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/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 | |
23 | struct 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 | |
34 | static 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, fmt: "%s\n" , data->name); |
40 | } |
41 | |
42 | static 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, fmt: "enabled\n" ); |
49 | |
50 | return sprintf(buf, fmt: "disabled\n" ); |
51 | } |
52 | |
53 | static 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(s1: buf, s2: "enabled\n" ) || sysfs_streq(s1: buf, s2: "1" )) |
65 | enabled = true; |
66 | else if (sysfs_streq(s1: buf, s2: "disabled\n" ) || sysfs_streq(s1: buf, s2: "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(num_consumers: data->num_supplies, |
77 | consumers: data->supplies); |
78 | else |
79 | ret = regulator_bulk_disable(num_consumers: data->num_supplies, |
80 | consumers: 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(lock: &data->lock); |
88 | |
89 | return count; |
90 | } |
91 | |
92 | static DEVICE_ATTR_RO(name); |
93 | static DEVICE_ATTR_RW(state); |
94 | |
95 | static struct attribute *attributes[] = { |
96 | &dev_attr_name.attr, |
97 | &dev_attr_state.attr, |
98 | NULL, |
99 | }; |
100 | |
101 | static 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 | |
113 | static const struct attribute_group attr_group = { |
114 | .attrs = attributes, |
115 | .is_visible = attr_visible, |
116 | }; |
117 | |
118 | static 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(dev: &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(dev: &pdev->dev, size: 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(dev: &pdev->dev, |
147 | size: 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(dev: &pdev->dev, num_consumers: drvdata->num_supplies, |
160 | consumers: drvdata->supplies); |
161 | if (ret) { |
162 | dev_err(&pdev->dev, "Failed to get supplies: %d\n" , ret); |
163 | return ret; |
164 | } |
165 | |
166 | platform_set_drvdata(pdev, data: drvdata); |
167 | |
168 | ret = sysfs_create_group(kobj: &pdev->dev.kobj, grp: &attr_group); |
169 | if (ret != 0) |
170 | return ret; |
171 | |
172 | if (pdata->init_on && !pdata->no_autoswitch) { |
173 | ret = regulator_bulk_enable(num_consumers: drvdata->num_supplies, |
174 | consumers: drvdata->supplies); |
175 | if (ret) { |
176 | dev_err(&pdev->dev, |
177 | "Failed to set initial state: %d\n" , ret); |
178 | goto err_enable; |
179 | } |
180 | } |
181 | |
182 | ret = regulator_is_enabled(regulator: pdata->supplies[0].consumer); |
183 | if (ret < 0) { |
184 | dev_err(&pdev->dev, "Failed to get regulator status\n" ); |
185 | goto err_enable; |
186 | } |
187 | drvdata->enabled = !!ret; |
188 | |
189 | return 0; |
190 | |
191 | err_enable: |
192 | sysfs_remove_group(kobj: &pdev->dev.kobj, grp: &attr_group); |
193 | |
194 | return ret; |
195 | } |
196 | |
197 | static int regulator_userspace_consumer_remove(struct platform_device *pdev) |
198 | { |
199 | struct userspace_consumer_data *data = platform_get_drvdata(pdev); |
200 | |
201 | sysfs_remove_group(kobj: &pdev->dev.kobj, grp: &attr_group); |
202 | |
203 | if (data->enabled && !data->no_autoswitch) |
204 | regulator_bulk_disable(num_consumers: data->num_supplies, consumers: data->supplies); |
205 | |
206 | return 0; |
207 | } |
208 | |
209 | static const struct of_device_id regulator_userspace_consumer_of_match[] = { |
210 | { .compatible = "regulator-output" , }, |
211 | {}, |
212 | }; |
213 | |
214 | static struct platform_driver regulator_userspace_consumer_driver = { |
215 | .probe = regulator_userspace_consumer_probe, |
216 | .remove = regulator_userspace_consumer_remove, |
217 | .driver = { |
218 | .name = "reg-userspace-consumer" , |
219 | .probe_type = PROBE_PREFER_ASYNCHRONOUS, |
220 | .of_match_table = regulator_userspace_consumer_of_match, |
221 | }, |
222 | }; |
223 | |
224 | module_platform_driver(regulator_userspace_consumer_driver); |
225 | |
226 | MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>" ); |
227 | MODULE_DESCRIPTION("Userspace consumer for voltage and current regulators" ); |
228 | MODULE_LICENSE("GPL" ); |
229 | |