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, .owner = THIS_MODULE }, \
  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 *health_text[] = {
  47                 "Unknown", "Good", "Overheat", "Dead", "Over voltage",
  48                 "Unspecified failure"
  49         };
  50         static char *technology_text[] = {
  51                 "Unknown", "NiMH", "Li-ion", "Li-poly", "LiFe", "NiCd",
  52                 "LiMn"
  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_MODEL_NAME)
  75                 return sprintf(buf, "%s\n", value.strval);
  76
  77         return sprintf(buf, "%d\n", value.intval);
  78 }
  79
  80 /* Must be in the same order as POWER_SUPPLY_PROP_* */
  81 static struct device_attribute power_supply_attrs[] = {
  82         /* Properties of type `int' */
  83         POWER_SUPPLY_ATTR(status),
  84         POWER_SUPPLY_ATTR(health),
  85         POWER_SUPPLY_ATTR(present),
  86         POWER_SUPPLY_ATTR(online),
  87         POWER_SUPPLY_ATTR(technology),
  88         POWER_SUPPLY_ATTR(voltage_max),
  89         POWER_SUPPLY_ATTR(voltage_min),
  90         POWER_SUPPLY_ATTR(voltage_max_design),
  91         POWER_SUPPLY_ATTR(voltage_min_design),
  92         POWER_SUPPLY_ATTR(voltage_now),
  93         POWER_SUPPLY_ATTR(voltage_avg),
  94         POWER_SUPPLY_ATTR(current_now),
  95         POWER_SUPPLY_ATTR(current_avg),
  96         POWER_SUPPLY_ATTR(charge_full_design),
  97         POWER_SUPPLY_ATTR(charge_empty_design),
  98         POWER_SUPPLY_ATTR(charge_full),
  99         POWER_SUPPLY_ATTR(charge_empty),
 100         POWER_SUPPLY_ATTR(charge_now),
 101         POWER_SUPPLY_ATTR(charge_avg),
 102         POWER_SUPPLY_ATTR(energy_full_design),
 103         POWER_SUPPLY_ATTR(energy_empty_design),
 104         POWER_SUPPLY_ATTR(energy_full),
 105         POWER_SUPPLY_ATTR(energy_empty),
 106         POWER_SUPPLY_ATTR(energy_now),
 107         POWER_SUPPLY_ATTR(energy_avg),
 108         POWER_SUPPLY_ATTR(capacity),
 109         POWER_SUPPLY_ATTR(temp),
 110         POWER_SUPPLY_ATTR(temp_ambient),
 111         POWER_SUPPLY_ATTR(time_to_empty_now),
 112         POWER_SUPPLY_ATTR(time_to_empty_avg),
 113         POWER_SUPPLY_ATTR(time_to_full_now),
 114         POWER_SUPPLY_ATTR(time_to_full_avg),
 115         /* Properties of type `const char *' */
 116         POWER_SUPPLY_ATTR(model_name),
 117         POWER_SUPPLY_ATTR(manufacturer),
 118 };
 119
 120 static ssize_t power_supply_show_static_attrs(struct device *dev,
 121                                               struct device_attribute *attr,
 122                                               char *buf) {
 123         static char *type_text[] = { "Battery", "UPS", "Mains", "USB" };
 124         struct power_supply *psy = dev_get_drvdata(dev);
 125
 126         return sprintf(buf, "%s\n", type_text[psy->type]);
 127 }
 128
 129 static struct device_attribute power_supply_static_attrs[] = {
 130         __ATTR(type, 0444, power_supply_show_static_attrs, NULL),
 131 };
 132
 133 int power_supply_create_attrs(struct power_supply *psy)
 134 {
 135         int rc = 0;
 136         int i, j;
 137
 138         for (i = 0; i < ARRAY_SIZE(power_supply_static_attrs); i++) {
 139                 rc = device_create_file(psy->dev,
 140                             &power_supply_static_attrs[i]);
 141                 if (rc)
 142                         goto statics_failed;
 143         }
 144
 145         for (j = 0; j < psy->num_properties; j++) {
 146                 rc = device_create_file(psy->dev,
 147                             &power_supply_attrs[psy->properties[j]]);
 148                 if (rc)
 149                         goto dynamics_failed;
 150         }
 151
 152         goto succeed;
 153
 154 dynamics_failed:
 155         while (j--)
 156                 device_remove_file(psy->dev,
 157                            &power_supply_attrs[psy->properties[j]]);
 158 statics_failed:
 159         while (i--)
 160                 device_remove_file(psy->dev, &power_supply_static_attrs[i]);
 161 succeed:
 162         return rc;
 163 }
