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 },                                     \
  35         .show = power_supply_show_property,                             \
  36         .store = power_supply_store_property,                           \
  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 *type_text[] = {
  45                 "Battery", "UPS", "Mains", "USB",
  46                 "USB_DCP", "USB_CDP", "USB_ACA"
  47         };
  48         static char *status_text[] = {
  49                 "Unknown", "Charging", "Discharging", "Not charging", "Full"
  50         };
  51         static char *charge_type[] = {
  52                 "Unknown", "N/A", "Trickle", "Fast"
  53         };
  54         static char *health_text[] = {
  55                 "Unknown", "Good", "Overheat", "Dead", "Over voltage",
  56                 "Unspecified failure", "Cold",
  57         };
  58         static char *technology_text[] = {
  59                 "Unknown", "NiMH", "Li-ion", "Li-poly", "LiFe", "NiCd",
  60                 "LiMn"
  61         };
  62         static char *capacity_level_text[] = {
  63                 "Unknown", "Critical", "Low", "Normal", "High", "Full"
  64         };
  65         ssize_t ret = 0;
  66         struct power_supply *psy = dev_get_drvdata(dev);
  67         const ptrdiff_t off = attr - power_supply_attrs;
  68         union power_supply_propval value;
  69
  70         if (off == POWER_SUPPLY_PROP_TYPE)
  71                 value.intval = psy->type;
  72         else
  73                 ret = psy->get_property(psy, off, &value);
  74
  75         if (ret < 0) {
  76                 if (ret == -ENODATA)
  77                         dev_dbg(dev, "driver has no data for `%s' property\n",
  78                                 attr->attr.name);
  79                 else if (ret != -ENODEV)
  80                         dev_err(dev, "driver failed to report `%s' property\n",
  81                                 attr->attr.name);
  82                 return ret;
  83         }
  84
  85         if (off == POWER_SUPPLY_PROP_STATUS)
  86                 return sprintf(buf, "%s\n", status_text[value.intval]);
  87         else if (off == POWER_SUPPLY_PROP_CHARGE_TYPE)
  88                 return sprintf(buf, "%s\n", charge_type[value.intval]);
  89         else if (off == POWER_SUPPLY_PROP_HEALTH)
  90                 return sprintf(buf, "%s\n", health_text[value.intval]);
  91         else if (off == POWER_SUPPLY_PROP_TECHNOLOGY)
  92                 return sprintf(buf, "%s\n", technology_text[value.intval]);
  93         else if (off == POWER_SUPPLY_PROP_CAPACITY_LEVEL)
  94                 return sprintf(buf, "%s\n", capacity_level_text[value.intval]);
  95         else if (off == POWER_SUPPLY_PROP_TYPE)
  96                 return sprintf(buf, "%s\n", type_text[value.intval]);
  97         else if (off >= POWER_SUPPLY_PROP_MODEL_NAME)
  98                 return sprintf(buf, "%s\n", value.strval);
  99
 100         return sprintf(buf, "%d\n", value.intval);
 101 }
 102
 103 static ssize_t power_supply_store_property(struct device *dev,
 104                                            struct device_attribute *attr,
 105                                            const char *buf, size_t count) {
 106         ssize_t ret;
 107         struct power_supply *psy = dev_get_drvdata(dev);
 108         const ptrdiff_t off = attr - power_supply_attrs;
 109         union power_supply_propval value;
 110         long long_val;
 111
 112         /* TODO: support other types than int */
 113         ret = strict_strtol(buf, 10, &long_val);
 114         if (ret < 0)
 115                 return ret;
 116
 117         value.intval = long_val;
 118
 119         ret = psy->set_property(psy, off, &value);
 120         if (ret < 0)
 121                 return ret;
 122
 123         return count;
 124 }
 125
 126 /* Must be in the same order as POWER_SUPPLY_PROP_* */
 127 static struct device_attribute power_supply_attrs[] = {
 128         /* Properties of type `int' */
 129         POWER_SUPPLY_ATTR(status),
 130         POWER_SUPPLY_ATTR(charge_type),
 131         POWER_SUPPLY_ATTR(health),
 132         POWER_SUPPLY_ATTR(present),
 133         POWER_SUPPLY_ATTR(online),
 134         POWER_SUPPLY_ATTR(technology),
 135         POWER_SUPPLY_ATTR(cycle_count),
 136         POWER_SUPPLY_ATTR(voltage_max),
 137         POWER_SUPPLY_ATTR(voltage_min),
 138         POWER_SUPPLY_ATTR(voltage_max_design),
 139         POWER_SUPPLY_ATTR(voltage_min_design),
 140         POWER_SUPPLY_ATTR(voltage_now),
 141         POWER_SUPPLY_ATTR(voltage_avg),
 142         POWER_SUPPLY_ATTR(current_max),
 143         POWER_SUPPLY_ATTR(current_now),
 144         POWER_SUPPLY_ATTR(current_avg),
 145         POWER_SUPPLY_ATTR(power_now),
 146         POWER_SUPPLY_ATTR(power_avg),
 147         POWER_SUPPLY_ATTR(charge_full_design),
 148         POWER_SUPPLY_ATTR(charge_empty_design),
 149         POWER_SUPPLY_ATTR(charge_full),
 150         POWER_SUPPLY_ATTR(charge_empty),
 151         POWER_SUPPLY_ATTR(charge_now),
 152         POWER_SUPPLY_ATTR(charge_avg),
 153         POWER_SUPPLY_ATTR(charge_counter),
