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