summaryrefslogtreecommitdiff
path: root/drivers/regulator/vexpress.c
blob: 147ecc7c11bf2db837c8f5069995815a7283f015 (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
135
136
137
138
139
140
141
142
143
144
145
146
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * Copyright (C) 2012 ARM Limited
 */

#define DRVNAME "vexpress-regulator"
#define pr_fmt(fmt) DRVNAME ": " fmt

#include <linux/device.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/of_regulator.h>
#include <linux/vexpress.h>

struct vexpress_regulator {
	struct regulator_desc desc;
	struct regulator_dev *regdev;
	struct vexpress_config_func *func;
};

static int vexpress_regulator_get_voltage(struct regulator_dev *regdev)
{
	struct vexpress_regulator *reg = rdev_get_drvdata(regdev);
	u32 uV;
	int err = vexpress_config_read(reg->func, 0, &uV);

	return err ? err : uV;
}

static int vexpress_regulator_set_voltage(struct regulator_dev *regdev,
		int min_uV, int max_uV, unsigned *selector)
{
	struct vexpress_regulator *reg = rdev_get_drvdata(regdev);

	return vexpress_config_write(reg->func, 0, min_uV);
}

static struct regulator_ops vexpress_regulator_ops_ro = {
	.get_voltage = vexpress_regulator_get_voltage,
};

static struct regulator_ops vexpress_regulator_ops = {
	.get_voltage = vexpress_regulator_get_voltage,
	.set_voltage = vexpress_regulator_set_voltage,
};

static int vexpress_regulator_probe(struct platform_device *pdev)
{
	int err;
	struct vexpress_regulator *reg;
	struct regulator_init_data *init_data;
	struct regulator_config config = { };

	reg = devm_kzalloc(&pdev->dev, sizeof(*reg), GFP_KERNEL);
	if (!reg) {
		err = -ENOMEM;
		goto error_kzalloc;
	}

	reg->func = vexpress_config_func_get_by_dev(&pdev->dev);
	if (!reg->func) {
		err = -ENXIO;
		goto error_get_func;
	}

	reg->desc.name = dev_name(&pdev->dev);
	reg->desc.type = REGULATOR_VOLTAGE;
	reg->desc.owner = THIS_MODULE;
	reg->desc.continuous_voltage_range = true;

	init_data = of_get_regulator_init_data(&pdev->dev, pdev->dev.of_node);
	if (!init_data) {
		err = -EINVAL;
		goto error_get_regulator_init_data;
	}

	init_data->constraints.apply_uV = 0;
	if (init_data->constraints.min_uV && init_data->constraints.max_uV)
		reg->desc.ops = &vexpress_regulator_ops;
	else
		reg->desc.ops = &vexpress_regulator_ops_ro;

	config.dev = &pdev->dev;
	config.init_data = init_data;
	config.driver_data = reg;
	config.of_node = pdev->dev.of_node;

	reg->regdev = devm_regulator_register(&pdev->dev, &reg->desc, &config);
	if (IS_ERR(reg->regdev)) {
		err = PTR_ERR(reg->regdev);
		goto error_regulator_register;
	}

	platform_set_drvdata(pdev, reg);

	return 0;

error_regulator_register:
error_get_regulator_init_data:
	vexpress_config_func_put(reg->func);
error_get_func:
error_kzalloc:
	return err;
}

static int vexpress_regulator_remove(struct platform_device *pdev)
{
	struct vexpress_regulator *reg = platform_get_drvdata(pdev);

	vexpress_config_func_put(reg->func);

	return 0;
}

static const struct of_device_id vexpress_regulator_of_match[] = {
	{ .compatible = "arm,vexpress-volt", },
	{ }
};

static struct platform_driver vexpress_regulator_driver = {
	.probe = vexpress_regulator_probe,
	.remove = vexpress_regulator_remove,
	.driver	= {
		.name = DRVNAME,
		.owner = THIS_MODULE,
		.of_match_table = vexpress_regulator_of_match,
	},
};

module_platform_driver(vexpress_regulator_driver);

MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
MODULE_DESCRIPTION("Versatile Express regulator");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:vexpress-regulator");