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