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
of_get_regulation_constraints(struct device_node * np,struct regulator_init_data ** init_data)22 static 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 */
of_get_regulator_init_data(struct device * dev,struct device_node * node)86 struct 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 }
101 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
102
103 struct devm_of_regulator_matches {
104 struct of_regulator_match *matches;
105 unsigned int num_matches;
106 };
107
devm_of_regulator_put_matches(struct device * dev,void * res)108 static 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 */
of_regulator_match(struct device * dev,struct device_node * node,struct of_regulator_match * matches,unsigned int num_matches)135 int 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 }
194 EXPORT_SYMBOL_GPL(of_regulator_match);
195
regulator_of_get_init_data(struct device * dev,const struct regulator_desc * desc,struct device_node ** node)196 struct 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