root/drivers/power/supply/power_supply_sysfs.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Sysfs interface for the universal power supply monitor class
 *
 *  Copyright © 2007  David Woodhouse <dwmw2@infradead.org>
 *  Copyright © 2007  Anton Vorontsov <cbou@mail.ru>
 *  Copyright © 2004  Szabolcs Gyurko
 *  Copyright © 2003  Ian Molton <spyro@f2s.com>
 *
 *  Modified: 2004, Oct     Szabolcs Gyurko
 */

#include <linux/ctype.h>
#include <linux/device.h>
#include <linux/power_supply.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/string_helpers.h>

#include "power_supply.h"

#define MAX_PROP_NAME_LEN 30

struct power_supply_attr {
        const char *prop_name;
        char attr_name[MAX_PROP_NAME_LEN + 1];
        struct device_attribute dev_attr;
        const char * const *text_values;
        int text_values_len;
};

#define _POWER_SUPPLY_ATTR(_name, _text, _len)  \
[POWER_SUPPLY_PROP_ ## _name] =                 \
{                                               \
        .prop_name = #_name,                    \
        .attr_name = #_name,                    \
        .text_values = _text,                   \
        .text_values_len = _len,                \
}

#define POWER_SUPPLY_ATTR(_name) _POWER_SUPPLY_ATTR(_name, NULL, 0)
#define _POWER_SUPPLY_ENUM_ATTR(_name, _text)   \
        _POWER_SUPPLY_ATTR(_name, _text, ARRAY_SIZE(_text))
#define POWER_SUPPLY_ENUM_ATTR(_name)   \
        _POWER_SUPPLY_ENUM_ATTR(_name, POWER_SUPPLY_ ## _name ## _TEXT)

static const char * const POWER_SUPPLY_TYPE_TEXT[] = {
        [POWER_SUPPLY_TYPE_UNKNOWN]             = "Unknown",
        [POWER_SUPPLY_TYPE_BATTERY]             = "Battery",
        [POWER_SUPPLY_TYPE_UPS]                 = "UPS",
        [POWER_SUPPLY_TYPE_MAINS]               = "Mains",
        [POWER_SUPPLY_TYPE_USB]                 = "USB",
        [POWER_SUPPLY_TYPE_USB_DCP]             = "USB_DCP",
        [POWER_SUPPLY_TYPE_USB_CDP]             = "USB_CDP",
        [POWER_SUPPLY_TYPE_USB_ACA]             = "USB_ACA",
        [POWER_SUPPLY_TYPE_USB_TYPE_C]          = "USB_C",
        [POWER_SUPPLY_TYPE_USB_PD]              = "USB_PD",
        [POWER_SUPPLY_TYPE_USB_PD_DRP]          = "USB_PD_DRP",
        [POWER_SUPPLY_TYPE_APPLE_BRICK_ID]      = "BrickID",
        [POWER_SUPPLY_TYPE_WIRELESS]            = "Wireless",
};

static const char * const POWER_SUPPLY_USB_TYPE_TEXT[] = {
        [POWER_SUPPLY_USB_TYPE_UNKNOWN]         = "Unknown",
        [POWER_SUPPLY_USB_TYPE_SDP]             = "SDP",
        [POWER_SUPPLY_USB_TYPE_DCP]             = "DCP",
        [POWER_SUPPLY_USB_TYPE_CDP]             = "CDP",
        [POWER_SUPPLY_USB_TYPE_ACA]             = "ACA",
        [POWER_SUPPLY_USB_TYPE_C]               = "C",
        [POWER_SUPPLY_USB_TYPE_PD]              = "PD",
        [POWER_SUPPLY_USB_TYPE_PD_DRP]          = "PD_DRP",
        [POWER_SUPPLY_USB_TYPE_PD_PPS]          = "PD_PPS",
        [POWER_SUPPLY_USB_TYPE_APPLE_BRICK_ID]  = "BrickID",
};

static const char * const POWER_SUPPLY_STATUS_TEXT[] = {
        [POWER_SUPPLY_STATUS_UNKNOWN]           = "Unknown",
        [POWER_SUPPLY_STATUS_CHARGING]          = "Charging",
        [POWER_SUPPLY_STATUS_DISCHARGING]       = "Discharging",
        [POWER_SUPPLY_STATUS_NOT_CHARGING]      = "Not charging",
        [POWER_SUPPLY_STATUS_FULL]              = "Full",
};

