// 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 <linux/module.h>

  #include <linux/slab.h>
  #include <linux/of.h>
  #include <linux/regulator/machine.h>

  #include <linux/regulator/driver.h>

  #include <linux/regulator/of_regulator.h>

  #include "internal.h"

  static const char *const regulator_states[PM_SUSPEND_MAX + 1] = {

  	[PM_SUSPEND_STANDBY]	= "regulator-state-standby",

  	[PM_SUSPEND_MEM]	= "regulator-state-mem",
  	[PM_SUSPEND_MAX]	= "regulator-state-disk",
  };

  static int of_get_regulation_constraints(struct device *dev,
  					struct device_node *np,

  					struct regulator_init_data **init_data,
  					const struct regulator_desc *desc)

  {

  	struct regulation_constraints *constraints = &(*init_data)->constraints;

  	struct regulator_state *suspend_state;
  	struct device_node *suspend_np;

  	unsigned int mode;

  	int ret, i, len;

  	int n_phandles;

  	u32 pval;

  	n_phandles = of_count_phandle_with_args(np, "regulator-coupled-with",
  						NULL);
  	n_phandles = max(n_phandles, 0);

  	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'
  ",
  			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'
  ",
  			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-initial-mode", &pval)) {
  		if (desc && desc->of_map_mode) {

  			mode = desc->of_map_mode(pval);
  			if (mode == REGULATOR_MODE_INVALID)

  				pr_err("%pOFn: invalid mode %u
  ", np, pval);

  			else

  				constraints->initial_mode = mode;

  		} else {

  			pr_warn("%pOFn: mapping for mode %d not defined
  ",
  				np, pval);

  		}
  	}

  	len = of_property_count_elems_of_size(np, "regulator-allowed-modes",
  						sizeof(u32));
  	if (len > 0) {
  		if (desc && desc->of_map_mode) {
  			for (i = 0; i < len; i++) {
  				ret = of_property_read_u32_index(np,
  					"regulator-allowed-modes", i, &pval);
  				if (ret) {

  					pr_err("%pOFn: couldn't read allowed modes index %d, ret=%d
  ",
  						np, i, ret);

  					break;
  				}
  				mode = desc->of_map_mode(pval);
  				if (mode == REGULATOR_MODE_INVALID)

  					pr_err("%pOFn: invalid regulator-allowed-modes element %u
  ",
  						np, pval);

  				else
  					constraints->valid_modes_mask |= mode;
  			}
  			if (constraints->valid_modes_mask)
  				constraints->valid_ops_mask
  					|= REGULATOR_CHANGE_MODE;
  		} else {

  			pr_warn("%pOFn: mode mapping not defined
  ", np);

  		}
  	}

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

  	if (n_phandles) {
  		constraints->max_spread = devm_kzalloc(dev,
  				sizeof(*constraints->max_spread) * n_phandles,
  				GFP_KERNEL);
  
  		if (!constraints->max_spread)
  			return -ENOMEM;
  
  		of_property_read_u32_array(np, "regulator-coupled-max-spread",
  					   constraints->max_spread, n_phandles);
  	}

  	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");

  	for (i = 0; i < ARRAY_SIZE(regulator_states); i++) {
  		switch (i) {
  		case PM_SUSPEND_MEM:
  			suspend_state = &constraints->state_mem;
  			break;
  		case PM_SUSPEND_MAX:
  			suspend_state = &constraints->state_disk;
  			break;

  		case PM_SUSPEND_STANDBY:
  			suspend_state = &constraints->state_standby;
  			break;

  		case PM_SUSPEND_ON:

  		case PM_SUSPEND_TO_IDLE:

  		default:
  			continue;

  		}

  
  		suspend_np = of_get_child_by_name(np, regulator_states[i]);
  		if (!suspend_np || !suspend_state)
  			continue;

  		if (!of_property_read_u32(suspend_np, "regulator-mode",
  					  &pval)) {
  			if (desc && desc->of_map_mode) {

  				mode = desc->of_map_mode(pval);
  				if (mode == REGULATOR_MODE_INVALID)

  					pr_err("%pOFn: invalid mode %u
  ",
  					       np, pval);

  				else

  					suspend_state->mode = mode;

  			} else {

  				pr_warn("%pOFn: mapping for mode %d not defined
  ",
  					np, pval);

