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
  17 #include "power_supply.h"
  18
  19 /*
  20  * This is because the name "current" breaks the device attr macro.
  21  * The "current" word resolves to "(get_current())" so instead of
  22  * "current" "(get_current())" appears in the sysfs.
  23  *
  24  * The source of this definition is the device.h which calls __ATTR
  25  * macro in sysfs.h which calls the __stringify macro.
  26  *
  27  * Only modification that the name is not tried to be resolved
  28  * (as a macro let's say).
  29  */
  30
  31 #define POWER_SUPPLY_ATTR(_name)                                        \
  32 {                                                                       \
  33         .attr = { .name = #_name, .mode = 0444, .owner = THIS_MODULE }, \
  34         .show = power_supply_show_property,                             \
  35         .store = NULL,                                                  \
  36 }
  37
  38 static struct device_attribute power_supply_attrs[];
  39
  40 static ssize_t power_supply_show_property(struct device *dev,
  41                                           struct device_attribute *attr,
  42                                           char *buf) {
  43         static char *status_text[] = {
  44                 "Unknown", "Charging", "Discharging", "Not charging", "Full"
  45         };
  46         static char *health_text[] = {
  47                 "Unknown", "Good", "Overheat", "Dead", "Over voltage",
  48                 "Unspecified failure"
  49         };
  50         static char *technology_text[] = {
  51                 "Unknown", "NiMH", "Li-ion", "Li-poly", "LiFe", "NiCd",
  52                 "LiMn"
  53         };
  54         ssize_t ret;
  55         struct power_supply *psy = dev_get_drvdata(dev);
  56         const ptrdiff_t off = attr - power_supply_attrs;
  57         union power_supply_propval value;
  58
  59         ret = psy->get_property(psy, off, &value);
  60
  61         if (ret < 0) {
  62                 if (ret != -ENODEV)
  63                         dev_err(dev, "driver failed to report `%s' property\n",
  64                                 attr->attr.name);
  65                 return ret;
  66         }
  67
  68         if (off == POWER_SUPPLY_PROP_STATUS)
  69                 return sprintf(buf, "%s\n", status_text[value.intval]);
  70         else if (off == POWER_SUPPLY_PROP_HEALTH)
  71                 return sprintf(buf, "%s\n", health_text[value.intval]);
  72         else if (off == POWER_SUPPLY_PROP_TECHNOLOGY)
  73                 return sprintf(buf, "%s\n", technology_text[value.intval]);
  74         else if (off >= POWER_SUPPLY_PROP_MODEL_NAME)
  75                 return sprintf(buf, "%s\n", value.strval);
  76
  77         return sprintf(buf, "%d\n", value.intval);
  78 }
  79
  80 /* Must be in the same order as POWER_SUPPLY_PROP_* */
  81 static struct device_attribute power_supply_attrs[] = {
  82         /* Properties of type `int' */
  83         POWER_SUPPLY_ATTR(status),
  84         POWER_SUPPLY_ATTR(health),
  85         POWER_SUPPLY_ATTR(present),
  86         POWER_SUPPLY_ATTR(online),
  87         POWER_SUPPLY_ATTR(technology),
  88         POWER_SUPPLY_ATTR(voltage_max),
  89         POWER_SUPPLY_ATTR(voltage_min),
  90         POWER_SUPPLY_ATTR(voltage_max_design),
  91         POWER_SUPPLY_ATTR(voltage_min_design),
  92         POWER_SUPPLY_ATTR(voltage_now),
  93         POWER_SUPPLY_ATTR(voltage_avg),
  94         POWER_SUPPLY_ATTR(current_now),
  95         POWER_SUPPLY_ATTR(current_avg),
  96         POWER_SUPPLY_ATTR(charge_full_design),
  97         POWER_SUPPLY_ATTR(charge_empty_design),
  98         POWER_SUPPLY_ATTR(charge_full),
  99         POWER_SUPPLY_ATTR(charge_empty),
 100         POWER_SUPPLY_ATTR(charge_now),
 101         POWER_SUPPLY_ATTR(charge_avg),
 102         POWER_SUPPLY_ATTR(energy_full_design),
 103         POWER_SUPPLY_ATTR(energy_empty_design),
 104         POWER_SUPPLY_ATTR(energy_full),
 105         POWER_SUPPLY_ATTR(energy_empty),
 106         POWER_SUPPLY_ATTR(energy_now),
 107         POWER_SUPPLY_ATTR(energy_avg),
 108         POWER_SUPPLY_ATTR(capacity),
 109         POWER_SUPPLY_ATTR(capacity_level),
 110         POWER_SUPPLY_ATTR(temp),
 111         POWER_SUPPLY_ATTR(temp_ambient),
 112         POWER_SUPPLY_ATTR(time_to_empty_now),
 113         POWER_SUPPLY_ATTR(time_to_empty_avg),
 114         POWER_SUPPLY_ATTR(time_to_full_now),
 115         POWER_SUPPLY_ATTR(time_to_full_avg),
 116         /* Properties of type `const char *' */
 117         POWER_SUPPLY_ATTR(model_name),
 118         POWER_SUPPLY_ATTR(manufacturer),
 119 };
 120
 121 static ssize_t power_supply_show_static_attrs(struct device *dev,
 122                                               struct device_attribute *attr,
 123                                               char *buf) {
 124         static char *type_text[] = { "Battery", "UPS", "Mains", "USB" };
 125         struct power_supply *psy = dev_get_drvdata(dev);
 126
 127         return sprintf(buf, "%s\n", type_text[psy->type]);
 128 }
 129
 130 static struct device_attribute power_supply_static_attrs[] = {
 131         __ATTR(type, 0444, power_supply_show_static_attrs, NULL),
