/*
 *  Universal power supply monitor class
 *
 *  Copyright © 2007  Anton Vorontsov <cbou@mail.ru>
 *  Copyright © 2004  Szabolcs Gyurko
 *  Copyright © 2003  Ian Molton <spyro@f2s.com>
 *
 *  Modified: 2004, Oct     Szabolcs Gyurko
 *
 *  You may use this code as per GPL version 2
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/power_supply.h>
#include <linux/thermal.h>
#include "power_supply.h"

/* exported for the APM Power driver, APM emulation */
struct class *power_supply_class;
EXPORT_SYMBOL_GPL(power_supply_class);

static struct device_type power_supply_dev_type;

static bool __power_supply_is_supplied_by(struct power_supply *supplier,
                                         struct power_supply *supply)
{
        int i;

        if (!supply->supplied_from && !supplier->supplied_to)
                return false;

        /* Support both supplied_to and supplied_from modes */
        if (supply->supplied_from) {
                if (!supplier->name)
                        return false;
                for (i = 0; i < supply->num_supplies; i++)
                        if (!strcmp(supplier->name, supply->supplied_from[i]))
                                return true;
        } else {
                if (!supply->name)
                        return false;
                for (i = 0; i < supplier->num_supplicants; i++)
                        if (!strcmp(supplier->supplied_to[i], supply->name))
                                return true;
        }

        return false;
}

static int __power_supply_changed_work(struct device *dev, void *data)
{
        struct power_supply *psy = (struct power_supply *)data;
        struct power_supply *pst = dev_get_drvdata(dev);

        if (__power_supply_is_supplied_by(psy, pst)) {
                if (pst->external_power_changed)
                        pst->external_power_changed(pst);
        }

        return 0;
}

static void power_supply_changed_work(struct work_struct *work)
{
        struct power_supply *psy = container_of(work, struct power_supply,
                                                changed_work);

        dev_dbg(psy->dev, "%s\n", __func__);

        class_for_each_device(power_supply_class, NULL, psy,
                              __power_supply_changed_work);

        power_supply_update_leds(psy);

        kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
}

void power_supply_changed(struct power_supply *psy)
{
        dev_dbg(psy->dev, "%s\n", __func__);

        schedule_work(&psy->changed_work);
}
EXPORT_SYMBOL_GPL(power_supply_changed);

#ifdef CONFIG_OF
#include <linux/of.h>

static int __power_supply_populate_supplied_from(struct device *dev,
                                                 void *data)
{
        struct power_supply *psy = (struct power_supply *)data;
        struct power_supply *epsy = dev_get_drvdata(dev);
        struct device_node *np;
        int i = 0;

        do {
                np = of_parse_phandle(psy->of_node, "power-supplies", i++);
                if (!np)
                        continue;

                if (np == epsy->of_node) {
                        dev_info(psy->dev, "%s: Found supply : %s\n",
                                psy->name, epsy->name);
                        psy->supplied_from[i-1] = (char *)epsy->name;
                        psy->num_supplies++;
                        break;
                }
        } while (np);

        return 0;
}

static int power_supply_populate_supplied_from(struct power_supply *psy)
{
        int error;

        error = class_for_each_device(power_supply_class, NULL, psy,
                                      __power_supply_populate_supplied_from);

        dev_dbg(psy->dev, "%s %d\n", __func__, error);

        return error;
}

static int  __power_supply_find_supply_from_node(struct device *dev,
                                                 void *data)
{
        struct device_node *np = (struct device_node *)data;
        struct power_supply *epsy = dev_get_drvdata(dev);

        /* return error breaks out of class_for_each_device loop */
        if (epsy->of_node == np)
                return -EINVAL;

        return 0;
}

static int power_supply_find_supply_from_node(struct device_node *supply_node)
{
        int error;
        struct device *dev;
        struct class_dev_iter iter;

        /*
         * Use iterator to see if any other device is registered.
         * This is required since class_for_each_device returns 0
         * if there are no devices registered.
         */
        class_dev_iter_init(&iter, power_supply_class, NULL, NULL);
        dev = class_dev_iter_next(&iter);

        if (!dev)
                return -EPROBE_DEFER;

        /*
         * We have to treat the return value as inverted, because if
         * we return error on not found, then it won't continue looking.
         * So we trick it by returning error on success to stop looking
         * once the matching device is found.
         */
        error = class_for_each_device(power_supply_class, NULL, supply_node,
                                       __power_supply_find_supply_from_node);

        return error ? 0 : -EPROBE_DEFER;
}

static int power_supply_check_supplies(struct power_supply *psy)
{
        struct device_node *np;
        int cnt = 0;

        /* If there is already a list honor it */
        if (psy->supplied_from && psy->num_supplies > 0)
                return 0;

        /* No device node found, nothing to do */
        if (!psy->of_node)
                return 0;

        do {
                int ret;

                np = of_parse_phandle(psy->of_node, "power-supplies", cnt++);
                if (!np)
                        continue;

                ret = power_supply_find_supply_from_node(np);
                if (ret) {
                        dev_dbg(psy->dev, "Failed to find supply, defer!\n");
                        return -EPROBE_DEFER;
                }
        } while (np);

