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Diffstat (limited to 'Documentation/devicetree/bindings/regulator/pwm-regulator.yaml')
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diff --git a/Documentation/devicetree/bindings/regulator/pwm-regulator.yaml b/Documentation/devicetree/bindings/regulator/pwm-regulator.yaml new file mode 100644 index 0000000000..80ecf938b7 --- /dev/null +++ b/Documentation/devicetree/bindings/regulator/pwm-regulator.yaml @@ -0,0 +1,127 @@ +# 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>; + }; +... |