linux/drivers/power/power_supply_sysfs.c
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   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
  41static struct device_attribute power_supply_attrs[];
  42
  43static 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
 111static 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_* */
 135static 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
 198static struct attribute *
 199__power_supply_attrs[ARRAY_SIZE(power_supply_attrs) + 1];
 200
 201static 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
 228static struct attribute_group power_supply_attr_group = {
 229        .attrs = __power_supply_attrs,
 230        .is_visible = power_supply_attr_is_visible,
 231};
 232
 233static const struct attribute_group *power_supply_attr_groups[] = {
 234        &power_supply_attr_group,
 235        NULL,
 236};
 237
 238void 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
 248static 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
 265int 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
 324out:
 325        free_page((unsigned long)prop_buf);
 326
 327        return ret;
 328}
 329
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