linux/drivers/power/power_supply_sysfs.c
<<
>>
Prefs
   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 },       \
  34        .show = power_supply_show_property,                             \
  35        .store = NULL,                                                  \
  36}
  37
  38static struct device_attribute power_supply_attrs[];
  39
  40static 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", "Cold",
  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_* */
  81static 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(power_now),
  97        POWER_SUPPLY_ATTR(power_avg),
  98        POWER_SUPPLY_ATTR(charge_full_design),
  99        POWER_SUPPLY_ATTR(charge_empty_design),
 100        POWER_SUPPLY_ATTR(charge_full),
 101        POWER_SUPPLY_ATTR(charge_empty),
 102        POWER_SUPPLY_ATTR(charge_now),
 103        POWER_SUPPLY_ATTR(charge_avg),
 104        POWER_SUPPLY_ATTR(charge_counter),
 105        POWER_SUPPLY_ATTR(energy_full_design),
 106        POWER_SUPPLY_ATTR(energy_empty_design),
 107        POWER_SUPPLY_ATTR(energy_full),
 108        POWER_SUPPLY_ATTR(energy_empty),
 109        POWER_SUPPLY_ATTR(energy_now),
 110        POWER_SUPPLY_ATTR(energy_avg),
 111        POWER_SUPPLY_ATTR(capacity),
 112        POWER_SUPPLY_ATTR(temp),
 113        POWER_SUPPLY_ATTR(temp_ambient),
 114        POWER_SUPPLY_ATTR(time_to_empty_now),
 115        POWER_SUPPLY_ATTR(time_to_empty_avg),
 116        POWER_SUPPLY_ATTR(time_to_full_now),
 117        POWER_SUPPLY_ATTR(time_to_full_avg),
 118        /* Properties of type `const char *' */
 119        POWER_SUPPLY_ATTR(model_name),
 120        POWER_SUPPLY_ATTR(manufacturer),
 121        POWER_SUPPLY_ATTR(serial_number),
 122};
 123
 124static ssize_t power_supply_show_static_attrs(struct device *dev,
 125                                              struct device_attribute *attr,
 126                                              char *buf) {
 127        static char *type_text[] = { "Battery", "UPS", "Mains", "USB" };
 128        struct power_supply *psy = dev_get_drvdata(dev);
 129
 130        return sprintf(buf, "%s\n", type_text[psy->type]);
 131}
 132
 133static struct device_attribute power_supply_static_attrs[] = {
 134        __ATTR(type, 0444, power_supply_show_static_attrs, NULL),
 135};
 136
 137int power_supply_create_attrs(struct power_supply *psy)
 138{
 139        int rc = 0;
 140        int i, j;
 141
 142        for (i = 0; i < ARRAY_SIZE(power_supply_static_attrs); i++) {
 143                rc = device_create_file(psy->dev,
 144                            &power_supply_static_attrs[i]);
 145                if (rc)
 146                        goto statics_failed;
 147        }
 148
 149        for (j = 0; j < psy->num_properties; j++) {
 150                rc = device_create_file(psy->dev,
 151                            &power_supply_attrs[psy->properties[j]]);
 152                if (rc)
 153                        goto dynamics_failed;
 154        }
 155
 156        goto succeed;
 157
 158dynamics_failed:
 159        while (j--)
 160                device_remove_file(psy->dev,
 161                           &power_supply_attrs[psy->properties[j]]);
 162statics_failed:
 163        while (i--)
 164                device_remove_file(psy->dev, &power_supply_static_attrs[i]);
 165succeed:
 166        return rc;
 167}
 168
 169void power_supply_remove_attrs(struct power_supply *psy)
 170{
 171        int i;
 172
 173        for (i = 0; i < ARRAY_SIZE(power_supply_static_attrs); i++)
 174                device_remove_file(psy->dev, &power_supply_static_attrs[i]);
 175
 176        for (i = 0; i < psy->num_properties; i++)
 177                device_remove_file(psy->dev,
 178                            &power_supply_attrs[psy->properties[i]]);
 179}
 180
 181static char *kstruprdup(const char *str, gfp_t gfp)
 182{
 183        char *ret, *ustr;
 184
 185        ustr = ret = kmalloc(strlen(str) + 1, gfp);
 186
 187        if (!ret)
 188                return NULL;
 189
 190        while (*str)
 191                *ustr++ = toupper(*str++);
 192
 193        *ustr = 0;
 194
 195        return ret;
 196}
 197
 198int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
 199{
 200        struct power_supply *psy = dev_get_drvdata(dev);
 201        int ret = 0, j;
 202        char *prop_buf;
 203        char *attrname;
 204
 205        dev_dbg(dev, "uevent\n");
 206
 207        if (!psy || !psy->dev) {
 208                dev_dbg(dev, "No power supply yet\n");
 209                return ret;
 210        }
 211
 212        dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->name);
 213
 214        ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->name);
 215        if (ret)
 216                return ret;
 217
 218        prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
 219        if (!prop_buf)
 220                return -ENOMEM;
 221
 222        for (j = 0; j < ARRAY_SIZE(power_supply_static_attrs); j++) {
 223                struct device_attribute *attr;
 224                char *line;
 225
 226                attr = &power_supply_static_attrs[j];
 227
 228                ret = power_supply_show_static_attrs(dev, attr, prop_buf);
 229                if (ret < 0)
 230                        goto out;
 231
 232                line = strchr(prop_buf, '\n');
 233                if (line)
 234                        *line = 0;
 235
 236                attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 237                if (!attrname) {
 238                        ret = -ENOMEM;
 239                        goto out;
 240                }
 241
 242                dev_dbg(dev, "Static prop %s=%s\n", attrname, prop_buf);
 243
 244                ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 245                kfree(attrname);
 246                if (ret)
 247                        goto out;
 248        }
 249
 250        dev_dbg(dev, "%zd dynamic props\n", psy->num_properties);
 251
 252        for (j = 0; j < psy->num_properties; j++) {
 253                struct device_attribute *attr;
 254                char *line;
 255
 256                attr = &power_supply_attrs[psy->properties[j]];
 257
 258                ret = power_supply_show_property(dev, attr, prop_buf);
 259                if (ret == -ENODEV) {
 260                        /* When a battery is absent, we expect -ENODEV. Don't abort;
 261                           send the uevent with at least the the PRESENT=0 property */
 262                        ret = 0;
 263                        continue;
 264                }
 265
 266                if (ret < 0)
 267                        goto out;
 268
 269                line = strchr(prop_buf, '\n');
 270                if (line)
 271                        *line = 0;
 272
 273                attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 274                if (!attrname) {
 275                        ret = -ENOMEM;
 276                        goto out;
 277                }
 278
 279                dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
 280
 281                ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 282                kfree(attrname);
 283                if (ret)
 284                        goto out;
 285        }
 286
 287out:
 288        free_page((unsigned long)prop_buf);
 289
 290        return ret;
 291}
 292
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.