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/driver.h>
18#include <linux/regulator/of_regulator.h>
19
20#include "internal.h"
21
22static void of_get_regulation_constraints(struct device_node *np,
23					struct regulator_init_data **init_data)
24{
25	const __be32 *min_uV, *max_uV;
26	struct regulation_constraints *constraints = &(*init_data)->constraints;
27	int ret;
28	u32 pval;
29
30	constraints->name = of_get_property(np, "regulator-name", NULL);
31
32	min_uV = of_get_property(np, "regulator-min-microvolt", NULL);
33	if (min_uV)
34		constraints->min_uV = be32_to_cpu(*min_uV);
35	max_uV = of_get_property(np, "regulator-max-microvolt", NULL);
36	if (max_uV)
37		constraints->max_uV = be32_to_cpu(*max_uV);
38
39	/* Voltage change possible? */
40	if (constraints->min_uV != constraints->max_uV)
41		constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
42	/* Only one voltage?  Then make sure it's set. */
43	if (min_uV && max_uV && constraints->min_uV == constraints->max_uV)
44		constraints->apply_uV = true;
45
46	if (!of_property_read_u32(np, "regulator-microvolt-offset", &pval))
47		constraints->uV_offset = pval;
48	if (!of_property_read_u32(np, "regulator-min-microamp", &pval))
49		constraints->min_uA = pval;
50	if (!of_property_read_u32(np, "regulator-max-microamp", &pval))
51		constraints->max_uA = pval;
52
53	/* Current change possible? */
54	if (constraints->min_uA != constraints->max_uA)
55		constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
56
57	constraints->boot_on = of_property_read_bool(np, "regulator-boot-on");
58	constraints->always_on = of_property_read_bool(np, "regulator-always-on");
59	if (!constraints->always_on) /* status change should be possible. */
60		constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
61
62	if (of_property_read_bool(np, "regulator-allow-bypass"))
63		constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS;
64
65	ret = of_property_read_u32(np, "regulator-ramp-delay", &pval);
66	if (!ret) {
67		if (pval)
68			constraints->ramp_delay = pval;
69		else
70			constraints->ramp_disable = true;
71	}
72
73	ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval);
74	if (!ret)
75		constraints->enable_time = pval;
76}
77
78/**
79 * of_get_regulator_init_data - extract regulator_init_data structure info
80 * @dev: device requesting for regulator_init_data
81 *
82 * Populates regulator_init_data structure by extracting data from device
83 * tree node, returns a pointer to the populated struture or NULL if memory
84 * alloc fails.
85 */
86struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
87						struct device_node *node)
88{
89	struct regulator_init_data *init_data;
90
91	if (!node)
92		return NULL;
93
94	init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
95	if (!init_data)
96		return NULL; /* Out of memory? */
97
98	of_get_regulation_constraints(node, &init_data);
99	return init_data;
100}
101EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
102
103struct devm_of_regulator_matches {
104	struct of_regulator_match *matches;
105	unsigned int num_matches;
106};
107
108static void devm_of_regulator_put_matches(struct device *dev, void *res)
109{
110	struct devm_of_regulator_matches *devm_matches = res;
111	int i;
112
113	for (i = 0; i < devm_matches->num_matches; i++)
114		of_node_put(devm_matches->matches[i].of_node);
115}
116
117/**
118 * of_regulator_match - extract multiple regulator init data from device tree.
119 * @dev: device requesting the data
120 * @node: parent device node of the regulators
121 * @matches: match table for the regulators
122 * @num_matches: number of entries in match table
123 *
124 * This function uses a match table specified by the regulator driver to
125 * parse regulator init data from the device tree. @node is expected to
126 * contain a set of child nodes, each providing the init data for one
127 * regulator. The data parsed from a child node will be matched to a regulator
128 * based on either the deprecated property regulator-compatible if present,
129 * or otherwise the child node's name. Note that the match table is modified
130 * in place and an additional of_node reference is taken for each matched
131 * regulator.
132 *
133 * Returns the number of matches found or a negative error code on failure.
134 */
135int of_regulator_match(struct device *dev, struct device_node *node,
136		       struct of_regulator_match *matches,
137		       unsigned int num_matches)
138{
139	unsigned int count = 0;
140	unsigned int i;
141	const char *name;
142	struct device_node *child;
143	struct devm_of_regulator_matches *devm_matches;
144
145	if (!dev || !node)
146		return -EINVAL;
147
148	devm_matches = devres_alloc(devm_of_regulator_put_matches,
149				    sizeof(struct devm_of_regulator_matches),
150				    GFP_KERNEL);
151	if (!devm_matches)
152		return -ENOMEM;
153
154	devm_matches->matches = matches;
155	devm_matches->num_matches = num_matches;
156
157	devres_add(dev, devm_matches);
158
159	for (i = 0; i < num_matches; i++) {
160		struct of_regulator_match *match = &matches[i];
161		match->init_data = NULL;
162		match->of_node = NULL;
163	}
164
165	for_each_child_of_node(node, child) {
166		name = of_get_property(child,
167					"regulator-compatible", NULL);
168		if (!name)
169			name = child->name;
170		for (i = 0; i < num_matches; i++) {
171			struct of_regulator_match *match = &matches[i];
172			if (match->of_node)
173				continue;
174
175			if (strcmp(match->name, name))
176				continue;
177
178			match->init_data =
179				of_get_regulator_init_data(dev, child);
180			if (!match->init_data) {
181				dev_err(dev,
182					"failed to parse DT for regulator %s\n",
183					child->name);
184				return -EINVAL;
185			}
186			match->of_node = of_node_get(child);
187			count++;
188			break;
189		}
190	}
191
192	return count;
193}
194EXPORT_SYMBOL_GPL(of_regulator_match);
195
196struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
197					    const struct regulator_desc *desc,
198					    struct device_node **node)
199{
200	struct device_node *search, *child;
201	struct regulator_init_data *init_data = NULL;
202	const char *name;
203
204	if (!dev->of_node || !desc->of_match)
205		return NULL;
206
207	if (desc->regulators_node)
208		search = of_get_child_by_name(dev->of_node,
209					      desc->regulators_node);
210	else
211		search = dev->of_node;
212
213	if (!search) {
214		dev_dbg(dev, "Failed to find regulator container node '%s'\n",
215			desc->regulators_node);
216		return NULL;
217	}
218
219	for_each_child_of_node(search, child) {
220		name = of_get_property(child, "regulator-compatible", NULL);
221		if (!name)
222			name = child->name;
223
224		if (strcmp(desc->of_match, name))
225			continue;
226
227		init_data = of_get_regulator_init_data(dev, child);
228		if (!init_data) {
229			dev_err(dev,
230				"failed to parse DT for regulator %s\n",
231				child->name);
232			break;
233		}
234
235		of_node_get(child);
236		*node = child;
237		break;
238	}
239
240	of_node_put(search);
241
242	return init_data;
243}
244