 132 };
 133
 134 int power_supply_create_attrs(struct power_supply *psy)
 135 {
 136         int rc = 0;
 137         int i, j;
 138
 139         for (i = 0; i < ARRAY_SIZE(power_supply_static_attrs); i++) {
 140                 rc = device_create_file(psy->dev,
 141                             &power_supply_static_attrs[i]);
 142                 if (rc)
 143                         goto statics_failed;
 144         }
 145
 146         for (j = 0; j < psy->num_properties; j++) {
 147                 rc = device_create_file(psy->dev,
 148                             &power_supply_attrs[psy->properties[j]]);
 149                 if (rc)
 150                         goto dynamics_failed;
 151         }
 152
 153         goto succeed;
 154
 155 dynamics_failed:
 156         while (j--)
 157                 device_remove_file(psy->dev,
 158                            &power_supply_attrs[psy->properties[j]]);
 159 statics_failed:
 160         while (i--)
 161                 device_remove_file(psy->dev, &power_supply_static_attrs[i]);
 162 succeed:
 163         return rc;
 164 }
 165
 166 void power_supply_remove_attrs(struct power_supply *psy)
 167 {
 168         int i;
 169
 170         for (i = 0; i < ARRAY_SIZE(power_supply_static_attrs); i++)
 171                 device_remove_file(psy->dev, &power_supply_static_attrs[i]);
 172
 173         for (i = 0; i < psy->num_properties; i++)
 174                 device_remove_file(psy->dev,
 175                             &power_supply_attrs[psy->properties[i]]);
 176 }
 177
 178 static char *kstruprdup(const char *str, gfp_t gfp)
 179 {
 180         char *ret, *ustr;
 181
 182         ustr = ret = kmalloc(strlen(str) + 1, gfp);
 183
 184         if (!ret)
 185                 return NULL;
 186
 187         while (*str)
 188                 *ustr++ = toupper(*str++);
 189
 190         *ustr = 0;
 191
 192         return ret;
 193 }
 194
 195 int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
 196 {
 197         struct power_supply *psy = dev_get_drvdata(dev);
 198         int ret = 0, j;
 199         char *prop_buf;
 200         char *attrname;
 201
 202         dev_dbg(dev, "uevent\n");
 203
 204         if (!psy) {
 205                 dev_dbg(dev, "No power supply yet\n");
 206                 return ret;
 207         }
 208
 209         dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->name);
 210
 211         ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->name);
 212         if (ret)
 213                 return ret;
 214
 215         prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
 216         if (!prop_buf)
 217                 return -ENOMEM;
 218
 219         for (j = 0; j < ARRAY_SIZE(power_supply_static_attrs); j++) {
 220                 struct device_attribute *attr;
 221                 char *line;
 222
 223                 attr = &power_supply_static_attrs[j];
 224
 225                 ret = power_supply_show_static_attrs(dev, attr, prop_buf);
 226                 if (ret < 0)
 227                         goto out;
 228
 229                 line = strchr(prop_buf, '\n');
 230                 if (line)
 231                         *line = 0;
 232
 233                 attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 234                 if (!attrname) {
 235                         ret = -ENOMEM;
 236                         goto out;
 237                 }
 238
 239                 dev_dbg(dev, "Static prop %s=%s\n", attrname, prop_buf);
 240
 241                 ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 242                 kfree(attrname);
 243                 if (ret)
 244                         goto out;
 245         }
 246
 247         dev_dbg(dev, "%zd dynamic props\n", psy->num_properties);
 248
 249         for (j = 0; j < psy->num_properties; j++) {
 250                 struct device_attribute *attr;
 251                 char *line;
 252
 253                 attr = &power_supply_attrs[psy->properties[j]];
 254
 255                 ret = power_supply_show_property(dev, attr, prop_buf);
 256                 if (ret == -ENODEV) {
 257                         /* When a battery is absent, we expect -ENODEV. Don't abort;
 258                            send the uevent with at least the the PRESENT=0 property */
 259                         ret = 0;
 260                         continue;
 261                 }
 262
 263                 if (ret < 0)
 264                         goto out;
 265
 266                 line = strchr(prop_buf, '\n');
 267                 if (line)
 268                         *line = 0;
 269
 270                 attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 271                 if (!attrname) {
 272                         ret = -ENOMEM;
 273                         goto out;
 274                 }
 275
 276                 dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
 277
 278                 ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 279                 kfree(attrname);
 280                 if (ret)
 281                         goto out;
 282         }
 283
 284 out:
 285         free_page((unsigned long)prop_buf);
 286
 287         return ret;
 288 }