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 != -ENODEV)
  69                         dev_err(dev, "driver failed to report `%s' property\n",
  70                                 attr->attr.name);
  71                 return ret;
  72         }
  73
  74         if (off == POWER_SUPPLY_PROP_STATUS)
  75                 return sprintf(buf, "%s\n", status_text[value.intval]);
  76         else if (off == POWER_SUPPLY_PROP_CHARGE_TYPE)
  77                 return sprintf(buf, "%s\n", charge_type[value.intval]);
  78         else if (off == POWER_SUPPLY_PROP_HEALTH)
  79                 return sprintf(buf, "%s\n", health_text[value.intval]);
  80         else if (off == POWER_SUPPLY_PROP_TECHNOLOGY)
  81                 return sprintf(buf, "%s\n", technology_text[value.intval]);
  82         else if (off == POWER_SUPPLY_PROP_CAPACITY_LEVEL)
  83                 return sprintf(buf, "%s\n", capacity_level_text[value.intval]);
  84         else if (off >= POWER_SUPPLY_PROP_MODEL_NAME)
  85                 return sprintf(buf, "%s\n", value.strval);
  86
  87         return sprintf(buf, "%d\n", value.intval);
  88 }
  89
  90 /* Must be in the same order as POWER_SUPPLY_PROP_* */
  91 static struct device_attribute power_supply_attrs[] = {
  92         /* Properties of type `int' */
  93         POWER_SUPPLY_ATTR(status),
  94         POWER_SUPPLY_ATTR(charge_type),
  95         POWER_SUPPLY_ATTR(health),
  96         POWER_SUPPLY_ATTR(present),
  97         POWER_SUPPLY_ATTR(online),
  98         POWER_SUPPLY_ATTR(technology),
  99         POWER_SUPPLY_ATTR(voltage_max),
 100         POWER_SUPPLY_ATTR(voltage_min),
 101         POWER_SUPPLY_ATTR(voltage_max_design),
 102         POWER_SUPPLY_ATTR(voltage_min_design),
 103         POWER_SUPPLY_ATTR(voltage_now),
 104         POWER_SUPPLY_ATTR(voltage_avg),
 105         POWER_SUPPLY_ATTR(current_now),
 106         POWER_SUPPLY_ATTR(current_avg),
 107         POWER_SUPPLY_ATTR(power_now),
 108         POWER_SUPPLY_ATTR(power_avg),
 109         POWER_SUPPLY_ATTR(charge_full_design),
 110         POWER_SUPPLY_ATTR(charge_empty_design),
 111         POWER_SUPPLY_ATTR(charge_full),
 112         POWER_SUPPLY_ATTR(charge_empty),
 113         POWER_SUPPLY_ATTR(charge_now),
 114         POWER_SUPPLY_ATTR(charge_avg),
 115         POWER_SUPPLY_ATTR(charge_counter),
 116         POWER_SUPPLY_ATTR(energy_full_design),
 117         POWER_SUPPLY_ATTR(energy_empty_design),
 118         POWER_SUPPLY_ATTR(energy_full),
 119         POWER_SUPPLY_ATTR(energy_empty),
 120         POWER_SUPPLY_ATTR(energy_now),
 121         POWER_SUPPLY_ATTR(energy_avg),
 122         POWER_SUPPLY_ATTR(capacity),
 123         POWER_SUPPLY_ATTR(capacity_level),
 124         POWER_SUPPLY_ATTR(temp),
 125         POWER_SUPPLY_ATTR(temp_ambient),
 126         POWER_SUPPLY_ATTR(time_to_empty_now),
 127         POWER_SUPPLY_ATTR(time_to_empty_avg),
 128         POWER_SUPPLY_ATTR(time_to_full_now),
 129         POWER_SUPPLY_ATTR(time_to_full_avg),
 130         /* Properties of type `const char *' */
 131         POWER_SUPPLY_ATTR(model_name),
 132         POWER_SUPPLY_ATTR(manufacturer),
 133         POWER_SUPPLY_ATTR(serial_number),
 134 };
 135
 136 static ssize_t power_supply_show_static_attrs(struct device *dev,
 137                                               struct device_attribute *attr,
 138                                               char *buf) {
 139         static char *type_text[] = { "Battery", "UPS", "Mains", "USB" };
 140         struct power_supply *psy = dev_get_drvdata(dev);
 141
 142         return sprintf(buf, "%s\n", type_text[psy->type]);
 143 }
 144
 145 static struct device_attribute power_supply_static_attrs[] = {
 146         __ATTR(type, 0444, power_supply_show_static_attrs, NULL),
 147 };
 148
 149 int power_supply_create_attrs(struct power_supply *psy)
 150 {
 151         int rc = 0;
 152         int i, j;
 153
 154         for (i = 0; i < ARRAY_SIZE(power_supply_static_attrs); i++) {
 155                 rc = device_create_file(psy->dev,
 156                             &power_supply_static_attrs[i]);
 157                 if (rc)
 158                         goto statics_failed;
 159         }
 160
 161         for (j = 0; j < psy->num_properties; j++) {
 162                 rc = device_create_file(psy->dev,
 163                             &power_supply_attrs[psy->properties[j]]);
 164                 if (rc)
 165                         goto dynamics_failed;
 166         }
 167
