Documentation/devicetree/bindings/display/panel/panel-timing.yaml

   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
   7 title: panel timing bindings
   8
   9 maintainers:
  10   - Thierry Reding <thierry.reding@gmail.com>
  11   - Sam Ravnborg <sam@ravnborg.org>
  12
  13 description: |
  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   |          |        |vback_porch                 |          |       |
  23   |          |        v                            |          |       |
  24   +----------#######################################----------+-------+
  25   |          #        ^                            #          |       |
  26   |          #        |                            #          |       |
  27   |  hback   #        |                            #  hfront  | hsync |
  28   |   porch  #        |       hactive              #  porch   |  len  |
  29   |<-------->#<-------+--------------------------->#<-------->|<----->|
  30   |          #        |                            #          |       |
  31   |          #        |vactive                     #          |       |
  32   |          #        |                            #          |       |
  33   |          #        v                            #          |       |
  34   +----------#######################################----------+-------+
  35   |          |        ^                            |          |       |
  36   |          |        |vfront_porch                |          |       |
  37   |          |        v                            |          |       |
  38   +----------+-------------------------------------+----------+-------+
  39   |          |        ^                            |          |       |
  40   |          |        |vsync_len                   |          |       |
  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
  59 properties:
  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     oneOf:
  75       - $ref: /schemas/types.yaml#/definitions/uint32
  76         maxItems: 1
  77         items:
  78           description: typical number of pixels
  79       - $ref: /schemas/types.yaml#/definitions/uint32-array
  80         minItems: 3
  81         maxItems: 3
  82         items:
  83           description: min, typ, max number of pixels
  84
  85   hback-porch:
  86     description: Horizontal back porch timing
  87     oneOf:
  88       - $ref: /schemas/types.yaml#/definitions/uint32
  89         maxItems: 1
  90         items:
  91           description: typical number of pixels
  92       - $ref: /schemas/types.yaml#/definitions/uint32-array
  93         minItems: 3
  94         maxItems: 3
  95         items:
  96           description: min, typ, max number of pixels
  97
  98   hsync-len:
  99     description: Horizontal sync length panel timing
 100     oneOf:
 101       - $ref: /schemas/types.yaml#/definitions/uint32
 102         maxItems: 1
 103         items:
 104           description: typical number of pixels
 105       - $ref: /schemas/types.yaml#/definitions/uint32-array
 106         minItems: 3
 107         maxItems: 3
 108         items:
 109           description: min, typ, max number of pixels
 110
 111   vfront-porch:
 112     description: Vertical front porch panel timing
 113     oneOf:
 114       - $ref: /schemas/types.yaml#/definitions/uint32
 115         maxItems: 1
 116         items:
 117           description: typical number of lines
 118       - $ref: /schemas/types.yaml#/definitions/uint32-array
 119         minItems: 3
 120         maxItems: 3
 121         items:
 122           description: min, typ, max number of lines
 123
 124   vback-porch:
 125     description: Vertical back porch panel timing
 126     oneOf:
 127       - $ref: /schemas/types.yaml#/definitions/uint32
 128         maxItems: 1
 129         items:
 130           description: typical number of lines
 131       - $ref: /schemas/types.yaml#/definitions/uint32-array
 132         minItems: 3
 133         maxItems: 3
 134         items:
 135           description: min, typ, max number of lines
 136
 137   vsync-len:
 138     description: Vertical sync length panel timing
 139     oneOf:
 140       - $ref: /schemas/types.yaml#/definitions/uint32
 141         maxItems: 1
 142         items:
 143           description: typical number of lines
 144       - $ref: /schemas/types.yaml#/definitions/uint32-array
 145         minItems: 3
 146         maxItems: 3
 147         items:
 148           description: min, typ, max number of lines
 149
 150   hsync-active:
 151     description: |
 152       Horizontal sync pulse.
 153       0 selects active low, 1 selects active high.
 154       If omitted then it is not used by the hardware
 155     enum: [0, 1]
 156
 157   vsync-active:
 158     description: |
 159       Vertical sync pulse.
 160       0 selects active low, 1 selects active high.
 161       If omitted then it is not used by the hardware
 162     enum: [0, 1]
 163
 164   de-active:
 165     description: |
 166       Data enable.
 167       0 selects active low, 1 selects active high.
 168       If omitted then it is not used by the hardware
 169     enum: [0, 1]
 170
 171   pixelclk-active:
 172     description: |
 173       Data driving on rising or falling edge.
 174       Use 0 to drive pixel data on falling edge and
 175       sample data on rising edge.
 176       Use 1 to drive pixel data on rising edge and
 177       sample data on falling edge
 178     enum: [0, 1]
 179
 180   syncclk-active:
 181     description: |
 182       Drive sync on rising or sample sync on falling edge.
 183       If not specified then the setup is as specified by pixelclk-active.
 184       Use 0 to drive sync on falling edge and
 185       sample sync on rising edge of pixel clock.
 186       Use 1 to drive sync on rising edge and
 187       sample sync on falling edge of pixel clock
 188     enum: [0, 1]
 189
 190   interlaced:
 191     type: boolean
 192     description: Enable interlaced mode
 193
 194   doublescan:
 195     type: boolean
 196     description: Enable double scan mode
 197
 198   doubleclk:
 199     type: boolean
 200     description: Enable double clock mode
 201
 202 required:
 203   - clock-frequency
 204   - hactive
 205   - vactive
 206   - hfront-porch
 207   - hback-porch
 208   - hsync-len
 209   - vfront-porch
 210   - vback-porch
 211   - vsync-len
 212
 213 additionalProperties: false
 214
 215 ...