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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
19 static 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, *ramp_delay;
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         ramp_delay = of_get_property(np, "regulator-ramp-delay", NULL);
65         if (ramp_delay)
66                 constraints->ramp_delay = be32_to_cpu(*ramp_delay);
67 }
68
69 /**
70  * of_get_regulator_init_data - extract regulator_init_data structure info
71  * @dev: device requesting for regulator_init_data
72  *
73  * Populates regulator_init_data structure by extracting data from device
74  * tree node, returns a pointer to the populated struture or NULL if memory
75  * alloc fails.
76  */
77 struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
78                                                 struct device_node *node)
79 {
80         struct regulator_init_data *init_data;
81
82         if (!node)
83                 return NULL;
84
85         init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
86         if (!init_data)
87                 return NULL; /* Out of memory? */
88
89         of_get_regulation_constraints(node, &init_data);
90         return init_data;
91 }
92 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
93
94 /**
95  * of_regulator_match - extract multiple regulator init data from device tree.
96  * @dev: device requesting the data
97  * @node: parent device node of the regulators
98  * @matches: match table for the regulators
99  * @num_matches: number of entries in match table
100  *
101  * This function uses a match table specified by the regulator driver to
102  * parse regulator init data from the device tree. @node is expected to
103  * contain a set of child nodes, each providing the init data for one
104  * regulator. The data parsed from a child node will be matched to a regulator
105  * based on either the deprecated property regulator-compatible if present,
106  * or otherwise the child node's name. Note that the match table is modified
107  * in place.
108  *
109  * Returns the number of matches found or a negative error code on failure.
110  */
111 int of_regulator_match(struct device *dev, struct device_node *node,
112                        struct of_regulator_match *matches,
113                        unsigned int num_matches)
114 {
115         unsigned int count = 0;
116         unsigned int i;
117         const char *name;
118         struct device_node *child;
119
120         if (!dev || !node)
121                 return -EINVAL;
122
123         for_each_child_of_node(node, child) {
124                 name = of_get_property(child,
125                                         "regulator-compatible", NULL);
126                 if (!name)
127                         name = child->name;
128                 for (i = 0; i < num_matches; i++) {
129                         struct of_regulator_match *match = &matches[i];
130                         if (match->of_node)
131                                 continue;
132
133                         if (strcmp(match->name, name))
134                                 continue;
135
136                         match->init_data =
137                                 of_get_regulator_init_data(dev, child);
138                         if (!match->init_data) {
139                                 dev_err(dev,
140                                         "failed to parse DT for regulator %s\n",
141                                         child->name);
142                                 return -EINVAL;
143                         }
144                         match->of_node = child;
145                         count++;
146                         break;
147                 }
148         }
149
150         return count;
151 }
152 EXPORT_SYMBOL_GPL(of_regulator_match);