  			}
  		}

  		if (of_property_read_bool(suspend_np,
  					"regulator-on-in-suspend"))

  			suspend_state->enabled = ENABLE_IN_SUSPEND;

  		else if (of_property_read_bool(suspend_np,
  					"regulator-off-in-suspend"))

  			suspend_state->enabled = DISABLE_IN_SUSPEND;

  		if (!of_property_read_u32(suspend_np,
  				"regulator-suspend-min-microvolt", &pval))

  			suspend_state->min_uV = pval;

  		if (!of_property_read_u32(suspend_np,
  				"regulator-suspend-max-microvolt", &pval))

  			suspend_state->max_uV = pval;

  		if (!of_property_read_u32(suspend_np,
  					"regulator-suspend-microvolt", &pval))
  			suspend_state->uV = pval;

  		else /* otherwise use min_uV as default suspend voltage */
  			suspend_state->uV = suspend_state->min_uV;
  
  		if (of_property_read_bool(suspend_np,
  					"regulator-changeable-in-suspend"))
  			suspend_state->changeable = true;

  		if (i == PM_SUSPEND_MEM)
  			constraints->initial_state = PM_SUSPEND_MEM;

  		of_node_put(suspend_np);

  		suspend_state = NULL;
  		suspend_np = NULL;
  	}

  
  	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 *dev,

  					  struct device_node *node,
  					  const struct regulator_desc *desc)

  {
  	struct regulator_init_data *init_data;

  	if (!node)

  		return NULL;
  
  	init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
  	if (!init_data)
  		return NULL; /* Out of memory? */

  	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;
  };
  
  static void devm_of_regulator_put_matches(struct device *dev, void *res)
  {
  	struct devm_of_regulator_matches *devm_matches = res;
  	int i;
  
  	for (i = 0; i < devm_matches->num_matches; i++)
  		of_node_put(devm_matches->matches[i].of_node);
  }

  /**

   * 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 *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 = devres_alloc(devm_of_regulator_put_matches,
  				    sizeof(struct devm_of_regulator_matches),
  				    GFP_KERNEL);
  	if (!devm_matches)
  		return -ENOMEM;
  
  	devm_matches->matches = matches;
  	devm_matches->num_matches = num_matches;
  
  	devres_add(dev, devm_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
  ",
  					child);

  				of_node_put(child);

  				return -EINVAL;
  			}

  			match->of_node = of_node_get(child);

  			count++;
  			break;

  		}

  	}
  
  	return count;
  }
  EXPORT_SYMBOL_GPL(of_regulator_match);

  static struct
  device_node *regulator_of_get_init_node(struct device *dev,
  					const struct regulator_desc *desc)

  {
  	struct device_node *search, *child;

  	const char *name;
  
  	if (!dev->of_node || !desc->of_match)
  		return NULL;

  	if (desc->regulators_node) {

  		search = of_get_child_by_name(dev->of_node,
  					      desc->regulators_node);

  	} else {

  		search = of_node_get(dev->of_node);

  		if (!strcmp(desc->of_match, search->name))
  			return search;
  	}

  	if (!search) {

  		dev_dbg(dev, "Failed to find regulator container node '%s'
  ",
  			desc->regulators_node);

  		return NULL;
  	}

  	for_each_available_child_of_node(search, child) {

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

  		if (!strcmp(desc->of_match, name)) {
  			of_node_put(search);

  			return of_node_get(child);

  		}

  	}

  	of_node_put(search);

  	return NULL;
  }

  struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
  					    const struct regulator_desc *desc,
  					    struct regulator_config *config,
  					    struct device_node **node)
  {
  	struct device_node *child;
  	struct regulator_init_data *init_data = NULL;
  
  	child = regulator_of_get_init_node(dev, desc);
  	if (!child)
  		return NULL;
  
  	init_data = of_get_regulator_init_data(dev, child, desc);
  	if (!init_data) {
  		dev_err(dev, "failed to parse DT for regulator %pOFn
  ", child);
  		goto error;

  	}

  	if (desc->of_parse_cb) {
  		int ret;
  
  		ret = desc->of_parse_cb(child, desc, config);
  		if (ret) {
  			if (ret == -EPROBE_DEFER) {
  				of_node_put(child);
  				return ERR_PTR(-EPROBE_DEFER);
  			}
  			dev_err(dev,
  				"driver callback failed to parse DT for regulator %pOFn
  ",
  				child);
  			goto error;
  		}

  	}
  
  	*node = child;

  
  	return init_data;

  
  error:
  	of_node_put(child);
  
  	return NULL;

