1/*
  2 * OF helpers for regulator framework
  3 *
  4 * Copyright (C) 2011 Texas Instruments, Inc.
  5 * Rajendra Nayak <rnayak@ti.com>
  6 *
  7 * This program is free software; you can redistribute it and/or modify
  8 * it under the terms of the GNU General Public License as published by
  9 * the Free Software Foundation; either version 2 of the License, or
 10 * (at your option) any later version.
 11 */
 12
 13#include <linux/module.h>
 14#include <linux/slab.h>
 15#include <linux/of.h>
 16#include <linux/regulator/machine.h>
 17#include <linux/regulator/of_regulator.h>
 18
 19static void of_get_regulation_constraints(struct device_node *np,
 20					struct regulator_init_data **init_data)
 21{
 22	const __be32 *min_uV, *max_uV, *uV_offset;
 23	const __be32 *min_uA, *max_uA;
 24	struct regulation_constraints *constraints = &(*init_data)->constraints;
 25
 26	constraints->name = of_get_property(np, "regulator-name", NULL);
 27
 28	min_uV = of_get_property(np, "regulator-min-microvolt", NULL);
 29	if (min_uV)
 30		constraints->min_uV = be32_to_cpu(*min_uV);
 31	max_uV = of_get_property(np, "regulator-max-microvolt", NULL);
 32	if (max_uV)
 33		constraints->max_uV = be32_to_cpu(*max_uV);
 34
 35	/* Voltage change possible? */
 36	if (constraints->min_uV != constraints->max_uV)
 37		constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
 38	/* Only one voltage?  Then make sure it's set. */
 39	if (min_uV && max_uV && constraints->min_uV == constraints->max_uV)
 40		constraints->apply_uV = true;
 41
 42	uV_offset = of_get_property(np, "regulator-microvolt-offset", NULL);
 43	if (uV_offset)
 44		constraints->uV_offset = be32_to_cpu(*uV_offset);
 45	min_uA = of_get_property(np, "regulator-min-microamp", NULL);
 46	if (min_uA)
 47		constraints->min_uA = be32_to_cpu(*min_uA);
 48	max_uA = of_get_property(np, "regulator-max-microamp", NULL);
 49	if (max_uA)
 50		constraints->max_uA = be32_to_cpu(*max_uA);
 51
 52	/* Current change possible? */
 53	if (constraints->min_uA != constraints->max_uA)
 54		constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
 55
 56	if (of_find_property(np, "regulator-boot-on", NULL))
 57		constraints->boot_on = true;
 58
 59	if (of_find_property(np, "regulator-always-on", NULL))
 60		constraints->always_on = true;
 61	else /* status change should be possible if not always on. */
 62		constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
 63}
 64
 65/**
 66 * of_get_regulator_init_data - extract regulator_init_data structure info
 67 * @dev: device requesting for regulator_init_data
 68 *
 69 * Populates regulator_init_data structure by extracting data from device
 70 * tree node, returns a pointer to the populated struture or NULL if memory
 71 * alloc fails.
 72 */
 73struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
 74						struct device_node *node)
 75{
 76	struct regulator_init_data *init_data;
 77
 78	if (!node)
 79		return NULL;
 80
 81	init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
 82	if (!init_data)
 83		return NULL; /* Out of memory? */
 84
 85	of_get_regulation_constraints(node, &init_data);
 86	return init_data;
 87}
 88EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
 89
 90/**
 91 * of_regulator_match - extract regulator init data
 92 * @dev: device requesting the data
 93 * @node: parent device node of the regulators
 94 * @matches: match table for the regulators
 95 * @num_matches: number of entries in match table
 96 *
 97 * This function uses a match table specified by the regulator driver and
 98 * looks up the corresponding init data in the device tree. Note that the
 99 * match table is modified in place.
100 *
101 * Returns the number of matches found or a negative error code on failure.
102 */
103int of_regulator_match(struct device *dev, struct device_node *node,
104		       struct of_regulator_match *matches,
105		       unsigned int num_matches)
106{
107	unsigned int count = 0;
108	unsigned int i;
109
110	if (!dev || !node)
111		return -EINVAL;
112
113	for (i = 0; i < num_matches; i++) {
114		struct of_regulator_match *match = &matches[i];
115		struct device_node *child;
116
117		child = of_find_node_by_name(node, match->name);
118		if (!child)
119			continue;
120
121		match->init_data = of_get_regulator_init_data(dev, child);
122		if (!match->init_data) {
123			dev_err(dev, "failed to parse DT for regulator %s\n",
124				child->name);
125			return -EINVAL;
126		}
127
128		match->of_node = child;
129		count++;
130	}
131
132	return count;
133}
134EXPORT_SYMBOL_GPL(of_regulator_match);