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(charge_counter),
 103         POWER_SUPPLY_ATTR(energy_full_design),
 104         POWER_SUPPLY_ATTR(energy_empty_design),
 105         POWER_SUPPLY_ATTR(energy_full),
 106         POWER_SUPPLY_ATTR(energy_empty),
 107         POWER_SUPPLY_ATTR(energy_now),
 108         POWER_SUPPLY_ATTR(energy_avg),
 109         POWER_SUPPLY_ATTR(capacity),
 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         POWER_SUPPLY_ATTR(serial_number),
 120 };
 121
 122 static ssize_t power_supply_show_static_attrs(struct device *dev,
 123                                               struct device_attribute *attr,
 124                                               char *buf) {
 125         static char *type_text[] = { "Battery", "UPS", "Mains", "USB" };
 126         struct power_supply *psy = dev_get_drvdata(dev);
 127
 128         return sprintf(buf, "%s\n", type_text[psy->type]);
 129 }
 130
 131 static struct device_attribute power_supply_static_attrs[] = {
 132         __ATTR(type, 0444, power_supply_show_static_attrs, NULL),
 133 };
 134
 135 int power_supply_create_attrs(struct power_supply *psy)
 136 {
 137         int rc = 0;
 138         int i, j;
 139
 140         for (i = 0; i < ARRAY_SIZE(power_supply_static_attrs); i++) {
 141                 rc = device_create_file(psy->dev,
 142                             &power_supply_static_attrs[i]);
 143                 if (rc)
 144                         goto statics_failed;
 145         }
 146
 147         for (j = 0; j < psy->num_properties; j++) {
 148                 rc = device_create_file(psy->dev,
 149                             &power_supply_attrs[psy->properties[j]]);
 150                 if (rc)
 151                         goto dynamics_failed;
 152         }
 153
 154         goto succeed;
 155
 156 dynamics_failed:
 157         while (j--)
 158                 device_remove_file(psy->dev,
 159                            &power_supply_attrs[psy->properties[j]]);
 160 statics_failed:
 161         while (i--)
 162                 device_remove_file(psy->dev, &power_supply_static_attrs[i]);
 163 succeed:
 164         return rc;
 165 }
 166
 167 void power_supply_remove_attrs(struct power_supply *psy)
 168 {
 169         int i;
 170
 171         for (i = 0; i < ARRAY_SIZE(power_supply_static_attrs); i++)
 172                 device_remove_file(psy->dev, &power_supply_static_attrs[i]);
 173
 174         for (i = 0; i < psy->num_properties; i++)
 175                 device_remove_file(psy->dev,
 176                             &power_supply_attrs[psy->properties[i]]);
 177 }
 178
 179 static char *kstruprdup(const char *str, gfp_t gfp)
 180 {
 181         char *ret, *ustr;
 182
 183         ustr = ret = kmalloc(strlen(str) + 1, gfp);
 184
 185         if (!ret)
 186                 return NULL;
 187
 188         while (*str)
 189                 *ustr++ = toupper(*str++);
 190
 191         *ustr = 0;
 192
 193         return ret;
 194 }
 195
 196 int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
 197 {
 198         struct power_supply *psy = dev_get_drvdata(dev);
 199         int ret = 0, j;
 200         char *prop_buf;
 201         char *attrname;
 202
 203         dev_dbg(dev, "uevent\n");
 204
 205         if (!psy || !psy->dev) {
 206                 dev_dbg(dev, "No power supply yet\n");
 207                 return ret;
 208         }
 209
 210         dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->name);
 211
 212         ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->name);
 213         if (ret)
 214                 return ret;
 215
 216         prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
 217         if (!prop_buf)
 218                 return -ENOMEM;
 219
 220         for (j = 0; j < ARRAY_SIZE(power_supply_static_attrs); j++) {
 221                 struct device_attribute *attr;
 222                 char *line;
 223
 224                 attr = &power_supply_static_attrs[j];
 225
 226                 ret = power_supply_show_static_attrs(dev, attr, prop_buf);
 227                 if (ret < 0)
 228                         goto out;
 229
 230                 line = strchr(prop_buf, '\n');
 231                 if (line)
 232                         *line = 0;
 233
 234                 attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 235                 if (!attrname) {
 236                         ret = -ENOMEM;
 237                         goto out;
 238                 }
 239
 240                 dev_dbg(dev, "Static prop %s=%s\n", attrname, prop_buf);
 241
 242                 ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 243                 kfree(attrname);
 244                 if (ret)
 245                         goto out;
 246         }
 247
 248         dev_dbg(dev, "%zd dynamic props\n", psy->num_properties);
 249
 250         for (j = 0; j < psy->num_properties; j++) {
 251                 struct device_attribute *attr;
 252                 char *line;
 253
 254                 attr = &power_supply_attrs[psy->properties[j]];
 255
 256                 ret = power_supply_show_property(dev, attr, prop_buf);
 257                 if (ret == -ENODEV) {
 258                         /* When a battery is absent, we expect -ENODEV. Don't abort;
 259                            send the uevent with at least the the PRESENT=0 property */
 260                         ret = 0;
 261                         continue;
 262                 }
 263
 264                 if (ret < 0)
 265                         goto out;
 266
 267                 line = strchr(prop_buf, '\n');
 268                 if (line)
 269                         *line = 0;
 270
 271                 attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 272                 if (!attrname) {
 273                         ret = -ENOMEM;
 274                         goto out;
 275                 }
 276
 277                 dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
 278
 279                 ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 280                 kfree(attrname);
 281                 if (ret)
 282                         goto out;
 283         }
 284
 285 out:
 286         free_page((unsigned long)prop_buf);
 287
 288         return ret;
 289 }