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power_supply_sysfs.c
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1 /*
2  * Sysfs interface for the universal power supply monitor class
3  *
4  * Copyright © 2007 David Woodhouse <[email protected]>
5  * Copyright © 2007 Anton Vorontsov <[email protected]>
6  * Copyright © 2004 Szabolcs Gyurko
7  * Copyright © 2003 Ian Molton <[email protected]>
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/device.h>
16 #include <linux/power_supply.h>
17 #include <linux/slab.h>
18 #include <linux/stat.h>
19 
20 #include "power_supply.h"
21 
22 /*
23  * This is because the name "current" breaks the device attr macro.
24  * The "current" word resolves to "(get_current())" so instead of
25  * "current" "(get_current())" appears in the sysfs.
26  *
27  * The source of this definition is the device.h which calls __ATTR
28  * macro in sysfs.h which calls the __stringify macro.
29  *
30  * Only modification that the name is not tried to be resolved
31  * (as a macro let's say).
32  */
33 
34 #define POWER_SUPPLY_ATTR(_name) \
35 { \
36  .attr = { .name = #_name }, \
37  .show = power_supply_show_property, \
38  .store = power_supply_store_property, \
39 }
40 
41 static struct device_attribute power_supply_attrs[];
42 
43 static ssize_t power_supply_show_property(struct device *dev,
44  struct device_attribute *attr,
45  char *buf) {
46  static char *type_text[] = {
47  "Unknown", "Battery", "UPS", "Mains", "USB",
48  "USB_DCP", "USB_CDP", "USB_ACA"
49  };
50  static char *status_text[] = {
51  "Unknown", "Charging", "Discharging", "Not charging", "Full"
52  };
53  static char *charge_type[] = {
54  "Unknown", "N/A", "Trickle", "Fast"
55  };
56  static char *health_text[] = {
57  "Unknown", "Good", "Overheat", "Dead", "Over voltage",
58  "Unspecified failure", "Cold",
59  };
60  static char *technology_text[] = {
61  "Unknown", "NiMH", "Li-ion", "Li-poly", "LiFe", "NiCd",
62  "LiMn"
63  };
64  static char *capacity_level_text[] = {
65  "Unknown", "Critical", "Low", "Normal", "High", "Full"
66  };
67  static char *scope_text[] = {
68  "Unknown", "System", "Device"
69  };
70  ssize_t ret = 0;
71  struct power_supply *psy = dev_get_drvdata(dev);
72  const ptrdiff_t off = attr - power_supply_attrs;
73  union power_supply_propval value;
74 
75  if (off == POWER_SUPPLY_PROP_TYPE)
76  value.intval = psy->type;
77  else
78  ret = psy->get_property(psy, off, &value);
79 
80  if (ret < 0) {
81  if (ret == -ENODATA)
82  dev_dbg(dev, "driver has no data for `%s' property\n",
83  attr->attr.name);
84  else if (ret != -ENODEV)
85  dev_err(dev, "driver failed to report `%s' property: %zd\n",
86  attr->attr.name, ret);
87  return ret;
88  }
89 
90  if (off == POWER_SUPPLY_PROP_STATUS)
91  return sprintf(buf, "%s\n", status_text[value.intval]);
92  else if (off == POWER_SUPPLY_PROP_CHARGE_TYPE)
93  return sprintf(buf, "%s\n", charge_type[value.intval]);
94  else if (off == POWER_SUPPLY_PROP_HEALTH)
95  return sprintf(buf, "%s\n", health_text[value.intval]);
96  else if (off == POWER_SUPPLY_PROP_TECHNOLOGY)
97  return sprintf(buf, "%s\n", technology_text[value.intval]);
98  else if (off == POWER_SUPPLY_PROP_CAPACITY_LEVEL)
99  return sprintf(buf, "%s\n", capacity_level_text[value.intval]);
100  else if (off == POWER_SUPPLY_PROP_TYPE)
