// SPDX-License-Identifier: GPL-2.0-only
/*
 * Driver for LP8727 Micro/Mini USB IC with integrated charger
 *
 *                      Copyright (C) 2011 Texas Instruments
 *                      Copyright (C) 2011 National Semiconductor
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/power_supply.h>
#include <linux/platform_data/lp8727.h>
#include <linux/of.h>

#define LP8788_NUM_INTREGS      2
#define DEFAULT_DEBOUNCE_MSEC   270

/* Registers */
#define LP8727_CTRL1            0x1
#define LP8727_CTRL2            0x2
#define LP8727_SWCTRL           0x3
#define LP8727_INT1             0x4
#define LP8727_INT2             0x5
#define LP8727_STATUS1          0x6
#define LP8727_STATUS2          0x7
#define LP8727_CHGCTRL2         0x9

/* CTRL1 register */
#define LP8727_CP_EN            BIT(0)
#define LP8727_ADC_EN           BIT(1)
#define LP8727_ID200_EN         BIT(4)

/* CTRL2 register */
#define LP8727_CHGDET_EN        BIT(1)
#define LP8727_INT_EN           BIT(6)

/* SWCTRL register */
#define LP8727_SW_DM1_DM        (0x0 << 0)
#define LP8727_SW_DM1_HiZ       (0x7 << 0)
#define LP8727_SW_DP2_DP        (0x0 << 3)
#define LP8727_SW_DP2_HiZ       (0x7 << 3)

/* INT1 register */
#define LP8727_IDNO             (0xF << 0)
#define LP8727_VBUS             BIT(4)

/* STATUS1 register */
#define LP8727_CHGSTAT          (3 << 4)
#define LP8727_CHPORT           BIT(6)
#define LP8727_DCPORT           BIT(7)
#define LP8727_STAT_EOC         0x30

/* STATUS2 register */
#define LP8727_TEMP_STAT        (3 << 5)
#define LP8727_TEMP_SHIFT       5

/* CHGCTRL2 register */
#define LP8727_ICHG_SHIFT       4

enum lp8727_dev_id {
        LP8727_ID_NONE,
        LP8727_ID_TA,
        LP8727_ID_DEDICATED_CHG,
        LP8727_ID_USB_CHG,
        LP8727_ID_USB_DS,
        LP8727_ID_MAX,
};

enum lp8727_die_temp {
        LP8788_TEMP_75C,
        LP8788_TEMP_95C,
        LP8788_TEMP_115C,
        LP8788_TEMP_135C,
};

struct lp8727_psy {
        struct power_supply *ac;
        struct power_supply *usb;
        struct power_supply *batt;
};

struct lp8727_chg {
        struct device *dev;
        struct i2c_client *client;
        struct mutex xfer_lock;
        struct lp8727_psy *psy;
        struct lp8727_platform_data *pdata;

        /* Charger Data */
        enum lp8727_dev_id devid;
        struct lp8727_chg_param *chg_param;

        /* Interrupt Handling */
        int irq;
        struct delayed_work work;
        unsigned long debounce_jiffies;
};

static int lp8727_read_bytes(struct lp8727_chg *pchg, u8 reg, u8 *data, u8 len)
{
        s32 ret;

        mutex_lock(&pchg->xfer_lock);
        ret = i2c_smbus_read_i2c_block_data(pchg->client, reg, len, data);
        mutex_unlock(&pchg->xfer_lock);

        return (ret != len) ? -EIO : 0;
}

static inline int lp8727_read_byte(struct lp8727_chg *pchg, u8 reg, u8 *data)
{
        return lp8727_read_bytes(pchg, reg, data, 1);
}

static int lp8727_write_byte(struct lp8727_chg *pchg, u8 reg, u8 data)
{
        int ret;

        mutex_lock(&pchg->xfer_lock);
        ret = i2c_smbus_write_byte_data(pchg->client, reg, data);
        mutex_unlock(&pchg->xfer_lock);

