summaryrefslogtreecommitdiffstats
path: root/drivers/regulator/of_regulator.c
blob: 56593b75168a28e830946201778cd1937f08a724 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
/*
 * OF helpers for regulator framework
 *
 * Copyright (C) 2011 Texas Instruments, Inc.
 * Rajendra Nayak <rnayak@ti.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

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

static void of_get_regulation_constraints(struct device_node *np,
					struct regulator_init_data **init_data)
{
	const __be32 *min_uV, *max_uV, *uV_offset;
	const __be32 *min_uA, *max_uA;
	struct regulation_constraints *constraints = &(*init_data)->constraints;

	constraints->name = of_get_property(np, "regulator-name", NULL);

	min_uV = of_get_property(np, "regulator-min-microvolt", NULL);
	if (min_uV)
		constraints->min_uV = be32_to_cpu(*min_uV);
	max_uV = of_get_property(np, "regulator-max-microvolt", NULL);
	if (max_uV)
		constraints->max_uV = be32_to_cpu(*max_uV);

	/* Voltage change possible? */
	if (constraints->min_uV != constraints->max_uV)
		constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
	/* Only one voltage?  Then make sure it's set. */
	if (min_uV && max_uV && constraints->min_uV == constraints->max_uV)
		constraints->apply_uV = true;

	uV_offset = of_get_property(np, "regulator-microvolt-offset", NULL);
	if (uV_offset)
		constraints->uV_offset = be32_to_cpu(*uV_offset);
	min_uA = of_get_property(np, "regulator-min-microamp", NULL);
	if (min_uA)
		constraints->min_uA = be32_to_cpu(*min_uA);
	max_uA = of_get_property(np, "regulator-max-microamp", NULL);
	if (max_uA)
		constraints->max_uA = be32_to_cpu(*max_uA);

	/* Current change possible? */
	if (constraints->min_uA != constraints->max_uA)
		constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;

	if (of_find_property(np, "regulator-boot-on", NULL))
		constraints->boot_on = true;

	if (of_find_property(np, "regulator-always-on", NULL))
		constraints->always_on = true;
	else /* status change should be possible if not always on. */
		constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
}

/**
 * of_get_regulator_init_data - extract regulator_init_data structure info
 * @dev: device requesting for regulator_init_data
 *
 * Populates regulator_init_data structure by extracting data from device
 * tree node, returns a pointer to the populated struture or NULL if memory
 * alloc fails.
 */
struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
						struct device_node *node)
{
	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? */

	of_get_regulation_constraints(node, &init_data);
	return init_data;
}
EXPORT_SYMBOL_GPL(of_get_regulator_init_data);

/**
 * of_regulator_match - extract regulator init data
 * @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 and
 * looks up the corresponding init data in the device tree. Note that the
 * match table is modified in place.
 *
 * 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;

	if (!dev || !node)
		return -EINVAL;

	for (i = 0; i < num_matches; i++) {
		struct of_regulator_match *match = &matches[i];
		struct device_node *child;

		child = of_find_node_by_name(node, match->name);
		if (!child)
			continue;

		match->init_data = of_get_regulator_init_data(dev, child);
		if (!match->init_data) {
			dev_err(dev, "failed to parse DT for regulator %s\n",
				child->name);
			return -EINVAL;
		}

		match->of_node = child;
		count++;
	}

	return count;
}
EXPORT_SYMBOL_GPL(of_regulator_match);