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authorMatthias Kaehlcke <mka@chromium.org>2017-04-07 12:51:58 -0700
committerMark Brown <broonie@kernel.org>2017-04-10 17:30:40 +0100
commit9dee7a72d0c7cdfa2573c48b1e5f928c721d54d5 (patch)
treeef2cd230ca98ee074faf3698ddac6c7380d4b22e /Documentation/devicetree/bindings
parentd00b74613fb18dfd0a5aa99270ee2e72d5c808d7 (diff)
regulator: Add driver for voltage controlled regulators
The output voltage of a voltage controlled regulator can be controlled through the voltage of another regulator. The current version of this driver assumes that the output voltage is a linear function of the control voltage. Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'Documentation/devicetree/bindings')
-rw-r--r--Documentation/devicetree/bindings/regulator/vctrl.txt49
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diff --git a/Documentation/devicetree/bindings/regulator/vctrl.txt b/Documentation/devicetree/bindings/regulator/vctrl.txt
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+Bindings for Voltage controlled regulators
+==========================================
+
+Required properties:
+--------------------
+- compatible : must be "vctrl-regulator".
+- regulator-min-microvolt : smallest voltage consumers may set
+- regulator-max-microvolt : largest voltage consumers may set
+- ctrl-supply : The regulator supplying the control voltage.
+- ctrl-voltage-range : an array of two integer values describing the range
+ (min/max) of the control voltage. The values specify
+ the control voltage needed to generate the corresponding
+ regulator-min/max-microvolt output voltage.
+
+Optional properties:
+--------------------
+- ovp-threshold-percent : overvoltage protection (OVP) threshold of the
+ regulator in percent. Some regulators have an OVP
+ circuitry which shuts down the regulator when the
+ actual output voltage deviates beyond a certain
+ margin from the expected value for a given control
+ voltage. On larger voltage decreases this can occur
+ undesiredly since the output voltage does not adjust
+ inmediately to changes in the control voltage. To
+ avoid this situation the vctrl driver breaks down
+ larger voltage decreases into multiple steps, where
+ each step is within the OVP threshold.
+- min-slew-down-rate : Describes how slowly the regulator voltage will decay
+ down in the worst case (lightest expected load).
+ Specified in uV / us (like main regulator ramp rate).
+ This value is required when ovp-threshold-percent is
+ specified.
+
+Example:
+
+ vctrl-reg {
+ compatible = "vctrl-regulator";
+ regulator-name = "vctrl_reg";
+
+ ctrl-supply = <&ctrl_reg>;
+
+ regulator-min-microvolt = <800000>;
+ regulator-max-microvolt = <1500000>;
+
+ ctrl-voltage-range = <200000 500000>;
+
+ min-slew-down-rate = <225>;
+ ovp-threshold-percent = <16>;
+ };