root/drivers/power/supply/max8997_charger.c
// SPDX-License-Identifier: GPL-2.0+
//
// max8997_charger.c - Power supply consumer driver for the Maxim 8997/8966
//
//  Copyright (C) 2011 Samsung Electronics
//  MyungJoo Ham <myungjoo.ham@samsung.com>

#include <linux/err.h>
#include <linux/extcon.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/mfd/max8997.h>
#include <linux/mfd/max8997-private.h>
#include <linux/regulator/consumer.h>
#include <linux/devm-helpers.h>

/* MAX8997_REG_STATUS4 */
#define DCINOK_SHIFT            1
#define DCINOK_MASK             (1 << DCINOK_SHIFT)
#define DETBAT_SHIFT            2
#define DETBAT_MASK             (1 << DETBAT_SHIFT)

/* MAX8997_REG_MBCCTRL1 */
#define TFCH_SHIFT              4
#define TFCH_MASK               (7 << TFCH_SHIFT)

/* MAX8997_REG_MBCCTRL5 */
#define ITOPOFF_SHIFT           0
#define ITOPOFF_MASK            (0xF << ITOPOFF_SHIFT)

struct charger_data {
        struct device *dev;
        struct max8997_dev *iodev;
        struct power_supply *battery;
        struct regulator *reg;
        struct extcon_dev *edev;
        struct notifier_block extcon_nb;
        struct work_struct extcon_work;
};

static enum power_supply_property max8997_battery_props[] = {
        POWER_SUPPLY_PROP_STATUS, /* "FULL", "CHARGING" or "DISCHARGING". */
        POWER_SUPPLY_PROP_PRESENT, /* the presence of battery */
        POWER_SUPPLY_PROP_ONLINE, /* charger is active or not */
};

/* Note that the charger control is done by a current regulator "CHARGER" */
static int max8997_battery_get_property(struct power_supply *psy,
                enum power_supply_property psp,
                union power_supply_propval *val)
{
        struct charger_data *charger = power_supply_get_drvdata(psy);
        struct i2c_client *i2c = charger->iodev->i2c;
        int ret;
        u8 reg;

        switch (psp) {
        case POWER_SUPPLY_PROP_STATUS:
                val->intval = 0;
                ret = max8997_read_reg(i2c, MAX8997_REG_STATUS4, &reg);
                if (ret)
                        return ret;
                if ((reg & (1 << 0)) == 0x1)
                        val->intval = POWER_SUPPLY_STATUS_FULL;
                else if ((reg & DCINOK_MASK))
                        val->intval = POWER_SUPPLY_STATUS_CHARGING;
                else
                        val->intval = POWER_SUPPLY_STATUS_DISCHARGING;

                break;
        case POWER_SUPPLY_PROP_PRESENT:
                val->intval = 0;
                ret = max8997_read_reg(i2c, MAX8997_REG_STATUS4, &reg);
                if (ret)
                        return ret;
                if ((reg & DETBAT_MASK) == 0x0)
                        val->intval = 1;

                break;
        case POWER_SUPPLY_PROP_ONLINE:
                val->intval = 0;
                ret = max8997_read_reg(i2c, MAX8997_REG_STATUS4, &reg);
                if (ret)
                        return ret;
                if (reg & DCINOK_MASK)
                        val->intval = 1;

                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static void max8997_battery_extcon_evt_worker(struct work_struct *work)
{
        struct charger_data *charger =
            container_of(work, struct charger_data, extcon_work);
        struct extcon_dev *edev = charger->edev;
        int current_limit;

        if (extcon_get_state(edev, EXTCON_CHG_USB_SDP) > 0) {
                dev_dbg(charger->dev, "USB SDP charger is connected\n");
                current_limit = 450000;
        } else if (extcon_get_state(edev, EXTCON_CHG_USB_DCP) > 0) {
                dev_dbg(charger->dev, "USB DCP charger is connected\n");
                current_limit = 650000;
        } else if (extcon_get_state(edev, EXTCON_CHG_USB_FAST) > 0) {
                dev_dbg(charger->dev, "USB FAST charger is connected\n");
                current_limit = 650000;
        } else if (extcon_get_state(edev, EXTCON_CHG_USB_SLOW) > 0) {
                dev_dbg(charger->dev, "USB SLOW charger is connected\n");
                current_limit = 650000;
        } else if (extcon_get_state(edev, EXTCON_CHG_USB_CDP) > 0) {
                dev_dbg(charger->dev, "USB CDP charger is connected\n");
                current_limit = 650000;
        } else {
                dev_dbg(charger->dev, "USB charger is disconnected\n");
                current_limit = -1;
        }

        if (current_limit > 0) {
                int ret = regulator_set_current_limit(charger->reg, current_limit, current_limit);

                if (ret) {
                        dev_err(charger->dev, "failed to set current limit: %d\n", ret);
                        return;
                }
                ret = regulator_enable(charger->reg);
                if (ret)
                        dev_err(charger->dev, "failed to enable regulator: %d\n", ret);
        } else {
                int ret  = regulator_disable(charger->reg);

                if (ret)
                        dev_err(charger->dev, "failed to disable regulator: %d\n", ret);
        }
}

