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", "Watchdog timer expire",
  59                 "Safety timer expire"
  60         };
  61         static char *technology_text[] = {
  62                 "Unknown", "NiMH", "Li-ion", "Li-poly", "LiFe", "NiCd",
  63                 "LiMn"
  64         };
  65         static char *capacity_level_text[] = {
  66                 "Unknown", "Critical", "Low", "Normal", "High", "Full"
  67         };
  68         static char *scope_text[] = {
  69                 "Unknown", "System", "Device"
  70         };
  71         ssize_t ret = 0;
  72         struct power_supply *psy = dev_get_drvdata(dev);
  73         const ptrdiff_t off = attr - power_supply_attrs;
  74         union power_supply_propval value;
  75
  76         if (off == POWER_SUPPLY_PROP_TYPE)
  77                 value.intval = psy->type;
  78         else
  79                 ret = psy->get_property(psy, off, &value);
  80
  81         if (ret < 0) {
  82                 if (ret == -ENODATA)
  83                         dev_dbg(dev, "driver has no data for `%s' property\n",
  84                                 attr->attr.name);
  85                 else if (ret != -ENODEV)
  86                         dev_err(dev, "driver failed to report `%s' property: %zd\n",
  87                                 attr->attr.name, ret);
  88                 return ret;
  89         }
  90
  91         if (off == POWER_SUPPLY_PROP_STATUS)
  92                 return sprintf(buf, "%s\n", status_text[value.intval]);
  93         else if (off == POWER_SUPPLY_PROP_CHARGE_TYPE)
  94                 return sprintf(buf, "%s\n", charge_type[value.intval]);
  95         else if (off == POWER_SUPPLY_PROP_HEALTH)
  96                 return sprintf(buf, "%s\n", health_text[value.intval]);
  97         else if (off == POWER_SUPPLY_PROP_TECHNOLOGY)
  98                 return sprintf(buf, "%s\n", technology_text[value.intval]);
  99         else if (off == POWER_SUPPLY_PROP_CAPACITY_LEVEL)
 100                 return sprintf(buf, "%s\n", capacity_level_text[value.intval]);
 101         else if (off == POWER_SUPPLY_PROP_TYPE)
 102                 return sprintf(buf, "%s\n", type_text[value.intval]);
 103         else if (off == POWER_SUPPLY_PROP_SCOPE)
 104                 return sprintf(buf, "%s\n", scope_text[value.intval]);
 105         else if (off >= POWER_SUPPLY_PROP_MODEL_NAME)
 106                 return sprintf(buf, "%s\n", value.strval);
 107
 108         return sprintf(buf, "%d\n", value.intval);
 109 }
 110
 111 static ssize_t power_supply_store_property(struct device *dev,
 112                                            struct device_attribute *attr,
 113                                            const char *buf, size_t count) {
 114         ssize_t ret;
 115         struct power_supply *psy = dev_get_drvdata(dev);
 116         const ptrdiff_t off = attr - power_supply_attrs;
 117         union power_supply_propval value;
 118         long long_val;
 119
 120         /* TODO: support other types than int */
 121         ret = kstrtol(buf, 10, &long_val);
 122         if (ret < 0)
 123                 return ret;
 124
 125         value.intval = long_val;
 126
 127         ret = psy->set_property(psy, off, &value);
 128         if (ret < 0)
 129                 return ret;
 130
 131         return count;
 132 }
 133
 134 /* Must be in the same order as POWER_SUPPLY_PROP_* */
 135 static struct device_attribute power_supply_attrs[] = {
 136         /* Properties of type `int' */
 137         POWER_SUPPLY_ATTR(status),
 138         POWER_SUPPLY_ATTR(charge_type),
 139         POWER_SUPPLY_ATTR(health),
 140         POWER_SUPPLY_ATTR(present),
 141         POWER_SUPPLY_ATTR(online),
 142         POWER_SUPPLY_ATTR(authentic),
 143         POWER_SUPPLY_ATTR(technology),
 144         POWER_SUPPLY_ATTR(cycle_count),
 145         POWER_SUPPLY_ATTR(voltage_max),
 146         POWER_SUPPLY_ATTR(voltage_min),
 147         POWER_SUPPLY_ATTR(voltage_max_design),
 148         POWER_SUPPLY_ATTR(voltage_min_design),
 149         POWER_SUPPLY_ATTR(voltage_now),
 150         POWER_SUPPLY_ATTR(voltage_avg),
 151         POWER_SUPPLY_ATTR(voltage_ocv),
 152         POWER_SUPPLY_ATTR(current_max),
 153         POWER_SUPPLY_ATTR(current_now),
 154         POWER_SUPPLY_ATTR(current_avg),
 155         POWER_SUPPLY_ATTR(power_now),
 156         POWER_SUPPLY_ATTR(power_avg),
 157         POWER_SUPPLY_ATTR(charge_full_design),
 158         POWER_SUPPLY_ATTR(charge_empty_design),
 159         POWER_SUPPLY_ATTR(charge_full),
 160         POWER_SUPPLY_ATTR(charge_empty),
 161         POWER_SUPPLY_ATTR(charge_now),
 162         POWER_SUPPLY_ATTR(charge_avg),
 163         POWER_SUPPLY_ATTR(charge_counter),
 164         POWER_SUPPLY_ATTR(constant_charge_current),
 165         POWER_SUPPLY_ATTR(constant_charge_current_max),
 166         POWER_SUPPLY_ATTR(constant_charge_voltage),
 167         POWER_SUPPLY_ATTR(constant_charge_voltage_max),
 168         POWER_SUPPLY_ATTR(charge_control_limit),
 169         POWER_SUPPLY_ATTR(charge_control_limit_max),
 170         POWER_SUPPLY_ATTR(energy_full_design),
 171         POWER_SUPPLY_ATTR(energy_empty_design),
 172         POWER_SUPPLY_ATTR(energy_full),
 173         POWER_SUPPLY_ATTR(energy_empty),
 174         POWER_SUPPLY_ATTR(energy_now),
