* msm-qpnp-gpio

msm-qpnp-gpio is a GPIO chip driver for the MSM SPMI implementation.
It creates a spmi_device for every spmi-dev-container block of device_nodes.
These device_nodes contained within specify the PMIC GPIO number associated
with each GPIO chip. The driver will map these to Linux GPIO numbers.

[PMIC GPIO Device Declarations]

-Root Node-

Required properties :
 - spmi-dev-container : Used to specify the following child nodes as part of the
   same SPMI device.
 - gpio-controller : Specify as gpio-contoller. All child nodes will belong to this
   gpio_chip.
 - #gpio-cells: We encode a PMIC GPIO number and a 32-bit flag field to
   specify the gpio configuration. This must be set to '2'.
 - #address-cells: Specify one address field. This must be set to '1'.
 - #size-cells: Specify one size-cell. This must be set to '1'.
 - compatible = "qcom,qpnp-gpio" : Specify driver matching for this driver.

-Child Nodes-

Required properties :
 - reg : Specify the spmi offset and size for this gpio device.
 - qcom,gpio-num : Specify the PMIC GPIO number for this gpio device.

Optional configuration properties :
 -  qcom,direction:	indicates whether the gpio should be input, output, or
			both.
			QPNP_GPIO_DIR_IN   = 0,
			QPNP_GPIO_DIR_OUT  = 1,
			QPNP_GPIO_DIR_BOTH = 2

 - qcom,output-type:	indicates gpio should be configured as CMOS or open
			drain.
			QPNP_GPIO_OUT_BUF_CMOS = 0
			QPNP_GPIO_OUT_BUF_OPEN_DRAIN_NMOS = 1,
			QPNP_GPIO_OUT_BUF_OPEN_DRAIN_PMOS = 2,

 - qcom,invert:		Invert the signal of the gpio line -
			QPNP_GPIO_INVERT_DISABLE = 0
			QPNP_GPIO_INVERT_ENABLE = 1

 - qcom,pull:		Indicates whether a pull up or pull down should be
			applied. If a pullup is required the current strength
			needs to be specified. Current values of 30uA, 1.5uA,
			31.5uA, 1.5uA with 30uA boost are supported.
			QPNP_GPIO_PULL_UP_30	 = 0,
			QPNP_GPIO_PULL_UP_1P5	 = 1,
			QPNP_GPIO_PULL_UP_31P5	 = 2,
			QPNP_GPIO_PULL_UP_1P5_30 = 3,
			QPNP_GPIO_PULL_DN	 = 4,
			QPNP_GPIO_PULL_NO	 = 5

  - qcom,vin-sel:	specifies the voltage level when the output is set to 1.
			For an input gpio specifies the voltage level at which
			the input is interpreted as a logical 1.
			QPNP_GPIO_VIN0 = 0,
			QPNP_GPIO_VIN1 = 1,
			QPNP_GPIO_VIN2 = 2,
			QPNP_GPIO_VIN3 = 3,
			QPNP_GPIO_VIN4 = 4,
			QPNP_GPIO_VIN5 = 5,
			QPNP_GPIO_VIN6 = 6,
			QPNP_GPIO_VIN7 = 7

  - qcom,out-strength:	the amount of current supplied for an output gpio.
			QPNP_GPIO_OUT_STRENGTH_LOW  = 1
			QPNP_GPIO_OUT_STRENGTH_MED  = 2,
			QPNP_GPIO_OUT_STRENGTH_HIGH = 3,

  - qcom,source-sel:	choose alternate function for the gpio. Certain gpios
			can be paired (shorted) with each other. Some gpio pin
			can act as alternate functions.
			QPNP_GPIO_FUNC_NORMAL   = 0,
			QPNP_GPIO_FUNC_PAIRED   = 1
			QPNP_GPIO_FUNC_1	= 2,
			QPNP_GPIO_FUNC_2	= 3,
			QPNP_GPIO_DTEST1	= 4,
			QPNP_GPIO_DTEST2	= 5,
			QPNP_GPIO_DTEST3	= 6,
			QPNP_GPIO_DTEST4	= 7

 - qcom,master-en:	1 = Enable features within the
			GPIO block based on configurations.
			0 = Completely disable the GPIO
			block and let the pin float with high impedance
			regardless of other settings.

*Note: If any of the configuration properties are not specified, then the
       qpnp-gpio driver will not modify that respective configuration in
       hardware.

[PMIC GPIO clients]

Required properties :
 - gpios : Contains 3 fields of the form <&gpio_controller pmic_gpio_num flags>

[Example]

qpnp: qcom,spmi@fc4c0000 {
		#address-cells = <1>;
		#size-cells = <0>;
		interrupt-controller;
		#interrupt-cells = <3>;

		qcom,pm8941@0 {
			spmi-slave-container;
			reg = <0x0>;
			#address-cells = <1>;
			#size-cells = <1>;

			pm8941_gpios: gpios {
				spmi-dev-container;
				compatible = "qcom,qpnp-gpio";
				gpio-controller;
				#gpio-cells = <2>;
				#address-cells = <1>;
				#size-cells = <1>;

				gpio@c000 {
					reg = <0xc000 0x100>;
					qcom,gpio-num = <62>;
				};

				gpio@c100 {
					reg = <0xc100 0x100>;
					qcom,gpio-num = <20>;
					qcom,source_sel = <2>;
					qcom,pull = <5>;
				};
			};

			qcom,testgpio@1000 {
				compatible = "qcom,qpnp-testgpio";
				reg = <0x1000 0x1000>;
				gpios = <&pm8941_gpios 62 0x0 &pm8941_gpios 20 0x1>;
			};
		};
	};
};