static const char * const POWER_SUPPLY_CHARGE_TYPE_TEXT[] = {
        [POWER_SUPPLY_CHARGE_TYPE_UNKNOWN]      = "Unknown",
        [POWER_SUPPLY_CHARGE_TYPE_NONE]         = "N/A",
        [POWER_SUPPLY_CHARGE_TYPE_TRICKLE]      = "Trickle",
        [POWER_SUPPLY_CHARGE_TYPE_FAST]         = "Fast",
        [POWER_SUPPLY_CHARGE_TYPE_STANDARD]     = "Standard",
        [POWER_SUPPLY_CHARGE_TYPE_ADAPTIVE]     = "Adaptive",
        [POWER_SUPPLY_CHARGE_TYPE_CUSTOM]       = "Custom",
        [POWER_SUPPLY_CHARGE_TYPE_LONGLIFE]     = "Long Life",
        [POWER_SUPPLY_CHARGE_TYPE_BYPASS]       = "Bypass",
};

static const char * const POWER_SUPPLY_HEALTH_TEXT[] = {
        [POWER_SUPPLY_HEALTH_UNKNOWN]               = "Unknown",
        [POWER_SUPPLY_HEALTH_GOOD]                  = "Good",
        [POWER_SUPPLY_HEALTH_OVERHEAT]              = "Overheat",
        [POWER_SUPPLY_HEALTH_DEAD]                  = "Dead",
        [POWER_SUPPLY_HEALTH_OVERVOLTAGE]           = "Over voltage",
        [POWER_SUPPLY_HEALTH_UNDERVOLTAGE]          = "Under voltage",
        [POWER_SUPPLY_HEALTH_UNSPEC_FAILURE]        = "Unspecified failure",
        [POWER_SUPPLY_HEALTH_COLD]                  = "Cold",
        [POWER_SUPPLY_HEALTH_WATCHDOG_TIMER_EXPIRE] = "Watchdog timer expire",
        [POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE]   = "Safety timer expire",
        [POWER_SUPPLY_HEALTH_OVERCURRENT]           = "Over current",
        [POWER_SUPPLY_HEALTH_CALIBRATION_REQUIRED]  = "Calibration required",
        [POWER_SUPPLY_HEALTH_WARM]                  = "Warm",
        [POWER_SUPPLY_HEALTH_COOL]                  = "Cool",
        [POWER_SUPPLY_HEALTH_HOT]                   = "Hot",
        [POWER_SUPPLY_HEALTH_NO_BATTERY]            = "No battery",
        [POWER_SUPPLY_HEALTH_BLOWN_FUSE]            = "Blown fuse",
        [POWER_SUPPLY_HEALTH_CELL_IMBALANCE]        = "Cell imbalance",
};

static const char * const POWER_SUPPLY_TECHNOLOGY_TEXT[] = {
        [POWER_SUPPLY_TECHNOLOGY_UNKNOWN]       = "Unknown",
        [POWER_SUPPLY_TECHNOLOGY_NiMH]          = "NiMH",
        [POWER_SUPPLY_TECHNOLOGY_LION]          = "Li-ion",
        [POWER_SUPPLY_TECHNOLOGY_LIPO]          = "Li-poly",
        [POWER_SUPPLY_TECHNOLOGY_LiFe]          = "LiFe",
        [POWER_SUPPLY_TECHNOLOGY_NiCd]          = "NiCd",
        [POWER_SUPPLY_TECHNOLOGY_LiMn]          = "LiMn",
};

static const char * const POWER_SUPPLY_CAPACITY_LEVEL_TEXT[] = {
        [POWER_SUPPLY_CAPACITY_LEVEL_UNKNOWN]   = "Unknown",
        [POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL]  = "Critical",
        [POWER_SUPPLY_CAPACITY_LEVEL_LOW]       = "Low",
        [POWER_SUPPLY_CAPACITY_LEVEL_NORMAL]    = "Normal",
        [POWER_SUPPLY_CAPACITY_LEVEL_HIGH]      = "High",
        [POWER_SUPPLY_CAPACITY_LEVEL_FULL]      = "Full",
};

