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+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/regulator/pwm-regulator.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Generic PWM Regulator
+
+maintainers:
+ - Brian Norris <briannorris@chromium.org>
+ - Lee Jones <lee@kernel.org>
+ - Alexandre Courbot <acourbot@nvidia.com>
+
+description: |
+ Currently supports 2 modes of operation:
+
+ Voltage Table:
+ When in this mode, a voltage table (See below) of predefined voltage <=>
+ duty-cycle values must be provided via DT. Limitations are that the
+ regulator can only operate at the voltages supplied in the table.
+ Intermediary duty-cycle values which would normally allow finer grained
+ voltage selection are ignored and rendered useless. Although more control
+ is given to the user if the assumptions made in continuous-voltage mode do
+ not reign true.
+
+ Continuous Voltage:
+ This mode uses the regulator's maximum and minimum supplied voltages
+ specified in the regulator-{min,max}-microvolt properties to calculate
+ appropriate duty-cycle values. This allows for a much more fine grained
+ solution when compared with voltage-table mode above. This solution does
+ make an assumption that a %50 duty-cycle value will cause the regulator
+ voltage to run at half way between the supplied max_uV and min_uV values.
+
+ If voltage-table is provided, then the device will be used in Voltage Table
+ Mode. If no voltage-table is provided, then the device will be used in
+ Continuous Voltage Mode.
+
+allOf:
+ - $ref: regulator.yaml#
+
+properties:
+ compatible:
+ const: pwm-regulator
+
+ pwms:
+ maxItems: 1
+
+ voltage-table:
+ description: Voltage and Duty-Cycle table.
+ $ref: /schemas/types.yaml#/definitions/uint32-matrix
+ items:
+ items:
+ - description: voltage in microvolts (uV)
+ - description: duty-cycle in percent (%)
+
+ enable-gpios:
+ description: Regulator enable GPIO
+ maxItems: 1
+
+ # Optional properties for Continuous mode:
+ pwm-dutycycle-unit:
+ description:
+ Integer value encoding the duty cycle unit. If not
+ defined, <100> is assumed, meaning that
+ pwm-dutycycle-range contains values expressed in
+ percent.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ default: 100
+
+ pwm-dutycycle-range:
+ description:
+ Should contain 2 entries. The first entry is encoding
+ the dutycycle for regulator-min-microvolt and the
+ second one the dutycycle for regulator-max-microvolt.
+ Duty cycle values are expressed in pwm-dutycycle-unit.
+ If not defined, <0 100> is assumed.
+ $ref: /schemas/types.yaml#/definitions/uint32-array
+ items:
+ - description: the dutycycle for regulator-min-microvolt
+ - description: the dutycycle for regulator-max-microvolt
+ default: [ 0 100 ]
+
+required:
+ - compatible
+ - pwms
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+
+ // Continuous Voltage With Enable GPIO Example:
+ regulator {
+ compatible = "pwm-regulator";
+ pwms = <&pwm1 0 8448 0>;
+ enable-gpios = <&gpio0 23 GPIO_ACTIVE_HIGH>;
+ regulator-min-microvolt = <1016000>;
+ regulator-max-microvolt = <1114000>;
+ regulator-name = "vdd_logic";
+ /* unit == per-mille */
+ pwm-dutycycle-unit = <1000>;
+ /*
+ * Inverted PWM logic, and the duty cycle range is limited
+ * to 30%-70%.
+ */
+ pwm-dutycycle-range = <700 300>; /* */
+ };
+
+ - |
+ // Voltage Table Example:
+ regulator {
+ compatible = "pwm-regulator";
+ pwms = <&pwm1 0 8448 0>;
+ regulator-min-microvolt = <1016000>;
+ regulator-max-microvolt = <1114000>;
+ regulator-name = "vdd_logic";
+
+ /* Voltage Duty-Cycle */
+ voltage-table = <1114000 0>,
+ <1095000 10>,
+ <1076000 20>,
+ <1056000 30>,
+ <1036000 40>,
+ <1016000 50>;
+ };
+...