[PATCH 8/8] dt: regulator: pwm-regulator: Re-write bindings
Lee Jones
lee.jones at linaro.org
Fri Jun 5 11:47:11 PDT 2015
Whoops, nearly forgot the DT folks.
Sorry chaps.
> * Add support for continuous-voltage mode
> * Put more meat on the bones with regards to voltage-table mode
> * Sort out formatting for ease of consumption
>
> Signed-off-by: Lee Jones <lee.jones at linaro.org>
> ---
> .../bindings/regulator/pwm-regulator.txt | 66 ++++++++++++++++++----
> 1 file changed, 54 insertions(+), 12 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/regulator/pwm-regulator.txt b/Documentation/devicetree/bindings/regulator/pwm-regulator.txt
> index ce91f61..9a8269f 100644
> --- a/Documentation/devicetree/bindings/regulator/pwm-regulator.txt
> +++ b/Documentation/devicetree/bindings/regulator/pwm-regulator.txt
> @@ -1,27 +1,69 @@
> -pwm regulator bindings
> +Bindings for the Generic PWM Regulator
> +======================================
> +
> +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.
>
> Required properties:
> -- compatible: Should be "pwm-regulator"
> -- pwms: OF device-tree PWM specification (see PWM binding pwm.txt)
> -- voltage-table: voltage and duty table, include 2 members in each set of
> - brackets, first one is voltage(unit: uv), the next is duty(unit: percent)
> +--------------------
> +- compatible: Should be "pwm-regulator"
> +
> +- pwms: PWM specification (See: ../pwm/pwm.txt)
> +
> +One of these must be provided:
> +- voltage-table: Voltage and Duty-Cycle table consisting of 2 cells
> + First cell is voltage in microvolts (uV)
> + Second cell is duty-cycle in percent (%)
> +
> +- max-duty-cycle: Maximum Duty-Cycle value -- this will normally be 255 (0xff)
> + for an 8 bit PMU device
>
> -Any property defined as part of the core regulator binding defined in
> -regulator.txt can also be used.
> +If both are provided, the current default is voltage-table mode.
>
> -Example:
> +Any property defined as part of the core regulator binding can also be used.
> +(See: ../regulator/regulator.txt)
> +
> +Continuous Voltage Example:
> pwm_regulator {
> compatible = "pwm-regulator;
> pwms = <&pwm1 0 8448 0>;
> + regulator-min-microvolt = <1016000>;
> + regulator-max-microvolt = <1114000>;
> + regulator-name = "vdd_logic";
> +
> + max-duty-cycle = <255>; /* 8bit PWM */
> + };
>
> +Voltage Table Example:
> + pwm_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>;
> -
> - regulator-min-microvolt = <1016000>;
> - regulator-max-microvolt = <1114000>;
> - regulator-name = "vdd_logic";
> };
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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