regulator: Add helpers for low-level register access (04eca28c) · Commits · 戴 / test

Documentation/power/regulator/consumer.txt

+35 −0

Original line number	Diff line number	Diff line
		@@ -180,3 +180,38 @@ int regulator_unregister_notifier(struct regulator *regulator,

		Regulators use the kernel notifier framework to send event to their interested
		consumers.

		7. Regulator Direct Register Access
		===================================
		Some kinds of power management hardware or firmware are designed such that
		they need to do low-level hardware access to regulators, with no involvement
		from the kernel. Examples of such devices are:

		- clocksource with a voltage-controlled oscillator and control logic to change
		the supply voltage over I2C to achieve a desired output clock rate
		- thermal management firmware that can issue an arbitrary I2C transaction to
		perform system poweroff during overtemperature conditions

		To set up such a device/firmware, various parameters like I2C address of the
		regulator, addresses of various regulator registers etc. need to be configured
		to it. The regulator framework provides the following helpers for querying
		these details.

		Bus-specific details, like I2C addresses or transfer rates are handled by the
		regmap framework. To get the regulator's regmap (if supported), use :-

		struct regmap regulator_get_regmap(struct regulator regulator);

		To obtain the hardware register offset and bitmask for the regulator's voltage
		selector register, use :-

		int regulator_get_hardware_vsel_register(struct regulator *regulator,
		unsigned *vsel_reg,
		unsigned *vsel_mask);

		To convert a regulator framework voltage selector code (used by
		regulator_list_voltage) to a hardware-specific voltage selector that can be
		directly written to the voltage selector register, use :-

		int regulator_list_hardware_vsel(struct regulator *regulator,
		unsigned selector);

drivers/regulator/core.c

+71 −0

Original line number	Diff line number	Diff line
		@@ -2221,6 +2221,77 @@ int regulator_list_voltage(struct regulator *regulator, unsigned selector)
		}
		EXPORT_SYMBOL_GPL(regulator_list_voltage);

		/**
		* regulator_get_regmap - get the regulator's register map
		* @regulator: regulator source
		*
		* Returns the register map for the given regulator, or an ERR_PTR value
		* if the regulator doesn't use regmap.
		*/
		struct regmap regulator_get_regmap(struct regulator regulator)
		{
		struct regmap *map = regulator->rdev->regmap;

		return map ? map : ERR_PTR(-EOPNOTSUPP);
		}

		/**
		* regulator_get_hardware_vsel_register - get the HW voltage selector register
		* @regulator: regulator source
		* @vsel_reg: voltage selector register, output parameter
		* @vsel_mask: mask for voltage selector bitfield, output parameter
		*
		* Returns the hardware register offset and bitmask used for setting the
		* regulator voltage. This might be useful when configuring voltage-scaling
		* hardware or firmware that can make I2C requests behind the kernel's back,
		* for example.
		*
		* On success, the output parameters @vsel_reg and @vsel_mask are filled in
		* and 0 is returned, otherwise a negative errno is returned.
		*/
		int regulator_get_hardware_vsel_register(struct regulator *regulator,
		unsigned *vsel_reg,
		unsigned *vsel_mask)
		{
		struct regulator_dev *rdev = regulator->rdev;
		struct regulator_ops *ops = rdev->desc->ops;

		if (ops->set_voltage_sel != regulator_set_voltage_sel_regmap)
		return -EOPNOTSUPP;

		*vsel_reg = rdev->desc->vsel_reg;
		*vsel_mask = rdev->desc->vsel_mask;

		return 0;
		}
		EXPORT_SYMBOL_GPL(regulator_get_hardware_vsel_register);

		/**
		* regulator_list_hardware_vsel - get the HW-specific register value for a selector
		* @regulator: regulator source
		* @selector: identify voltage to list
		*
		* Converts the selector to a hardware-specific voltage selector that can be
		* directly written to the regulator registers. The address of the voltage
		* register can be determined by calling @regulator_get_hardware_vsel_register.
		*
		* On error a negative errno is returned.
		*/
		int regulator_list_hardware_vsel(struct regulator *regulator,
		unsigned selector)
		{
		struct regulator_dev *rdev = regulator->rdev;
		struct regulator_ops *ops = rdev->desc->ops;

		if (selector >= rdev->desc->n_voltages)
		return -EINVAL;
		if (ops->set_voltage_sel != regulator_set_voltage_sel_regmap)
		return -EOPNOTSUPP;

		return selector;
		}
		EXPORT_SYMBOL_GPL(regulator_list_hardware_vsel);

		/**
		* regulator_get_linear_step - return the voltage step size between VSEL values
		* @regulator: regulator source

include/linux/regulator/consumer.h

+26 −0

Original line number	Diff line number	Diff line
		@@ -37,6 +37,7 @@

		struct device;
		struct notifier_block;
		struct regmap;

		/*
		* Regulator operating modes.
		@@ -215,6 +216,13 @@ int regulator_set_optimum_mode(struct regulator *regulator, int load_uA);

		int regulator_allow_bypass(struct regulator *regulator, bool allow);

		struct regmap regulator_get_regmap(struct regulator regulator);
		int regulator_get_hardware_vsel_register(struct regulator *regulator,
		unsigned *vsel_reg,
		unsigned *vsel_mask);
		int regulator_list_hardware_vsel(struct regulator *regulator,
		unsigned selector);

		/* regulator notifier block */
		int regulator_register_notifier(struct regulator *regulator,
		struct notifier_block *nb);
		@@ -452,6 +460,24 @@ static inline int regulator_allow_bypass(struct regulator *regulator,
		return 0;
		}

		struct regmap regulator_get_regmap(struct regulator regulator)
		{
		return ERR_PTR(-EOPNOTSUPP);
		}

		int regulator_get_hardware_vsel_register(struct regulator *regulator,
		unsigned *vsel_reg,
		unsigned *vsel_mask)
		{
		return -EOPNOTSUPP;
		}

		int regulator_list_hardware_vsel(struct regulator *regulator,
		unsigned selector)
		{
		return -EOPNOTSUPP;
		}

		static inline int regulator_register_notifier(struct regulator *regulator,
		struct notifier_block *nb)
		{

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