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(technology),
 142        POWER_SUPPLY_ATTR(cycle_count),
 143        POWER_SUPPLY_ATTR(voltage_max),
 144        POWER_SUPPLY_ATTR(voltage_min),
 145        POWER_SUPPLY_ATTR(voltage_max_design),
 146        POWER_SUPPLY_ATTR(voltage_min_design),
 147        POWER_SUPPLY_ATTR(voltage_now),
 148        POWER_SUPPLY_ATTR(voltage_avg),
 149        POWER_SUPPLY_ATTR(voltage_ocv),
 150        POWER_SUPPLY_ATTR(current_max),
 151        POWER_SUPPLY_ATTR(current_now),
 152        POWER_SUPPLY_ATTR(current_avg),
 153        POWER_SUPPLY_ATTR(power_now),
 154        POWER_SUPPLY_ATTR(power_avg),
 155        POWER_SUPPLY_ATTR(charge_full_design),
 156        POWER_SUPPLY_ATTR(charge_empty_design),
 157        POWER_SUPPLY_ATTR(charge_full),
 158        POWER_SUPPLY_ATTR(charge_empty),
 159        POWER_SUPPLY_ATTR(charge_now),
 160        POWER_SUPPLY_ATTR(charge_avg),
 161        POWER_SUPPLY_ATTR(charge_counter),
 162        POWER_SUPPLY_ATTR(constant_charge_current),
 163        POWER_SUPPLY_ATTR(constant_charge_voltage),
 164        POWER_SUPPLY_ATTR(energy_full_design),
 165        POWER_SUPPLY_ATTR(energy_empty_design),
 166        POWER_SUPPLY_ATTR(energy_full),
 167        POWER_SUPPLY_ATTR(energy_empty),
 168        POWER_SUPPLY_ATTR(energy_now),
 169        POWER_SUPPLY_ATTR(energy_avg),
 170        POWER_SUPPLY_ATTR(capacity),
 171        POWER_SUPPLY_ATTR(capacity_alert_min),
 172        POWER_SUPPLY_ATTR(capacity_alert_max),
 173        POWER_SUPPLY_ATTR(capacity_level),
 174        POWER_SUPPLY_ATTR(temp),
 175        POWER_SUPPLY_ATTR(temp_alert_min),
 176        POWER_SUPPLY_ATTR(temp_alert_max),
 177        POWER_SUPPLY_ATTR(temp_ambient),
 178        POWER_SUPPLY_ATTR(temp_ambient_alert_min),
 179        POWER_SUPPLY_ATTR(temp_ambient_alert_max),
 180        POWER_SUPPLY_ATTR(time_to_empty_now),
 181        POWER_SUPPLY_ATTR(time_to_empty_avg),
 182        POWER_SUPPLY_ATTR(time_to_full_now),
 183        POWER_SUPPLY_ATTR(time_to_full_avg),
 184        POWER_SUPPLY_ATTR(type),
 185        POWER_SUPPLY_ATTR(scope),
 186        /* Properties of type `const char *' */
 187        POWER_SUPPLY_ATTR(model_name),
 188        POWER_SUPPLY_ATTR(manufacturer),
 189        POWER_SUPPLY_ATTR(serial_number),
 190};
 191
 192static struct attribute *
 193__power_supply_attrs[ARRAY_SIZE(power_supply_attrs) + 1];
 194
 195static umode_t power_supply_attr_is_visible(struct kobject *kobj,
 196                                           struct attribute *attr,
 197                                           int attrno)
 198{
 199        struct device *dev = container_of(kobj, struct device, kobj);
 200        struct power_supply *psy = dev_get_drvdata(dev);
 201        umode_t mode = S_IRUSR | S_IRGRP | S_IROTH;
 202        int i;
 203
 204        if (attrno == POWER_SUPPLY_PROP_TYPE)
 205                return mode;
 206
 207        for (i = 0; i < psy->num_properties; i++) {
 208                int property = psy->properties[i];
 209
 210                if (property == attrno) {
 211                        if (psy->property_is_writeable &&
 212                            psy->property_is_writeable(psy, property) > 0)
 213                                mode |= S_IWUSR;
 214
 215                        return mode;
 216                }
 217        }
 218
 219        return 0;
 220}
 221
 222static struct attribute_group power_supply_attr_group = {
 223        .attrs = __power_supply_attrs,
 224        .is_visible = power_supply_attr_is_visible,
 225};
 226
 227static const struct attribute_group *power_supply_attr_groups[] = {
 228        &power_supply_attr_group,
 229        NULL,
 230};
 231
 232void power_supply_init_attrs(struct device_type *dev_type)
 233{
 234        int i;
 235
 236        dev_type->groups = power_supply_attr_groups;
 237
 238        for (i = 0; i < ARRAY_SIZE(power_supply_attrs); i++)
 239                __power_supply_attrs[i] = &power_supply_attrs[i].attr;
 240}
 241
 242static char *kstruprdup(const char *str, gfp_t gfp)
 243{
 244        char *ret, *ustr;
 245
 246        ustr = ret = kmalloc(strlen(str) + 1, gfp);
 247
 248        if (!ret)
 249                return NULL;
 250
 251        while (*str)
 252                *ustr++ = toupper(*str++);
 253
 254        *ustr = 0;
 255
 256        return ret;
 257}
 258
 259int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
 260{
 261        struct power_supply *psy = dev_get_drvdata(dev);
 262        int ret = 0, j;
 263        char *prop_buf;
 264        char *attrname;
 265
 266        dev_dbg(dev, "uevent\n");
 267
 268        if (!psy || !psy->dev) {
 269                dev_dbg(dev, "No power supply yet\n");
 270                return ret;
 271        }
 272
 273        dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->name);
 274
 275        ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->name);
 276        if (ret)
 277                return ret;
 278
 279        prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
 280        if (!prop_buf)
 281                return -ENOMEM;
 282
 283        for (j = 0; j < psy->num_properties; j++) {
 284                struct device_attribute *attr;
 285                char *line;
 286
 287                attr = &power_supply_attrs[psy->properties[j]];
 288
 289                ret = power_supply_show_property(dev, attr, prop_buf);
 290                if (ret == -ENODEV || ret == -ENODATA) {
 291                        /* When a battery is absent, we expect -ENODEV. Don't abort;
 292                           send the uevent with at least the the PRESENT=0 property */
 293                        ret = 0;
 294                        continue;
 295                }
 296
 297                if (ret < 0)
 298                        goto out;
 299
 300                line = strchr(prop_buf, '\n');
 301                if (line)
 302                        *line = 0;
 303
 304                attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
 305                if (!attrname) {
 306                        ret = -ENOMEM;
 307                        goto out;
 308                }
 309
 310                dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
 311
 312                ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 313                kfree(attrname);
 314                if (ret)
 315                        goto out;
 316        }
 317
 318out:
 319        free_page((unsigned long)prop_buf);
 320
 321        return ret;
 322}
 323
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