        /* All supplies found, allocate char ** array for filling */
        psy->supplied_from = devm_kzalloc(psy->dev, sizeof(psy->supplied_from),
                                          GFP_KERNEL);
        if (!psy->supplied_from) {
                dev_err(psy->dev, "Couldn't allocate memory for supply list\n");
                return -ENOMEM;
        }

        *psy->supplied_from = devm_kzalloc(psy->dev, sizeof(char *) * cnt,
                                           GFP_KERNEL);
        if (!*psy->supplied_from) {
                dev_err(psy->dev, "Couldn't allocate memory for supply list\n");
                return -ENOMEM;
        }

        return power_supply_populate_supplied_from(psy);
}
#else
static inline int power_supply_check_supplies(struct power_supply *psy)
{
        return 0;
}
#endif

static int __power_supply_am_i_supplied(struct device *dev, void *data)
{
        union power_supply_propval ret = {0,};
        struct power_supply *psy = (struct power_supply *)data;
        struct power_supply *epsy = dev_get_drvdata(dev);

        if (__power_supply_is_supplied_by(epsy, psy))
                if (!epsy->get_property(epsy, POWER_SUPPLY_PROP_ONLINE, &ret)) {
                        if (ret.intval)
                                return ret.intval;
                }

        return 0;
}

int power_supply_am_i_supplied(struct power_supply *psy)
{
        int error;

        error = class_for_each_device(power_supply_class, NULL, psy,
                                      __power_supply_am_i_supplied);

        dev_dbg(psy->dev, "%s %d\n", __func__, error);

        return error;
}
EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);

static int __power_supply_is_system_supplied(struct device *dev, void *data)
{
        union power_supply_propval ret = {0,};
        struct power_supply *psy = dev_get_drvdata(dev);
        unsigned int *count = data;

        (*count)++;
        if (psy->type != POWER_SUPPLY_TYPE_BATTERY) {
                if (psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret))
                        return 0;
                if (ret.intval)
                        return ret.intval;
        }
        return 0;
}

int power_supply_is_system_supplied(void)
{
        int error;
        unsigned int count = 0;

        error = class_for_each_device(power_supply_class, NULL, &count,
                                      __power_supply_is_system_supplied);

        /*
         * If no power class device was found at all, most probably we are
         * running on a desktop system, so assume we are on mains power.
         */
        if (count == 0)
                return 1;

        return error;
}
EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);

int power_supply_set_battery_charged(struct power_supply *psy)
{
        if (psy->type == POWER_SUPPLY_TYPE_BATTERY && psy->set_charged) {
                psy->set_charged(psy);
                return 0;
        }

        return -EINVAL;
}
EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);

static int power_supply_match_device_by_name(struct device *dev, const void *data)
{
        const char *name = data;
        struct power_supply *psy = dev_get_drvdata(dev);

        return strcmp(psy->name, name) == 0;
}

struct power_supply *power_supply_get_by_name(const char *name)
{
        struct device *dev = class_find_device(power_supply_class, NULL, name,
                                        power_supply_match_device_by_name);

        return dev ? dev_get_drvdata(dev) : NULL;
}
EXPORT_SYMBOL_GPL(power_supply_get_by_name);

int power_supply_powers(struct power_supply *psy, struct device *dev)
{
        return sysfs_create_link(&psy->dev->kobj, &dev->kobj, "powers");
}
EXPORT_SYMBOL_GPL(power_supply_powers);

static void power_supply_dev_release(struct device *dev)
{
        pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
        kfree(dev);
}

#ifdef CONFIG_THERMAL
static int power_supply_read_temp(struct thermal_zone_device *tzd,
                unsigned long *temp)
{
        struct power_supply *psy;
        union power_supply_propval val;
        int ret;

        WARN_ON(tzd == NULL);
        psy = tzd->devdata;
        ret = psy->get_property(psy, POWER_SUPPLY_PROP_TEMP, &val);

        /* Convert tenths of degree Celsius to milli degree Celsius. */
        if (!ret)
                *temp = val.intval * 100;

        return ret;
}

static struct thermal_zone_device_ops psy_tzd_ops = {
        .get_temp = power_supply_read_temp,
};

static int psy_register_thermal(struct power_supply *psy)
{
        int i;

        /* Register battery zone device psy reports temperature */
        for (i = 0; i < psy->num_properties; i++) {
                if (psy->properties[i] == POWER_SUPPLY_PROP_TEMP) {
                        psy->tzd = thermal_zone_device_register(psy->name, 0, 0,
                                        psy, &psy_tzd_ops, NULL, 0, 0);
                        if (IS_ERR(psy->tzd))
                                return PTR_ERR(psy->tzd);
                        break;
                }
        }
        return 0;
}

static void psy_unregister_thermal(struct power_supply *psy)
{
        if (IS_ERR_OR_NULL(psy->tzd))
                return;
        thermal_zone_device_unregister(psy->tzd);
}

