On Tue, Mar 08, 2016 at 04:23:25PM +0530, Laxman Dewangan wrote:
> Add support for Linear Equal Step mode in pwm regulators on which
> specified regulator's minimum and maximum voltages are divided into
> specified equal steps. The number of steps must divided the range of
> minimum to maximum as well as PWM periods in equal parts.
>
> Add DT property to specify number of steps and its details.
>
> Signed-off-by: Laxman Dewangan <ldewan...@nvidia.com>
> Cc: Lee Jones <lee.jo...@linaro.org>
> ---
> .../bindings/regulator/pwm-regulator.txt | 32
> +++++++++++++++++++---
> 1 file changed, 28 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/regulator/pwm-regulator.txt
> b/Documentation/devicetree/bindings/regulator/pwm-regulator.txt
> index ed936f0..b61ff59 100644
> --- a/Documentation/devicetree/bindings/regulator/pwm-regulator.txt
> +++ b/Documentation/devicetree/bindings/regulator/pwm-regulator.txt
> @@ -1,7 +1,7 @@
> Bindings for the Generic PWM Regulator
> ======================================
>
> -Currently supports 2 modes of operation:
> +Currently supports following modes of operation:
>
> Voltage Table: When in this mode, a voltage table (See below)
> of
> predefined voltage <=> duty-cycle values must be
> @@ -23,20 +23,34 @@ Continuous Voltage: This mode uses the regulator's
> maximum and minimum
> regulator voltage to run at half way between the
> supplied max_uV and min_uV values.
>
> +Linear Equal Step: This modes divides the regulator's maximum and minimum
> + supplied voltages into specified equal steps. The
> + number of steps must equally divides the PWM periods.
s/divides/divide/
> + On this case, step is translated into number of pulse
In this case...
s/pulse/pulses/
> + in PWM periods and then multiplied by voltage
> + selectors number to get the duty cycles of PWM.
This description is not so clear to me. This equates to Vmax-Vmin/steps
== step voltage?
> +
> Required properties:
> --------------------
> - compatible: Should be "pwm-regulator"
>
> - pwms: PWM specification (See: ../pwm/pwm.txt)
>
> -Only required for Voltage Table Mode:
> +Optional properties:
> +--------------------
> +For Voltage Table Mode, following properties must be supplied:
> - 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 (%)
>
> +For Linear Equal Steps, following properties must be supplied:
> +- regulator-n-voltages: Number of voltage steps between regulator's
> minimum
> + and maximum.
> +
> NB: To be clear, 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.
> +in Voltage Table Mode. If regulator-n-voltages is provided then the device
> +will be used in Linear Equal Step Mode. If both properties are not provided,
"both properties" provided would be invalid. "If neither property is
provided" would be a bit more clear.
> +then the device will be used in Continuous Voltage Mode.
>
> Any property defined as part of the core regulator binding can also be used.
> (See: ../regulator/regulator.txt)
> @@ -66,3 +80,13 @@ Voltage Table Example:
> <1036000 40>,
> <1016000 50>;
> };
> +
> +Linear Equal Step Mode Example:
> + pwm-regulator@1 {
Drop the unit address. No reg property.
> + compatible = "pwm-regulator";
> + pwms = <&pwm 1 4880>;
> + regulator-name = "vdd-gpu";
> + regulator-min-microvolt = <710000>;
> + regulator-max-microvolt = <1320000>;
> + regulator-n-voltages = <62>;
> + };
> --
> 2.1.4
>
