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/device.h>
  16 #include <linux/power_supply.h>
  17 #include <linux/slab.h>
  18 #include <linux/stat.h>
  19
  20 #include "power_supply.h"
  21
  22 /*
  23  * This is because the name "current" breaks the device attr macro.
  24  * The "current" word resolves to "(get_current())" so instead of
  25  * "current" "(get_current())" appears in the sysfs.
  26  *
  27  * The source of this definition is the device.h which calls __ATTR
  28  * macro in sysfs.h which calls the __stringify macro.
  29  *
  30  * Only modification that the name is not tried to be resolved
  31  * (as a macro let's say).
  32  */
  33
  34 #define POWER_SUPPLY_ATTR(_name)                                        \
  35 {                                                                       \
  36         .attr = { .name = #_name },                                     \
  37         .show = power_supply_show_property,                             \
  38         .store = power_supply_store_property,                           \
  39 }
  40
  41 static struct device_attribute power_supply_attrs[];
  42
  43 static ssize_t power_supply_show_property(struct device *dev,
  44                                           struct device_attribute *attr,
  45                                           char *buf) {
  46         static char *type_text[] = {
  47                 "Unknown", "Battery", "UPS", "Mains", "USB",
  48                 "USB_DCP", "USB_CDP", "USB_ACA"
  49         };
  50         static char *status_text[] = {
  51                 "Unknown", "Charging", "Discharging", "Not charging", "Full"
  52         };
  53         static char *charge_type[] = {
  54                 "Unknown", "N/A", "Trickle", "Fast"
  55         };
  56         static char *health_text[] = {
  57                 "Unknown", "Good", "Overheat", "Dead", "Over voltage",
  58                 "Unspecified failure", "Cold",
  59         };
  60         static char *technology_text[] = {
  61                 "Unknown", "NiMH", "Li-ion", "Li-poly", "LiFe", "NiCd",
  62                 "LiMn"
  63         };
  64         static char *capacity_level_text[] = {
  65                 "Unknown", "Critical", "Low", "Normal", "High", "Full"
  66         };
  67         static char *scope_text[] = {
  68                 "Unknown", "System", "Device"
  69         };
  70         ssize_t ret = 0;
  71         struct power_supply *psy = dev_get_drvdata(dev);
  72         const ptrdiff_t off = attr - power_supply_attrs;
  73         union power_supply_propval value;
  74
  75         if (off == POWER_SUPPLY_PROP_TYPE)
  76                 value.intval = psy->type;
  77         else
  78                 ret = psy->get_property(psy, off, &value);
  79
  80         if (ret < 0) {
  81                 if (ret == -ENODATA)
  82                         dev_dbg(dev, "driver has no data for `%s' property\n",
  83                                 attr->attr.name);
  84                 else if (ret != -ENODEV)
  85                         dev_err(dev, "driver failed to report `%s' property: %zd\n",
  86                                 attr->attr.name, ret);
  87                 return ret;
  88         }
  89
  90         if (off == POWER_SUPPLY_PROP_STATUS)
  91                 return sprintf(buf, "%s\n", status_text[value.intval]);
  92         else if (off == POWER_SUPPLY_PROP_CHARGE_TYPE)
  93                 return sprintf(buf, "%s\n", charge_type[value.intval]);
  94         else if (off == POWER_SUPPLY_PROP_HEALTH)
  95                 return sprintf(buf, "%s\n", health_text[value.intval]);
  96         else if (off == POWER_SUPPLY_PROP_TECHNOLOGY)
  97                 return sprintf(buf, "%s\n", technology_text[value.intval]);
  98         else if (off == POWER_SUPPLY_PROP_CAPACITY_LEVEL)
  99                 return sprintf(buf, "%s\n", capacity_level_text[value.intval]);
