regulator: add support for RPM SMD regulator

Qualcomm RPM Regulators

rpm-regulator-smd is a regulator driver which supports regulators inside of

PMICs which are controlled by the RPM processor.  Communication with the RPM

processor takes place over SMD.

Required structure:

- RPM regulators must be described in two levels of devices nodes.  The first

	level describes the interface with the RPM.  The second level describes

	properties of one regulator framework interface (of potentially many) to

	the regulator.

[First Level Nodes]

Required properties:

- compatible:          Must be "qcom,rpm-smd-regulator-resource"

- qcom,resource-name:  Resource name string for this regulator to be used in RPM

			transactions.  Length is 4 characters max.

- qcom,resource-id:    Resource instance ID for this regulator to be used in RPM

			transactions.

- qcom,regulator-type: Type of this regulator.  Supported values are:

				0 = LDO

				1 = SMPS

				2 = VS

				3 = NCP

Optional properties:

- qcom,allow-atomic:   Flag specifying if atomic access is allowed for this

			regulator.  Supported values are:

				0 or not present = mutex locks used

				1 = spinlocks used

- qcom,enable-time:    Time in us to delay after enabling the regulator

- qcom,hpm-min-load:   Load current in uA which corresponds to the minimum load

			which requires the regulator to be in high power mode.

- qcom,apps-only:      Flag which indicates that the regulator only has

			consumers on the application processor. If this flag

			is specified, then voltage and current updates are

			only sent to the RPM if the regulator is enabled.

[Second Level Nodes]

Required properties:

- compatible:          Must be "qcom,rpm-smd-regulator"

- regulator-name:      A string used as a descriptive name for regulator outputs

- qcom,set:            Specifies which sets that requests made with this

			regulator interface should be sent to.  Regulator

			requests sent in the active set take effect immediately.

			Requests sent in the sleep set take effect when the Apps

			processor transitions into RPM assisted power collapse.

			Supported values are:

				1 = Active set only

				2 = Sleep set only

				3 = Both active and sleep sets

Optional properties:

- parent-supply:               phandle to the parent supply/regulator node

- qcom,system-load:            Load in uA present on regulator that is not

				captured by any consumer request

- qcom,use-voltage-corner:     Flag that signifies if regulator_set_voltage

				calls should modify the corner parameter instead

				of the voltage parameter.  When used, voltages

				specified inside of the regulator framework

				represent corners that have been incremented by

				1.  This value shift is necessary to work around

				limitations in the regulator framework which

				treat 0 uV as an error.

- qcom,use-voltage-floor-corner:  Flag that signifies if regulator_set_voltage

				calls should modify the floor corner parameter

				instead of the voltage parameter.  When used,

				voltages specified inside of the regulator

				framework represent corners that have been

				incremented by 1.  The properties

				qcom,use-voltage-corner and

				qcom,use-voltage-floor-corner are mutually

				exclusive.  Only one may be specified for a

				given regulator.

- qcom,always-send-voltage:    Flag which indicates that updates to the voltage

				or voltage corner set point should always be

				sent immediately to the RPM.  If this flag is

				not specified, then voltage set point updates

				are only sent if the given regulator has also

				been enabled by a Linux consumer.

- qcom,always-send-current:    Flag which indicates that updates to the load

				current should always be sent immediately to the

				RPM.  If this flag is not specified, then load

				current updates are only sent if the given

				regulator has also been enabled by a Linux

				consumer.

The following properties specify initial values for parameters to be sent to the

RPM in regulator requests.

- qcom,init-enable:            0 = regulator disabled

			       1 = regulator enabled

- qcom,init-voltage:           Voltage in uV

- qcom,init-current:           Current in mA

- qcom,init-ldo-mode:          Operating mode to be used with LDO regulators

				Supported values are:

					0 = mode determined by current requests

					1 = force HPM (NPM)

- qcom,init-smps-mode:         Operating mode to be used with SMPS regulators

				Supported values are:

					0 = auto; hardware determines mode

					1 = mode determined by current requests

					2 = force HPM (PWM)

- qcom,init-pin-ctrl-enable:   Bit mask specifying which hardware pins should be

				used to enable the regulator, if any; supported

				bits are:

					0 = ignore all hardware enable signals

					BIT(0) = follow HW0_EN signal

					BIT(1) = follow HW1_EN signal

					BIT(2) = follow HW2_EN signal

					BIT(3) = follow HW3_EN signal

- qcom,init-pin-ctrl-mode:     Bit mask specifying which hardware pins should be

				used to force the regulator into high power

				mode, if any.  Supported bits are:

					0 = ignore all hardware enable signals

					BIT(0) = follow HW0_EN signal

					BIT(1) = follow HW1_EN signal

					BIT(2) = follow HW2_EN signal

					BIT(3) = follow HW3_EN signal

					BIT(4) = follow PMIC awake state

- qcom,init-frequency:         Switching frequency divisor for SMPS regulators.

