Re: [PATCH v3 1/3] devicetree: bindings: bd718x7: document HW state related ROHM specific properties

[Angus Ainslie <angus@akkea.ca>]

On 2019-02-14 01:34, Matti Vaittinen wrote:
> Add ROHM BD71837 / BD71847 specific device tree bindings for
> controlling the PMIC shutdown/reset states and voltages for
> different HW states. The PMIC was designed to be used with NXP
> i.MX8 SoC and it supports SNVS low power state which seems to
> be typical for NXP i.MX SoCs. However, when SNVS is used we must
> not allow SW to control enabling/disabling those regulators which
> are crucial for system to boot as there is a HW limitation which
> causes SW controlled regulators to be kept shut down after SNVS
> reset.
> 
> Allow setting the SNVS to be used as reset target state and allow
> marking those regulators which are critical for boot.
> 
> Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>

One small nit below

Tested-by: Angus Ainslie <angus@akkea.ca>
Reviewed-by: Angus Ainslie <angus@akkea.ca>

> ---
>  .../devicetree/bindings/mfd/rohm,bd71837-pmic.txt  | 17 ++++++++++
>  .../bindings/regulator/rohm,bd71837-regulator.txt  | 38 
> ++++++++++++++++++++++
>  2 files changed, 55 insertions(+)
> 
> diff --git
> a/Documentation/devicetree/bindings/mfd/rohm,bd71837-pmic.txt
> b/Documentation/devicetree/bindings/mfd/rohm,bd71837-pmic.txt
> index a4b056761eaa..d5f68ac78d15 100644
> --- a/Documentation/devicetree/bindings/mfd/rohm,bd71837-pmic.txt
> +++ b/Documentation/devicetree/bindings/mfd/rohm,bd71837-pmic.txt
> @@ -23,6 +23,20 @@ Required properties:
> 
>  Optional properties:
>  - clock-output-names	: Should contain name for output clock.
> +- rohm,reset-snvs-powered : Transfer BD718x7 to SNVS state at reset.
> +
> +The BD718x7 supports two different HW states as reset target states. 
> States
> +are called as SNVS and READY. At READY state all the PMIC power 
> outputs go
> +down and OTP is reload. At the SNVS state all other logic and external
> +devices apart from the SNVS power domain are shut off. Please refer to 
> NXP
> +i.MX8 documentation for further information regarding SNVS state. When 
> a
> +reset is done via SNVS state the PMIC OTP data is not reload. This 
> causes

Typo s/reload/reloaded/

> +power outputs that have been under SW control to stay down when reset 
> has
> +switched power state to SNVS. If reset is done via READY state the 
> power
> +outputs will be returned to HW control by OTP loading. Thus the reset
> +target state is set to READY by default. If SNVS state is used the 
> boot
> +crucial regulators must have the regulator-always-on and 
> regulator-boot-on
> +properties set in regulator node.
> 
>  Example:
> 
> @@ -43,6 +57,7 @@ Example:
>  		#clock-cells = <0>;
>  		clocks = <&osc 0>;
>  		clock-output-names = "bd71837-32k-out";
> +		rohm,reset-snvs-powered;
> 
>  		regulators {
>  			buck1: BUCK1 {
> @@ -50,8 +65,10 @@ Example:
>  				regulator-min-microvolt = <700000>;
>  				regulator-max-microvolt = <1300000>;
>  				regulator-boot-on;
> +				regulator-always-on;
>  				regulator-ramp-delay = <1250>;
>  			};
> +			// [...]
>  		};
>  	};
> 
> diff --git
> a/Documentation/devicetree/bindings/regulator/rohm,bd71837-regulator.txt
> b/Documentation/devicetree/bindings/regulator/rohm,bd71837-regulator.txt
> index 4b98ca26e61a..cbce62c22b60 100644
> --- 
> a/Documentation/devicetree/bindings/regulator/rohm,bd71837-regulator.txt
> +++ 
> b/Documentation/devicetree/bindings/regulator/rohm,bd71837-regulator.txt
> @@ -27,8 +27,38 @@ BUCK1, BUCK2, BUCK3, BUCK4, BUCK5, BUCK6
>  LDO1, LDO2, LDO3, LDO4, LDO5, LDO6
> 
>  Optional properties:
> +- rohm,dvs-run-voltage		: PMIC default "RUN" state voltage in uV.
> +				  See below table for bucks which support this.
> +- rohm,dvs-idle-voltage		: PMIC default "IDLE" state voltage in uV.
> +				  See below table for bucks which support this.
> +- rohm,dvs-suspend-voltage	: PMIC default "SUSPEND" state voltage in 
> uV.
> +				  See below table for bucks which support this.
>  - Any optional property defined in bindings/regulator/regulator.txt
> 
> +Supported default DVS states:
> +
> +BD71837:
> +buck	| dvs-run-voltage	| dvs-idle-voltage	| dvs-suspend-voltage
> +-----------------------------------------------------------------------------
> +1	| supported		| supported		| supported
> +----------------------------------------------------------------------------
> +2	| supported		| supported		| not supported
> +----------------------------------------------------------------------------
> +3	| supported		| not supported		| not supported
> +----------------------------------------------------------------------------
> +4	| supported		| not supported		| not supported
> +----------------------------------------------------------------------------
> +rest	| not supported		| not supported		| not supported
> +
> +BD71847:
> +buck	| dvs-run-voltage	| dvs-idle-voltage	| dvs-suspend-voltage
> +-----------------------------------------------------------------------------
> +1	| supported		| supported		| supported
> +----------------------------------------------------------------------------
> +2	| supported		| supported		| not supported
> +----------------------------------------------------------------------------
> +rest	| not supported		| not supported		| not supported
> +
>  Example:
>  regulators {
>  	buck1: BUCK1 {
> @@ -36,7 +66,11 @@ regulators {
>  		regulator-min-microvolt = <700000>;
>  		regulator-max-microvolt = <1300000>;
>  		regulator-boot-on;
> +		regulator-always-on;
>  		regulator-ramp-delay = <1250>;
> +		rohm,dvs-run-voltage = <900000>;
> +		rohm,dvs-idle-voltage = <850000>;
> +		rohm,dvs-suspend-voltage = <800000>;
>  	};
>  	buck2: BUCK2 {
>  		regulator-name = "buck2";
> @@ -45,18 +79,22 @@ regulators {
>  		regulator-boot-on;
>  		regulator-always-on;
>  		regulator-ramp-delay = <1250>;
> +		rohm,dvs-run-voltage = <1000000>;
> +		rohm,dvs-idle-voltage = <900000>;
>  	};
>  	buck3: BUCK3 {
>  		regulator-name = "buck3";
>  		regulator-min-microvolt = <700000>;
>  		regulator-max-microvolt = <1300000>;
>  		regulator-boot-on;
> +		rohm,dvs-run-voltage = <1000000>;
>  	};
>  	buck4: BUCK4 {
>  		regulator-name = "buck4";
>  		regulator-min-microvolt = <700000>;
>  		regulator-max-microvolt = <1300000>;
>  		regulator-boot-on;
> +		rohm,dvs-run-voltage = <1000000>;
>  	};
>  	buck5: BUCK5 {
>  		regulator-name = "buck5";
> --
> 2.14.3