# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/display/panel/panel-timing.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: panel timing
maintainers:
- Thierry Reding <[email protected]>
- Sam Ravnborg <[email protected]>
description: |
There are different ways of describing the timing data of a panel. The
devicetree representation corresponds to the one commonly found in datasheets
for panels.
The parameters are defined as seen in the following illustration.
+-------+----------+-------------------------------------+----------+
| | | ^ | |
| | | |vsync_len | |
| | | v | |
+-------+----------+-------------------------------------+----------+
| | | ^ | |
| | | |vback_porch | |
| | | v | |
+-------+----------#######################################----------+
| | # ^ # |
| | # | # |
| hsync | hback # | # hfront |
| len | porch # | hactive # porch |
|<----->|<-------->#<-------+--------------------------->#<-------->|
| | # | # |
| | # |vactive # |
| | # | # |
| | # v # |
+-------+----------#######################################----------+
| | | ^ | |
| | | |vfront_porch | |
| | | v | |
+-------+----------+-------------------------------------+----------+
The following is the panel timings shown with time on the x-axis.
This matches the timing diagrams often found in data sheets.
Active Front Sync Back
Region Porch Porch
<-----------------------><----------------><-------------><-------------->
//////////////////////|
////////////////////// |
////////////////////// |.................. ................
_______________
Timing can be specified either as a typical value or as a tuple
of min, typ, max values.
properties:
clock-frequency:
description: Panel clock in Hz
hactive:
$ref: /schemas/types.yaml#/definitions/uint32
description: Horizontal panel resolution in pixels
vactive:
$ref: /schemas/types.yaml#/definitions/uint32
description: Vertical panel resolution in pixels
hfront-porch:
description: Horizontal front porch panel timing
$ref: /schemas/types.yaml#/definitions/uint32-array
oneOf:
- maxItems: 1
items:
description: typical number of pixels
- minItems: 3
maxItems: 3
items:
description: min, typ, max number of pixels
hback-porch:
description: Horizontal back porch timing
$ref: /schemas/types.yaml#/definitions/uint32-array
oneOf:
- maxItems: 1
items:
description: typical number of pixels
- minItems: 3
maxItems: 3
items:
description: min, typ, max number of pixels
hsync-len:
description: Horizontal sync length panel timing
$ref: /schemas/types.yaml#/definitions/uint32-array
oneOf:
- maxItems: 1
items:
description: typical number of pixels
- minItems: 3
maxItems: 3
items:
description: min, typ, max number of pixels
vfront-porch:
description: Vertical front porch panel timing
$ref: /schemas/types.yaml#/definitions/uint32-array
oneOf:
- maxItems: 1
items:
description: typical number of lines
- minItems: 3
maxItems: 3
items:
description: min, typ, max number of lines
vback-porch:
description: Vertical back porch panel timing
$ref: /schemas/types.yaml#/definitions/uint32-array
oneOf:
- maxItems: 1
items:
description: typical number of lines
- minItems: 3
maxItems: 3
items:
description: min, typ, max number of lines
vsync-len:
description: Vertical sync length panel timing
$ref: /schemas/types.yaml#/definitions/uint32-array
oneOf:
- maxItems: 1
items:
description: typical number of lines
- minItems: 3
maxItems: 3
items:
description: min, typ, max number of lines
hsync-active:
description: |
Horizontal sync pulse.
0 selects active low, 1 selects active high.
If omitted then it is not used by the hardware
$ref: /schemas/types.yaml#/definitions/uint32
enum: [0, 1]
vsync-active:
description: |
Vertical sync pulse.
0 selects active low, 1 selects active high.
If omitted then it is not used by the hardware
$ref: /schemas/types.yaml#/definitions/uint32
enum: [0, 1]
de-active:
description: |
Data enable.
0 selects active low, 1 selects active high.
If omitted then it is not used by the hardware
$ref: /schemas/types.yaml#/definitions/uint32
enum: [0, 1]
pixelclk-active:
description: |
Data driving on rising or falling edge.
Use 0 to drive pixel data on falling edge and
sample data on rising edge.
Use 1 to drive pixel data on rising edge and
sample data on falling edge
$ref: /schemas/types.yaml#/definitions/uint32
enum: [0, 1]
syncclk-active:
description: |
Drive sync on rising or sample sync on falling edge.
If not specified then the setup is as specified by pixelclk-active.
Use 0 to drive sync on falling edge and
sample sync on rising edge of pixel clock.
Use 1 to drive sync on rising edge and
sample sync on falling edge of pixel clock
$ref: /schemas/types.yaml#/definitions/uint32
enum: [0, 1]
interlaced:
type: boolean
description: Enable interlaced mode
doublescan:
type: boolean
description: Enable double scan mode
doubleclk:
type: boolean
description: Enable double clock mode
required:
- clock-frequency
- hactive
- vactive
- hfront-porch
- hback-porch
- hsync-len
- vfront-porch
- vback-porch
- vsync-len
additionalProperties: false
...
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