 168         goto succeed;
 169
 170 dynamics_failed:
 171         while (j--)
 172                 device_remove_file(psy->dev,
 173                            &power_supply_attrs[psy->properties[j]]);
 174 statics_failed:
 175         while (i--)
 176                 device_remove_file(psy->dev, &power_supply_static_attrs[i]);
 177 succeed:
 178         return rc;
 179 }
 180
 181 void power_supply_remove_attrs(struct power_supply *psy)
 182 {
 183         int i;
 184
 185         for (i = 0; i < ARRAY_SIZE(power_supply_static_attrs); i++)
 186                 device_remove_file(psy->dev, &power_supply_static_attrs[i]);
 187
 188         for (i = 0; i < psy->num_properties; i++)
 189                 device_remove_file(psy->dev,
 190                             &power_supply_attrs[psy->properties[i]]);
 191 }
 192
 193 static char *kstruprdup(const char *str, gfp_t gfp)
 194 {
 195         char *ret, *ustr;
 196
 197         ustr = ret = kmalloc(strlen(str) + 1, gfp);
 198
 199         if (!ret)
 200                 return NULL;
 201
 202         while (*str)
 203                 *ustr++ = toupper(*str++);
 204
 205         *ustr = 0;
 206
 207         return ret;
 208 }
 209
 210 int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
 211 {
 212         struct power_supply *psy = dev_get_drvdata(dev);
 213         int ret = 0, j;
 214         char *prop_buf;
 215         char *attrname;
 216
 217         dev_dbg(dev, "uevent\n");
 218
 219         if (!psy || !psy->dev) {
 220                 dev_dbg(dev, "No power supply yet\n");
 221                 return ret;
 222         }
 223
 224         dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->name);
 225
 226         ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->name);
 227         if (ret)
 228                 return ret;
 229
 230         prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
 231         if (!prop_buf)
 232                 return -ENOMEM;
 233
 234         for (j = 0; j < ARRAY_SIZE(power_supply_static_attrs); j++) {
 235                 struct device_attribute *attr;
 236                 char *line;
 237
 238                 attr = &power_supply_static_attrs[j];
 239
 240                 ret = power_supply_show_static_attrs(dev, attr, prop_buf);
 241                 if (ret < 0)
 242                         goto out;
 243
 244                 line = strchr(prop_buf, '\n');
 245                 if (line)
 246                         *line = 0;
 247
 248                 attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 249                 if (!attrname) {
 250                         ret = -ENOMEM;
 251                         goto out;
 252                 }
 253
 254                 dev_dbg(dev, "Static prop %s=%s\n", attrname, prop_buf);
 255
 256                 ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 257                 kfree(attrname);
 258                 if (ret)
 259                         goto out;
 260         }
 261
 262         dev_dbg(dev, "%zd dynamic props\n", psy->num_properties);
 263
 264         for (j = 0; j < psy->num_properties; j++) {
 265                 struct device_attribute *attr;
 266                 char *line;
 267
 268                 attr = &power_supply_attrs[psy->properties[j]];
 269
 270                 ret = power_supply_show_property(dev, attr, prop_buf);
 271                 if (ret == -ENODEV) {
 272                         /* When a battery is absent, we expect -ENODEV. Don't abort;
 273                            send the uevent with at least the the PRESENT=0 property */
 274                         ret = 0;
 275                         continue;
 276                 }
 277
 278                 if (ret < 0)
 279                         goto out;
 280
 281                 line = strchr(prop_buf, '\n');
 282                 if (line)
 283                         *line = 0;
 284
 285                 attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 286                 if (!attrname) {
 287                         ret = -ENOMEM;
 288                         goto out;
 289                 }
 290
 291                 dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
 292
 293                 ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 294                 kfree(attrname);
 295                 if (ret)
 296                         goto out;
 297         }
 298
 299 out:
 300         free_page((unsigned long)prop_buf);
 301
 302         return ret;
 303 }