 175         POWER_SUPPLY_ATTR(energy_avg),
 176         POWER_SUPPLY_ATTR(capacity),
 177         POWER_SUPPLY_ATTR(capacity_alert_min),
 178         POWER_SUPPLY_ATTR(capacity_alert_max),
 179         POWER_SUPPLY_ATTR(capacity_level),
 180         POWER_SUPPLY_ATTR(temp),
 181         POWER_SUPPLY_ATTR(temp_alert_min),
 182         POWER_SUPPLY_ATTR(temp_alert_max),
 183         POWER_SUPPLY_ATTR(temp_ambient),
 184         POWER_SUPPLY_ATTR(temp_ambient_alert_min),
 185         POWER_SUPPLY_ATTR(temp_ambient_alert_max),
 186         POWER_SUPPLY_ATTR(time_to_empty_now),
 187         POWER_SUPPLY_ATTR(time_to_empty_avg),
 188         POWER_SUPPLY_ATTR(time_to_full_now),
 189         POWER_SUPPLY_ATTR(time_to_full_avg),
 190         POWER_SUPPLY_ATTR(type),
 191         POWER_SUPPLY_ATTR(scope),
 192         /* Properties of type `const char *' */
 193         POWER_SUPPLY_ATTR(model_name),
 194         POWER_SUPPLY_ATTR(manufacturer),
 195         POWER_SUPPLY_ATTR(serial_number),
 196 };
 197
 198 static struct attribute *
 199 __power_supply_attrs[ARRAY_SIZE(power_supply_attrs) + 1];
 200
 201 static umode_t power_supply_attr_is_visible(struct kobject *kobj,
 202                                            struct attribute *attr,
 203                                            int attrno)
 204 {
 205         struct device *dev = container_of(kobj, struct device, kobj);
 206         struct power_supply *psy = dev_get_drvdata(dev);
 207         umode_t mode = S_IRUSR | S_IRGRP | S_IROTH;
 208         int i;
 209
 210         if (attrno == POWER_SUPPLY_PROP_TYPE)
 211                 return mode;
 212
 213         for (i = 0; i < psy->num_properties; i++) {
 214                 int property = psy->properties[i];
 215
 216                 if (property == attrno) {
 217                         if (psy->property_is_writeable &&
 218                             psy->property_is_writeable(psy, property) > 0)
 219                                 mode |= S_IWUSR;
 220
 221                         return mode;
 222                 }
 223         }
 224
 225         return 0;
 226 }
 227
 228 static struct attribute_group power_supply_attr_group = {
 229         .attrs = __power_supply_attrs,
 230         .is_visible = power_supply_attr_is_visible,
 231 };
 232
 233 static const struct attribute_group *power_supply_attr_groups[] = {
 234         &power_supply_attr_group,
 235         NULL,
 236 };
 237
 238 void power_supply_init_attrs(struct device_type *dev_type)
 239 {
 240         int i;
 241
 242         dev_type->groups = power_supply_attr_groups;
 243
 244         for (i = 0; i < ARRAY_SIZE(power_supply_attrs); i++)
 245                 __power_supply_attrs[i] = &power_supply_attrs[i].attr;
 246 }
 247
 248 static char *kstruprdup(const char *str, gfp_t gfp)
 249 {
 250         char *ret, *ustr;
 251
 252         ustr = ret = kmalloc(strlen(str) + 1, gfp);
 253
 254         if (!ret)
 255                 return NULL;
 256
 257         while (*str)
 258                 *ustr++ = toupper(*str++);
 259
 260         *ustr = 0;
 261
 262         return ret;
 263 }
 264
 265 int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
 266 {
 267         struct power_supply *psy = dev_get_drvdata(dev);
 268         int ret = 0, j;
 269         char *prop_buf;
 270         char *attrname;
 271
 272         dev_dbg(dev, "uevent\n");
 273
 274         if (!psy || !psy->dev) {
 275                 dev_dbg(dev, "No power supply yet\n");
 276                 return ret;
 277         }
 278
 279         dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->name);
 280
 281         ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->name);
 282         if (ret)
 283                 return ret;
 284
 285         prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
 286         if (!prop_buf)
 287                 return -ENOMEM;
 288
 289         for (j = 0; j < psy->num_properties; j++) {
 290                 struct device_attribute *attr;
 291                 char *line;
 292
 293                 attr = &power_supply_attrs[psy->properties[j]];
 294
 295                 ret = power_supply_show_property(dev, attr, prop_buf);
 296                 if (ret == -ENODEV || ret == -ENODATA) {
 297                         /* When a battery is absent, we expect -ENODEV. Don't abort;
 298                            send the uevent with at least the the PRESENT=0 property */
 299                         ret = 0;
 300                         continue;
 301                 }
 302
 303                 if (ret < 0)
 304                         goto out;
 305
 306                 line = strchr(prop_buf, '\n');
 307                 if (line)
 308                         *line = 0;
 309
 310                 attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 311                 if (!attrname) {
 312                         ret = -ENOMEM;
 313                         goto out;
 314                 }
 315
 316                 dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
 317
 318                 ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 319                 kfree(attrname);
 320                 if (ret)
 321                         goto out;
 322         }
 323
 324 out:
 325         free_page((unsigned long)prop_buf);
 326
 327         return ret;
 328 }