static const char * const POWER_SUPPLY_SCOPE_TEXT[] = {
        [POWER_SUPPLY_SCOPE_UNKNOWN]    = "Unknown",
        [POWER_SUPPLY_SCOPE_SYSTEM]     = "System",
        [POWER_SUPPLY_SCOPE_DEVICE]     = "Device",
};

static const char * const POWER_SUPPLY_CHARGE_BEHAVIOUR_TEXT[] = {
        [POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO]                    = "auto",
        [POWER_SUPPLY_CHARGE_BEHAVIOUR_INHIBIT_CHARGE]          = "inhibit-charge",
        [POWER_SUPPLY_CHARGE_BEHAVIOUR_INHIBIT_CHARGE_AWAKE]    = "inhibit-charge-awake",
        [POWER_SUPPLY_CHARGE_BEHAVIOUR_FORCE_DISCHARGE]         = "force-discharge",
};

static struct power_supply_attr power_supply_attrs[] __ro_after_init = {
        /* Properties of type `int' */
        POWER_SUPPLY_ENUM_ATTR(STATUS),
        POWER_SUPPLY_ENUM_ATTR(CHARGE_TYPE),
        POWER_SUPPLY_ENUM_ATTR(HEALTH),
        POWER_SUPPLY_ATTR(PRESENT),
        POWER_SUPPLY_ATTR(ONLINE),
        POWER_SUPPLY_ATTR(AUTHENTIC),
        POWER_SUPPLY_ENUM_ATTR(TECHNOLOGY),
        POWER_SUPPLY_ATTR(CYCLE_COUNT),
        POWER_SUPPLY_ATTR(VOLTAGE_MAX),
        POWER_SUPPLY_ATTR(VOLTAGE_MIN),
        POWER_SUPPLY_ATTR(VOLTAGE_MAX_DESIGN),
        POWER_SUPPLY_ATTR(VOLTAGE_MIN_DESIGN),
        POWER_SUPPLY_ATTR(VOLTAGE_NOW),
        POWER_SUPPLY_ATTR(VOLTAGE_AVG),
        POWER_SUPPLY_ATTR(VOLTAGE_OCV),
        POWER_SUPPLY_ATTR(VOLTAGE_BOOT),
        POWER_SUPPLY_ATTR(CURRENT_MAX),
        POWER_SUPPLY_ATTR(CURRENT_NOW),
        POWER_SUPPLY_ATTR(CURRENT_AVG),
        POWER_SUPPLY_ATTR(CURRENT_BOOT),
        POWER_SUPPLY_ATTR(POWER_NOW),
        POWER_SUPPLY_ATTR(POWER_AVG),
        POWER_SUPPLY_ATTR(CHARGE_FULL_DESIGN),
        POWER_SUPPLY_ATTR(CHARGE_EMPTY_DESIGN),
        POWER_SUPPLY_ATTR(CHARGE_FULL),
        POWER_SUPPLY_ATTR(CHARGE_EMPTY),
        POWER_SUPPLY_ATTR(CHARGE_NOW),
        POWER_SUPPLY_ATTR(CHARGE_AVG),
        POWER_SUPPLY_ATTR(CHARGE_COUNTER),
        POWER_SUPPLY_ATTR(CONSTANT_CHARGE_CURRENT),
        POWER_SUPPLY_ATTR(CONSTANT_CHARGE_CURRENT_MAX),
        POWER_SUPPLY_ATTR(CONSTANT_CHARGE_VOLTAGE),
        POWER_SUPPLY_ATTR(CONSTANT_CHARGE_VOLTAGE_MAX),
        POWER_SUPPLY_ATTR(CHARGE_CONTROL_LIMIT),
        POWER_SUPPLY_ATTR(CHARGE_CONTROL_LIMIT_MAX),
        POWER_SUPPLY_ATTR(CHARGE_CONTROL_START_THRESHOLD),
        POWER_SUPPLY_ATTR(CHARGE_CONTROL_END_THRESHOLD),
        POWER_SUPPLY_ENUM_ATTR(CHARGE_BEHAVIOUR),
        /* Same enum value texts as "charge_type" without the 's' at the end */
        _POWER_SUPPLY_ENUM_ATTR(CHARGE_TYPES, POWER_SUPPLY_CHARGE_TYPE_TEXT),
        POWER_SUPPLY_ATTR(INPUT_CURRENT_LIMIT),
