tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 vexpress_config_func *func;
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 = vexpress_config_read(reg->func, 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 vexpress_config_write(reg->func, 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 int err;
61 struct vexpress_regulator *reg;
62 struct regulator_init_data *init_data;
63 struct regulator_config config = { };
64
65 reg = devm_kzalloc(&pdev->dev, sizeof(*reg), GFP_KERNEL);
66 if (!reg) {
67 err = -ENOMEM;
68 goto error_kzalloc;
69 }
70
71 reg->func = vexpress_config_func_get_by_dev(&pdev->dev);
72 if (!reg->func) {
73 err = -ENXIO;
74 goto error_get_func;
75 }
76
77 reg->desc.name = dev_name(&pdev->dev);
78 reg->desc.type = REGULATOR_VOLTAGE;
79 reg->desc.owner = THIS_MODULE;
80 reg->desc.continuous_voltage_range = true;
81
82 init_data = of_get_regulator_init_data(&pdev->dev, pdev->dev.of_node);
83 if (!init_data) {
84 err = -EINVAL;
85 goto error_get_regulator_init_data;
86 }
87
88 init_data->constraints.apply_uV = 0;
89 if (init_data->constraints.min_uV && init_data->constraints.max_uV)
90 reg->desc.ops = &vexpress_regulator_ops;
91 else
92 reg->desc.ops = &vexpress_regulator_ops_ro;
93
94 config.dev = &pdev->dev;
95 config.init_data = init_data;
96 config.driver_data = reg;
97 config.of_node = pdev->dev.of_node;
98
99 reg->regdev = regulator_register(®->desc, &config);
100 if (IS_ERR(reg->regdev)) {
101 err = PTR_ERR(reg->regdev);
102 goto error_regulator_register;
103 }
104
105 platform_set_drvdata(pdev, reg);
106
107 return 0;
108
109error_regulator_register:
110error_get_regulator_init_data:
111 vexpress_config_func_put(reg->func);
112error_get_func:
113error_kzalloc:
114 return err;
115}
116
117static int vexpress_regulator_remove(struct platform_device *pdev)
118{
119 struct vexpress_regulator *reg = platform_get_drvdata(pdev);
120
121 vexpress_config_func_put(reg->func);
122 regulator_unregister(reg->regdev);
123
124 return 0;
125}
126
127static struct of_device_id vexpress_regulator_of_match[] = {
128 { .compatible = "arm,vexpress-volt", },
129 { }
130};
131
132static struct platform_driver vexpress_regulator_driver = {
133 .probe = vexpress_regulator_probe,
134 .remove = vexpress_regulator_remove,
135 .driver = {
136 .name = DRVNAME,
137 .owner = THIS_MODULE,
138 .of_match_table = vexpress_regulator_of_match,
139 },
140};
141
142module_platform_driver(vexpress_regulator_driver);
143
144MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
145MODULE_DESCRIPTION("Versatile Express regulator");
146MODULE_LICENSE("GPL");
147MODULE_ALIAS("platform:vexpress-regulator");