/* thermal cooling device callbacks */
static int ps_get_max_charge_cntl_limit(struct thermal_cooling_device *tcd,
                                        unsigned long *state)
{
        struct power_supply *psy;
        union power_supply_propval val;
        int ret;

        psy = tcd->devdata;
        ret = psy->get_property(psy,
                POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX, &val);
        if (!ret)
                *state = val.intval;

        return ret;
}

static int ps_get_cur_chrage_cntl_limit(struct thermal_cooling_device *tcd,
                                        unsigned long *state)
{
        struct power_supply *psy;
        union power_supply_propval val;
        int ret;

        psy = tcd->devdata;
        ret = psy->get_property(psy,
                POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT, &val);
        if (!ret)
                *state = val.intval;

        return ret;
}

static int ps_set_cur_charge_cntl_limit(struct thermal_cooling_device *tcd,
                                        unsigned long state)
{
        struct power_supply *psy;
        union power_supply_propval val;
        int ret;

        psy = tcd->devdata;
        val.intval = state;
        ret = psy->set_property(psy,
                POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT, &val);

        return ret;
}

static struct thermal_cooling_device_ops psy_tcd_ops = {
        .get_max_state = ps_get_max_charge_cntl_limit,
        .get_cur_state = ps_get_cur_chrage_cntl_limit,
        .set_cur_state = ps_set_cur_charge_cntl_limit,
};

static int psy_register_cooler(struct power_supply *psy)
{
        int i;

        /* Register for cooling device if psy can control charging */
        for (i = 0; i < psy->num_properties; i++) {
                if (psy->properties[i] ==
                                POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT) {
                        psy->tcd = thermal_cooling_device_register(
                                                        (char *)psy->name,
                                                        psy, &psy_tcd_ops);
                        if (IS_ERR(psy->tcd))
                                return PTR_ERR(psy->tcd);
                        break;
                }
        }
        return 0;
}

static void psy_unregister_cooler(struct power_supply *psy)
{
        if (IS_ERR_OR_NULL(psy->tcd))
                return;
        thermal_cooling_device_unregister(psy->tcd);
}
#else
static int psy_register_thermal(struct power_supply *psy)
{
        return 0;
}

static void psy_unregister_thermal(struct power_supply *psy)
{
}

static int psy_register_cooler(struct power_supply *psy)
{
        return 0;
}

static void psy_unregister_cooler(struct power_supply *psy)
{
}
#endif

int power_supply_register(struct device *parent, struct power_supply *psy)
{
        struct device *dev;
        int rc;

        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
        if (!dev)
                return -ENOMEM;

        device_initialize(dev);

        dev->class = power_supply_class;
        dev->type = &power_supply_dev_type;
        dev->parent = parent;
        dev->release = power_supply_dev_release;
        dev_set_drvdata(dev, psy);
        psy->dev = dev;

        INIT_WORK(&psy->changed_work, power_supply_changed_work);

        rc = power_supply_check_supplies(psy);
        if (rc) {
                dev_info(dev, "Not all required supplies found, defer probe\n");
                goto check_supplies_failed;
        }

        rc = kobject_set_name(&dev->kobj, "%s", psy->name);
        if (rc)
                goto kobject_set_name_failed;

        rc = device_add(dev);
        if (rc)
                goto device_add_failed;

        rc = psy_register_thermal(psy);
        if (rc)
                goto register_thermal_failed;

        rc = psy_register_cooler(psy);
        if (rc)
                goto register_cooler_failed;

        rc = power_supply_create_triggers(psy);
        if (rc)
                goto create_triggers_failed;

        power_supply_changed(psy);

        goto success;

create_triggers_failed:
        psy_unregister_cooler(psy);
register_cooler_failed:
        psy_unregister_thermal(psy);
register_thermal_failed:
        device_del(dev);
kobject_set_name_failed:
device_add_failed:
check_supplies_failed:
        put_device(dev);
success:
        return rc;
}
EXPORT_SYMBOL_GPL(power_supply_register);

void power_supply_unregister(struct power_supply *psy)
{
        cancel_work_sync(&psy->changed_work);
        sysfs_remove_link(&psy->dev->kobj, "powers");
        power_supply_remove_triggers(psy);
        psy_unregister_cooler(psy);
        psy_unregister_thermal(psy);
        device_unregister(psy->dev);
}
EXPORT_SYMBOL_GPL(power_supply_unregister);

static int __init power_supply_class_init(void)
{
        power_supply_class = class_create(THIS_MODULE, "power_supply");

        if (IS_ERR(power_supply_class))
                return PTR_ERR(power_supply_class);

        power_supply_class->dev_uevent = power_supply_uevent;
        power_supply_init_attrs(&power_supply_dev_type);

        return 0;
}

static void __exit power_supply_class_exit(void)
{
        class_destroy(power_supply_class);
}

subsys_initcall(power_supply_class_init);
module_exit(power_supply_class_exit);

MODULE_DESCRIPTION("Universal power supply monitor class");
MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
              "Szabolcs Gyurko, "
              "Anton Vorontsov <cbou@mail.ru>");
MODULE_LICENSE("GPL");