        return ret;
}

static bool lp8727_is_charger_attached(const char *name, int id)
{
        if (!strcmp(name, "ac"))
                return id == LP8727_ID_TA || id == LP8727_ID_DEDICATED_CHG;
        else if (!strcmp(name, "usb"))
                return id == LP8727_ID_USB_CHG;

        return id >= LP8727_ID_TA && id <= LP8727_ID_USB_CHG;
}

static int lp8727_init_device(struct lp8727_chg *pchg)
{
        u8 val;
        int ret;
        u8 intstat[LP8788_NUM_INTREGS];

        /* clear interrupts */
        ret = lp8727_read_bytes(pchg, LP8727_INT1, intstat, LP8788_NUM_INTREGS);
        if (ret)
                return ret;

        val = LP8727_ID200_EN | LP8727_ADC_EN | LP8727_CP_EN;
        ret = lp8727_write_byte(pchg, LP8727_CTRL1, val);
        if (ret)
                return ret;

        val = LP8727_INT_EN | LP8727_CHGDET_EN;
        return lp8727_write_byte(pchg, LP8727_CTRL2, val);
}

static int lp8727_is_dedicated_charger(struct lp8727_chg *pchg)
{
        u8 val;

        lp8727_read_byte(pchg, LP8727_STATUS1, &val);
        return val & LP8727_DCPORT;
}

static int lp8727_is_usb_charger(struct lp8727_chg *pchg)
{
        u8 val;

        lp8727_read_byte(pchg, LP8727_STATUS1, &val);
        return val & LP8727_CHPORT;
}

static inline void lp8727_ctrl_switch(struct lp8727_chg *pchg, u8 sw)
{
        lp8727_write_byte(pchg, LP8727_SWCTRL, sw);
}

static void lp8727_id_detection(struct lp8727_chg *pchg, u8 id, int vbusin)
{
        struct lp8727_platform_data *pdata = pchg->pdata;
        u8 devid = LP8727_ID_NONE;
        u8 swctrl = LP8727_SW_DM1_HiZ | LP8727_SW_DP2_HiZ;

        switch (id) {
        case 0x5:
                devid = LP8727_ID_TA;
                pchg->chg_param = pdata ? pdata->ac : NULL;
                break;
        case 0xB:
                if (lp8727_is_dedicated_charger(pchg)) {
                        pchg->chg_param = pdata ? pdata->ac : NULL;
                        devid = LP8727_ID_DEDICATED_CHG;
                } else if (lp8727_is_usb_charger(pchg)) {
                        pchg->chg_param = pdata ? pdata->usb : NULL;
                        devid = LP8727_ID_USB_CHG;
                        swctrl = LP8727_SW_DM1_DM | LP8727_SW_DP2_DP;
                } else if (vbusin) {
                        devid = LP8727_ID_USB_DS;
                        swctrl = LP8727_SW_DM1_DM | LP8727_SW_DP2_DP;
                }
                break;
        default:
                devid = LP8727_ID_NONE;
                pchg->chg_param = NULL;
                break;
        }

        pchg->devid = devid;
        lp8727_ctrl_switch(pchg, swctrl);
}

static void lp8727_enable_chgdet(struct lp8727_chg *pchg)
{
        u8 val;

        lp8727_read_byte(pchg, LP8727_CTRL2, &val);
        val |= LP8727_CHGDET_EN;
        lp8727_write_byte(pchg, LP8727_CTRL2, val);
}

static void lp8727_delayed_func(struct work_struct *_work)
{
        struct lp8727_chg *pchg = container_of(_work, struct lp8727_chg,
                                                work.work);
        u8 intstat[LP8788_NUM_INTREGS];
        u8 idno;
        u8 vbus;

        if (lp8727_read_bytes(pchg, LP8727_INT1, intstat, LP8788_NUM_INTREGS)) {
                dev_err(pchg->dev, "can not read INT registers\n");
                return;
        }

