 * `x8r8g8b8` - 32-bit pixels, d[23:16]=r, d[15:8]=g, d[7:0]=b 97 enum: 98 - a1r5g5b5 99 - a2r10g10b10 100 - a8b8g8r8 101 - a8r8g8b8 102 - r5g6b5 103 - r5g5b5a1 104 - r8g8b8 105 - x1r5g5b5 106 - x2r10g10b10 107 - x8r8g8b8 108 109 display: 110 $ref: /schemas/types.yaml#/definitions/phandle 111 description: Primary display hardware node 112 113 allwinner,pipeline: 114 description: Pipeline used by the framebuffer on Allwinner SoCs 115 enum: 116 - de_be0-lcd0 117 - de_be0-lcd0-hdmi 118 - de_be0-lcd0-tve0 119 - de_be1-lcd0 120 - de_be1-lcd1-hdmi 121 - de_fe0-de_be0-lcd0 122 - de_fe0-de_be0-lcd0-hdmi 123 - de_fe0-de_be0-lcd0-tve0 124 - mixer0-lcd0 125 - mixer0-lcd0-hdmi 126 - mixer1-lcd1-hdmi 127 - mixer1-lcd1-tve 128 129 amlogic,pipeline: 130 description: Pipeline used by the framebuffer on Amlogic SoCs 131 enum: 132 - vpu-cvbs 133 - vpu-hdmi 134 135patternProperties: 136 "^[a-zA-Z0-9-]+-supply$": 137 $ref: /schemas/types.yaml#/definitions/phandle 138 description: 139 Regulators used by the framebuffer. These should be named 140 according to the names in the device design. 141 142required: 143 # The binding requires also reg, width, height, stride and format, 144 # but usually they will be filled by the bootloader. 145 - compatible 146 147allOf: 148 - if: 149 properties: 150 compatible: 151 contains: 152 const: allwinner,simple-framebuffer 153 154 then: 155 required: 156 - allwinner,pipeline 157 158 - if: 159 properties: 160 compatible: 161 contains: 162 const: amlogic,simple-framebuffer 163 164 then: 165 required: 166 - amlogic,pipeline 167 168 169additionalProperties: false 170 171examples: 172 - | 173 / { 174 compatible = "foo"; 175 model = "foo"; 176 #address-cells = <1>; 177 #size-cells = <1>; 178 179 chosen { 180 #address-cells = <1>; 181 #size-cells = <1>; 182 framebuffer0: framebuffer@1d385000 { 183 compatible = "allwinner,simple-framebuffer", "simple-framebuffer"; 184 allwinner,pipeline = "de_be0-lcd0"; 185 reg = <0x1d385000 3840000>; 186 width = <1600>; 187 height = <1200>; 188 stride = <3200>; 189 format = "r5g6b5"; 190 clocks = <&ahb_gates 36>, <&ahb_gates 43>, <&ahb_gates 44>; 191 lcd-supply = <®_dc1sw>; 192 display = <&lcdc0>; 193 }; 194 }; 195 }; 196 197... 198