        POWER_SUPPLY_ATTR(INPUT_VOLTAGE_LIMIT),
        POWER_SUPPLY_ATTR(INPUT_POWER_LIMIT),
        POWER_SUPPLY_ATTR(ENERGY_FULL_DESIGN),
        POWER_SUPPLY_ATTR(ENERGY_EMPTY_DESIGN),
        POWER_SUPPLY_ATTR(ENERGY_FULL),
        POWER_SUPPLY_ATTR(ENERGY_EMPTY),
        POWER_SUPPLY_ATTR(ENERGY_NOW),
        POWER_SUPPLY_ATTR(ENERGY_AVG),
        POWER_SUPPLY_ATTR(CAPACITY),
        POWER_SUPPLY_ATTR(CAPACITY_ALERT_MIN),
        POWER_SUPPLY_ATTR(CAPACITY_ALERT_MAX),
        POWER_SUPPLY_ATTR(CAPACITY_ERROR_MARGIN),
        POWER_SUPPLY_ENUM_ATTR(CAPACITY_LEVEL),
        POWER_SUPPLY_ATTR(TEMP),
        POWER_SUPPLY_ATTR(TEMP_MAX),
        POWER_SUPPLY_ATTR(TEMP_MIN),
        POWER_SUPPLY_ATTR(TEMP_ALERT_MIN),
        POWER_SUPPLY_ATTR(TEMP_ALERT_MAX),
        POWER_SUPPLY_ATTR(TEMP_AMBIENT),
        POWER_SUPPLY_ATTR(TEMP_AMBIENT_ALERT_MIN),
        POWER_SUPPLY_ATTR(TEMP_AMBIENT_ALERT_MAX),
        POWER_SUPPLY_ATTR(TIME_TO_EMPTY_NOW),
        POWER_SUPPLY_ATTR(TIME_TO_EMPTY_AVG),
        POWER_SUPPLY_ATTR(TIME_TO_FULL_NOW),
        POWER_SUPPLY_ATTR(TIME_TO_FULL_AVG),
        POWER_SUPPLY_ENUM_ATTR(TYPE),
        POWER_SUPPLY_ENUM_ATTR(USB_TYPE),
        POWER_SUPPLY_ENUM_ATTR(SCOPE),
        POWER_SUPPLY_ATTR(PRECHARGE_CURRENT),
        POWER_SUPPLY_ATTR(CHARGE_TERM_CURRENT),
        POWER_SUPPLY_ATTR(CALIBRATE),
        POWER_SUPPLY_ATTR(MANUFACTURE_YEAR),
        POWER_SUPPLY_ATTR(MANUFACTURE_MONTH),
        POWER_SUPPLY_ATTR(MANUFACTURE_DAY),
        POWER_SUPPLY_ATTR(INTERNAL_RESISTANCE),
        POWER_SUPPLY_ATTR(STATE_OF_HEALTH),
        /* Properties of type `const char *' */
        POWER_SUPPLY_ATTR(MODEL_NAME),
        POWER_SUPPLY_ATTR(MANUFACTURER),
        POWER_SUPPLY_ATTR(SERIAL_NUMBER),
};
#define POWER_SUPPLY_ATTR_CNT ARRAY_SIZE(power_supply_attrs)

static struct attribute *
__power_supply_attrs[POWER_SUPPLY_ATTR_CNT + 1] __ro_after_init;

static const struct power_supply_attr *to_ps_attr(const struct device_attribute *attr)
{
        return container_of_const(attr, struct power_supply_attr, dev_attr);
}

static enum power_supply_property dev_attr_psp(const struct device_attribute *attr)
{
        return  to_ps_attr(attr) - power_supply_attrs;
}

static void power_supply_escape_spaces(const char *str, char *buf, size_t bufsize)
{
        strscpy(buf, str, bufsize);
        strreplace(buf, ' ', '_');
}

static int power_supply_match_string(const char * const *array, size_t n, const char *s)
{
        int ret;

        /* First try an exact match */
        ret = __sysfs_match_string(array, n, s);
        if (ret >= 0)
                return ret;

