drivers/regulator/helpers.c

Source file repositories/reference/linux-study-clean/drivers/regulator/helpers.c

File Facts

System
Linux kernel
Corpus path
drivers/regulator/helpers.c
Extension
.c
Size
26780 bytes
Lines
1004
Domain
Driver Families
Bucket
drivers/regulator
Inferred role
Driver Families: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

if (ret < best_val && ret >= min_uV && ret <= max_uV) {
			best_val = ret;
			selector = i;
		}
	}

	if (best_val != INT_MAX)
		return selector;
	else
		return -EINVAL;
}
EXPORT_SYMBOL_GPL(regulator_map_voltage_iterate);

/**
 * regulator_map_voltage_ascend - map_voltage() for ascendant voltage list
 *
 * @rdev: Regulator to operate on
 * @min_uV: Lower bound for voltage
 * @max_uV: Upper bound for voltage
 *
 * Drivers that have ascendant voltage list can use this as their
 * map_voltage() operation.
 */
int regulator_map_voltage_ascend(struct regulator_dev *rdev,
				 int min_uV, int max_uV)
{
	int i, ret;

	for (i = 0; i < rdev->desc->n_voltages; i++) {
		ret = rdev->desc->ops->list_voltage(rdev, i);
		if (ret < 0)
			continue;

		if (ret > max_uV)
			break;

		if (ret >= min_uV && ret <= max_uV)
			return i;
	}

	return -EINVAL;
}
EXPORT_SYMBOL_GPL(regulator_map_voltage_ascend);

/**
 * regulator_map_voltage_linear - map_voltage() for simple linear mappings
 *
 * @rdev: Regulator to operate on
 * @min_uV: Lower bound for voltage
 * @max_uV: Upper bound for voltage
 *
 * Drivers providing min_uV and uV_step in their regulator_desc can
 * use this as their map_voltage() operation.
 */
int regulator_map_voltage_linear(struct regulator_dev *rdev,
				 int min_uV, int max_uV)
{
	int ret, voltage;

	/* Allow uV_step to be 0 for fixed voltage */
	if (rdev->desc->n_voltages == 1 && rdev->desc->uV_step == 0) {
		if (min_uV <= rdev->desc->min_uV && rdev->desc->min_uV <= max_uV)
			return 0;
		else
			return -EINVAL;
	}

	if (!rdev->desc->uV_step) {
		BUG_ON(!rdev->desc->uV_step);
		return -EINVAL;
	}

	if (min_uV < rdev->desc->min_uV)
		min_uV = rdev->desc->min_uV;

	ret = DIV_ROUND_UP(min_uV - rdev->desc->min_uV, rdev->desc->uV_step);
	if (ret < 0)
		return ret;

	ret += rdev->desc->linear_min_sel;

	/* 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);

Annotation

Implementation Notes