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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * userspace-consumer.c
4 *
5 * Copyright 2009 CompuLab, Ltd.
6 *
7 * Author: Mike Rapoport <[email protected]>
8 *
9 * Based of virtual consumer driver:
10 * Copyright 2008 Wolfson Microelectronics PLC.
11 * Author: Mark Brown <[email protected]>
12 */
13
14#include <linux/err.h>
15#include <linux/mutex.h>
16#include <linux/module.h>
17#include <linux/of.h>
18#include <linux/platform_device.h>
19#include <linux/regulator/consumer.h>
20#include <linux/regulator/userspace-consumer.h>
21#include <linux/slab.h>
22
23struct userspace_consumer_data {
24 const char *name;
25
26 struct mutex lock;
27 bool enabled;
28 bool no_autoswitch;
29
30 int num_supplies;
31 struct regulator_bulk_data *supplies;
32};
33
34static ssize_t name_show(struct device *dev,
35 struct device_attribute *attr, char *buf)
36{
37 struct userspace_consumer_data *data = dev_get_drvdata(dev);
38
39 return sprintf(buf, "%s\n", data->name);
40}
41
42static ssize_t state_show(struct device *dev,
43 struct device_attribute *attr, char *buf)
44{
45 struct userspace_consumer_data *data = dev_get_drvdata(dev);
46
47 if (data->enabled)
48 return sprintf(buf, "enabled\n");
49
50 return sprintf(buf, "disabled\n");
51}
52
53static ssize_t state_store(struct device *dev, struct device_attribute *attr,
54 const char *buf, size_t count)
55{
56 struct userspace_consumer_data *data = dev_get_drvdata(dev);
57 bool enabled;
58 int ret;
59
60 /*
61 * sysfs_streq() doesn't need the \n's, but we add them so the strings
62 * will be shared with show_state(), above.
63 */
64 if (sysfs_streq(buf, "enabled\n") || sysfs_streq(buf, "1"))
65 enabled = true;
66 else if (sysfs_streq(buf, "disabled\n") || sysfs_streq(buf, "0"))
67 enabled = false;
68 else {
69 dev_err(dev, "Configuring invalid mode\n");
70 return count;
71 }
72
73 mutex_lock(&data->lock);
74 if (enabled != data->enabled) {
75 if (enabled)
76 ret = regulator_bulk_enable(data->num_supplies,
77 data->supplies);
78 else
79 ret = regulator_bulk_disable(data->num_supplies,
80 data->supplies);
81
82 if (ret == 0)
83 data->enabled = enabled;
84 else
85 dev_err(dev, "Failed to configure state: %d\n", ret);
86 }
87 mutex_unlock(&data->lock);
88
89 return count;
90}
91
92static DEVICE_ATTR_RO(name);
93static DEVICE_ATTR_RW(state);
94
95static struct attribute *attributes[] = {
96 &dev_attr_name.attr,
97 &dev_attr_state.attr,
98 NULL,
99};
100
101static umode_t attr_visible(struct kobject *kobj, struct attribute *attr, int idx)
102{
103 struct device *dev = kobj_to_dev(kobj);
104 struct userspace_consumer_data *data = dev_get_drvdata(dev);
105
106 /* If a name hasn't been set, don't bother with the attribute */
107 if (attr == &dev_attr_name.attr && !data->name)
108 return 0;
109
110 return attr->mode;
111}
112
113static const struct attribute_group attr_group = {
114 .attrs = attributes,
115 .is_visible = attr_visible,
116};
117
118static int regulator_userspace_consumer_probe(struct platform_device *pdev)
119{
120 struct regulator_userspace_consumer_data tmpdata;
121 struct regulator_userspace_consumer_data *pdata;
122 struct userspace_consumer_data *drvdata;
123 int ret;
124
125 pdata = dev_get_platdata(&pdev->dev);
126 if (!pdata) {
127 if (!pdev->dev.of_node)
128 return -EINVAL;
129
130 pdata = &tmpdata;
131 memset(pdata, 0, sizeof(*pdata));
132
133 pdata->no_autoswitch = true;
134 pdata->num_supplies = 1;
135 pdata->supplies = devm_kzalloc(&pdev->dev, sizeof(*pdata->supplies), GFP_KERNEL);
136 if (!pdata->supplies)
137 return -ENOMEM;
138 pdata->supplies[0].supply = "vout";
139 }
140
141 if (pdata->num_supplies < 1) {
142 dev_err(&pdev->dev, "At least one supply required\n");
143 return -EINVAL;
144 }
145
146 drvdata = devm_kzalloc(&pdev->dev,
147 sizeof(struct userspace_consumer_data),
148 GFP_KERNEL);
149 if (drvdata == NULL)
150 return -ENOMEM;
151
152 drvdata->name = pdata->name;
153 drvdata->num_supplies = pdata->num_supplies;
154 drvdata->supplies = pdata->supplies;
155 drvdata->no_autoswitch = pdata->no_autoswitch;
156
157 mutex_init(&drvdata->lock);
158
159 ret = devm_regulator_bulk_get_exclusive(&pdev->dev, drvdata->num_supplies,
160 drvdata->supplies);
161 if (ret)
162 return dev_err_probe(&pdev->dev, ret, "Failed to get supplies\n");
163
164 platform_set_drvdata(pdev, drvdata);
165
166 ret = sysfs_create_group(&pdev->dev.kobj, &attr_group);
167 if (ret != 0)
168 return ret;
169
170 if (pdata->init_on && !pdata->no_autoswitch) {
171 ret = regulator_bulk_enable(drvdata->num_supplies,
172 drvdata->supplies);
173 if (ret) {
174 dev_err(&pdev->dev,
175 "Failed to set initial state: %d\n", ret);
176 goto err_enable;
177 }
178 }
179
180 ret = regulator_is_enabled(pdata->supplies[0].consumer);
181 if (ret < 0) {
182 dev_err(&pdev->dev, "Failed to get regulator status\n");
183 goto err_enable;
184 }
185 drvdata->enabled = !!ret;
186
187 return 0;
188
189err_enable:
190 sysfs_remove_group(&pdev->dev.kobj, &attr_group);
191
192 return ret;
193}
194
195static void regulator_userspace_consumer_remove(struct platform_device *pdev)
196{
197 struct userspace_consumer_data *data = platform_get_drvdata(pdev);
198
199 sysfs_remove_group(&pdev->dev.kobj, &attr_group);
200
201 if (data->enabled && !data->no_autoswitch)
202 regulator_bulk_disable(data->num_supplies, data->supplies);
203}
204
205static const struct of_device_id regulator_userspace_consumer_of_match[] = {
206 { .compatible = "regulator-output", },
207 {},
208};
209MODULE_DEVICE_TABLE(of, regulator_userspace_consumer_of_match);
210
211static struct platform_driver regulator_userspace_consumer_driver = {
212 .probe = regulator_userspace_consumer_probe,
213 .remove = regulator_userspace_consumer_remove,
214 .driver = {
215 .name = "reg-userspace-consumer",
216 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
217 .of_match_table = regulator_userspace_consumer_of_match,
218 },
219};
220
221module_platform_driver(regulator_userspace_consumer_driver);
222
223MODULE_AUTHOR("Mike Rapoport <[email protected]>");
224MODULE_DESCRIPTION("Userspace consumer for voltage and current regulators");
225MODULE_LICENSE("GPL");