        /* Second round, try matching with spaces replaced by '_' */
        for (size_t i = 0; i < n; i++) {
                char buf[32];

                power_supply_escape_spaces(array[i], buf, sizeof(buf));
                if (sysfs_streq(buf, s))
                        return i;
        }

        return -EINVAL;
}

static ssize_t power_supply_show_enum_with_available(
                        struct device *dev, const char * const labels[], int label_count,
                        unsigned int available_values, int value, char *buf)
{
        bool match = false, available, active;
        char escaped_label[32];
        ssize_t count = 0;
        int i;

        for (i = 0; i < label_count; i++) {
                available = available_values & BIT(i);
                active = i == value;
                power_supply_escape_spaces(labels[i], escaped_label, sizeof(escaped_label));

                if (available && active) {
                        count += sysfs_emit_at(buf, count, "[%s] ", escaped_label);
                        match = true;
                } else if (available) {
                        count += sysfs_emit_at(buf, count, "%s ", escaped_label);
                }
        }

        if (!match) {
                dev_warn(dev, "driver reporting unavailable enum value %d\n", value);
                return -EINVAL;
        }

        if (count)
                buf[count - 1] = '\n';

        return count;
}

static ssize_t power_supply_show_charge_behaviour(struct device *dev,
                                                  struct power_supply *psy,
                                                  union power_supply_propval *value,
                                                  char *buf)
{
        struct power_supply_ext_registration *reg;

        scoped_guard(rwsem_read, &psy->extensions_sem) {
                power_supply_for_each_extension(reg, psy) {
                        if (power_supply_ext_has_property(reg->ext,
                                                          POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR))
                                return power_supply_charge_behaviour_show(dev,
                                                reg->ext->charge_behaviours,
                                                value->intval, buf);
                }
        }

        return power_supply_charge_behaviour_show(dev, psy->desc->charge_behaviours,
                                                  value->intval, buf);
}

static ssize_t power_supply_show_charge_types(struct device *dev,
                                              struct power_supply *psy,
                                              enum power_supply_charge_type current_type,
                                              char *buf)
{
        struct power_supply_ext_registration *reg;

        scoped_guard(rwsem_read, &psy->extensions_sem) {
                power_supply_for_each_extension(reg, psy) {
                        if (power_supply_ext_has_property(reg->ext,
                                                          POWER_SUPPLY_PROP_CHARGE_TYPES))
                                return power_supply_charge_types_show(dev,
                                                reg->ext->charge_types,
                                                current_type, buf);
                }
        }

        return power_supply_charge_types_show(dev, psy->desc->charge_types,
                                                  current_type, buf);
}

static ssize_t power_supply_format_property(struct device *dev,
                                            bool uevent,
                                            struct device_attribute *attr,
                                            char *buf)
{
        ssize_t ret;
        struct power_supply *psy = dev_to_psy(dev);
        const struct power_supply_attr *ps_attr = to_ps_attr(attr);
        enum power_supply_property psp = dev_attr_psp(attr);
        union power_supply_propval value;

        if (psp == POWER_SUPPLY_PROP_TYPE) {
                value.intval = psy->desc->type;
        } else {
                ret = power_supply_get_property(psy, psp, &value);

                if (ret < 0) {
                        if (ret == -ENODATA)
                                dev_dbg_ratelimited(dev,
                                        "driver has no data for `%s' property\n",
                                        attr->attr.name);
                        else if (ret != -ENODEV && ret != -EAGAIN && ret != -EINVAL)
                                dev_err_ratelimited(dev,
                                        "driver failed to report `%s' property: %zd\n",
                                        attr->attr.name, ret);
                        return ret;
                }
        }

