linux/Documentation/devicetree/bindings/regulator/regulator.yaml
Douglas Anderson 87fd0db6d7
regulator: Document "regulator-boot-on" binding more thoroughly
The description of "regulator-boot-on" was a little unclear, at least
to me.  Did this property mean that we should turn the regulator on at
boot?  Or perhaps it was intended only to be used for regulators where
we couldn't read the state at bootup to indicate what state we should
assume?  The answer, it turns out, is both [1].

Let's document this.

[1] https://lore.kernel.org/r/20190923181431.GU2036@sirena.org.uk

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20191001124531.v2.1.Ice34ad5970a375c3c03cb15c3859b3ee501561bf@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-10-02 12:58:37 +01:00

206 lines
7.3 KiB
YAML

# SPDX-License-Identifier: GPL-2.0
%YAML 1.2
---
$id: http://devicetree.org/schemas/regulator/regulator.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Voltage/Current Regulators
maintainers:
- Liam Girdwood <lgirdwood@gmail.com>
- Mark Brown <broonie@kernel.org>
properties:
regulator-name:
description: A string used as a descriptive name for regulator outputs
$ref: "/schemas/types.yaml#/definitions/string"
regulator-min-microvolt:
description: smallest voltage consumers may set
regulator-max-microvolt:
description: largest voltage consumers may set
regulator-microvolt-offset:
description: Offset applied to voltages to compensate for voltage drops
regulator-min-microamp:
description: smallest current consumers may set
regulator-max-microamp:
description: largest current consumers may set
regulator-input-current-limit-microamp:
description: maximum input current regulator allows
regulator-always-on:
description: boolean, regulator should never be disabled
type: boolean
regulator-boot-on:
description: bootloader/firmware enabled regulator.
It's expected that this regulator was left on by the bootloader.
If the bootloader didn't leave it on then OS should turn it on
at boot but shouldn't prevent it from being turned off later.
This property is intended to only be used for regulators where
software cannot read the state of the regulator.
type: boolean
regulator-allow-bypass:
description: allow the regulator to go into bypass mode
type: boolean
regulator-allow-set-load:
description: allow the regulator performance level to be configured
type: boolean
regulator-ramp-delay:
description: ramp delay for regulator(in uV/us) For hardware which supports
disabling ramp rate, it should be explicitly initialised to zero (regulator-ramp-delay
= <0>) for disabling ramp delay.
$ref: "/schemas/types.yaml#/definitions/uint32"
regulator-enable-ramp-delay:
description: The time taken, in microseconds, for the supply rail to
reach the target voltage, plus/minus whatever tolerance the board
design requires. This property describes the total system ramp time
required due to the combination of internal ramping of the regulator
itself, and board design issues such as trace capacitance and load
on the supply.
$ref: "/schemas/types.yaml#/definitions/uint32"
regulator-settling-time-us:
description: Settling time, in microseconds, for voltage change if regulator
have the constant time for any level voltage change. This is useful
when regulator have exponential voltage change.
regulator-settling-time-up-us:
description: Settling time, in microseconds, for voltage increase if
the regulator needs a constant time to settle after voltage increases
of any level. This is useful for regulators with exponential voltage
changes.
regulator-settling-time-down-us:
description: Settling time, in microseconds, for voltage decrease if
the regulator needs a constant time to settle after voltage decreases
of any level. This is useful for regulators with exponential voltage
changes.
regulator-soft-start:
description: Enable soft start so that voltage ramps slowly
type: boolean
regulator-initial-mode:
description: initial operating mode. The set of possible operating modes
depends on the capabilities of every hardware so each device binding
documentation explains which values the regulator supports.
$ref: "/schemas/types.yaml#/definitions/uint32"
regulator-allowed-modes:
description: list of operating modes that software is allowed to configure
for the regulator at run-time. Elements may be specified in any order.
The set of possible operating modes depends on the capabilities of
every hardware so each device binding document explains which values
the regulator supports.
$ref: "/schemas/types.yaml#/definitions/uint32-array"
regulator-system-load:
description: Load in uA present on regulator that is not captured by
any consumer request.
$ref: "/schemas/types.yaml#/definitions/uint32"
regulator-pull-down:
description: Enable pull down resistor when the regulator is disabled.
type: boolean
regulator-over-current-protection:
description: Enable over current protection.
type: boolean
regulator-active-discharge:
description: |
tristate, enable/disable active discharge of regulators. The values are:
0: Disable active discharge.
1: Enable active discharge.
Absence of this property will leave configuration to default.
allOf:
- $ref: "/schemas/types.yaml#/definitions/uint32"
- enum: [ 0, 1 ]
regulator-coupled-with:
description: Regulators with which the regulator is coupled. The linkage
is 2-way - all coupled regulators should be linked with each other.
A regulator should not be coupled with its supplier.
$ref: "/schemas/types.yaml#/definitions/phandle-array"
regulator-coupled-max-spread:
description: Array of maximum spread between voltages of coupled regulators
in microvolts, each value in the array relates to the corresponding
couple specified by the regulator-coupled-with property.
$ref: "/schemas/types.yaml#/definitions/uint32"
regulator-max-step-microvolt:
description: Maximum difference between current and target voltages
that can be changed safely in a single step.
patternProperties:
".*-supply$":
description: Input supply phandle(s) for this node
regulator-state-(standby|mem|disk):
type: object
description:
sub-nodes for regulator state in Standby, Suspend-to-RAM, and
Suspend-to-DISK modes. Equivalent with standby, mem, and disk Linux
sleep states.
properties:
regulator-on-in-suspend:
description: regulator should be on in suspend state.
type: boolean
regulator-off-in-suspend:
description: regulator should be off in suspend state.
type: boolean
regulator-suspend-min-microvolt:
description: minimum voltage may be set in suspend state.
regulator-suspend-max-microvolt:
description: maximum voltage may be set in suspend state.
regulator-suspend-microvolt:
description: the default voltage which regulator would be set in
suspend. This property is now deprecated, instead setting voltage
for suspend mode via the API which regulator driver provides is
recommended.
regulator-changeable-in-suspend:
description: whether the default voltage and the regulator on/off
in suspend can be changed in runtime.
type: boolean
regulator-mode:
description: operating mode in the given suspend state. The set
of possible operating modes depends on the capabilities of every
hardware so the valid modes are documented on each regulator device
tree binding document.
$ref: "/schemas/types.yaml#/definitions/uint32"
additionalProperties: false
examples:
- |
xyzreg: regulator@0 {
regulator-min-microvolt = <1000000>;
regulator-max-microvolt = <2500000>;
regulator-always-on;
vin-supply = <&vin>;
regulator-state-mem {
regulator-on-in-suspend;
};
};
...