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, char **envp, int num_envp,
 199                         char *buffer, int buffer_size)
 200 {
 201         struct power_supply *psy = dev_get_drvdata(dev);
 202         int i = 0, length = 0, ret = 0, j;
 203         char *prop_buf;
 204         char *attrname;
 205
 206         dev_dbg(dev, "uevent\n");
 207
 208         if (!psy) {
 209                 dev_dbg(dev, "No power supply yet\n");
 210                 return ret;
 211         }
 212
 213         dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->name);
 214
 215         ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
 216                              &length, "POWER_SUPPLY_NAME=%s", psy->name);
 217         if (ret)
 218                 return ret;
 219
 220         prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
 221         if (!prop_buf)
 222                 return -ENOMEM;
 223
 224         for (j = 0; j < ARRAY_SIZE(power_supply_static_attrs); j++) {
 225                 struct device_attribute *attr;
 226                 char *line;
 227
 228                 attr = &power_supply_static_attrs[j];
 229
 230                 ret = power_supply_show_static_attrs(dev, attr, prop_buf);
 231                 if (ret < 0)
 232                         goto out;
 233
 234                 line = strchr(prop_buf, '\n');
 235                 if (line)
 236                         *line = 0;
 237
 238                 attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 239                 if (!attrname) {
 240                         ret = -ENOMEM;
 241                         goto out;
 242                 }
 243
 244                 dev_dbg(dev, "Static prop %s=%s\n", attrname, prop_buf);
 245
 246                 ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
 247                                      &length, "POWER_SUPPLY_%s=%s",
 248                                      attrname, prop_buf);
 249                 kfree(attrname);
 250                 if (ret)
 251                         goto out;
 252         }
 253
 254         dev_dbg(dev, "%zd dynamic props\n", psy->num_properties);
 255
 256         for (j = 0; j < psy->num_properties; j++) {
 257                 struct device_attribute *attr;
 258                 char *line;
 259
 260                 attr = &power_supply_attrs[psy->properties[j]];
 261
 262                 ret = power_supply_show_property(dev, attr, prop_buf);
 263                 if (ret == -ENODEV) {
 264                         /* When a battery is absent, we expect -ENODEV. Don't abort;
 265                            send the uevent with at least the the PRESENT=0 property */
 266                         ret = 0;
 267                         continue;
 268                 }
 269
 270                 if (ret < 0)
 271                         goto out;
 272
 273                 line = strchr(prop_buf, '\n');
 274                 if (line)
 275                         *line = 0;
 276
 277                 attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 278                 if (!attrname) {
 279                         ret = -ENOMEM;
 280                         goto out;
 281                 }
 282
 283                 dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
 284
 285                 ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
 286                                      &length, "POWER_SUPPLY_%s=%s",
 287                                      attrname, prop_buf);
 288                 kfree(attrname);
 289                 if (ret)
 290                         goto out;
 291         }
 292
 293 out:
 294         free_page((unsigned long)prop_buf);
 295
 296         return ret;
 297 }