Re: [PATCH 6/8] regulator: max77686: Add external GPIO control

[Krzysztof Kozlowski <k.kozlowski@samsung.com>]

On wto, 2014-10-28 at 09:52 +0100, Krzysztof Kozlowski wrote:
> On pon, 2014-10-27 at 21:03 +0100, Javier Martinez Canillas wrote:
> > Hello Krzysztof,
> > 
> > On 10/27/2014 04:03 PM, Krzysztof Kozlowski wrote:
> > > @@ -85,6 +91,9 @@ struct max77686_data {
> > >  	struct max77686_regulator_data *regulators;
> > >  	int num_regulators;
> > >  
> > > +	/* Array of size num_regulators with GPIOs for external control. */
> > > +	int *ext_control_gpio;
> > > +
> > 
> > The integer-based GPIO API is deprecated in favor of the descriptor-based GPIO
> > interface (Documentation/gpio/consumer.txt). Could you please use the later?
> 
> Sure, I can. Please have in mind that regulator core still accepts old
> GPIO so I will have to use desc_to_gpio(). That should work... and
> should be future-ready.

It seems I was too hasty... I think usage of the new gpiod API implies
completely different bindings.

The gpiod_get() gets GPIO from a device level, not from given sub-node
pointer. This means that you cannot have DTS like this:
ldo21_reg: ldo21 {
	regulator-compatible = "LDO21";
	regulator-name = "VTF_2.8V";
	regulator-min-microvolt = <2800000>;
	regulator-max-microvolt = <2800000>;
	ec-gpio = <&gpy2 0 0>;
};

ldo22_reg: ldo22 {
	regulator-compatible = "LDO22";
	regulator-name = "VMEM_VDD_2.8V";
	regulator-min-microvolt = <2800000>;
	regulator-max-microvolt = <2800000>;
	ec-gpio = <&gpk0 2 0>;
};


I could put GPIOs in device node:

max77686_pmic@09 {
	compatible = "maxim,max77686";
	interrupt-parent = <&gpx0>;
	interrupts = <7 0>;
	reg = <0x09>;
	#clock-cells = <1>;
	ldo21-gpio = <&gpy2 0 0>;
	ldo22-gpio = <&gpk0 2 0>;

	ldo21_reg: ldo21 {
		regulator-compatible = "LDO21";
		regulator-name = "VTF_2.8V";
		regulator-min-microvolt = <2800000>;
		regulator-max-microvolt = <2800000>;
	};

	ldo22_reg: ldo22 {
		regulator-compatible = "LDO22";
		regulator-name = "VMEM_VDD_2.8V";
		regulator-min-microvolt = <2800000>;
		regulator-max-microvolt = <2800000>;
	};

This would work but I don't like it. The properties of a regulator are
above the node configuring that regulator.

Any ideas?

Best regards,
Krzysztof