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 #include <linux/slab.h>
  17
  18 #include "power_supply.h"
  19
  20 /*
  21  * This is because the name "current" breaks the device attr macro.
  22  * The "current" word resolves to "(get_current())" so instead of
  23  * "current" "(get_current())" appears in the sysfs.
  24  *
  25  * The source of this definition is the device.h which calls __ATTR
  26  * macro in sysfs.h which calls the __stringify macro.
  27  *
  28  * Only modification that the name is not tried to be resolved
  29  * (as a macro let's say).
  30  */
  31
  32 #define POWER_SUPPLY_ATTR(_name)                                        \
  33 {                                                                       \
  34         .attr = { .name = #_name, .mode = 0444 },       \
  35         .show = power_supply_show_property,                             \
  36         .store = NULL,                                                  \
  37 }
  38
  39 static struct device_attribute power_supply_attrs[];
  40
  41 static ssize_t power_supply_show_property(struct device *dev,
  42                                           struct device_attribute *attr,
  43                                           char *buf) {
  44         static char *status_text[] = {
  45                 "Unknown", "Charging", "Discharging", "Not charging", "Full"
  46         };
  47         static char *charge_type[] = {
  48                 "Unknown", "N/A", "Trickle", "Fast"
  49         };
  50         static char *health_text[] = {
  51                 "Unknown", "Good", "Overheat", "Dead", "Over voltage",
  52                 "Unspecified failure", "Cold",
  53         };
  54         static char *technology_text[] = {
  55                 "Unknown", "NiMH", "Li-ion", "Li-poly", "LiFe", "NiCd",
  56                 "LiMn"
  57         };
  58         static char *capacity_level_text[] = {
  59                 "Unknown", "Critical", "Low", "Normal", "High", "Full"
  60         };
  61         ssize_t ret;
  62         struct power_supply *psy = dev_get_drvdata(dev);
  63         const ptrdiff_t off = attr - power_supply_attrs;
  64         union power_supply_propval value;
  65
  66         ret = psy->get_property(psy, off, &value);
  67
  68         if (ret < 0) {
  69                 if (ret == -ENODATA)
  70                         dev_dbg(dev, "driver has no data for `%s' property\n",
  71                                 attr->attr.name);
  72                 else if (ret != -ENODEV)
  73                         dev_err(dev, "driver failed to report `%s' property\n",
  74                                 attr->attr.name);
  75                 return ret;
  76         }
  77
  78         if (off == POWER_SUPPLY_PROP_STATUS)
  79                 return sprintf(buf, "%s\n", status_text[value.intval]);
  80         else if (off == POWER_SUPPLY_PROP_CHARGE_TYPE)
  81                 return sprintf(buf, "%s\n", charge_type[value.intval]);
  82         else if (off == POWER_SUPPLY_PROP_HEALTH)
  83                 return sprintf(buf, "%s\n", health_text[value.intval]);
  84         else if (off == POWER_SUPPLY_PROP_TECHNOLOGY)
  85                 return sprintf(buf, "%s\n", technology_text[value.intval]);
  86         else if (off == POWER_SUPPLY_PROP_CAPACITY_LEVEL)
  87                 return sprintf(buf, "%s\n", capacity_level_text[value.intval]);
  88         else if (off >= POWER_SUPPLY_PROP_MODEL_NAME)
  89                 return sprintf(buf, "%s\n", value.strval);
  90
  91         return sprintf(buf, "%d\n", value.intval);
  92 }
  93
  94 /* Must be in the same order as POWER_SUPPLY_PROP_* */
  95 static struct device_attribute power_supply_attrs[] = {
  96         /* Properties of type `int' */
  97         POWER_SUPPLY_ATTR(status),
  98         POWER_SUPPLY_ATTR(charge_type),
  99         POWER_SUPPLY_ATTR(health),
 100         POWER_SUPPLY_ATTR(present),
 101         POWER_SUPPLY_ATTR(online),
 102         POWER_SUPPLY_ATTR(technology),
 103         POWER_SUPPLY_ATTR(cycle_count),
 104         POWER_SUPPLY_ATTR(voltage_max),
 105         POWER_SUPPLY_ATTR(voltage_min),
 106         POWER_SUPPLY_ATTR(voltage_max_design),
 107         POWER_SUPPLY_ATTR(voltage_min_design),
 108         POWER_SUPPLY_ATTR(voltage_now),
 109         POWER_SUPPLY_ATTR(voltage_avg),
 110         POWER_SUPPLY_ATTR(current_now),
 111         POWER_SUPPLY_ATTR(current_avg),
 112         POWER_SUPPLY_ATTR(power_now),
 113         POWER_SUPPLY_ATTR(power_avg),
 114         POWER_SUPPLY_ATTR(charge_full_design),
 115         POWER_SUPPLY_ATTR(charge_empty_design),
 116         POWER_SUPPLY_ATTR(charge_full),
 117         POWER_SUPPLY_ATTR(charge_empty),
 118         POWER_SUPPLY_ATTR(charge_now),
 119         POWER_SUPPLY_ATTR(charge_avg),
 120         POWER_SUPPLY_ATTR(charge_counter),
 121         POWER_SUPPLY_ATTR(energy_full_design),
 122         POWER_SUPPLY_ATTR(energy_empty_design),
 123         POWER_SUPPLY_ATTR(energy_full),
 124         POWER_SUPPLY_ATTR(energy_empty),
 125         POWER_SUPPLY_ATTR(energy_now),
 126         POWER_SUPPLY_ATTR(energy_avg),
 127         POWER_SUPPLY_ATTR(capacity),
 128         POWER_SUPPLY_ATTR(capacity_level),
 129         POWER_SUPPLY_ATTR(temp),
 130         POWER_SUPPLY_ATTR(temp_ambient),
 131         POWER_SUPPLY_ATTR(time_to_empty_now),
 132         POWER_SUPPLY_ATTR(time_to_empty_avg),
 133         POWER_SUPPLY_ATTR(time_to_full_now),
 134         POWER_SUPPLY_ATTR(time_to_full_avg),
 135         /* Properties of type `const char *' */
 136         POWER_SUPPLY_ATTR(model_name),
 137         POWER_SUPPLY_ATTR(manufacturer),
 138         POWER_SUPPLY_ATTR(serial_number),
 139 };
 140
 141 static ssize_t power_supply_show_static_attrs(struct device *dev,
