lp8727_charger.c

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/*
 * Driver for LP8727 Micro/Mini USB IC with integrated charger
 *
 *          Copyright (C) 2011 Texas Instruments
 *          Copyright (C) 2011 National Semiconductor
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#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>

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

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

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

        if (pdata->get_batt_temp)
            val->intval = pchg->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->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 int lp8727_register_psy(struct lp8727_chg *pchg)
{
    struct lp8727_psy *psy;

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

    pchg->psy = psy;

    psy->ac.name = "ac";
    psy->ac.type = POWER_SUPPLY_TYPE_MAINS;
    psy->ac.properties = lp8727_charger_prop;
    psy->ac.num_properties = ARRAY_SIZE(lp8727_charger_prop);
    psy->ac.get_property = lp8727_charger_get_property;
    psy->ac.supplied_to = battery_supplied_to;
    psy->ac.num_supplicants = ARRAY_SIZE(battery_supplied_to);

    if (power_supply_register(pchg->dev, &psy->ac))
        goto err_psy_ac;

    psy->usb.name = "usb";
    psy->usb.type = POWER_SUPPLY_TYPE_USB;
    psy->usb.properties = lp8727_charger_prop;
    psy->usb.num_properties = ARRAY_SIZE(lp8727_charger_prop);
    psy->usb.get_property = lp8727_charger_get_property;
    psy->usb.supplied_to = battery_supplied_to;
    psy->usb.num_supplicants = ARRAY_SIZE(battery_supplied_to);

    if (power_supply_register(pchg->dev, &psy->usb))
        goto err_psy_usb;

    psy->batt.name = "main_batt";
    psy->batt.type = POWER_SUPPLY_TYPE_BATTERY;
    psy->batt.properties = lp8727_battery_prop;
    psy->batt.num_properties = ARRAY_SIZE(lp8727_battery_prop);
    psy->batt.get_property = lp8727_battery_get_property;
    psy->batt.external_power_changed = lp8727_charger_changed;

    if (power_supply_register(pchg->dev, &psy->batt))
        goto err_psy_batt;

    return 0;

err_psy_batt:
    power_supply_unregister(&psy->usb);
err_psy_usb:
    power_supply_unregister(&psy->ac);
err_psy_ac:
    return -EPERM;
}

static void lp8727_unregister_psy(struct lp8727_chg *pchg)
{
    struct lp8727_psy *psy = pchg->psy;

    if (!psy)
        return;

    power_supply_unregister(&psy->ac);
    power_supply_unregister(&psy->usb);
    power_supply_unregister(&psy->batt);
}

static int lp8727_probe(struct i2c_client *cl, const struct i2c_device_id *id)
{
    struct lp8727_chg *pchg;
    int ret;

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

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

    pchg->client = cl;
    pchg->dev = &cl->dev;
    pchg->pdata = cl->dev.platform_data;
    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);
        lp8727_unregister_psy(pchg);
        return ret;
    }

    return 0;
}

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

    lp8727_release_irq(pchg);
    lp8727_unregister_psy(pchg);
    return 0;
}

static const struct i2c_device_id lp8727_ids[] = {
    {"lp8727", 0},
    { }
};
MODULE_DEVICE_TABLE(i2c, lp8727_ids);

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

MODULE_DESCRIPTION("TI/National Semiconductor LP8727 charger driver");
MODULE_AUTHOR("Milo Kim <[email protected]>, Daniel Jeong <[email protected]>");
MODULE_LICENSE("GPL");