        switch (psp) {
        case POWER_SUPPLY_PROP_USB_TYPE:
                ret = power_supply_show_enum_with_available(
                                dev, POWER_SUPPLY_USB_TYPE_TEXT,
                                ARRAY_SIZE(POWER_SUPPLY_USB_TYPE_TEXT),
                                psy->desc->usb_types, value.intval, buf);
                break;
        case POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR:
                if (uevent) /* no possible values in uevents */
                        goto default_format;
                ret = power_supply_show_charge_behaviour(dev, psy, &value, buf);
                break;
        case POWER_SUPPLY_PROP_CHARGE_TYPES:
                if (uevent) /* no possible values in uevents */
                        goto default_format;
                ret = power_supply_show_charge_types(dev, psy,
                                                     value.intval, buf);
                break;
        case POWER_SUPPLY_PROP_MODEL_NAME ... POWER_SUPPLY_PROP_SERIAL_NUMBER:
                ret = sysfs_emit(buf, "%s\n", value.strval);
                break;
        default:
default_format:
                if (ps_attr->text_values_len > 0 &&
                                value.intval < ps_attr->text_values_len && value.intval >= 0) {
                        ret = sysfs_emit(buf, "%s\n", ps_attr->text_values[value.intval]);
                } else {
                        ret = sysfs_emit(buf, "%d\n", value.intval);
                }
        }

        return ret;
}

static ssize_t power_supply_show_property(struct device *dev,
                                          struct device_attribute *attr,
                                          char *buf)
{
        return power_supply_format_property(dev, false, attr, buf);
}

static ssize_t power_supply_store_property(struct device *dev,
                                           struct device_attribute *attr,
                                           const char *buf, size_t count) {
        ssize_t ret;
        struct power_supply *psy = dev_to_psy(dev);
        const struct power_supply_attr *ps_attr = to_ps_attr(attr);
        enum power_supply_property psp = dev_attr_psp(attr);
        union power_supply_propval value;

        ret = -EINVAL;
        if (ps_attr->text_values_len > 0) {
                ret = power_supply_match_string(ps_attr->text_values,
                                                ps_attr->text_values_len, buf);
        }

        /*
         * If no match was found, then check to see if it is an integer.
         * Integer values are valid for enums in addition to the text value.
         */
        if (ret < 0) {
                long long_val;

                ret = kstrtol(buf, 10, &long_val);
                if (ret < 0)
                        return ret;

                ret = long_val;
        }

        value.intval = ret;

        ret = power_supply_set_property(psy, psp, &value);
        if (ret < 0)
                return ret;

        return count;
}

static umode_t power_supply_attr_is_visible(struct kobject *kobj,
                                           struct attribute *attr,
                                           int attrno)
{
        struct device *dev = kobj_to_dev(kobj);
        struct power_supply *psy = dev_to_psy(dev);
        umode_t mode = S_IRUSR | S_IRGRP | S_IROTH;

        if (!power_supply_attrs[attrno].prop_name)
                return 0;

        if (attrno == POWER_SUPPLY_PROP_TYPE)
                return mode;

        guard(rwsem_read)(&psy->extensions_sem);

        if (power_supply_has_property(psy, attrno)) {
                if (power_supply_property_is_writeable(psy, attrno) > 0)
                        mode |= S_IWUSR;
                return mode;
        }

        return 0;
}

static const struct attribute_group power_supply_attr_group = {
        .attrs = __power_supply_attrs,
        .is_visible = power_supply_attr_is_visible,
};

static struct attribute *power_supply_extension_attrs[] = {
        NULL
};

static const struct attribute_group power_supply_extension_group = {
        .name = "extensions",
        .attrs = power_supply_extension_attrs,
};

const struct attribute_group *power_supply_attr_groups[] = {
        &power_supply_attr_group,
        &power_supply_extension_group,
        NULL
};

void __init power_supply_init_attrs(void)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(power_supply_attrs); i++) {
                struct device_attribute *attr;

                if (!power_supply_attrs[i].prop_name) {
                        pr_warn("%s: Property %d skipped because it is missing from power_supply_attrs\n",
                                __func__, i);
                        sprintf(power_supply_attrs[i].attr_name, "_err_%d", i);
                } else {
                        string_lower(power_supply_attrs[i].attr_name,
                                     power_supply_attrs[i].attr_name);
                }

                attr = &power_supply_attrs[i].dev_attr;

                attr->attr.name = power_supply_attrs[i].attr_name;
                attr->show = power_supply_show_property;
                attr->store = power_supply_store_property;
                __power_supply_attrs[i] = &attr->attr;
        }
}

static int add_prop_uevent(const struct device *dev, struct kobj_uevent_env *env,
                           enum power_supply_property prop, char *prop_buf)
{
        int ret = 0;
        struct power_supply_attr *pwr_attr;
        struct device_attribute *dev_attr;
        char *line;

        pwr_attr = &power_supply_attrs[prop];
        dev_attr = &pwr_attr->dev_attr;

