root/drivers/power/supply/lenovo_yoga_c630_battery.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2022-2024, Linaro Ltd
 * Authors:
 *    Bjorn Andersson
 *    Dmitry Baryshkov
 */
#include <linux/auxiliary_bus.h>
#include <linux/bits.h>
#include <linux/cleanup.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/power_supply.h>
#include <linux/platform_data/lenovo-yoga-c630.h>

struct yoga_c630_psy {
        struct yoga_c630_ec *ec;
        struct device *dev;
        struct fwnode_handle *fwnode;
        struct notifier_block nb;

        /* guards all battery properties and registration of power supplies */
        struct mutex lock;

        struct power_supply *adp_psy;
        struct power_supply *bat_psy;

        unsigned long last_status_update;

        bool adapter_online;

        bool unit_mA;

        bool bat_present;
        unsigned int bat_status;
        unsigned int design_capacity;
        unsigned int design_voltage;
        unsigned int full_charge_capacity;

        unsigned int capacity_now;
        unsigned int voltage_now;

        int current_now;
        int rate_now;
};

#define LENOVO_EC_CACHE_TIME            (10 * HZ)

#define LENOVO_EC_ADPT_STATUS           0xa3
#define LENOVO_EC_ADPT_STATUS_PRESENT           BIT(7)
#define LENOVO_EC_BAT_ATTRIBUTES        0xc0
#define LENOVO_EC_BAT_ATTRIBUTES_UNIT_IS_MA     BIT(1)
#define LENOVO_EC_BAT_STATUS            0xc1
#define LENOVO_EC_BAT_STATUS_DISCHARGING        BIT(0)
#define LENOVO_EC_BAT_STATUS_CHARGING           BIT(1)
#define LENOVO_EC_BAT_REMAIN_CAPACITY   0xc2
#define LENOVO_EC_BAT_VOLTAGE           0xc6
#define LENOVO_EC_BAT_DESIGN_VOLTAGE    0xc8
#define LENOVO_EC_BAT_DESIGN_CAPACITY   0xca
#define LENOVO_EC_BAT_FULL_CAPACITY     0xcc
#define LENOVO_EC_BAT_CURRENT           0xd2
#define LENOVO_EC_BAT_FULL_FACTORY      0xd6
#define LENOVO_EC_BAT_PRESENT           0xda
#define LENOVO_EC_BAT_PRESENT_IS_PRESENT        BIT(0)
#define LENOVO_EC_BAT_FULL_REGISTER     0xdb
#define LENOVO_EC_BAT_FULL_REGISTER_IS_FACTORY  BIT(0)

static int yoga_c630_psy_update_bat_info(struct yoga_c630_psy *ecbat)
{
        struct yoga_c630_ec *ec = ecbat->ec;
        int val;

        lockdep_assert_held(&ecbat->lock);

        val = yoga_c630_ec_read8(ec, LENOVO_EC_BAT_PRESENT);
        if (val < 0)
                return val;
        ecbat->bat_present = !!(val & LENOVO_EC_BAT_PRESENT_IS_PRESENT);
        if (!ecbat->bat_present)
                return val;

        val = yoga_c630_ec_read8(ec, LENOVO_EC_BAT_ATTRIBUTES);
        if (val < 0)
                return val;
        ecbat->unit_mA = val & LENOVO_EC_BAT_ATTRIBUTES_UNIT_IS_MA;

        val = yoga_c630_ec_read16(ec, LENOVO_EC_BAT_DESIGN_CAPACITY);
        if (val < 0)
                return val;
        ecbat->design_capacity = val * 1000;

        /*
         * DSDT has delays after most of EC reads in these methods.
         * Having no documentation for the EC we have to follow and sleep here.
         */
        msleep(50);

        val = yoga_c630_ec_read16(ec, LENOVO_EC_BAT_DESIGN_VOLTAGE);
        if (val < 0)
                return val;
        ecbat->design_voltage = val;

        msleep(50);

        val = yoga_c630_ec_read8(ec, LENOVO_EC_BAT_FULL_REGISTER);
        if (val < 0)
                return val;
        val = yoga_c630_ec_read16(ec,
                                  val & LENOVO_EC_BAT_FULL_REGISTER_IS_FACTORY ?
                                  LENOVO_EC_BAT_FULL_FACTORY :
                                  LENOVO_EC_BAT_FULL_CAPACITY);
        if (val < 0)
                return val;

        ecbat->full_charge_capacity = val * 1000;

