87 lines
3.2 KiB
YAML
87 lines
3.2 KiB
YAML
|
# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
|
||
|
|
%YAML 1.2
|
||
|
|
---
|
||
|
|
$id: http://devicetree.org/schemas/power/reset/gpio-restart.yaml#
|
||
|
|
$schema: http://devicetree.org/meta-schemas/core.yaml#
|
||
|
|
|
||
|
|
title: GPIO controlled reset
|
||
|
|
|
||
|
|
maintainers:
|
||
|
|
- Sebastian Reichel <sre@kernel.org>
|
||
|
|
|
||
|
|
description: >
|
||
|
|
Drive a GPIO line that can be used to restart the system from a restart handler.
|
||
|
|
|
||
|
|
This binding supports level and edge triggered reset. At driver load time, the driver will
|
||
|
|
request the given gpio line and install a restart handler. If the optional properties
|
||
|
|
'open-source' is not found, the GPIO line will be driven in the inactive state. Otherwise its
|
||
|
|
not driven until the restart is initiated.
|
||
|
|
|
||
|
|
When the system is restarted, the restart handler will be invoked in priority order. The GPIO
|
||
|
|
is configured as an output, and driven active, triggering a level triggered reset condition.
|
||
|
|
This will also cause an inactive->active edge condition, triggering positive edge triggered
|
||
|
|
reset. After a delay specified by active-delay, the GPIO is set to inactive, thus causing an
|
||
|
|
active->inactive edge, triggering negative edge triggered reset. After a delay specified by
|
||
|
|
inactive-delay, the GPIO is driven active again. After a delay specified by wait-delay, the
|
||
|
|
restart handler completes allowing other restart handlers to be attempted.
|
||
|
|
|
||
|
|
properties:
|
||
|
|
compatible:
|
||
|
|
const: gpio-restart
|
||
|
|
|
||
|
|
gpios:
|
||
|
|
description: The GPIO to set high/low, see "gpios property" in
|
||
|
|
Documentation/devicetree/bindings/gpio/gpio.txt. If the pin should be low to reset the board
|
||
|
|
set it to "Active Low", otherwise set GPIO to "Active High".
|
||
|
|
|
||
|
|
open-source:
|
||
|
|
$ref: /schemas/types.yaml#/definitions/flag
|
||
|
|
description: Treat the GPIO as being open source and defer driving it to when the restart is
|
||
|
|
initiated. If this optional property is not specified, the GPIO is initialized as an output
|
||
|
|
in its inactive state.
|
||
|
|
|
||
|
|
priority:
|
||
|
|
$ref: /schemas/types.yaml#/definitions/uint32
|
||
|
|
description: |
|
||
|
|
A priority ranging from 0 to 255 (default 129) according to the following guidelines:
|
||
|
|
|
||
|
|
0: Restart handler of last resort, with limited restart capabilities.
|
||
|
|
128: Default restart handler; use if no other restart handler is expected to be available,
|
||
|
|
and/or if restart functionality is sufficient to restart the entire system.
|
||
|
|
255: Highest priority restart handler, will preempt all other restart handlers.
|
||
|
|
minimum: 0
|
||
|
|
maximum: 255
|
||
|
|
default: 129
|
||
|
|
|
||
|
|
active-delay:
|
||
|
|
$ref: /schemas/types.yaml#/definitions/uint32
|
||
|
|
description: Delay (default 100) to wait after driving gpio active [ms]
|
||
|
|
default: 100
|
||
|
|
|
||
|
|
inactive-delay:
|
||
|
|
$ref: /schemas/types.yaml#/definitions/uint32
|
||
|
|
description: Delay (default 100) to wait after driving gpio inactive [ms]
|
||
|
|
default: 100
|
||
|
|
|
||
|
|
wait-delay:
|
||
|
|
$ref: /schemas/types.yaml#/definitions/uint32
|
||
|
|
description: Delay (default 3000) to wait after completing restart sequence [ms]
|
||
|
|
default: 100
|
||
|
|
|
||
|
|
additionalProperties: false
|
||
|
|
|
||
|
|
required:
|
||
|
|
- compatible
|
||
|
|
- gpios
|
||
|
|
|
||
|
|
examples:
|
||
|
|
- |
|
||
|
|
gpio-restart {
|
||
|
|
compatible = "gpio-restart";
|
||
|
|
gpios = <&gpio 4 0>;
|
||
|
|
priority = <128>;
|
||
|
|
active-delay = <100>;
|
||
|
|
inactive-delay = <100>;
|
||
|
|
wait-delay = <3000>;
|
||
|
|
};
|