1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License version 2 as
4 * published by the Free Software Foundation.
5 *
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
9 * GNU General Public License for more details.
10 *
11 * Copyright (C) 2012 ARM Limited
12 */
13
14#define DRVNAME "vexpress-regulator"
15#define pr_fmt(fmt) DRVNAME ": " fmt
16
17#include <linux/device.h>
18#include <linux/err.h>
19#include <linux/module.h>
20#include <linux/of_device.h>
21#include <linux/regulator/driver.h>
22#include <linux/regulator/machine.h>
23#include <linux/regulator/of_regulator.h>
24#include <linux/vexpress.h>
25
26struct vexpress_regulator {
27	struct regulator_desc desc;
28	struct regulator_dev *regdev;
29	struct regmap *regmap;
30};
31
32static int vexpress_regulator_get_voltage(struct regulator_dev *regdev)
33{
34	struct vexpress_regulator *reg = rdev_get_drvdata(regdev);
35	u32 uV;
36	int err = regmap_read(reg->regmap, 0, &uV);
37
38	return err ? err : uV;
39}
40
41static int vexpress_regulator_set_voltage(struct regulator_dev *regdev,
42		int min_uV, int max_uV, unsigned *selector)
43{
44	struct vexpress_regulator *reg = rdev_get_drvdata(regdev);
45
46	return regmap_write(reg->regmap, 0, min_uV);
47}
48
49static struct regulator_ops vexpress_regulator_ops_ro = {
50	.get_voltage = vexpress_regulator_get_voltage,
51};
52
53static struct regulator_ops vexpress_regulator_ops = {
54	.get_voltage = vexpress_regulator_get_voltage,
55	.set_voltage = vexpress_regulator_set_voltage,
56};
57
58static int vexpress_regulator_probe(struct platform_device *pdev)
59{
60	struct vexpress_regulator *reg;
61	struct regulator_init_data *init_data;
62	struct regulator_config config = { };
63
64	reg = devm_kzalloc(&pdev->dev, sizeof(*reg), GFP_KERNEL);
65	if (!reg)
66		return -ENOMEM;
67
68	reg->regmap = devm_regmap_init_vexpress_config(&pdev->dev);
69	if (IS_ERR(reg->regmap))
70		return PTR_ERR(reg->regmap);
71
72	reg->desc.name = dev_name(&pdev->dev);
73	reg->desc.type = REGULATOR_VOLTAGE;
74	reg->desc.owner = THIS_MODULE;
75	reg->desc.continuous_voltage_range = true;
76
77	init_data = of_get_regulator_init_data(&pdev->dev, pdev->dev.of_node);
78	if (!init_data)
79		return -EINVAL;
80
81	init_data->constraints.apply_uV = 0;
82	if (init_data->constraints.min_uV && init_data->constraints.max_uV)
83		reg->desc.ops = &vexpress_regulator_ops;
84	else
85		reg->desc.ops = &vexpress_regulator_ops_ro;
86
87	config.dev = &pdev->dev;
88	config.init_data = init_data;
89	config.driver_data = reg;
90	config.of_node = pdev->dev.of_node;
91
92	reg->regdev = devm_regulator_register(&pdev->dev, &reg->desc, &config);
93	if (IS_ERR(reg->regdev))
94		return PTR_ERR(reg->regdev);
95
96	platform_set_drvdata(pdev, reg);
97
98	return 0;
99}
100
101static const struct of_device_id vexpress_regulator_of_match[] = {
102	{ .compatible = "arm,vexpress-volt", },
103	{ }
104};
105
106static struct platform_driver vexpress_regulator_driver = {
107	.probe = vexpress_regulator_probe,
108	.driver	= {
109		.name = DRVNAME,
110		.owner = THIS_MODULE,
111		.of_match_table = vexpress_regulator_of_match,
112	},
113};
114
115module_platform_driver(vexpress_regulator_driver);
116
117MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
118MODULE_DESCRIPTION("Versatile Express regulator");
119MODULE_LICENSE("GPL");
120MODULE_ALIAS("platform:vexpress-regulator");
121