        if (!ecbat->unit_mA) {
                ecbat->design_capacity *= 10;
                ecbat->full_charge_capacity *= 10;
        }

        return 0;
}

static int yoga_c630_psy_maybe_update_bat_status(struct yoga_c630_psy *ecbat)
{
        struct yoga_c630_ec *ec = ecbat->ec;
        int current_mA;
        int val;

        guard(mutex)(&ecbat->lock);
        if (time_before(jiffies, ecbat->last_status_update + LENOVO_EC_CACHE_TIME))
                return 0;

        val = yoga_c630_ec_read8(ec, LENOVO_EC_BAT_STATUS);
        if (val < 0)
                return val;
        ecbat->bat_status = val;

        msleep(50);

        val = yoga_c630_ec_read16(ec, LENOVO_EC_BAT_REMAIN_CAPACITY);
        if (val < 0)
                return val;
        ecbat->capacity_now = val * 1000;

        msleep(50);

        val = yoga_c630_ec_read16(ec, LENOVO_EC_BAT_VOLTAGE);
        if (val < 0)
                return val;
        ecbat->voltage_now = val * 1000;

        msleep(50);

        val = yoga_c630_ec_read16(ec, LENOVO_EC_BAT_CURRENT);
        if (val < 0)
                return val;
        current_mA = sign_extend32(val, 15);
        ecbat->current_now = current_mA * 1000;
        ecbat->rate_now = current_mA * (ecbat->voltage_now / 1000);

        msleep(50);

        if (!ecbat->unit_mA)
                ecbat->capacity_now *= 10;

        ecbat->last_status_update = jiffies;

        return 0;
}

static int yoga_c630_psy_update_adapter_status(struct yoga_c630_psy *ecbat)
{
        struct yoga_c630_ec *ec = ecbat->ec;
        int val;

        guard(mutex)(&ecbat->lock);

        val = yoga_c630_ec_read8(ec, LENOVO_EC_ADPT_STATUS);
        if (val < 0)
                return val;

        ecbat->adapter_online = !!(val & LENOVO_EC_ADPT_STATUS_PRESENT);

        return 0;
}

static bool yoga_c630_psy_is_charged(struct yoga_c630_psy *ecbat)
{
        if (ecbat->bat_status != 0)
                return false;

        if (ecbat->full_charge_capacity <= ecbat->capacity_now)
                return true;

        if (ecbat->design_capacity <= ecbat->capacity_now)
                return true;

        return false;
}

static int yoga_c630_psy_bat_get_property(struct power_supply *psy,
                                         enum power_supply_property psp,
                                         union power_supply_propval *val)
{
        struct yoga_c630_psy *ecbat = power_supply_get_drvdata(psy);
        int rc = 0;

        if (!ecbat->bat_present && psp != POWER_SUPPLY_PROP_PRESENT)
                return -ENODEV;

        rc = yoga_c630_psy_maybe_update_bat_status(ecbat);
        if (rc)
                return rc;

        switch (psp) {
        case POWER_SUPPLY_PROP_STATUS:
                if (ecbat->bat_status & LENOVO_EC_BAT_STATUS_DISCHARGING)
                        val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
                else if (ecbat->bat_status & LENOVO_EC_BAT_STATUS_CHARGING)
                        val->intval = POWER_SUPPLY_STATUS_CHARGING;
                else if (yoga_c630_psy_is_charged(ecbat))
                        val->intval = POWER_SUPPLY_STATUS_FULL;
                else
                        val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
                break;
        case POWER_SUPPLY_PROP_PRESENT:
                val->intval = ecbat->bat_present;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
                val->intval = ecbat->design_voltage;
                break;
        case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
        case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
                val->intval = ecbat->design_capacity;
                break;
        case POWER_SUPPLY_PROP_CHARGE_FULL:
        case POWER_SUPPLY_PROP_ENERGY_FULL:
                val->intval = ecbat->full_charge_capacity;
                break;
        case POWER_SUPPLY_PROP_CHARGE_NOW:
        case POWER_SUPPLY_PROP_ENERGY_NOW:
                val->intval = ecbat->capacity_now;
                break;
        case POWER_SUPPLY_PROP_CURRENT_NOW:
                val->intval = ecbat->current_now;
                break;
        case POWER_SUPPLY_PROP_POWER_NOW:
                val->intval = ecbat->rate_now;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
                val->intval = ecbat->voltage_now;
                break;
        case POWER_SUPPLY_PROP_TECHNOLOGY:
                val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
                break;
        case POWER_SUPPLY_PROP_MODEL_NAME:
                val->strval = "PABAS0241231";
                break;
        case POWER_SUPPLY_PROP_MANUFACTURER:
                val->strval = "Compal";
                break;
        case POWER_SUPPLY_PROP_SCOPE:
                val->intval = POWER_SUPPLY_SCOPE_SYSTEM;
                break;
        default:
                rc = -EINVAL;
                break;
        }

