Driver core: change add_uevent_var to use a struct
[linux-3.10.git] / drivers / power / power_supply_sysfs.c
1 /*
2  *  Sysfs interface for the universal power supply monitor class
3  *
4  *  Copyright © 2007  David Woodhouse <dwmw2@infradead.org>
5  *  Copyright © 2007  Anton Vorontsov <cbou@mail.ru>
6  *  Copyright © 2004  Szabolcs Gyurko
7  *  Copyright © 2003  Ian Molton <spyro@f2s.com>
8  *
9  *  Modified: 2004, Oct     Szabolcs Gyurko
10  *
11  *  You may use this code as per GPL version 2
12  */
13
14 #include <linux/ctype.h>
15 #include <linux/power_supply.h>
16
17 /*
18  * This is because the name "current" breaks the device attr macro.
19  * The "current" word resolves to "(get_current())" so instead of
20  * "current" "(get_current())" appears in the sysfs.
21  *
22  * The source of this definition is the device.h which calls __ATTR
23  * macro in sysfs.h which calls the __stringify macro.
24  *
25  * Only modification that the name is not tried to be resolved
26  * (as a macro let's say).
27  */
28
29 #define POWER_SUPPLY_ATTR(_name)                                        \
30 {                                                                       \
31         .attr = { .name = #_name, .mode = 0444, .owner = THIS_MODULE }, \
32         .show = power_supply_show_property,                             \
33         .store = NULL,                                                  \
34 }
35
36 static struct device_attribute power_supply_attrs[];
37
38 static ssize_t power_supply_show_property(struct device *dev,
39                                           struct device_attribute *attr,
40                                           char *buf) {
41         static char *status_text[] = {
42                 "Unknown", "Charging", "Discharging", "Not charging", "Full"
43         };
44         static char *health_text[] = {
45                 "Unknown", "Good", "Overheat", "Dead", "Over voltage",
46                 "Unspecified failure"
47         };
48         static char *technology_text[] = {
49                 "Unknown", "NiMH", "Li-ion", "Li-poly", "LiFe", "NiCd"
50         };
51         static char *capacity_level_text[] = {
52                 "Unknown", "Critical", "Low", "Normal", "High", "Full"
53         };
54         ssize_t ret;
55         struct power_supply *psy = dev_get_drvdata(dev);
56         const ptrdiff_t off = attr - power_supply_attrs;
57         union power_supply_propval value;
58
59         ret = psy->get_property(psy, off, &value);
60
61         if (ret < 0) {
62                 if (ret != -ENODEV)
63                         dev_err(dev, "driver failed to report `%s' property\n",
64                                 attr->attr.name);
65                 return ret;
66         }
67
68         if (off == POWER_SUPPLY_PROP_STATUS)
69                 return sprintf(buf, "%s\n", status_text[value.intval]);
70         else if (off == POWER_SUPPLY_PROP_HEALTH)
71                 return sprintf(buf, "%s\n", health_text[value.intval]);
72         else if (off == POWER_SUPPLY_PROP_TECHNOLOGY)
73                 return sprintf(buf, "%s\n", technology_text[value.intval]);
74         else if (off == POWER_SUPPLY_PROP_CAPACITY_LEVEL)
75                 return sprintf(buf, "%s\n",
76                                capacity_level_text[value.intval]);
77         else if (off >= POWER_SUPPLY_PROP_MODEL_NAME)
78                 return sprintf(buf, "%s\n", value.strval);
79
80         return sprintf(buf, "%d\n", value.intval);
81 }
82
83 /* Must be in the same order as POWER_SUPPLY_PROP_* */
84 static struct device_attribute power_supply_attrs[] = {
85         /* Properties of type `int' */
86         POWER_SUPPLY_ATTR(status),
87         POWER_SUPPLY_ATTR(health),
88         POWER_SUPPLY_ATTR(present),
89         POWER_SUPPLY_ATTR(online),
90         POWER_SUPPLY_ATTR(technology),
91         POWER_SUPPLY_ATTR(voltage_max_design),
92         POWER_SUPPLY_ATTR(voltage_min_design),
93         POWER_SUPPLY_ATTR(voltage_now),
94         POWER_SUPPLY_ATTR(voltage_avg),
95         POWER_SUPPLY_ATTR(current_now),
96         POWER_SUPPLY_ATTR(current_avg),
97         POWER_SUPPLY_ATTR(charge_full_design),
98         POWER_SUPPLY_ATTR(charge_empty_design),
99         POWER_SUPPLY_ATTR(charge_full),
100         POWER_SUPPLY_ATTR(charge_empty),
101         POWER_SUPPLY_ATTR(charge_now),
102         POWER_SUPPLY_ATTR(charge_avg),
103         POWER_SUPPLY_ATTR(energy_full_design),
104         POWER_SUPPLY_ATTR(energy_empty_design),
105         POWER_SUPPLY_ATTR(energy_full),
106         POWER_SUPPLY_ATTR(energy_empty),
107         POWER_SUPPLY_ATTR(energy_now),
108         POWER_SUPPLY_ATTR(energy_avg),
109         POWER_SUPPLY_ATTR(capacity),
110         POWER_SUPPLY_ATTR(capacity_level),
111         POWER_SUPPLY_ATTR(temp),
112         POWER_SUPPLY_ATTR(temp_ambient),
113         POWER_SUPPLY_ATTR(time_to_empty_now),
114         POWER_SUPPLY_ATTR(time_to_empty_avg),
115         POWER_SUPPLY_ATTR(time_to_full_now),
116         POWER_SUPPLY_ATTR(time_to_full_avg),
117         /* Properties of type `const char *' */
118         POWER_SUPPLY_ATTR(model_name),
119         POWER_SUPPLY_ATTR(manufacturer),
120 };
121
122 static ssize_t power_supply_show_static_attrs(struct device *dev,
123                                               struct device_attribute *attr,
124                                               char *buf) {
