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",
  59        };
  60        static char *technology_text[] = {
  61                "Unknown", "NiMH", "Li-ion", "Li-poly", "LiFe", "NiCd",
  62                "LiMn"
  63        };
  64        static char *capacity_level_text[] = {
  65                "Unknown", "Critical", "Low", "Normal", "High", "Full"
  66        };
  67        static char *scope_text[] = {
  68                "Unknown", "System", "Device"
  69        };
  70        ssize_t ret = 0;
  71        struct power_supply *psy = dev_get_drvdata(dev);
  72        const ptrdiff_t off = attr - power_supply_attrs;
  73        union power_supply_propval value;
  74
  75        if (off == POWER_SUPPLY_PROP_TYPE)
  76                value.intval = psy->type;
  77        else
  78                ret = psy->get_property(psy, off, &value);
  79
  80        if (ret < 0) {
  81                if (ret == -ENODATA)
  82                        dev_dbg(dev, "driver has no data for `%s' property\n",
  83                                attr->attr.name);
  84                else if (ret != -ENODEV)
  85                        dev_err(dev, "driver failed to report `%s' property: %zd\n",
  86                                attr->attr.name, ret);
  87                return ret;
  88        }
  89
  90        if (off == POWER_SUPPLY_PROP_STATUS)
  91                return sprintf(buf, "%s\n", status_text[value.intval]);
  92        else if (off == POWER_SUPPLY_PROP_CHARGE_TYPE)
  93                return sprintf(buf, "%s\n", charge_type[value.intval]);
  94        else if (off == POWER_SUPPLY_PROP_HEALTH)
  95                return sprintf(buf, "%s\n", health_text[value.intval]);
  96        else if (off == POWER_SUPPLY_PROP_TECHNOLOGY)
  97                return sprintf(buf, "%s\n", technology_text[value.intval]);
  98        else if (off == POWER_SUPPLY_PROP_CAPACITY_LEVEL)
  99                return sprintf(buf, "%s\n", capacity_level_text[value.intval]);
 100        else if (off == POWER_SUPPLY_PROP_TYPE)
 101                return sprintf(buf, "%s\n", type_text[value.intval]);
 102        else if (off == POWER_SUPPLY_PROP_SCOPE)
 103                return sprintf(buf, "%s\n", scope_text[value.intval]);
 104        else if (off >= POWER_SUPPLY_PROP_MODEL_NAME)
 105                return sprintf(buf, "%s\n", value.strval);
 106
 107        return sprintf(buf, "%d\n", value.intval);
 108}
 109
 110static ssize_t power_supply_store_property(struct device *dev,
 111                                           struct device_attribute *attr,
 112                                           const char *buf, size_t count) {
 113        ssize_t ret;
 114        struct power_supply *psy = dev_get_drvdata(dev);
 115        const ptrdiff_t off = attr - power_supply_attrs;
 116        union power_supply_propval value;
 117        long long_val;
 118
 119        /* TODO: support other types than int */
 120        ret = strict_strtol(buf, 10, &long_val);
 121        if (ret < 0)
 122                return ret;
 123
 124        value.intval = long_val;
 125
 126        ret = psy->set_property(psy, off, &value);
 127        if (ret < 0)
 128                return ret;
 129
 130        return count;
 131}
 132
 133/* Must be in the same order as POWER_SUPPLY_PROP_* */
 134static struct device_attribute power_supply_attrs[] = {
 135        /* Properties of type `int' */
 136        POWER_SUPPLY_ATTR(status),
 137        POWER_SUPPLY_ATTR(charge_type),
 138        POWER_SUPPLY_ATTR(health),
 139        POWER_SUPPLY_ATTR(present),
 140        POWER_SUPPLY_ATTR(online),
 141        POWER_SUPPLY_ATTR(authentic),
 142        POWER_SUPPLY_ATTR(technology),
 143        POWER_SUPPLY_ATTR(cycle_count),
 144        POWER_SUPPLY_ATTR(voltage_max),
 145        POWER_SUPPLY_ATTR(voltage_min),
 146        POWER_SUPPLY_ATTR(voltage_max_design),
 147        POWER_SUPPLY_ATTR(voltage_min_design),
 148        POWER_SUPPLY_ATTR(voltage_now),
 149        POWER_SUPPLY_ATTR(voltage_avg),
 150        POWER_SUPPLY_ATTR(voltage_ocv),
 151        POWER_SUPPLY_ATTR(current_max),
 152        POWER_SUPPLY_ATTR(current_now),
 153        POWER_SUPPLY_ATTR(current_avg),
 154        POWER_SUPPLY_ATTR(power_now),
 155        POWER_SUPPLY_ATTR(power_avg),
 156        POWER_SUPPLY_ATTR(charge_full_design),
 157        POWER_SUPPLY_ATTR(charge_empty_design),
 158        POWER_SUPPLY_ATTR(charge_full),
 159        POWER_SUPPLY_ATTR(charge_empty),
 160        POWER_SUPPLY_ATTR(charge_now),
 161        POWER_SUPPLY_ATTR(charge_avg),
 162        POWER_SUPPLY_ATTR(charge_counter),
 163        POWER_SUPPLY_ATTR(constant_charge_current),
 164        POWER_SUPPLY_ATTR(constant_charge_current_max),
 165        POWER_SUPPLY_ATTR(constant_charge_voltage),
 166        POWER_SUPPLY_ATTR(constant_charge_voltage_max),
 167        POWER_SUPPLY_ATTR(energy_full_design),
 168        POWER_SUPPLY_ATTR(energy_empty_design),
 169        POWER_SUPPLY_ATTR(energy_full),
 170        POWER_SUPPLY_ATTR(energy_empty),
 171        POWER_SUPPLY_ATTR(energy_now),
 172        POWER_SUPPLY_ATTR(energy_avg),
 173        POWER_SUPPLY_ATTR(capacity),