 100         else if (off == POWER_SUPPLY_PROP_TYPE)
 101                 return sprintf(buf, "%s\n", type_text[value.intval]);
 102         else if (off == POWER_SUPPLY_PROP_SCOPE)
 103                 return sprintf(buf, "%s\n", scope_text[value.intval]);
 104         else if (off >= POWER_SUPPLY_PROP_MODEL_NAME)
 105                 return sprintf(buf, "%s\n", value.strval);
 106
 107         return sprintf(buf, "%d\n", value.intval);
 108 }
 109
 110 static ssize_t power_supply_store_property(struct device *dev,
 111                                            struct device_attribute *attr,
 112                                            const char *buf, size_t count) {
 113         ssize_t ret;
 114         struct power_supply *psy = dev_get_drvdata(dev);
 115         const ptrdiff_t off = attr - power_supply_attrs;
 116         union power_supply_propval value;
 117         long long_val;
 118
 119         /* TODO: support other types than int */
 120         ret = strict_strtol(buf, 10, &long_val);
 121         if (ret < 0)
 122                 return ret;
 123
 124         value.intval = long_val;
 125
 126         ret = psy->set_property(psy, off, &value);
 127         if (ret < 0)
 128                 return ret;
 129
 130         return count;
 131 }
 132
 133 /* Must be in the same order as POWER_SUPPLY_PROP_* */
 134 static struct device_attribute power_supply_attrs[] = {
 135         /* Properties of type `int' */
 136         POWER_SUPPLY_ATTR(status),
 137         POWER_SUPPLY_ATTR(charge_type),
 138         POWER_SUPPLY_ATTR(health),
 139         POWER_SUPPLY_ATTR(present),
 140         POWER_SUPPLY_ATTR(online),
 141         POWER_SUPPLY_ATTR(technology),
 142         POWER_SUPPLY_ATTR(cycle_count),
 143         POWER_SUPPLY_ATTR(voltage_max),
 144         POWER_SUPPLY_ATTR(voltage_min),
 145         POWER_SUPPLY_ATTR(voltage_max_design),
 146         POWER_SUPPLY_ATTR(voltage_min_design),
 147         POWER_SUPPLY_ATTR(voltage_now),
 148         POWER_SUPPLY_ATTR(voltage_avg),
 149         POWER_SUPPLY_ATTR(voltage_ocv),
 150         POWER_SUPPLY_ATTR(current_max),
 151         POWER_SUPPLY_ATTR(current_now),
 152         POWER_SUPPLY_ATTR(current_avg),
 153         POWER_SUPPLY_ATTR(power_now),
 154         POWER_SUPPLY_ATTR(power_avg),
 155         POWER_SUPPLY_ATTR(charge_full_design),
 156         POWER_SUPPLY_ATTR(charge_empty_design),
 157         POWER_SUPPLY_ATTR(charge_full),
 158         POWER_SUPPLY_ATTR(charge_empty),
 159         POWER_SUPPLY_ATTR(charge_now),
 160         POWER_SUPPLY_ATTR(charge_avg),
 161         POWER_SUPPLY_ATTR(charge_counter),
 162         POWER_SUPPLY_ATTR(energy_full_design),
 163         POWER_SUPPLY_ATTR(energy_empty_design),
 164         POWER_SUPPLY_ATTR(energy_full),
 165         POWER_SUPPLY_ATTR(energy_empty),
 166         POWER_SUPPLY_ATTR(energy_now),
 167         POWER_SUPPLY_ATTR(energy_avg),
 168         POWER_SUPPLY_ATTR(capacity),
 169         POWER_SUPPLY_ATTR(capacity_level),
 170         POWER_SUPPLY_ATTR(temp),
 171         POWER_SUPPLY_ATTR(temp_ambient),
 172         POWER_SUPPLY_ATTR(time_to_empty_now),
 173         POWER_SUPPLY_ATTR(time_to_empty_avg),
 174         POWER_SUPPLY_ATTR(time_to_full_now),
 175         POWER_SUPPLY_ATTR(time_to_full_avg),
 176         POWER_SUPPLY_ATTR(type),
 177         POWER_SUPPLY_ATTR(scope),
 178         /* Properties of type `const char *' */
 179         POWER_SUPPLY_ATTR(model_name),
 180         POWER_SUPPLY_ATTR(manufacturer),
 181         POWER_SUPPLY_ATTR(serial_number),
 182 };
 183
 184 static struct attribute *
 185 __power_supply_attrs[ARRAY_SIZE(power_supply_attrs) + 1];
 186
 187 static umode_t power_supply_attr_is_visible(struct kobject *kobj,
 188                                            struct attribute *attr,
 189                                            int attrno)
 190 {
 191         struct device *dev = container_of(kobj, struct device, kobj);