125         static char *type_text[] = { "Battery", "UPS", "Mains", "USB" };
126         struct power_supply *psy = dev_get_drvdata(dev);
127
128         return sprintf(buf, "%s\n", type_text[psy->type]);
129 }
130
131 static struct device_attribute power_supply_static_attrs[] = {
132         __ATTR(type, 0444, power_supply_show_static_attrs, NULL),
133 };
134
135 int power_supply_create_attrs(struct power_supply *psy)
136 {
137         int rc = 0;
138         int i, j;
139
140         for (i = 0; i < ARRAY_SIZE(power_supply_static_attrs); i++) {
141                 rc = device_create_file(psy->dev,
142                             &power_supply_static_attrs[i]);
143                 if (rc)
144                         goto statics_failed;
145         }
146
147         for (j = 0; j < psy->num_properties; j++) {
148                 rc = device_create_file(psy->dev,
149                             &power_supply_attrs[psy->properties[j]]);
150                 if (rc)
151                         goto dynamics_failed;
152         }
153
154         goto succeed;
155
156 dynamics_failed:
157         while (j--)
158                 device_remove_file(psy->dev,
159                            &power_supply_attrs[psy->properties[j]]);
160 statics_failed:
161         while (i--)
162                 device_remove_file(psy->dev,
163                            &power_supply_static_attrs[psy->properties[i]]);
164 succeed:
165         return rc;
166 }
167
168 void power_supply_remove_attrs(struct power_supply *psy)
169 {
170         int i;
171
172         for (i = 0; i < ARRAY_SIZE(power_supply_static_attrs); i++)
173                 device_remove_file(psy->dev,
174                             &power_supply_static_attrs[i]);
175
176         for (i = 0; i < psy->num_properties; i++)
177                 device_remove_file(psy->dev,
178                             &power_supply_attrs[psy->properties[i]]);
179 }
180
181 static char *kstruprdup(const char *str, gfp_t gfp)
182 {
183         char *ret, *ustr;
184
185         ustr = ret = kmalloc(strlen(str) + 1, gfp);
186
187         if (!ret)
188                 return NULL;
189
190         while (*str)
191                 *ustr++ = toupper(*str++);
192
193         *ustr = 0;
194
195         return ret;
196 }
197
198 int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
199 {
200         struct power_supply *psy = dev_get_drvdata(dev);
201         int ret = 0, j;
202         char *prop_buf;
203         char *attrname;
204
205         dev_dbg(dev, "uevent\n");
206
207         if (!psy) {
208                 dev_dbg(dev, "No power supply yet\n");
209                 return ret;
210         }
211
212         dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->name);
213
214         ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->name);
215         if (ret)
216                 return ret;
217
218         prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
219         if (!prop_buf)
220                 return -ENOMEM;
221
222         for (j = 0; j < ARRAY_SIZE(power_supply_static_attrs); j++) {
223                 struct device_attribute *attr;
224                 char *line;
225
226                 attr = &power_supply_static_attrs[j];
227
228                 ret = power_supply_show_static_attrs(dev, attr, prop_buf);
229                 if (ret < 0)
230                         goto out;
231
232                 line = strchr(prop_buf, '\n');
233                 if (line)
234                         *line = 0;
235
236                 attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
237                 if (!attrname) {
238                         ret = -ENOMEM;
239                         goto out;
240                 }
241
242                 dev_dbg(dev, "Static prop %s=%s\n", attrname, prop_buf);
243
244                 ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
245                 kfree(attrname);
246                 if (ret)
247                         goto out;
248         }
249
250         dev_dbg(dev, "%zd dynamic props\n", psy->num_properties);
251
252         for (j = 0; j < psy->num_properties; j++) {
253                 struct device_attribute *attr;
254                 char *line;
255
256                 attr = &power_supply_attrs[psy->properties[j]];
257
258                 ret = power_supply_show_property(dev, attr, prop_buf);
259                 if (ret == -ENODEV) {
260                         /* When a battery is absent, we expect -ENODEV. Don't abort;
261                            send the uevent with at least the the PRESENT=0 property */
262                         ret = 0;
263                         continue;
264                 }
265
266                 if (ret < 0)
267                         goto out;
268
269                 line = strchr(prop_buf, '\n');
270                 if (line)
271                         *line = 0;
272
273                 attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
274                 if (!attrname) {
275                         ret = -ENOMEM;
276                         goto out;
277                 }
278
279                 dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
280
281                 ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
282                 kfree(attrname);
283                 if (ret)
284                         goto out;
285         }
286
287 out:
288         free_page((unsigned long)prop_buf);
289
290         return ret;
291 }