drivers/soc/samsung/exynos-regulator-coupler.c

Source file repositories/reference/linux-study-clean/drivers/soc/samsung/exynos-regulator-coupler.c

File Facts

System
Linux kernel
Corpus path
drivers/soc/samsung/exynos-regulator-coupler.c
Extension
.c
Size
5380 bytes
Lines
222
Domain
Driver Families
Bucket
drivers/soc
Inferred role
Driver Families: implementation source
Status
source 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 (tmp_min == 0) {
			ret = regulator_get_voltage_rdev(c_rdevs[i]);
			if (ret < 0)
				return ret;
			tmp_min = ret;
		}

		/* apply constraints */
		ret = regulator_check_voltage(c_rdevs[i], &tmp_min, &tmp_max);
		if (ret < 0)
			return ret;

		highest_min_uV = max(highest_min_uV, tmp_min);

		if (i == 0) {
			desired_min_uV = tmp_min;
			desired_max_uV = tmp_max;
		}
	}

	max_spread = constraints->max_spread[0];

	/*
	 * Let target_uV be equal to the desired one if possible.
	 * If not, set it to minimum voltage, allowed by other coupled
	 * regulators.
	 */
	target_uV = max(desired_min_uV, highest_min_uV - max_spread);

	/*
	 * Find min and max voltages, which currently aren't violating
	 * max_spread.
	 */
	for (i = 1; i < n_coupled; i++) {
		int tmp_act;

		tmp_act = regulator_get_voltage_rdev(c_rdevs[i]);
		if (tmp_act < 0)
			return tmp_act;

		min_current_uV = min(tmp_act, min_current_uV);
		max_current_uV = max(tmp_act, max_current_uV);
	}

	/*
	 * Correct target voltage, so as it currently isn't
	 * violating max_spread
	 */
	possible_uV = max(target_uV, max_current_uV - max_spread);
	possible_uV = min(possible_uV, min_current_uV + max_spread);

	if (possible_uV > desired_max_uV)
		return -EINVAL;

	done = (possible_uV == target_uV);
	desired_min_uV = possible_uV;

	/* Set current_uV if wasn't done earlier in the code and if necessary */
	if (*current_uV == -1) {
		ret = regulator_get_voltage_rdev(rdev);
		if (ret < 0)
			return ret;
		*current_uV = ret;
	}

	*min_uV = desired_min_uV;
	*max_uV = desired_max_uV;

	return done;
}

static int exynos_coupler_balance_voltage(struct regulator_coupler *coupler,
					  struct regulator_dev *rdev,
					  suspend_state_t state)
{
	struct regulator_dev **c_rdevs;
	struct regulator_dev *best_rdev;
	struct coupling_desc *c_desc = &rdev->coupling_desc;
	int i, ret, n_coupled, best_min_uV, best_max_uV, best_c_rdev;
	unsigned int delta, best_delta;
	unsigned long c_rdev_done = 0;
	bool best_c_rdev_done;

	c_rdevs = c_desc->coupled_rdevs;
	n_coupled = c_desc->n_coupled;

	/*
	 * Find the best possible voltage change on each loop. Leave the loop
	 * if there isn't any possible change.
	 */

Annotation

Implementation Notes