// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * OF helpers for regulator framework
 *
 * Copyright (C) 2011 Texas Instruments, Inc.
 * Rajendra Nayak <rnayak@ti.com>
 */

#include <common.h>
#include <of.h>
#include <linux/regulator/of_regulator.h>
#include <linux/regulator/machine.h>

static int of_get_regulation_constraints(struct device_d *dev,
					struct device_node *np,
					struct regulator_init_data **init_data,
					const struct regulator_desc *desc)
{
	struct regulation_constraints *constraints = &(*init_data)->constraints;
	int ret;
	u32 pval;

	constraints->name = of_get_property(np, "regulator-name", NULL);

	if (!of_property_read_u32(np, "regulator-min-microvolt", &pval))
		constraints->min_uV = pval;

	if (!of_property_read_u32(np, "regulator-max-microvolt", &pval))
		constraints->max_uV = pval;

	/* Voltage change possible? */
	if (constraints->min_uV != constraints->max_uV)
		constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;

	/* Do we have a voltage range, if so try to apply it? */
	if (constraints->min_uV && constraints->max_uV)
		constraints->apply_uV = true;

	if (!of_property_read_u32(np, "regulator-microvolt-offset", &pval))
		constraints->uV_offset = pval;
	if (!of_property_read_u32(np, "regulator-min-microamp", &pval))
		constraints->min_uA = pval;
	if (!of_property_read_u32(np, "regulator-max-microamp", &pval))
		constraints->max_uA = pval;

	if (!of_property_read_u32(np, "regulator-input-current-limit-microamp",
				  &pval))
		constraints->ilim_uA = pval;

	/* Current change possible? */
	if (constraints->min_uA != constraints->max_uA)
		constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;

	constraints->boot_on = of_property_read_bool(np, "regulator-boot-on");
	constraints->always_on = of_property_read_bool(np, "regulator-always-on");
	if (!constraints->always_on) /* status change should be possible. */
		constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;

	constraints->pull_down = of_property_read_bool(np, "regulator-pull-down");

	if (of_property_read_bool(np, "regulator-allow-bypass"))
		constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS;

	if (of_property_read_bool(np, "regulator-allow-set-load"))
		constraints->valid_ops_mask |= REGULATOR_CHANGE_DRMS;

	ret = of_property_read_u32(np, "regulator-ramp-delay", &pval);
	if (!ret) {
		if (pval)
			constraints->ramp_delay = pval;
		else
			constraints->ramp_disable = true;
	}

	ret = of_property_read_u32(np, "regulator-settling-time-us", &pval);
	if (!ret)
		constraints->settling_time = pval;

	ret = of_property_read_u32(np, "regulator-settling-time-up-us", &pval);
	if (!ret)
		constraints->settling_time_up = pval;
	if (constraints->settling_time_up && constraints->settling_time) {
		pr_warn("%pOFn: ambiguous configuration for settling time, ignoring 'regulator-settling-time-up-us'\n",
			np);
		constraints->settling_time_up = 0;
	}

	ret = of_property_read_u32(np, "regulator-settling-time-down-us",
				   &pval);
	if (!ret)
		constraints->settling_time_down = pval;
	if (constraints->settling_time_down && constraints->settling_time) {
		pr_warn("%pOFn: ambiguous configuration for settling time, ignoring 'regulator-settling-time-down-us'\n",
			np);
		constraints->settling_time_down = 0;
	}

	ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval);
	if (!ret)
		constraints->enable_time = pval;

	constraints->soft_start = of_property_read_bool(np,
					"regulator-soft-start");
	ret = of_property_read_u32(np, "regulator-active-discharge", &pval);
	if (!ret) {
		constraints->active_discharge =
				(pval) ? REGULATOR_ACTIVE_DISCHARGE_ENABLE :
					REGULATOR_ACTIVE_DISCHARGE_DISABLE;
	}

	if (!of_property_read_u32(np, "regulator-system-load", &pval))
		constraints->system_load = pval;

	if (!of_property_read_u32(np, "regulator-max-step-microvolt",
				  &pval))
		constraints->max_uV_step = pval;

	constraints->over_current_protection = of_property_read_bool(np,
					"regulator-over-current-protection");

	return 0;
}

/**
 * of_get_regulator_init_data - extract regulator_init_data structure info
 * @dev: device requesting for regulator_init_data
 * @node: regulator device node
 * @desc: regulator description
 *
 * Populates regulator_init_data structure by extracting data from device
 * tree node, returns a pointer to the populated structure or NULL if memory
 * alloc fails.
 */
struct regulator_init_data *of_get_regulator_init_data(struct device_d *dev,
					  struct device_node *node,
					  const struct regulator_desc *desc)
{
	struct regulator_init_data *init_data;

	if (!node)
		return NULL;

	init_data = xzalloc(sizeof(*init_data));

	if (of_get_regulation_constraints(dev, node, &init_data, desc))
		return NULL;

	return init_data;
}
EXPORT_SYMBOL_GPL(of_get_regulator_init_data);

struct devm_of_regulator_matches {
	struct of_regulator_match *matches;
	unsigned int num_matches;
};

/**
 * of_regulator_match - extract multiple regulator init data from device tree.
 * @dev: device requesting the data
 * @node: parent device node of the regulators
 * @matches: match table for the regulators
 * @num_matches: number of entries in match table
 *
 * This function uses a match table specified by the regulator driver to
 * parse regulator init data from the device tree. @node is expected to
 * contain a set of child nodes, each providing the init data for one
 * regulator. The data parsed from a child node will be matched to a regulator
 * based on either the deprecated property regulator-compatible if present,
 * or otherwise the child node's name. Note that the match table is modified
 * in place and an additional of_node reference is taken for each matched
 * regulator.
 *
 * Returns the number of matches found or a negative error code on failure.
 */
int of_regulator_match(struct device_d *dev, struct device_node *node,
		       struct of_regulator_match *matches,
		       unsigned int num_matches)
{
	unsigned int count = 0;
	unsigned int i;
	const char *name;
	struct device_node *child;
	struct devm_of_regulator_matches *devm_matches;

	if (!dev || !node)
		return -EINVAL;

	devm_matches = xzalloc(sizeof(struct devm_of_regulator_matches));

	devm_matches->matches = matches;
	devm_matches->num_matches = num_matches;

	for (i = 0; i < num_matches; i++) {
		struct of_regulator_match *match = &matches[i];
		match->init_data = NULL;
		match->of_node = NULL;
	}

	for_each_child_of_node(node, child) {
		name = of_get_property(child,
					"regulator-compatible", NULL);
		if (!name)
			name = child->name;

		for (i = 0; i < num_matches; i++) {
			struct of_regulator_match *match = &matches[i];
			if (match->of_node)
				continue;

			if (strcmp(match->name, name))
				continue;

			match->init_data = of_get_regulator_init_data(dev, child,
								      match->desc);
			if (!match->init_data) {
				dev_err(dev,
					"failed to parse DT for regulator %pOFn\n",
					child);
				return -EINVAL;
			}
			match->of_node = child;
			count++;
			break;
		}
	}

	return count;
}
EXPORT_SYMBOL_GPL(of_regulator_match);