        ret = power_supply_format_property((struct device *)dev, true, dev_attr, prop_buf);
        if (ret == -ENODEV || ret == -ENODATA || ret == -EINVAL) {
                /*
                 * When a battery is absent, we expect -ENODEV. Don't abort;
                 * send the uevent with at least the PRESENT=0 property
                 */
                return 0;
        }

        if (ret < 0)
                return ret;

        line = strchr(prop_buf, '\n');
        if (line)
                *line = 0;

        return add_uevent_var(env, "POWER_SUPPLY_%s=%s",
                              pwr_attr->prop_name, prop_buf);
}

int power_supply_uevent(const struct device *dev, struct kobj_uevent_env *env)
{
        const struct power_supply *psy = dev_to_psy(dev);
        int ret = 0, j;
        char *prop_buf;

        if (!psy || !psy->desc) {
                dev_dbg(dev, "No power supply yet\n");
                return ret;
        }

        ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->desc->name);
        if (ret)
                return ret;

        /*
         * Kernel generates KOBJ_REMOVE uevent in device removal path, after
         * resources have been freed. Exit early to avoid use-after-free.
         */
        if (psy->removing)
                return 0;

        prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
        if (!prop_buf)
                return -ENOMEM;

        ret = add_prop_uevent(dev, env, POWER_SUPPLY_PROP_TYPE, prop_buf);
        if (ret)
                goto out;

        for (j = 0; j < POWER_SUPPLY_ATTR_CNT; j++) {
                ret = add_prop_uevent(dev, env, j, prop_buf);
                if (ret)
                        goto out;
        }

out:
        free_page((unsigned long)prop_buf);

        return ret;
}

ssize_t power_supply_charge_behaviour_show(struct device *dev,
                                           unsigned int available_behaviours,
                                           enum power_supply_charge_behaviour current_behaviour,
                                           char *buf)
{
        return power_supply_show_enum_with_available(
                                dev, POWER_SUPPLY_CHARGE_BEHAVIOUR_TEXT,
                                ARRAY_SIZE(POWER_SUPPLY_CHARGE_BEHAVIOUR_TEXT),
                                available_behaviours, current_behaviour, buf);
}
EXPORT_SYMBOL_GPL(power_supply_charge_behaviour_show);

int power_supply_charge_behaviour_parse(unsigned int available_behaviours, const char *buf)
{
        int i = sysfs_match_string(POWER_SUPPLY_CHARGE_BEHAVIOUR_TEXT, buf);

        if (i < 0)
                return i;

        if (available_behaviours & BIT(i))
                return i;

        return -EINVAL;
}
EXPORT_SYMBOL_GPL(power_supply_charge_behaviour_parse);

ssize_t power_supply_charge_types_show(struct device *dev,
                                       unsigned int available_types,
                                       enum power_supply_charge_type current_type,
                                       char *buf)
{
        return power_supply_show_enum_with_available(
                                dev, POWER_SUPPLY_CHARGE_TYPE_TEXT,
                                ARRAY_SIZE(POWER_SUPPLY_CHARGE_TYPE_TEXT),
                                available_types, current_type, buf);
}
EXPORT_SYMBOL_GPL(power_supply_charge_types_show);

int power_supply_charge_types_parse(unsigned int available_types, const char *buf)
{
        int i = power_supply_match_string(POWER_SUPPLY_CHARGE_TYPE_TEXT,
                                          ARRAY_SIZE(POWER_SUPPLY_CHARGE_TYPE_TEXT),
                                          buf);

        if (i < 0)
                return i;

        if (available_types & BIT(i))
                return i;

        return -EINVAL;
}
EXPORT_SYMBOL_GPL(power_supply_charge_types_parse);

int power_supply_sysfs_add_extension(struct power_supply *psy, const struct power_supply_ext *ext,
                                     struct device *dev)
{
        return sysfs_add_link_to_group(&psy->dev.kobj, power_supply_extension_group.name,
                                       &dev->kobj, ext->name);
}

void power_supply_sysfs_remove_extension(struct power_supply *psy,
                                         const struct power_supply_ext *ext)
{
        sysfs_remove_link_from_group(&psy->dev.kobj, power_supply_extension_group.name, ext->name);
}