        idno = intstat[0] & LP8727_IDNO;
        vbus = intstat[0] & LP8727_VBUS;

        lp8727_id_detection(pchg, idno, vbus);
        lp8727_enable_chgdet(pchg);

        power_supply_changed(pchg->psy->ac);
        power_supply_changed(pchg->psy->usb);
        power_supply_changed(pchg->psy->batt);
}

static irqreturn_t lp8727_isr_func(int irq, void *ptr)
{
        struct lp8727_chg *pchg = ptr;

        schedule_delayed_work(&pchg->work, pchg->debounce_jiffies);
        return IRQ_HANDLED;
}

static int lp8727_setup_irq(struct lp8727_chg *pchg)
{
        int ret;
        int irq = pchg->client->irq;
        unsigned delay_msec = pchg->pdata ? pchg->pdata->debounce_msec :
                                                DEFAULT_DEBOUNCE_MSEC;

        INIT_DELAYED_WORK(&pchg->work, lp8727_delayed_func);

        if (irq <= 0) {
                dev_warn(pchg->dev, "invalid irq number: %d\n", irq);
                return 0;
        }

        ret = request_threaded_irq(irq, NULL, lp8727_isr_func,
                                IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
                                "lp8727_irq", pchg);

        if (ret)
                return ret;

        pchg->irq = irq;
        pchg->debounce_jiffies = msecs_to_jiffies(delay_msec);

        return 0;
}

static void lp8727_release_irq(struct lp8727_chg *pchg)
{
        cancel_delayed_work_sync(&pchg->work);

        if (pchg->irq)
                free_irq(pchg->irq, pchg);
}

static enum power_supply_property lp8727_charger_prop[] = {
        POWER_SUPPLY_PROP_ONLINE,
};

static enum power_supply_property lp8727_battery_prop[] = {
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_HEALTH,
        POWER_SUPPLY_PROP_PRESENT,
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
        POWER_SUPPLY_PROP_CAPACITY,
        POWER_SUPPLY_PROP_TEMP,
};

static char *battery_supplied_to[] = {
        "main_batt",
};

static int lp8727_charger_get_property(struct power_supply *psy,
                                       enum power_supply_property psp,
                                       union power_supply_propval *val)
{
        struct lp8727_chg *pchg = dev_get_drvdata(psy->dev.parent);

        if (psp != POWER_SUPPLY_PROP_ONLINE)
                return -EINVAL;

        val->intval = lp8727_is_charger_attached(psy->desc->name, pchg->devid);

        return 0;
}

static bool lp8727_is_high_temperature(enum lp8727_die_temp temp)
{
        switch (temp) {
        case LP8788_TEMP_95C:
        case LP8788_TEMP_115C:
        case LP8788_TEMP_135C:
                return true;
        default:
                return false;
        }
}

static int lp8727_battery_get_property(struct power_supply *psy,
                                       enum power_supply_property psp,
                                       union power_supply_propval *val)
{
        struct lp8727_chg *pchg = dev_get_drvdata(psy->dev.parent);
        struct lp8727_platform_data *pdata = pchg->pdata;
        enum lp8727_die_temp temp;
        u8 read;

        switch (psp) {
        case POWER_SUPPLY_PROP_STATUS:
                if (!lp8727_is_charger_attached(psy->desc->name, pchg->devid)) {
                        val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
                        return 0;
                }

                lp8727_read_byte(pchg, LP8727_STATUS1, &read);

                val->intval = (read & LP8727_CHGSTAT) == LP8727_STAT_EOC ?
                                POWER_SUPPLY_STATUS_FULL :
                                POWER_SUPPLY_STATUS_CHARGING;
                break;
        case POWER_SUPPLY_PROP_HEALTH:
                lp8727_read_byte(pchg, LP8727_STATUS2, &read);
                temp = (read & LP8727_TEMP_STAT) >> LP8727_TEMP_SHIFT;

