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
name_show(struct device * dev,struct device_attribute * attr,char * buf)32 static ssize_t name_show(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
state_show(struct device * dev,struct device_attribute * attr,char * buf)40 static ssize_t state_show(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
state_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)51 static ssize_t state_store(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_RO(name);
91 static DEVICE_ATTR_RW(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
regulator_userspace_consumer_probe(struct platform_device * pdev)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
regulator_userspace_consumer_remove(struct platform_device * pdev)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");
182