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Diffstat (limited to 'Documentation/devicetree/bindings/regulator/regulator.txt')
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diff --git a/Documentation/devicetree/bindings/regulator/regulator.txt b/Documentation/devicetree/bindings/regulator/regulator.txt new file mode 100644 index 000000000..a7cd36877 --- /dev/null +++ b/Documentation/devicetree/bindings/regulator/regulator.txt @@ -0,0 +1,133 @@ +Voltage/Current Regulators + +Optional properties: +- regulator-name: A string used as a descriptive name for regulator outputs +- regulator-min-microvolt: smallest voltage consumers may set +- regulator-max-microvolt: largest voltage consumers may set +- regulator-microvolt-offset: Offset applied to voltages to compensate for voltage drops +- regulator-min-microamp: smallest current consumers may set +- regulator-max-microamp: largest current consumers may set +- regulator-input-current-limit-microamp: maximum input current regulator allows +- regulator-always-on: boolean, regulator should never be disabled +- regulator-boot-on: bootloader/firmware enabled regulator +- regulator-allow-bypass: allow the regulator to go into bypass mode +- regulator-allow-set-load: allow the regulator performance level to be configured +- <name>-supply: phandle to the parent supply/regulator node +- regulator-ramp-delay: 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. +- regulator-enable-ramp-delay: 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. +- regulator-settling-time-us: 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: 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: 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: Enable soft start so that voltage ramps slowly +- regulator-state-mem sub-root node for Suspend-to-RAM mode + : suspend to memory, the device goes to sleep, but all data stored in memory, + only some external interrupt can wake the device. +- regulator-state-disk sub-root node for Suspend-to-DISK mode + : suspend to disk, this state operates similarly to Suspend-to-RAM, + but includes a final step of writing memory contents to disk. +- regulator-state-[mem/disk] node has following common properties: + - regulator-on-in-suspend: regulator should be on in suspend state. + - regulator-off-in-suspend: regulator should be off in suspend state. + - regulator-suspend-min-microvolt: minimum voltage may be set in + suspend state. + - regulator-suspend-max-microvolt: maximum voltage may be set in + suspend state. + - regulator-suspend-microvolt: 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: whether the default voltage and + the regulator on/off in suspend can be changed in runtime. + - regulator-mode: 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. +- regulator-initial-mode: 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. +- regulator-allowed-modes: 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. +- regulator-system-load: Load in uA present on regulator that is not captured by + any consumer request. +- regulator-pull-down: Enable pull down resistor when the regulator is disabled. +- regulator-over-current-protection: Enable over current protection. +- regulator-active-discharge: 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. +- regulator-coupled-with: 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. +- regulator-coupled-max-spread: Max spread between voltages of coupled regulators + in microvolts. + +Deprecated properties: +- regulator-compatible: If a regulator chip contains multiple + regulators, and if the chip's binding contains a child node that + describes each regulator, then this property indicates which regulator + this child node is intended to configure. If this property is missing, + the node's name will be used instead. + +Example: + + xyzreg: regulator@0 { + regulator-min-microvolt = <1000000>; + regulator-max-microvolt = <2500000>; + regulator-always-on; + vin-supply = <&vin>; + + regulator-state-mem { + regulator-on-in-suspend; + }; + }; + +Regulator Consumers: +Consumer nodes can reference one or more of its supplies/ +regulators using the below bindings. + +- <name>-supply: phandle to the regulator node + +These are the same bindings that a regulator in the above +example used to reference its own supply, in which case +its just seen as a special case of a regulator being a +consumer itself. + +Example of a consumer device node (mmc) referencing two +regulators (twl_reg1 and twl_reg2), + + twl_reg1: regulator@0 { + ... + ... + ... + }; + + twl_reg2: regulator@1 { + ... + ... + ... + }; + + mmc: mmc@0 { + ... + ... + vmmc-supply = <&twl_reg1>; + vmmcaux-supply = <&twl_reg2>; + }; |