                val->intval = lp8727_is_high_temperature(temp) ?
                        POWER_SUPPLY_HEALTH_OVERHEAT :
                        POWER_SUPPLY_HEALTH_GOOD;
                break;
        case POWER_SUPPLY_PROP_PRESENT:
                if (!pdata)
                        return -EINVAL;

                if (pdata->get_batt_present)
                        val->intval = pdata->get_batt_present();
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
                if (!pdata)
                        return -EINVAL;

                if (pdata->get_batt_level)
                        val->intval = pdata->get_batt_level();
                break;
        case POWER_SUPPLY_PROP_CAPACITY:
                if (!pdata)
                        return -EINVAL;

                if (pdata->get_batt_capacity)
                        val->intval = pdata->get_batt_capacity();
                break;
        case POWER_SUPPLY_PROP_TEMP:
                if (!pdata)
                        return -EINVAL;

                if (pdata->get_batt_temp)
                        val->intval = pdata->get_batt_temp();
                break;
        default:
                break;
        }

        return 0;
}

static void lp8727_charger_changed(struct power_supply *psy)
{
        struct lp8727_chg *pchg = dev_get_drvdata(psy->dev.parent);
        u8 eoc_level;
        u8 ichg;
        u8 val;

        /* skip if no charger exists */
        if (!lp8727_is_charger_attached(psy->desc->name, pchg->devid))
                return;

        /* update charging parameters */
        if (pchg->chg_param) {
                eoc_level = pchg->chg_param->eoc_level;
                ichg = pchg->chg_param->ichg;
                val = (ichg << LP8727_ICHG_SHIFT) | eoc_level;
                lp8727_write_byte(pchg, LP8727_CHGCTRL2, val);
        }
}

static const struct power_supply_desc lp8727_ac_desc = {
        .name                   = "ac",
        .type                   = POWER_SUPPLY_TYPE_MAINS,
        .properties             = lp8727_charger_prop,
        .num_properties         = ARRAY_SIZE(lp8727_charger_prop),
        .get_property           = lp8727_charger_get_property,
};

static const struct power_supply_desc lp8727_usb_desc = {
        .name                   = "usb",
        .type                   = POWER_SUPPLY_TYPE_USB,
        .properties             = lp8727_charger_prop,
        .num_properties         = ARRAY_SIZE(lp8727_charger_prop),
        .get_property           = lp8727_charger_get_property,
};

static const struct power_supply_desc lp8727_batt_desc = {
        .name                   = "main_batt",
        .type                   = POWER_SUPPLY_TYPE_BATTERY,
        .properties             = lp8727_battery_prop,
        .num_properties         = ARRAY_SIZE(lp8727_battery_prop),
        .get_property           = lp8727_battery_get_property,
        .external_power_changed = lp8727_charger_changed,
};

static int lp8727_register_psy(struct lp8727_chg *pchg)
{
        struct power_supply_config psy_cfg = {}; /* Only for ac and usb */
        struct lp8727_psy *psy;

        psy = devm_kzalloc(pchg->dev, sizeof(*psy), GFP_KERNEL);
        if (!psy)
                return -ENOMEM;

        pchg->psy = psy;

        psy_cfg.supplied_to = battery_supplied_to;
        psy_cfg.num_supplicants = ARRAY_SIZE(battery_supplied_to);

        psy->ac = devm_power_supply_register(pchg->dev, &lp8727_ac_desc, &psy_cfg);
        if (IS_ERR(psy->ac))
                return -EPERM;

        psy->usb = devm_power_supply_register(pchg->dev, &lp8727_usb_desc,
                                              &psy_cfg);
        if (IS_ERR(psy->usb))
                return -EPERM;

        psy->batt = devm_power_supply_register(pchg->dev, &lp8727_batt_desc, NULL);
        if (IS_ERR(psy->batt))
                return -EPERM;