        return rc;
}

static enum power_supply_property yoga_c630_psy_bat_mA_properties[] = {
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_PRESENT,
        POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
        POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
        POWER_SUPPLY_PROP_CHARGE_FULL,
        POWER_SUPPLY_PROP_CHARGE_NOW,
        POWER_SUPPLY_PROP_CURRENT_NOW,
        POWER_SUPPLY_PROP_POWER_NOW,
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
        POWER_SUPPLY_PROP_TECHNOLOGY,
        POWER_SUPPLY_PROP_MODEL_NAME,
        POWER_SUPPLY_PROP_MANUFACTURER,
        POWER_SUPPLY_PROP_SCOPE,
};

static enum power_supply_property yoga_c630_psy_bat_mWh_properties[] = {
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_PRESENT,
        POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
        POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
        POWER_SUPPLY_PROP_ENERGY_FULL,
        POWER_SUPPLY_PROP_ENERGY_NOW,
        POWER_SUPPLY_PROP_CURRENT_NOW,
        POWER_SUPPLY_PROP_POWER_NOW,
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
        POWER_SUPPLY_PROP_TECHNOLOGY,
        POWER_SUPPLY_PROP_MODEL_NAME,
        POWER_SUPPLY_PROP_MANUFACTURER,
        POWER_SUPPLY_PROP_SCOPE,
};

static const struct power_supply_desc yoga_c630_psy_bat_psy_desc_mA = {
        .name = "yoga-c630-battery",
        .type = POWER_SUPPLY_TYPE_BATTERY,
        .properties = yoga_c630_psy_bat_mA_properties,
        .num_properties = ARRAY_SIZE(yoga_c630_psy_bat_mA_properties),
        .get_property = yoga_c630_psy_bat_get_property,
};

static const struct power_supply_desc yoga_c630_psy_bat_psy_desc_mWh = {
        .name = "yoga-c630-battery",
        .type = POWER_SUPPLY_TYPE_BATTERY,
        .properties = yoga_c630_psy_bat_mWh_properties,
        .num_properties = ARRAY_SIZE(yoga_c630_psy_bat_mWh_properties),
        .get_property = yoga_c630_psy_bat_get_property,
};

static int yoga_c630_psy_adpt_get_property(struct power_supply *psy,
                                          enum power_supply_property psp,
                                          union power_supply_propval *val)
{
        struct yoga_c630_psy *ecbat = power_supply_get_drvdata(psy);
        int ret = 0;

        ret = yoga_c630_psy_update_adapter_status(ecbat);
        if (ret < 0)
                return ret;

        switch (psp) {
        case POWER_SUPPLY_PROP_ONLINE:
                val->intval = ecbat->adapter_online;
                break;
        case POWER_SUPPLY_PROP_USB_TYPE:
                val->intval = POWER_SUPPLY_USB_TYPE_C;
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static enum power_supply_property yoga_c630_psy_adpt_properties[] = {
        POWER_SUPPLY_PROP_ONLINE,
        POWER_SUPPLY_PROP_USB_TYPE,
};

static const struct power_supply_desc yoga_c630_psy_adpt_psy_desc = {
        .name = "yoga-c630-adapter",
        .type = POWER_SUPPLY_TYPE_USB,
        .usb_types = BIT(POWER_SUPPLY_USB_TYPE_C),
        .properties = yoga_c630_psy_adpt_properties,
        .num_properties = ARRAY_SIZE(yoga_c630_psy_adpt_properties),
        .get_property = yoga_c630_psy_adpt_get_property,
};

static int yoga_c630_psy_register_bat_psy(struct yoga_c630_psy *ecbat)
{
        struct power_supply_config bat_cfg = {};

        bat_cfg.drv_data = ecbat;
        bat_cfg.fwnode = ecbat->fwnode;
        bat_cfg.no_wakeup_source = true;
        ecbat->bat_psy = power_supply_register(ecbat->dev,
                                               ecbat->unit_mA ?
                                               &yoga_c630_psy_bat_psy_desc_mA :
                                               &yoga_c630_psy_bat_psy_desc_mWh,
                                               &bat_cfg);
        if (IS_ERR(ecbat->bat_psy)) {
                dev_err(ecbat->dev, "failed to register battery supply\n");
                return PTR_ERR(ecbat->bat_psy);
        }

