140 lines
6.4 KiB
Plaintext
140 lines
6.4 KiB
Plaintext
Voltage/Current Regulators
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Optional properties:
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- regulator-name: A string used as a descriptive name for regulator outputs
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- regulator-min-microvolt: smallest voltage consumers may set
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- regulator-max-microvolt: largest voltage consumers may set
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- regulator-microvolt-offset: Offset applied to voltages to compensate for voltage drops
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- regulator-min-microamp: smallest current consumers may set
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- regulator-max-microamp: largest current consumers may set
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- regulator-input-current-limit-microamp: maximum input current regulator allows
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- regulator-always-on: boolean, regulator should never be disabled
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- regulator-boot-on: bootloader/firmware enabled regulator
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- regulator-allow-bypass: allow the regulator to go into bypass mode
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- regulator-allow-set-load: allow the regulator performance level to be configured
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- <name>-supply: phandle to the parent supply/regulator node
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- regulator-ramp-delay: ramp delay for regulator(in uV/us)
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For hardware which supports disabling ramp rate, it should be explicitly
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initialised to zero (regulator-ramp-delay = <0>) for disabling ramp delay.
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- regulator-enable-ramp-delay: The time taken, in microseconds, for the supply
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rail to reach the target voltage, plus/minus whatever tolerance the board
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design requires. This property describes the total system ramp time
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required due to the combination of internal ramping of the regulator itself,
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and board design issues such as trace capacitance and load on the supply.
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- regulator-settling-time-us: Settling time, in microseconds, for voltage
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change if regulator have the constant time for any level voltage change.
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This is useful when regulator have exponential voltage change.
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- regulator-settling-time-up-us: Settling time, in microseconds, for voltage
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increase if the regulator needs a constant time to settle after voltage
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increases of any level. This is useful for regulators with exponential
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voltage changes.
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- regulator-settling-time-down-us: Settling time, in microseconds, for voltage
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decrease if the regulator needs a constant time to settle after voltage
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decreases of any level. This is useful for regulators with exponential
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voltage changes.
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- regulator-soft-start: Enable soft start so that voltage ramps slowly
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- regulator-state-standby sub-root node for Standby mode
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: equivalent with standby Linux sleep state, which provides energy savings
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with a relatively quick transition back time.
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- regulator-state-mem sub-root node for Suspend-to-RAM mode
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: suspend to memory, the device goes to sleep, but all data stored in memory,
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only some external interrupt can wake the device.
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- regulator-state-disk sub-root node for Suspend-to-DISK mode
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: suspend to disk, this state operates similarly to Suspend-to-RAM,
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but includes a final step of writing memory contents to disk.
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- regulator-state-[mem/disk/standby] node has following common properties:
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- regulator-on-in-suspend: regulator should be on in suspend state.
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- regulator-off-in-suspend: regulator should be off in suspend state.
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- regulator-suspend-min-microvolt: minimum voltage may be set in
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suspend state.
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- regulator-suspend-max-microvolt: maximum voltage may be set in
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suspend state.
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- regulator-suspend-microvolt: the default voltage which regulator
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would be set in suspend. This property is now deprecated, instead
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setting voltage for suspend mode via the API which regulator
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driver provides is recommended.
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- regulator-changeable-in-suspend: whether the default voltage and
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the regulator on/off in suspend can be changed in runtime.
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- regulator-mode: operating mode in the given suspend state.
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The set of possible operating modes depends on the capabilities of
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every hardware so the valid modes are documented on each regulator
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device tree binding document.
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- regulator-initial-mode: initial operating mode. The set of possible operating
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modes depends on the capabilities of every hardware so each device binding
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documentation explains which values the regulator supports.
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- regulator-allowed-modes: list of operating modes that software is allowed to
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configure for the regulator at run-time. Elements may be specified in any
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order. The set of possible operating modes depends on the capabilities of
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every hardware so each device binding document explains which values the
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regulator supports.
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- regulator-system-load: Load in uA present on regulator that is not captured by
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any consumer request.
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- regulator-pull-down: Enable pull down resistor when the regulator is disabled.
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- regulator-over-current-protection: Enable over current protection.
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- regulator-active-discharge: tristate, enable/disable active discharge of
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regulators. The values are:
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0: Disable active discharge.
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1: Enable active discharge.
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Absence of this property will leave configuration to default.
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- regulator-coupled-with: Regulators with which the regulator
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is coupled. The linkage is 2-way - all coupled regulators should be linked
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with each other. A regulator should not be coupled with its supplier.
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- regulator-coupled-max-spread: Array of maximum spread between voltages of
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coupled regulators in microvolts, each value in the array relates to the
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corresponding couple specified by the regulator-coupled-with property.
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- regulator-max-step-microvolt: Maximum difference between current and target
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voltages that can be changed safely in a single step.
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Deprecated properties:
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- regulator-compatible: If a regulator chip contains multiple
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regulators, and if the chip's binding contains a child node that
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describes each regulator, then this property indicates which regulator
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this child node is intended to configure. If this property is missing,
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the node's name will be used instead.
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Example:
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xyzreg: regulator@0 {
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regulator-min-microvolt = <1000000>;
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regulator-max-microvolt = <2500000>;
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regulator-always-on;
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vin-supply = <&vin>;
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regulator-state-mem {
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regulator-on-in-suspend;
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};
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};
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Regulator Consumers:
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Consumer nodes can reference one or more of its supplies/
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regulators using the below bindings.
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- <name>-supply: phandle to the regulator node
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These are the same bindings that a regulator in the above
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example used to reference its own supply, in which case
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its just seen as a special case of a regulator being a
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consumer itself.
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Example of a consumer device node (mmc) referencing two
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regulators (twl_reg1 and twl_reg2),
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twl_reg1: regulator@0 {
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...
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...
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...
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};
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twl_reg2: regulator@1 {
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...
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...
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...
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};
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mmc: mmc@0 {
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...
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...
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vmmc-supply = <&twl_reg1>;
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vmmcaux-supply = <&twl_reg2>;
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};
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