 154         POWER_SUPPLY_ATTR(energy_full_design),
 155         POWER_SUPPLY_ATTR(energy_empty_design),
 156         POWER_SUPPLY_ATTR(energy_full),
 157         POWER_SUPPLY_ATTR(energy_empty),
 158         POWER_SUPPLY_ATTR(energy_now),
 159         POWER_SUPPLY_ATTR(energy_avg),
 160         POWER_SUPPLY_ATTR(capacity),
 161         POWER_SUPPLY_ATTR(capacity_level),
 162         POWER_SUPPLY_ATTR(temp),
 163         POWER_SUPPLY_ATTR(temp_ambient),
 164         POWER_SUPPLY_ATTR(time_to_empty_now),
 165         POWER_SUPPLY_ATTR(time_to_empty_avg),
 166         POWER_SUPPLY_ATTR(time_to_full_now),
 167         POWER_SUPPLY_ATTR(time_to_full_avg),
 168         POWER_SUPPLY_ATTR(type),
 169         /* Properties of type `const char *' */
 170         POWER_SUPPLY_ATTR(model_name),
 171         POWER_SUPPLY_ATTR(manufacturer),
 172         POWER_SUPPLY_ATTR(serial_number),
 173 };
 174
 175 static struct attribute *
 176 __power_supply_attrs[ARRAY_SIZE(power_supply_attrs) + 1];
 177
 178 static mode_t power_supply_attr_is_visible(struct kobject *kobj,
 179                                            struct attribute *attr,
 180                                            int attrno)
 181 {
 182         struct device *dev = container_of(kobj, struct device, kobj);
 183         struct power_supply *psy = dev_get_drvdata(dev);
 184         mode_t mode = S_IRUSR | S_IRGRP | S_IROTH;
 185         int i;
 186
 187         if (attrno == POWER_SUPPLY_PROP_TYPE)
 188                 return mode;
 189
 190         for (i = 0; i < psy->num_properties; i++) {
 191                 int property = psy->properties[i];
 192
 193                 if (property == attrno) {
 194                         if (psy->property_is_writeable &&
 195                             psy->property_is_writeable(psy, property) > 0)
 196                                 mode |= S_IWUSR;
 197
 198                         return mode;
 199                 }
 200         }
 201
 202         return 0;
 203 }
 204
 205 static struct attribute_group power_supply_attr_group = {
 206         .attrs = __power_supply_attrs,
 207         .is_visible = power_supply_attr_is_visible,
 208 };
 209
 210 static const struct attribute_group *power_supply_attr_groups[] = {
 211         &power_supply_attr_group,
 212         NULL,
 213 };
 214
 215 void power_supply_init_attrs(struct device_type *dev_type)
 216 {
 217         int i;
 218
 219         dev_type->groups = power_supply_attr_groups;
 220
 221         for (i = 0; i < ARRAY_SIZE(power_supply_attrs); i++)
 222                 __power_supply_attrs[i] = &power_supply_attrs[i].attr;
 223 }
 224
 225 static char *kstruprdup(const char *str, gfp_t gfp)
 226 {
 227         char *ret, *ustr;
 228
 229         ustr = ret = kmalloc(strlen(str) + 1, gfp);
 230
 231         if (!ret)
 232                 return NULL;
 233
 234         while (*str)
 235                 *ustr++ = toupper(*str++);
 236
 237         *ustr = 0;
 238
 239         return ret;
 240 }
 241
 242 int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
 243 {
 244         struct power_supply *psy = dev_get_drvdata(dev);
 245         int ret = 0, j;
 246         char *prop_buf;
 247         char *attrname;
 248
 249         dev_dbg(dev, "uevent\n");
 250
 251         if (!psy || !psy->dev) {
 252                 dev_dbg(dev, "No power supply yet\n");
 253                 return ret;
 254         }
 255
 256         dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->name);
 257
 258         ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->name);
 259         if (ret)
 260                 return ret;
 261
 262         prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
 263         if (!prop_buf)
 264                 return -ENOMEM;
 265
 266         for (j = 0; j < psy->num_properties; j++) {
 267                 struct device_attribute *attr;
 268                 char *line;
 269
 270                 attr = &power_supply_attrs[psy->properties[j]];
 271
 272                 ret = power_supply_show_property(dev, attr, prop_buf);
 273                 if (ret == -ENODEV || ret == -ENODATA) {
 274                         /* When a battery is absent, we expect -ENODEV. Don't abort;
 275                            send the uevent with at least the the PRESENT=0 property */
 276                         ret = 0;
 277                         continue;
 278                 }
 279
 280                 if (ret < 0)
 281                         goto out;
 282
 283                 line = strchr(prop_buf, '\n');
 284                 if (line)
 285                         *line = 0;
 286
 287                 attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 288                 if (!attrname) {
 289                         ret = -ENOMEM;
 290                         goto out;
 291                 }
 292
 293                 dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
 294
 295                 ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 296                 kfree(attrname);
 297                 if (ret)
 298                         goto out;
 299         }
 300
 301 out:
 302         free_page((unsigned long)prop_buf);
 303
 304         return ret;
 305 }