        return 0;
}

static void yoga_c630_ec_refresh_bat_info(struct yoga_c630_psy *ecbat)
{
        bool current_unit;

        guard(mutex)(&ecbat->lock);

        current_unit = ecbat->unit_mA;

        yoga_c630_psy_update_bat_info(ecbat);

        if (current_unit != ecbat->unit_mA) {
                power_supply_unregister(ecbat->bat_psy);
                yoga_c630_psy_register_bat_psy(ecbat);
        }
}

static int yoga_c630_psy_notify(struct notifier_block *nb,
                                unsigned long action, void *data)
{
        struct yoga_c630_psy *ecbat = container_of(nb, struct yoga_c630_psy, nb);

        switch (action) {
        case LENOVO_EC_EVENT_BAT_INFO:
                yoga_c630_ec_refresh_bat_info(ecbat);
                break;
        case LENOVO_EC_EVENT_BAT_ADPT_STATUS:
                power_supply_changed(ecbat->adp_psy);
                fallthrough;
        case LENOVO_EC_EVENT_BAT_STATUS:
                power_supply_changed(ecbat->bat_psy);
                break;
        }

        return NOTIFY_OK;
}

static int yoga_c630_psy_probe(struct auxiliary_device *adev,
                                   const struct auxiliary_device_id *id)
{
        struct yoga_c630_ec *ec = adev->dev.platform_data;
        struct power_supply_config adp_cfg = {};
        struct device *dev = &adev->dev;
        struct yoga_c630_psy *ecbat;
        int ret;

        ecbat = devm_kzalloc(&adev->dev, sizeof(*ecbat), GFP_KERNEL);
        if (!ecbat)
                return -ENOMEM;

        ecbat->ec = ec;
        ecbat->dev = dev;
        mutex_init(&ecbat->lock);
        ecbat->fwnode = adev->dev.parent->fwnode;
        ecbat->nb.notifier_call = yoga_c630_psy_notify;

        auxiliary_set_drvdata(adev, ecbat);

        adp_cfg.drv_data = ecbat;
        adp_cfg.fwnode = ecbat->fwnode;
        adp_cfg.supplied_to = (char **)&yoga_c630_psy_bat_psy_desc_mA.name;
        adp_cfg.num_supplicants = 1;
        adp_cfg.no_wakeup_source = true;
        ecbat->adp_psy = devm_power_supply_register(dev, &yoga_c630_psy_adpt_psy_desc, &adp_cfg);
        if (IS_ERR(ecbat->adp_psy)) {
                dev_err(dev, "failed to register AC adapter supply\n");
                return PTR_ERR(ecbat->adp_psy);
        }

        scoped_guard(mutex, &ecbat->lock) {
                ret = yoga_c630_psy_update_bat_info(ecbat);
                if (ret)
                        goto err_unreg_bat;

                ret = yoga_c630_psy_register_bat_psy(ecbat);
                if (ret)
                        goto err_unreg_bat;
        }

        ret = yoga_c630_ec_register_notify(ecbat->ec, &ecbat->nb);
        if (ret)
                goto err_unreg_bat;

        return 0;

err_unreg_bat:
        power_supply_unregister(ecbat->bat_psy);
        return ret;
}

static void yoga_c630_psy_remove(struct auxiliary_device *adev)
{
        struct yoga_c630_psy *ecbat = auxiliary_get_drvdata(adev);

        yoga_c630_ec_unregister_notify(ecbat->ec, &ecbat->nb);
        power_supply_unregister(ecbat->bat_psy);
}

static const struct auxiliary_device_id yoga_c630_psy_id_table[] = {
        { .name = YOGA_C630_MOD_NAME "." YOGA_C630_DEV_PSY, },
        {}
};
MODULE_DEVICE_TABLE(auxiliary, yoga_c630_psy_id_table);

static struct auxiliary_driver yoga_c630_psy_driver = {
        .name = YOGA_C630_DEV_PSY,
        .id_table = yoga_c630_psy_id_table,
        .probe = yoga_c630_psy_probe,
        .remove = yoga_c630_psy_remove,
};

module_auxiliary_driver(yoga_c630_psy_driver);

MODULE_DESCRIPTION("Lenovo Yoga C630 psy");
MODULE_LICENSE("GPL");