 142                                               struct device_attribute *attr,
 143                                               char *buf) {
 144         static char *type_text[] = { "Battery", "UPS", "Mains", "USB" };
 145         struct power_supply *psy = dev_get_drvdata(dev);
 146
 147         return sprintf(buf, "%s\n", type_text[psy->type]);
 148 }
 149
 150 static struct device_attribute power_supply_static_attrs[] = {
 151         __ATTR(type, 0444, power_supply_show_static_attrs, NULL),
 152 };
 153
 154 int power_supply_create_attrs(struct power_supply *psy)
 155 {
 156         int rc = 0;
 157         int i, j;
 158
 159         for (i = 0; i < ARRAY_SIZE(power_supply_static_attrs); i++) {
 160                 rc = device_create_file(psy->dev,
 161                             &power_supply_static_attrs[i]);
 162                 if (rc)
 163                         goto statics_failed;
 164         }
 165
 166         for (j = 0; j < psy->num_properties; j++) {
 167                 rc = device_create_file(psy->dev,
 168                             &power_supply_attrs[psy->properties[j]]);
 169                 if (rc)
 170                         goto dynamics_failed;
 171         }
 172
 173         goto succeed;
 174
 175 dynamics_failed:
 176         while (j--)
 177                 device_remove_file(psy->dev,
 178                            &power_supply_attrs[psy->properties[j]]);
 179 statics_failed:
 180         while (i--)
 181                 device_remove_file(psy->dev, &power_supply_static_attrs[i]);
 182 succeed:
 183         return rc;
 184 }
 185
 186 void power_supply_remove_attrs(struct power_supply *psy)
 187 {
 188         int i;
 189
 190         for (i = 0; i < ARRAY_SIZE(power_supply_static_attrs); i++)
 191                 device_remove_file(psy->dev, &power_supply_static_attrs[i]);
 192
 193         for (i = 0; i < psy->num_properties; i++)
 194                 device_remove_file(psy->dev,
 195                             &power_supply_attrs[psy->properties[i]]);
 196 }
 197
 198 static char *kstruprdup(const char *str, gfp_t gfp)
 199 {
 200         char *ret, *ustr;
 201
 202         ustr = ret = kmalloc(strlen(str) + 1, gfp);
 203
 204         if (!ret)
 205                 return NULL;
 206
 207         while (*str)
 208                 *ustr++ = toupper(*str++);
 209
 210         *ustr = 0;
 211
 212         return ret;
 213 }
 214
 215 int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
 216 {
 217         struct power_supply *psy = dev_get_drvdata(dev);
 218         int ret = 0, j;
 219         char *prop_buf;
 220         char *attrname;
 221
 222         dev_dbg(dev, "uevent\n");
 223
 224         if (!psy || !psy->dev) {
 225                 dev_dbg(dev, "No power supply yet\n");
 226                 return ret;
 227         }
 228
 229         dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->name);
 230
 231         ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->name);
 232         if (ret)
 233                 return ret;
 234
 235         prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
 236         if (!prop_buf)
 237                 return -ENOMEM;
 238
 239         for (j = 0; j < ARRAY_SIZE(power_supply_static_attrs); j++) {
 240                 struct device_attribute *attr;
 241                 char *line;
 242
 243                 attr = &power_supply_static_attrs[j];
 244
 245                 ret = power_supply_show_static_attrs(dev, attr, prop_buf);
 246                 if (ret < 0)
 247                         goto out;
 248
 249                 line = strchr(prop_buf, '\n');
 250                 if (line)
 251                         *line = 0;
 252
 253                 attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 254                 if (!attrname) {
 255                         ret = -ENOMEM;
 256                         goto out;
 257                 }
 258
 259                 dev_dbg(dev, "Static prop %s=%s\n", attrname, prop_buf);
 260
 261                 ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 262                 kfree(attrname);
 263                 if (ret)
 264                         goto out;
 265         }
 266
 267         dev_dbg(dev, "%zd dynamic props\n", psy->num_properties);
 268
 269         for (j = 0; j < psy->num_properties; j++) {
 270                 struct device_attribute *attr;
 271                 char *line;
 272
 273                 attr = &power_supply_attrs[psy->properties[j]];
 274
 275                 ret = power_supply_show_property(dev, attr, prop_buf);
 276                 if (ret == -ENODEV) {
 277                         /* When a battery is absent, we expect -ENODEV. Don't abort;
 278                            send the uevent with at least the the PRESENT=0 property */
 279                         ret = 0;
 280                         continue;
 281                 }
 282
 283                 if (ret < 0)
 284                         goto out;
 285
 286                 line = strchr(prop_buf, '\n');
 287                 if (line)
 288                         *line = 0;
 289
 290                 attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 291                 if (!attrname) {
 292                         ret = -ENOMEM;
 293                         goto out;
 294                 }
 295
 296                 dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
 297
 298                 ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 299                 kfree(attrname);
 300                 if (ret)
 301                         goto out;
 302         }
 303
 304 out:
 305         free_page((unsigned long)prop_buf);
 306
 307         return ret;
 308 }