 164
 165 void power_supply_remove_attrs(struct power_supply *psy)
 166 {
 167         int i;
 168
 169         for (i = 0; i < ARRAY_SIZE(power_supply_static_attrs); i++)
 170                 device_remove_file(psy->dev, &power_supply_static_attrs[i]);
 171
 172         for (i = 0; i < psy->num_properties; i++)
 173                 device_remove_file(psy->dev,
 174                             &power_supply_attrs[psy->properties[i]]);
 175 }
 176
 177 static char *kstruprdup(const char *str, gfp_t gfp)
 178 {
 179         char *ret, *ustr;
 180
 181         ustr = ret = kmalloc(strlen(str) + 1, gfp);
 182
 183         if (!ret)
 184                 return NULL;
 185
 186         while (*str)
 187                 *ustr++ = toupper(*str++);
 188
 189         *ustr = 0;
 190
 191         return ret;
 192 }
 193
 194 int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
 195 {
 196         struct power_supply *psy = dev_get_drvdata(dev);
 197         int ret = 0, j;
 198         char *prop_buf;
 199         char *attrname;
 200
 201         dev_dbg(dev, "uevent\n");
 202
 203         if (!psy) {
 204                 dev_dbg(dev, "No power supply yet\n");
 205                 return ret;
 206         }
 207
 208         dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->name);
 209
 210         ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->name);
 211         if (ret)
 212                 return ret;
 213
 214         prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
 215         if (!prop_buf)
 216                 return -ENOMEM;
 217
 218         for (j = 0; j < ARRAY_SIZE(power_supply_static_attrs); j++) {
 219                 struct device_attribute *attr;
 220                 char *line;
 221
 222                 attr = &power_supply_static_attrs[j];
 223
 224                 ret = power_supply_show_static_attrs(dev, attr, prop_buf);
 225                 if (ret < 0)
 226                         goto out;
 227
 228                 line = strchr(prop_buf, '\n');
 229                 if (line)
 230                         *line = 0;
 231
 232                 attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 233                 if (!attrname) {
 234                         ret = -ENOMEM;
 235                         goto out;
 236                 }
 237
 238                 dev_dbg(dev, "Static prop %s=%s\n", attrname, prop_buf);
 239
 240                 ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 241                 kfree(attrname);
 242                 if (ret)
 243                         goto out;
 244         }
 245
 246         dev_dbg(dev, "%zd dynamic props\n", psy->num_properties);
 247
 248         for (j = 0; j < psy->num_properties; j++) {
 249                 struct device_attribute *attr;
 250                 char *line;
 251
 252                 attr = &power_supply_attrs[psy->properties[j]];
 253
 254                 ret = power_supply_show_property(dev, attr, prop_buf);
 255                 if (ret == -ENODEV) {
 256                         /* When a battery is absent, we expect -ENODEV. Don't abort;
 257                            send the uevent with at least the the PRESENT=0 property */
 258                         ret = 0;
 259                         continue;
 260                 }
 261
 262                 if (ret < 0)
 263                         goto out;
 264
 265                 line = strchr(prop_buf, '\n');
 266                 if (line)
 267                         *line = 0;
 268
 269                 attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 270                 if (!attrname) {
 271                         ret = -ENOMEM;
 272                         goto out;
 273                 }
 274
 275                 dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
 276
 277                 ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 278                 kfree(attrname);
 279                 if (ret)
 280                         goto out;
 281         }
 282
 283 out:
 284         free_page((unsigned long)prop_buf);
 285
 286         return ret;
 287 }