  }

  struct regulator_dev *of_find_regulator_by_node(struct device_node *np)
  {
  	struct device *dev;

  	dev = class_find_device_by_of_node(&regulator_class, np);

  
  	return dev ? dev_to_rdev(dev) : NULL;
  }

  
  /*
   * Returns number of regulators coupled with rdev.
   */
  int of_get_n_coupled(struct regulator_dev *rdev)
  {
  	struct device_node *node = rdev->dev.of_node;
  	int n_phandles;
  
  	n_phandles = of_count_phandle_with_args(node,
  						"regulator-coupled-with",
  						NULL);
  
  	return (n_phandles > 0) ? n_phandles : 0;
  }
  
  /* Looks for "to_find" device_node in src's "regulator-coupled-with" property */
  static bool of_coupling_find_node(struct device_node *src,

  				  struct device_node *to_find,
  				  int *index)

  {
  	int n_phandles, i;
  	bool found = false;
  
  	n_phandles = of_count_phandle_with_args(src,
  						"regulator-coupled-with",
  						NULL);
  
  	for (i = 0; i < n_phandles; i++) {
  		struct device_node *tmp = of_parse_phandle(src,
  					   "regulator-coupled-with", i);
  
  		if (!tmp)
  			break;
  
  		/* found */
  		if (tmp == to_find)
  			found = true;
  
  		of_node_put(tmp);

  		if (found) {
  			*index = i;

  			break;

  		}

  	}
  
  	return found;
  }
  
  /**
   * of_check_coupling_data - Parse rdev's coupling properties and check data
   *			    consistency

   * @rdev: pointer to regulator_dev whose data is checked

   *
   * Function checks if all the following conditions are met:
   * - rdev's max_spread is greater than 0
   * - all coupled regulators have the same max_spread
   * - all coupled regulators have the same number of regulator_dev phandles
   * - all regulators are linked to each other
   *
   * Returns true if all conditions are met.
   */
  bool of_check_coupling_data(struct regulator_dev *rdev)
  {

  	struct device_node *node = rdev->dev.of_node;
  	int n_phandles = of_get_n_coupled(rdev);
  	struct device_node *c_node;

  	int index;

  	int i;
  	bool ret = true;

  	/* iterate over rdev's phandles */
  	for (i = 0; i < n_phandles; i++) {

  		int max_spread = rdev->constraints->max_spread[i];

  		int c_max_spread, c_n_phandles;

  		if (max_spread <= 0) {
  			dev_err(&rdev->dev, "max_spread value invalid
  ");
  			return false;
  		}

  		c_node = of_parse_phandle(node,
  					  "regulator-coupled-with", i);
  
  		if (!c_node)
  			ret = false;
  
  		c_n_phandles = of_count_phandle_with_args(c_node,
  							  "regulator-coupled-with",
  							  NULL);
  
  		if (c_n_phandles != n_phandles) {

  			dev_err(&rdev->dev, "number of coupled reg phandles mismatch
  ");

  			ret = false;
  			goto clean;
  		}

  		if (!of_coupling_find_node(c_node, node, &index)) {
  			dev_err(&rdev->dev, "missing 2-way linking for coupled regulators
  ");

  			ret = false;
  			goto clean;
  		}

  		if (of_property_read_u32_index(c_node, "regulator-coupled-max-spread",
  					       index, &c_max_spread)) {

  			ret = false;
  			goto clean;
  		}

  		if (c_max_spread != max_spread) {
  			dev_err(&rdev->dev,
  				"coupled regulators max_spread mismatch
  ");

  			ret = false;

  			goto clean;

  		}
  
  clean:
  		of_node_put(c_node);
  		if (!ret)
  			break;
  	}
  
  	return ret;
  }
  
  /**
   * of_parse_coupled regulator - Get regulator_dev pointer from rdev's property
   * @rdev: Pointer to regulator_dev, whose DTS is used as a source to parse
   *	  "regulator-coupled-with" property
   * @index: Index in phandles array
   *
   * Returns the regulator_dev pointer parsed from DTS. If it has not been yet
   * registered, returns NULL
   */
  struct regulator_dev *of_parse_coupled_regulator(struct regulator_dev *rdev,
  						 int index)
  {
  	struct device_node *node = rdev->dev.of_node;
  	struct device_node *c_node;
  	struct regulator_dev *c_rdev;
  
  	c_node = of_parse_phandle(node, "regulator-coupled-with", index);
  	if (!c_node)
  		return NULL;
  
  	c_rdev = of_find_regulator_by_node(c_node);
  
  	of_node_put(c_node);
  
  	return c_rdev;
  }