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