				Supported values are n = 0 to 31 where

				freq = 19.2 MHz / (n + 1).

- qcom,init-head-room:         Voltage head room in mV required for the

				regulator.  This head room value should be used

				in situations where the device connected to the

				output of the regulator has low noise tolerance.

				Note that the RPM independently enforces a

				safety head room value for subregulated LDOs

				which is sufficient to account for LDO drop-out

				voltage.

- qcom,init-quiet-mode:        Specify that quiet mode is needed for an SMPS

				regulator in order to have lower output noise.

				Supported values are:

					0 = No quiet mode

					1 = Quiet mode

					2 = Super quiet mode

- qcom,init-freq-reason:       Consumer requiring specified frequency for an

				SMPS regulator.  Supported values are:

					0 = None

					1 = Bluetooth

					2 = GPS

					4 = WLAN

					8 = WAN

- qcom,init-voltage-corner:    Performance corner to use in order to determine

				voltage set point.  This value corresponds to

				the actual value that will be sent and is not

				incremented by 1 like the values used inside of

				the regulator framework.  The meaning of corner

				values is set by the RPM.  It is possible that

				different regulators on a given platform or

				similar regulators on different platforms will

				utilize different corner values.  These are

				corner values supported on MSM8974 for PMIC

				PM8841 SMPS 2 (VDD_Dig); nominal voltages for

				these corners are also shown:

					0 = None         (don't care)

					1 = Retention    (0.5000 V)

					2 = SVS Krait    (0.7250 V)

					3 = SVS SOC      (0.8125 V)

					4 = Normal       (0.9000 V)

					5 = Turbo        (0.9875 V)

					6 = Super Turbo  (1.0500 V)

- qcom,init-disallow-bypass:   Specify that bypass mode should not be used for a

				given LDO regulator.  When in bypass mode, an

				LDO performs no regulation and acts as a simple

				switch.  The RPM can utilize this mode for an

				LDO that is subregulated from an SMPS when it is

				possible to reduce the SMPS voltage to the

				desired LDO output level.  Bypass mode may be

				disallowed if lower LDO output noise is

				required.  Supported values are:

					0 = Allow RPM to utilize LDO bypass mode

						if possible

					1 = Disallow LDO bypass mode

- qcom,init-voltage-floor-corner:  Minimum performance corner to use if any

				processor in the system is awake.  This property

				supports the same values as

				qcom,init-voltage-corner.

All properties specified within the core regulator framework can also be used in

second level nodes.  These bindings can be found in:

Documentation/devicetree/bindings/regulator/regulator.txt.

Example:

rpm-regulator-smpb1 {

	qcom,resource-name = "smpb";

	qcom,resource-id = <1>;

	qcom,regulator-type = <1>;

	qcom,hpm-min-load = <100000>;

	compatible = "qcom,rpm-smd-regulator-resource";

	status = "disabled";

	pm8841_s1: regulator-s1 {

		regulator-name = "8841_s1";

		qcom,set = <3>;

		regulator-min-microvolt = <900000>;

		regulator-max-microvolt = <1150000>;

		qcom,init-voltage = <1150000>;

		compatible = "qcom,rpm-smd-regulator";

	};

	pm8841_s1_ao: regulator-s1-ao {

		regulator-name = "8841_s1_ao";

		qcom,set = <1>;

		regulator-min-microvolt = <900000>;

		regulator-max-microvolt = <1150000>;

		compatible = "qcom,rpm-smd-regulator";

	};

	pm8841_s1_corner: regulator-s1-corner {

		regulator-name = "8841_s1_corner";

		qcom,set = <3>;

		regulator-min-microvolt = <1>;

		regulator-max-microvolt = <6>;

		qcom,init-voltage-corner = <3>;

		qcom,use-voltage-corner;

		compatible = "qcom,rpm-smd-regulator";

	};

};

	  This driver provides support for the voltage regulators on the

	  WM8994 CODEC.

config REGULATOR_RPM_SMD

	bool "RPM SMD regulator driver"

	depends on OF

	depends on MSM_RPM_SMD

	help

	  Compile in support for the RPM SMD regulator driver which is used for

	  setting voltages and other parameters of the various power rails

	  supplied by some Qualcomm PMICs. The RPM SMD regulator driver should

	  be used on systems which contain an RPM which communicates with the

	  application processor over SMD.

endif

obj-$(CONFIG_REGULATOR_WM8350) += wm8350-regulator.o

obj-$(CONFIG_REGULATOR_WM8400) += wm8400-regulator.o

obj-$(CONFIG_REGULATOR_WM8994) += wm8994-regulator.o

obj-$(CONFIG_REGULATOR_RPM_SMD) += rpm-smd-regulator.o

ccflags-$(CONFIG_REGULATOR_DEBUG) += -DDEBUG