1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) 2%YAML 1.2 3--- 4$id: http://devicetree.org/schemas/display/panel/panel-timing.yaml# 5$schema: http://devicetree.org/meta-schemas/core.yaml# 6 7title: panel timing 8 9maintainers: 10 - Thierry Reding <thierry.reding@gmail.com> 11 - Sam Ravnborg <sam@ravnborg.org> 12 13description: | 14 There are different ways of describing the timing data of a panel. The 15 devicetree representation corresponds to the one commonly found in datasheets 16 for panels. 17 18 The parameters are defined as seen in the following illustration. 19 20 +-------+----------+-------------------------------------+----------+ 21 | | | ^ | | 22 | | | |vsync_len | | 23 | | | v | | 24 +-------+----------+-------------------------------------+----------+ 25 | | | ^ | | 26 | | | |vback_porch | | 27 | | | v | | 28 +-------+----------#######################################----------+ 29 | | # ^ # | 30 | | # | # | 31 | hsync | hback # | # hfront | 32 | len | porch # | hactive # porch | 33 |<----->|<-------->#<-------+--------------------------->#<-------->| 34 | | # | # | 35 | | # |vactive # | 36 | | # | # | 37 | | # v # | 38 +-------+----------#######################################----------+ 39 | | | ^ | | 40 | | | |vfront_porch | | 41 | | | v | | 42 +-------+----------+-------------------------------------+----------+ 43 44 45 The following is the panel timings shown with time on the x-axis. 46 This matches the timing diagrams often found in data sheets. 47 48 Active Front Sync Back 49 Region Porch Porch 50 <-----------------------><----------------><-------------><--------------> 51 //////////////////////| 52 ////////////////////// | 53 ////////////////////// |.................. ................ 54 _______________ 55 56 Timing can be specified either as a typical value or as a tuple 57 of min, typ, max values. 58 59properties: 60 61 clock-frequency: 62 description: Panel clock in Hz 63 64 hactive: 65 $ref: /schemas/types.yaml#/definitions/uint32 66 description: Horizontal panel resolution in pixels 67 68 vactive: 69 $ref: /schemas/types.yaml#/definitions/uint32 70 description: Vertical panel resolution in pixels 71 72 hfront-porch: 73 description: Horizontal front porch panel timing 74 $ref: /schemas/types.yaml#/definitions/uint32-array 75 oneOf: 76 - maxItems: 1 77 items: 78 description: typical number of pixels 79 - minItems: 3 80 maxItems: 3 81 items: 82 description: min, typ, max number of pixels 83 84 hback-porch: 85 description: Horizontal back porch timing 86 $ref: /schemas/types.yaml#/definitions/uint32-array 87 oneOf: 88 - maxItems: 1 89 items: 90 description: typical number of pixels 91 - minItems: 3 92 maxItems: 3 93 items: 94 description: min, typ, max number of pixels 95 96 hsync-len: 97 description: Horizontal sync length panel timing 98 $ref: /schemas/types.yaml#/definitions/uint32-array 99 oneOf: 100 - maxItems: 1 101 items: 102 description: typical number of pixels 103 - minItems: 3 104 maxItems: 3 105 items: 106 description: min, typ, max number of pixels 107 108 vfront-porch: 109 description: Vertical front porch panel timing 110 $ref: /schemas/types.yaml#/definitions/uint32-array 111 oneOf: 112 - maxItems: 1 113 items: 114 description: typical number of lines 115 - minItems: 3 116 maxItems: 3 117 items: 118 description: min, typ, max number of lines 119 120 vback-porch: 121 description: Vertical back porch panel timing 122 $ref: /schemas/types.yaml#/definitions/uint32-array 123 oneOf: 124 - maxItems: 1 125 items: 126 description: typical number of lines 127 - minItems: 3 128 maxItems: 3 129 items: 130 description: min, typ, max number of lines 131 132 vsync-len: 133 description: Vertical sync length panel timing 134 $ref: /schemas/types.yaml#/definitions/uint32-array 135 oneOf: 136 - maxItems: 1 137 items: 138 description: typical number of lines 139 - minItems: 3 140 maxItems: 3 141 items: 142 description: min, typ, max number of lines 143 144 hsync-active: 145 description: | 146 Horizontal sync pulse. 147 0 selects active low, 1 selects active high. 148 If omitted then it is not used by the hardware 149 $ref: /schemas/types.yaml#/definitions/uint32 150 enum: [0, 1] 151 152 vsync-active: 153 description: | 154 Vertical sync pulse. 155 0 selects active low, 1 selects active high. 156 If omitted then it is not used by the hardware 157 $ref: /schemas/types.yaml#/definitions/uint32 158 enum: [0, 1] 159 160 de-active: 161 description: | 162 Data enable. 163 0 selects active low, 1 selects active high. 164 If omitted then it is not used by the hardware 165 $ref: /schemas/types.yaml#/definitions/uint32 166 enum: [0, 1] 167 168 pixelclk-active: 169 description: | 170 Data driving on rising or falling edge. 171 Use 0 to drive pixel data on falling edge and 172 sample data on rising edge. 173 Use 1 to drive pixel data on rising edge and 174 sample data on falling edge 175 $ref: /schemas/types.yaml#/definitions/uint32 176 enum: [0, 1] 177 178 syncclk-active: 179 description: | 180 Drive sync on rising or sample sync on falling edge. 181 If not specified then the setup is as specified by pixelclk-active. 182 Use 0 to drive sync on falling edge and 183 sample sync on rising edge of pixel clock. 184 Use 1 to drive sync on rising edge and 185 sample sync on falling edge of pixel clock 186 $ref: /schemas/types.yaml#/definitions/uint32 187 enum: [0, 1] 188 189 interlaced: 190 type: boolean 191 description: Enable interlaced mode 192 193 doublescan: 194 type: boolean 195 description: Enable double scan mode 196 197 doubleclk: 198 type: boolean 199 description: Enable double clock mode 200 201required: 202 - clock-frequency 203 - hactive 204 - vactive 205 - hfront-porch 206 - hback-porch 207 - hsync-len 208 - vfront-porch 209 - vback-porch 210 - vsync-len 211 212additionalProperties: false 213 214... 215