 192         struct power_supply *psy = dev_get_drvdata(dev);
 193         umode_t mode = S_IRUSR | S_IRGRP | S_IROTH;
 194         int i;
 195
 196         if (attrno == POWER_SUPPLY_PROP_TYPE)
 197                 return mode;
 198
 199         for (i = 0; i < psy->num_properties; i++) {
 200                 int property = psy->properties[i];
 201
 202                 if (property == attrno) {
 203                         if (psy->property_is_writeable &&
 204                             psy->property_is_writeable(psy, property) > 0)
 205                                 mode |= S_IWUSR;
 206
 207                         return mode;
 208                 }
 209         }
 210
 211         return 0;
 212 }
 213
 214 static struct attribute_group power_supply_attr_group = {
 215         .attrs = __power_supply_attrs,
 216         .is_visible = power_supply_attr_is_visible,
 217 };
 218
 219 static const struct attribute_group *power_supply_attr_groups[] = {
 220         &power_supply_attr_group,
 221         NULL,
 222 };
 223
 224 void power_supply_init_attrs(struct device_type *dev_type)
 225 {
 226         int i;
 227
 228         dev_type->groups = power_supply_attr_groups;
 229
 230         for (i = 0; i < ARRAY_SIZE(power_supply_attrs); i++)
 231                 __power_supply_attrs[i] = &power_supply_attrs[i].attr;
 232 }
 233
 234 static char *kstruprdup(const char *str, gfp_t gfp)
 235 {
 236         char *ret, *ustr;
 237
 238         ustr = ret = kmalloc(strlen(str) + 1, gfp);
 239
 240         if (!ret)
 241                 return NULL;
 242
 243         while (*str)
 244                 *ustr++ = toupper(*str++);
 245
 246         *ustr = 0;
 247
 248         return ret;
 249 }
 250
 251 int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
 252 {
 253         struct power_supply *psy = dev_get_drvdata(dev);
 254         int ret = 0, j;
 255         char *prop_buf;
 256         char *attrname;
 257
 258         dev_dbg(dev, "uevent\n");
 259
 260         if (!psy || !psy->dev) {
 261                 dev_dbg(dev, "No power supply yet\n");
 262                 return ret;
 263         }
 264
 265         dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->name);
 266
 267         ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->name);
 268         if (ret)
 269                 return ret;
 270
 271         prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
 272         if (!prop_buf)
 273                 return -ENOMEM;
 274
 275         for (j = 0; j < psy->num_properties; j++) {
 276                 struct device_attribute *attr;
 277                 char *line;
 278
 279                 attr = &power_supply_attrs[psy->properties[j]];
 280
 281                 ret = power_supply_show_property(dev, attr, prop_buf);
 282                 if (ret == -ENODEV || ret == -ENODATA) {
 283                         /* When a battery is absent, we expect -ENODEV. Don't abort;
 284                            send the uevent with at least the the PRESENT=0 property */
 285                         ret = 0;
 286                         continue;
 287                 }
 288
 289                 if (ret < 0)
 290                         goto out;
 291
 292                 line = strchr(prop_buf, '\n');
 293                 if (line)
 294                         *line = 0;
 295
 296                 attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 297                 if (!attrname) {
 298                         ret = -ENOMEM;
 299                         goto out;
 300                 }
 301
 302                 dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
 303
 304                 ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 305                 kfree(attrname);
 306                 if (ret)
 307                         goto out;
 308         }
 309
 310 out:
 311         free_page((unsigned long)prop_buf);
 312
 313         return ret;
 314 }