static int max8997_battery_extcon_evt(struct notifier_block *nb,
                                unsigned long event, void *param)
{
        struct charger_data *charger =
                container_of(nb, struct charger_data, extcon_nb);
        schedule_work(&charger->extcon_work);
        return NOTIFY_OK;
}

static const struct power_supply_desc max8997_battery_desc = {
        .name           = "max8997_pmic",
        .type           = POWER_SUPPLY_TYPE_BATTERY,
        .get_property   = max8997_battery_get_property,
        .properties     = max8997_battery_props,
        .num_properties = ARRAY_SIZE(max8997_battery_props),
};

static int max8997_battery_probe(struct platform_device *pdev)
{
        int ret = 0;
        struct charger_data *charger;
        struct max8997_dev *iodev = dev_get_drvdata(pdev->dev.parent);
        struct device_node *np = pdev->dev.of_node;
        struct i2c_client *i2c = iodev->i2c;
        struct max8997_platform_data *pdata = iodev->pdata;
        struct power_supply_config psy_cfg = {};

        if (!pdata) {
                dev_err(&pdev->dev, "No platform data supplied.\n");
                return -EINVAL;
        }

        if (pdata->eoc_mA) {
                int val = (pdata->eoc_mA - 50) / 10;
                if (val < 0)
                        val = 0;
                if (val > 0xf)
                        val = 0xf;

                ret = max8997_update_reg(i2c, MAX8997_REG_MBCCTRL5,
                                val << ITOPOFF_SHIFT, ITOPOFF_MASK);
                if (ret < 0) {
                        dev_err(&pdev->dev, "Cannot use i2c bus.\n");
                        return ret;
                }
        }
        switch (pdata->timeout) {
        case 5:
                ret = max8997_update_reg(i2c, MAX8997_REG_MBCCTRL1,
                                0x2 << TFCH_SHIFT, TFCH_MASK);
                break;
        case 6:
                ret = max8997_update_reg(i2c, MAX8997_REG_MBCCTRL1,
                                0x3 << TFCH_SHIFT, TFCH_MASK);
                break;
        case 7:
                ret = max8997_update_reg(i2c, MAX8997_REG_MBCCTRL1,
                                0x4 << TFCH_SHIFT, TFCH_MASK);
                break;
        case 0:
                ret = max8997_update_reg(i2c, MAX8997_REG_MBCCTRL1,
                                0x7 << TFCH_SHIFT, TFCH_MASK);
                break;
        default:
                dev_err(&pdev->dev, "incorrect timeout value (%d)\n",
                                pdata->timeout);
                return -EINVAL;
        }
        if (ret < 0) {
                dev_err(&pdev->dev, "Cannot use i2c bus.\n");
                return ret;
        }

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

        platform_set_drvdata(pdev, charger);

        charger->dev = &pdev->dev;
        charger->iodev = iodev;

        psy_cfg.drv_data = charger;

        charger->battery = devm_power_supply_register(&pdev->dev,
                                                 &max8997_battery_desc,
                                                 &psy_cfg);
        if (IS_ERR(charger->battery)) {
                dev_err(&pdev->dev, "failed: power supply register\n");
                return PTR_ERR(charger->battery);
        }

        // grab regulator from parent device's node
        pdev->dev.of_node = iodev->dev->of_node;
        charger->reg = devm_regulator_get_optional(&pdev->dev, "charger");
        pdev->dev.of_node = np;
        if (IS_ERR(charger->reg)) {
                if (PTR_ERR(charger->reg) == -EPROBE_DEFER)
                        return -EPROBE_DEFER;
                dev_info(&pdev->dev, "couldn't get charger regulator\n");
        }
        charger->edev = extcon_get_extcon_dev("max8997-muic");
        if (IS_ERR(charger->edev)) {
                dev_err_probe(charger->dev, PTR_ERR(charger->edev),
                              "couldn't get extcon device: max8997-muic\n");
                return PTR_ERR(charger->edev);
        }

        if (!IS_ERR(charger->reg) && !IS_ERR_OR_NULL(charger->edev)) {
                ret = devm_work_autocancel(&pdev->dev, &charger->extcon_work,
                                           max8997_battery_extcon_evt_worker);
                if (ret) {
                        dev_err(&pdev->dev, "failed to add extcon evt stop action: %d\n", ret);
                        return ret;
                }
                charger->extcon_nb.notifier_call = max8997_battery_extcon_evt;
                ret = devm_extcon_register_notifier_all(&pdev->dev, charger->edev,
                                                        &charger->extcon_nb);
                if (ret) {
                        dev_err(&pdev->dev, "failed to register extcon notifier\n");
                        return ret;
                }
        }

        return 0;
}

static const struct platform_device_id max8997_battery_id[] = {
        { "max8997-battery", 0 },
        { }
};
MODULE_DEVICE_TABLE(platform, max8997_battery_id);

static struct platform_driver max8997_battery_driver = {
        .driver = {
                .name = "max8997-battery",
        },
        .probe = max8997_battery_probe,
        .id_table = max8997_battery_id,
};
module_platform_driver(max8997_battery_driver);

MODULE_DESCRIPTION("MAXIM 8997/8966 battery control driver");
MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
MODULE_LICENSE("GPL");