Merge tag 'printk-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek...
[linux-2.6-block.git] / drivers / regulator / userspace-consumer.c
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 <mike@compulab.co.il>
8  *
9  * Based of virtual consumer driver:
10  *   Copyright 2008 Wolfson Microelectronics PLC.
11  *   Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
12  */
13
14 #include <linux/err.h>
15 #include <linux/mutex.h>
16 #include <linux/module.h>
17 #include <linux/platform_device.h>
18 #include <linux/regulator/consumer.h>
19 #include <linux/regulator/userspace-consumer.h>
20 #include <linux/slab.h>
21
22 struct userspace_consumer_data {
23         const char *name;
24
25         struct mutex lock;
26         bool enabled;
27
28         int num_supplies;
29         struct regulator_bulk_data *supplies;
30 };
31
32 static ssize_t reg_show_name(struct device *dev,
33                           struct device_attribute *attr, char *buf)
34 {
35         struct userspace_consumer_data *data = dev_get_drvdata(dev);
36
37         return sprintf(buf, "%s\n", data->name);
38 }
39
40 static ssize_t reg_show_state(struct device *dev,
41                           struct device_attribute *attr, char *buf)
42 {
43         struct userspace_consumer_data *data = dev_get_drvdata(dev);
44
45         if (data->enabled)
46                 return sprintf(buf, "enabled\n");
47
48         return sprintf(buf, "disabled\n");
49 }
50
51 static ssize_t reg_set_state(struct device *dev, struct device_attribute *attr,
52                          const char *buf, size_t count)
53 {
54         struct userspace_consumer_data *data = dev_get_drvdata(dev);
55         bool enabled;
56         int ret;
57
58         /*
59          * sysfs_streq() doesn't need the \n's, but we add them so the strings
60          * will be shared with show_state(), above.
61          */
62         if (sysfs_streq(buf, "enabled\n") || sysfs_streq(buf, "1"))
63                 enabled = true;
64         else if (sysfs_streq(buf, "disabled\n") || sysfs_streq(buf, "0"))
65                 enabled = false;
66         else {
67                 dev_err(dev, "Configuring invalid mode\n");
68                 return count;
69         }
70
71         mutex_lock(&data->lock);
72         if (enabled != data->enabled) {
73                 if (enabled)
74                         ret = regulator_bulk_enable(data->num_supplies,
75                                                     data->supplies);
76                 else
77                         ret = regulator_bulk_disable(data->num_supplies,
78                                                      data->supplies);
79
80                 if (ret == 0)
81                         data->enabled = enabled;
82                 else
83                         dev_err(dev, "Failed to configure state: %d\n", ret);
84         }
85         mutex_unlock(&data->lock);
86
87         return count;
88 }
89
90 static DEVICE_ATTR(name, 0444, reg_show_name, NULL);
91 static DEVICE_ATTR(state, 0644, reg_show_state, reg_set_state);
92
93 static struct attribute *attributes[] = {
94         &dev_attr_name.attr,
95         &dev_attr_state.attr,
96         NULL,
97 };
98
99 static const struct attribute_group attr_group = {
100         .attrs  = attributes,
101 };
102
103 static int regulator_userspace_consumer_probe(struct platform_device *pdev)
104 {
105         struct regulator_userspace_consumer_data *pdata;
106         struct userspace_consumer_data *drvdata;
107         int ret;
108
109         pdata = dev_get_platdata(&pdev->dev);
110         if (!pdata)
111                 return -EINVAL;
112
113         drvdata = devm_kzalloc(&pdev->dev,
114                                sizeof(struct userspace_consumer_data),
115                                GFP_KERNEL);
116         if (drvdata == NULL)
117                 return -ENOMEM;
118
119         drvdata->name = pdata->name;
120         drvdata->num_supplies = pdata->num_supplies;
121         drvdata->supplies = pdata->supplies;
122
123         mutex_init(&drvdata->lock);
124
125         ret = devm_regulator_bulk_get(&pdev->dev, drvdata->num_supplies,
126                                       drvdata->supplies);
127         if (ret) {
128                 dev_err(&pdev->dev, "Failed to get supplies: %d\n", ret);
129                 return ret;
130         }
131
132         ret = sysfs_create_group(&pdev->dev.kobj, &attr_group);
133         if (ret != 0)
134                 return ret;
135
136         if (pdata->init_on) {
137                 ret = regulator_bulk_enable(drvdata->num_supplies,
138                                             drvdata->supplies);
139                 if (ret) {
140                         dev_err(&pdev->dev,
141                                 "Failed to set initial state: %d\n", ret);
142                         goto err_enable;
143                 }
144         }
145
146         drvdata->enabled = pdata->init_on;
147         platform_set_drvdata(pdev, drvdata);
148
149         return 0;
150
151 err_enable:
152         sysfs_remove_group(&pdev->dev.kobj, &attr_group);
153
154         return ret;
155 }
156
157 static int regulator_userspace_consumer_remove(struct platform_device *pdev)
158 {
159         struct userspace_consumer_data *data = platform_get_drvdata(pdev);
160
161         sysfs_remove_group(&pdev->dev.kobj, &attr_group);
162
163         if (data->enabled)
164                 regulator_bulk_disable(data->num_supplies, data->supplies);
165
166         return 0;
167 }
168
169 static struct platform_driver regulator_userspace_consumer_driver = {
170         .probe          = regulator_userspace_consumer_probe,
171         .remove         = regulator_userspace_consumer_remove,
172         .driver         = {
173                 .name           = "reg-userspace-consumer",
174         },
175 };
176
177 module_platform_driver(regulator_userspace_consumer_driver);
178
179 MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
180 MODULE_DESCRIPTION("Userspace consumer for voltage and current regulators");
181 MODULE_LICENSE("GPL");