101  return sprintf(buf, "%s\n", type_text[value.intval]);
102  else if (off == POWER_SUPPLY_PROP_SCOPE)
103  return sprintf(buf, "%s\n", scope_text[value.intval]);
104  else if (off >= POWER_SUPPLY_PROP_MODEL_NAME)
105  return sprintf(buf, "%s\n", value.strval);
106 
107  return sprintf(buf, "%d\n", value.intval);
108 }
109 
110 static ssize_t power_supply_store_property(struct device *dev,
111  struct device_attribute *attr,
112  const char *buf, size_t count) {
113  ssize_t ret;
114  struct power_supply *psy = dev_get_drvdata(dev);
115  const ptrdiff_t off = attr - power_supply_attrs;
116  union power_supply_propval value;
117  long long_val;
118 
119  /* TODO: support other types than int */
120  ret = strict_strtol(buf, 10, &long_val);
121  if (ret < 0)
122  return ret;
123 
124  value.intval = long_val;
125 
126  ret = psy->set_property(psy, off, &value);
127  if (ret < 0)
128  return ret;
129 
130  return count;
131 }
132 
133 /* Must be in the same order as POWER_SUPPLY_PROP_* */
134 static struct device_attribute power_supply_attrs[] = {
135  /* Properties of type `int' */
136  POWER_SUPPLY_ATTR(status),
137  POWER_SUPPLY_ATTR(charge_type),
138  POWER_SUPPLY_ATTR(health),
139  POWER_SUPPLY_ATTR(present),
140  POWER_SUPPLY_ATTR(online),
141  POWER_SUPPLY_ATTR(authentic),
142  POWER_SUPPLY_ATTR(technology),
143  POWER_SUPPLY_ATTR(cycle_count),
144  POWER_SUPPLY_ATTR(voltage_max),
145  POWER_SUPPLY_ATTR(voltage_min),
146  POWER_SUPPLY_ATTR(voltage_max_design),
147  POWER_SUPPLY_ATTR(voltage_min_design),
148  POWER_SUPPLY_ATTR(voltage_now),
149  POWER_SUPPLY_ATTR(voltage_avg),
150  POWER_SUPPLY_ATTR(voltage_ocv),
151  POWER_SUPPLY_ATTR(current_max),
152  POWER_SUPPLY_ATTR(current_now),
153  POWER_SUPPLY_ATTR(current_avg),
154  POWER_SUPPLY_ATTR(power_now),
155  POWER_SUPPLY_ATTR(power_avg),
156  POWER_SUPPLY_ATTR(charge_full_design),
157  POWER_SUPPLY_ATTR(charge_empty_design),
158  POWER_SUPPLY_ATTR(charge_full),
159  POWER_SUPPLY_ATTR(charge_empty),
160  POWER_SUPPLY_ATTR(charge_now),
161  POWER_SUPPLY_ATTR(charge_avg),
162  POWER_SUPPLY_ATTR(charge_counter),
163  POWER_SUPPLY_ATTR(constant_charge_current),
164  POWER_SUPPLY_ATTR(constant_charge_current_max),
165  POWER_SUPPLY_ATTR(constant_charge_voltage),
166  POWER_SUPPLY_ATTR(constant_charge_voltage_max),
167  POWER_SUPPLY_ATTR(energy_full_design),
168  POWER_SUPPLY_ATTR(energy_empty_design),
169  POWER_SUPPLY_ATTR(energy_full),
170  POWER_SUPPLY_ATTR(energy_empty),
171  POWER_SUPPLY_ATTR(energy_now),
172  POWER_SUPPLY_ATTR(energy_avg),
173  POWER_SUPPLY_ATTR(capacity),
174  POWER_SUPPLY_ATTR(capacity_alert_min),
175  POWER_SUPPLY_ATTR(capacity_alert_max),
176  POWER_SUPPLY_ATTR(capacity_level),
177  POWER_SUPPLY_ATTR(temp),
178  POWER_SUPPLY_ATTR(temp_alert_min),
179  POWER_SUPPLY_ATTR(temp_alert_max),
180  POWER_SUPPLY_ATTR(temp_ambient),
181  POWER_SUPPLY_ATTR(temp_ambient_alert_min),
182  POWER_SUPPLY_ATTR(temp_ambient_alert_max),
183  POWER_SUPPLY_ATTR(time_to_empty_now),
184  POWER_SUPPLY_ATTR(time_to_empty_avg),
185  POWER_SUPPLY_ATTR(time_to_full_now),
186  POWER_SUPPLY_ATTR(time_to_full_avg),
187  POWER_SUPPLY_ATTR(type),
188  POWER_SUPPLY_ATTR(scope),
189  /* Properties of type `const char *' */
190  POWER_SUPPLY_ATTR(model_name),
191  POWER_SUPPLY_ATTR(manufacturer),