 174        POWER_SUPPLY_ATTR(capacity_alert_min),
 175        POWER_SUPPLY_ATTR(capacity_alert_max),
 176        POWER_SUPPLY_ATTR(capacity_level),
 177        POWER_SUPPLY_ATTR(temp),
 178        POWER_SUPPLY_ATTR(temp_alert_min),
 179        POWER_SUPPLY_ATTR(temp_alert_max),
 180        POWER_SUPPLY_ATTR(temp_ambient),
 181        POWER_SUPPLY_ATTR(temp_ambient_alert_min),
 182        POWER_SUPPLY_ATTR(temp_ambient_alert_max),
 183        POWER_SUPPLY_ATTR(time_to_empty_now),
 184        POWER_SUPPLY_ATTR(time_to_empty_avg),
 185        POWER_SUPPLY_ATTR(time_to_full_now),
 186        POWER_SUPPLY_ATTR(time_to_full_avg),
 187        POWER_SUPPLY_ATTR(type),
 188        POWER_SUPPLY_ATTR(scope),
 189        /* Properties of type `const char *' */
 190        POWER_SUPPLY_ATTR(model_name),
 191        POWER_SUPPLY_ATTR(manufacturer),
 192        POWER_SUPPLY_ATTR(serial_number),
 193};
 194
 195static struct attribute *
 196__power_supply_attrs[ARRAY_SIZE(power_supply_attrs) + 1];
 197
 198static umode_t power_supply_attr_is_visible(struct kobject *kobj,
 199                                           struct attribute *attr,
 200                                           int attrno)
 201{
 202        struct device *dev = container_of(kobj, struct device, kobj);
 203        struct power_supply *psy = dev_get_drvdata(dev);
 204        umode_t mode = S_IRUSR | S_IRGRP | S_IROTH;
 205        int i;
 206
 207        if (attrno == POWER_SUPPLY_PROP_TYPE)
 208                return mode;
 209
 210        for (i = 0; i < psy->num_properties; i++) {
 211                int property = psy->properties[i];
 212
 213                if (property == attrno) {
 214                        if (psy->property_is_writeable &&
 215                            psy->property_is_writeable(psy, property) > 0)
 216                                mode |= S_IWUSR;
 217
 218                        return mode;
 219                }
 220        }
 221
 222        return 0;
 223}
 224
 225static struct attribute_group power_supply_attr_group = {
 226        .attrs = __power_supply_attrs,
 227        .is_visible = power_supply_attr_is_visible,
 228};
 229
 230static const struct attribute_group *power_supply_attr_groups[] = {
 231        &power_supply_attr_group,
 232        NULL,
 233};
 234
 235void power_supply_init_attrs(struct device_type *dev_type)
 236{
 237        int i;
 238
 239        dev_type->groups = power_supply_attr_groups;
 240
 241        for (i = 0; i < ARRAY_SIZE(power_supply_attrs); i++)
 242                __power_supply_attrs[i] = &power_supply_attrs[i].attr;
 243}
 244
 245static char *kstruprdup(const char *str, gfp_t gfp)
 246{
 247        char *ret, *ustr;
 248
 249        ustr = ret = kmalloc(strlen(str) + 1, gfp);
 250
 251        if (!ret)
 252                return NULL;
 253
 254        while (*str)
 255                *ustr++ = toupper(*str++);
 256
 257        *ustr = 0;
 258
 259        return ret;
 260}
 261
 262int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
 263{
 264        struct power_supply *psy = dev_get_drvdata(dev);
 265        int ret = 0, j;
 266        char *prop_buf;
 267        char *attrname;
 268
 269        dev_dbg(dev, "uevent\n");
 270
 271        if (!psy || !psy->dev) {
 272                dev_dbg(dev, "No power supply yet\n");
 273                return ret;
 274        }
 275
 276        dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->name);
 277
 278        ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->name);
 279        if (ret)
 280                return ret;
 281
 282        prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
 283        if (!prop_buf)
 284                return -ENOMEM;
 285
 286        for (j = 0; j < psy->num_properties; j++) {
 287                struct device_attribute *attr;
 288                char *line;
 289
 290                attr = &power_supply_attrs[psy->properties[j]];
 291
 292                ret = power_supply_show_property(dev, attr, prop_buf);
 293                if (ret == -ENODEV || ret == -ENODATA) {
 294                        /* When a battery is absent, we expect -ENODEV. Don't abort;
 295                           send the uevent with at least the the PRESENT=0 property */
 296                        ret = 0;
 297                        continue;
 298                }
 299
 300                if (ret < 0)
 301                        goto out;
 302
 303                line = strchr(prop_buf, '\n');
 304                if (line)
 305                        *line = 0;
 306
 307                attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 308                if (!attrname) {
 309                        ret = -ENOMEM;
 310                        goto out;
 311                }
 312
 313                dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
 314
 315                ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 316                kfree(attrname);
 317                if (ret)
 318                        goto out;
 319        }
 320
 321out:
 322        free_page((unsigned long)prop_buf);
 323
 324        return ret;
 325}
 326
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