        return 0;
}

#ifdef CONFIG_OF
static struct lp8727_chg_param
*lp8727_parse_charge_pdata(struct device *dev, struct device_node *np)
{
        struct lp8727_chg_param *param;

        param = devm_kzalloc(dev, sizeof(*param), GFP_KERNEL);
        if (!param)
                goto out;

        of_property_read_u8(np, "eoc-level", (u8 *)&param->eoc_level);
        of_property_read_u8(np, "charging-current", (u8 *)&param->ichg);
out:
        return param;
}

static struct lp8727_platform_data *lp8727_parse_dt(struct device *dev)
{
        struct device_node *np = dev->of_node;
        struct device_node *child;
        struct lp8727_platform_data *pdata;
        const char *type;

        pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata)
                return ERR_PTR(-ENOMEM);

        of_property_read_u32(np, "debounce-ms", &pdata->debounce_msec);

        /* If charging parameter is not defined, just skip parsing the dt */
        if (of_get_child_count(np) == 0)
                return pdata;

        for_each_child_of_node(np, child) {
                of_property_read_string(child, "charger-type", &type);

                if (!strcmp(type, "ac"))
                        pdata->ac = lp8727_parse_charge_pdata(dev, child);

                if (!strcmp(type, "usb"))
                        pdata->usb = lp8727_parse_charge_pdata(dev, child);
        }

        return pdata;
}
#else
static struct lp8727_platform_data *lp8727_parse_dt(struct device *dev)
{
        return NULL;
}
#endif

static int lp8727_probe(struct i2c_client *cl)
{
        struct lp8727_chg *pchg;
        struct lp8727_platform_data *pdata;
        int ret;

        if (!i2c_check_functionality(cl->adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
                return -EIO;

        if (cl->dev.of_node) {
                pdata = lp8727_parse_dt(&cl->dev);
                if (IS_ERR(pdata))
                        return PTR_ERR(pdata);
        } else {
                pdata = dev_get_platdata(&cl->dev);
        }

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

        pchg->client = cl;
        pchg->dev = &cl->dev;
        pchg->pdata = pdata;
        i2c_set_clientdata(cl, pchg);

        mutex_init(&pchg->xfer_lock);

        ret = lp8727_init_device(pchg);
        if (ret) {
                dev_err(pchg->dev, "i2c communication err: %d", ret);
                return ret;
        }

        ret = lp8727_register_psy(pchg);
        if (ret) {
                dev_err(pchg->dev, "power supplies register err: %d", ret);
                return ret;
        }

        ret = lp8727_setup_irq(pchg);
        if (ret) {
                dev_err(pchg->dev, "irq handler err: %d", ret);
                return ret;
        }

        return 0;
}

static void lp8727_remove(struct i2c_client *cl)
{
        struct lp8727_chg *pchg = i2c_get_clientdata(cl);

        lp8727_release_irq(pchg);
}

static const struct of_device_id lp8727_dt_ids[] __maybe_unused = {
        { .compatible = "ti,lp8727", },
        { }
};
MODULE_DEVICE_TABLE(of, lp8727_dt_ids);

static const struct i2c_device_id lp8727_ids[] = {
        { "lp8727" },
        { }
};
MODULE_DEVICE_TABLE(i2c, lp8727_ids);

static struct i2c_driver lp8727_driver = {
        .driver = {
                   .name = "lp8727",
                   .of_match_table = of_match_ptr(lp8727_dt_ids),
                   },
        .probe = lp8727_probe,
        .remove = lp8727_remove,
        .id_table = lp8727_ids,
};
module_i2c_driver(lp8727_driver);

MODULE_DESCRIPTION("TI/National Semiconductor LP8727 charger driver");
MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>, Daniel Jeong <daniel.jeong@ti.com>");
MODULE_LICENSE("GPL");