192  POWER_SUPPLY_ATTR(serial_number),
193 };
194 
195 static struct attribute *
196 __power_supply_attrs[ARRAY_SIZE(power_supply_attrs) + 1];
197 
198 static umode_t power_supply_attr_is_visible(struct kobject *kobj,
199  struct attribute *attr,
200  int attrno)
201 {
202  struct device *dev = container_of(kobj, struct device, kobj);
203  struct power_supply *psy = dev_get_drvdata(dev);
204  umode_t mode = S_IRUSR | S_IRGRP | S_IROTH;
205  int i;
206 
207  if (attrno == POWER_SUPPLY_PROP_TYPE)
208  return mode;
209 
210  for (i = 0; i < psy->num_properties; i++) {
211  int property = psy->properties[i];
212 
213  if (property == attrno) {
214  if (psy->property_is_writeable &&
215  psy->property_is_writeable(psy, property) > 0)
216  mode |= S_IWUSR;
217 
218  return mode;
219  }
220  }
221 
222  return 0;
223 }
224 
225 static struct attribute_group power_supply_attr_group = {
226  .attrs = __power_supply_attrs,
227  .is_visible = power_supply_attr_is_visible,
228 };
229 
230 static const struct attribute_group *power_supply_attr_groups[] = {
231  &power_supply_attr_group,
232  NULL,
233 };
234 
235 void power_supply_init_attrs(struct device_type *dev_type)
236 {
237  int i;
238 
239  dev_type->groups = power_supply_attr_groups;
240 
241  for (i = 0; i < ARRAY_SIZE(power_supply_attrs); i++)
242  __power_supply_attrs[i] = &power_supply_attrs[i].attr;
243 }
244 
245 static char *kstruprdup(const char *str, gfp_t gfp)
246 {
247  char *ret, *ustr;
248 
249  ustr = ret = kmalloc(strlen(str) + 1, gfp);
250 
251  if (!ret)
252  return NULL;
253 
254  while (*str)
255  *ustr++ = toupper(*str++);
256 
257  *ustr = 0;
258 
259  return ret;
260 }
261 
262 int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
263 {
264  struct power_supply *psy = dev_get_drvdata(dev);
265  int ret = 0, j;
266  char *prop_buf;
267  char *attrname;
268 
269  dev_dbg(dev, "uevent\n");
270 
271  if (!psy || !psy->dev) {
272  dev_dbg(dev, "No power supply yet\n");
273  return ret;
274  }
275 
276  dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->name);
277 
278  ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->name);
279  if (ret)
280  return ret;
281 
282  prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
283  if (!prop_buf)
284  return -ENOMEM;
285 
286  for (j = 0; j < psy->num_properties; j++) {
287  struct device_attribute *attr;
288  char *line;
289 
290  attr = &power_supply_attrs[psy->properties[j]];
291 
292  ret = power_supply_show_property(dev, attr, prop_buf);
293  if (ret == -ENODEV || ret == -ENODATA) {
294  /* When a battery is absent, we expect -ENODEV. Don't abort;
295  send the uevent with at least the the PRESENT=0 property */
296  ret = 0;
297  continue;
298  }
299 
300  if (ret < 0)
301  goto out;
302 
303  line = strchr(prop_buf, '\n');
304  if (line)
305  *line = 0;
306 
307  attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
308  if (!attrname) {
309  ret = -ENOMEM;
310  goto out;
311  }
312 
313  dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
314 
315  ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
316  kfree(attrname);
317  if (ret)
318  goto out;
319  }
320 
321 out:
322  free_page((unsigned long)prop_buf);
323 
324  return ret;
325 }
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