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Commit 94d33c02 authored by Mark Brown's avatar Mark Brown
Browse files

regulator: core: Add helpers for multiple linear ranges 



Many regulators have several linear ranges of selector with different
step sizes, for example offering better resolution at lower voltages.
Provide regulator_{map,list}_voltage_linear_range() allowing these
regulators to use generic code. To do so a table of regulator_linear_range
structs needs to be pointed to from the descriptor.

This was inspired by similar code included in a driver submission from
Chao Xie and Yi Zhang at Marvell.

Signed-off-by: default avatarMark Brown <broonie@linaro.org>
parent ad81f054

drivers/regulator/core.c

+87 −0
Original line number Diff line number Diff line
@@ -2078,6 +2078,43 @@ int regulator_list_voltage_linear(struct regulator_dev *rdev, 
}

EXPORT_SYMBOL_GPL(regulator_list_voltage_linear);



/**

 * regulator_list_voltage_linear_range - List voltages for linear ranges

 *

 * @rdev: Regulator device

 * @selector: Selector to convert into a voltage

 *

 * Regulators with a series of simple linear mappings between voltages

 * and selectors can set linear_ranges in the regulator descriptor and

 * then use this function as their list_voltage() operation,

 */

int regulator_list_voltage_linear_range(struct regulator_dev *rdev,

					unsigned int selector)

{

	const struct regulator_linear_range *range;

	int i;



	if (!rdev->desc->n_linear_ranges) {

		BUG_ON(!rdev->desc->n_linear_ranges);

		return -EINVAL;

	}



	for (i = 0; i < rdev->desc->n_linear_ranges; i++) {

		range = &rdev->desc->linear_ranges[i];



		if (!(selector >= range->min_sel &&

		      selector <= range->max_sel))

			continue;



		selector -= range->min_sel;



		return range->min_uV + (range->uV_step * selector);

	}



	return -EINVAL;

}

EXPORT_SYMBOL_GPL(regulator_list_voltage_linear_range);



/**

 * regulator_list_voltage_table - List voltages with table based mapping

 *
@@ -2368,6 +2405,56 @@ int regulator_map_voltage_linear(struct regulator_dev *rdev, 
}

EXPORT_SYMBOL_GPL(regulator_map_voltage_linear);



/**

 * regulator_map_voltage_linear - map_voltage() for multiple linear ranges

 *

 * @rdev: Regulator to operate on

 * @min_uV: Lower bound for voltage

 * @max_uV: Upper bound for voltage

 *

 * Drivers providing linear_ranges in their descriptor can use this as

 * their map_voltage() callback.

 */

int regulator_map_voltage_linear_range(struct regulator_dev *rdev,

				       int min_uV, int max_uV)

{

	const struct regulator_linear_range *range;

	int ret = -EINVAL;

	int voltage, i;



	if (!rdev->desc->n_linear_ranges) {

		BUG_ON(!rdev->desc->n_linear_ranges);

		return -EINVAL;

	}



	for (i = 0; i < rdev->desc->n_linear_ranges; i++) {

		range = &rdev->desc->linear_ranges[i];



		if (!(min_uV <= range->max_uV && max_uV >= range->min_uV))

			continue;



		if (min_uV <= range->min_uV)

			min_uV = range->min_uV;



		ret = DIV_ROUND_UP(min_uV - range->min_uV, range->uV_step);

		if (ret < 0)

			return ret;



		break;

	}



	if (i == rdev->desc->n_linear_ranges)

		return -EINVAL;



	/* Map back into a voltage to verify we're still in bounds */

	voltage = rdev->desc->ops->list_voltage(rdev, ret);

	if (voltage < min_uV || voltage > max_uV)

		return -EINVAL;



	return ret;

}

EXPORT_SYMBOL_GPL(regulator_map_voltage_linear_range);



static int _regulator_do_set_voltage(struct regulator_dev *rdev,

				     int min_uV, int max_uV)

{

include/linux/regulator/driver.h

+25 −0
Original line number Diff line number Diff line
@@ -39,6 +39,24 @@ enum regulator_status { 
	REGULATOR_STATUS_UNDEFINED,

};



/**

 * Specify a range of voltages for regulator_map_linar_range() and

 * regulator_list_linear_range().

 *

 * @min_uV:  Lowest voltage in range

 * @max_uV:  Highest voltage in range

 * @min_sel: Lowest selector for range

 * @max_sel: Highest selector for range

 * @uV_step: Step size

 */

struct regulator_linear_range {

	unsigned int min_uV;

	unsigned int max_uV;

	unsigned int min_sel;

	unsigned int max_sel;

	unsigned int uV_step;

};



/**

 * struct regulator_ops - regulator operations.

 *
@@ -223,6 +241,9 @@ struct regulator_desc { 
	unsigned int linear_min_sel;

	unsigned int ramp_delay;



	const struct regulator_linear_range *linear_ranges;

	int n_linear_ranges;



	const unsigned int *volt_table;



	unsigned int vsel_reg;
@@ -326,10 +347,14 @@ int regulator_mode_to_status(unsigned int); 


int regulator_list_voltage_linear(struct regulator_dev *rdev,

				  unsigned int selector);

int regulator_list_voltage_linear_range(struct regulator_dev *rdev,

					unsigned int selector);

int regulator_list_voltage_table(struct regulator_dev *rdev,

				  unsigned int selector);

int regulator_map_voltage_linear(struct regulator_dev *rdev,

				  int min_uV, int max_uV);

int regulator_map_voltage_linear_range(struct regulator_dev *rdev,

				       int min_uV, int max_uV);

int regulator_map_voltage_iterate(struct regulator_dev *rdev,

				  int min_uV, int max_uV);

int regulator_map_voltage_ascend(struct regulator_dev *rdev,