ab8500_btemp.c

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/*
 * Copyright (C) ST-Ericsson SA 2012
 *
 * Battery temperature driver for AB8500
 *
 * License Terms: GNU General Public License v2
 * Author:
 *  Johan Palsson <[email protected]>
 *  Karl Komierowski <[email protected]>
 *  Arun R Murthy <[email protected]>
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/completion.h>
#include <linux/workqueue.h>
#include <linux/mfd/abx500/ab8500.h>
#include <linux/mfd/abx500.h>
#include <linux/mfd/abx500/ab8500-bm.h>
#include <linux/mfd/abx500/ab8500-gpadc.h>
#include <linux/jiffies.h>

#define VTVOUT_V            1800

#define BTEMP_THERMAL_LOW_LIMIT     -10
#define BTEMP_THERMAL_MED_LIMIT     0
#define BTEMP_THERMAL_HIGH_LIMIT_52 52
#define BTEMP_THERMAL_HIGH_LIMIT_57 57
#define BTEMP_THERMAL_HIGH_LIMIT_62 62

#define BTEMP_BATCTRL_CURR_SRC_7UA  7
#define BTEMP_BATCTRL_CURR_SRC_20UA 20

#define to_ab8500_btemp_device_info(x) container_of((x), \
    struct ab8500_btemp, btemp_psy);

struct ab8500_btemp_interrupts {
    char *name;
    irqreturn_t (*isr)(int irq, void *data);
};

struct ab8500_btemp_events {
    bool batt_rem;
    bool btemp_high;
    bool btemp_medhigh;
    bool btemp_lowmed;
    bool btemp_low;
    bool ac_conn;
    bool usb_conn;
};

struct ab8500_btemp_ranges {
    int btemp_high_limit;
    int btemp_med_limit;
    int btemp_low_limit;
};

struct ab8500_btemp {
    struct device *dev;
    struct list_head node;
    int curr_source;
    int bat_temp;
    int prev_bat_temp;
    struct ab8500 *parent;
    struct ab8500_gpadc *gpadc;
    struct ab8500_fg *fg;
    struct abx500_btemp_platform_data *pdata;
    struct abx500_bm_data *bat;
    struct power_supply btemp_psy;
    struct ab8500_btemp_events events;
    struct ab8500_btemp_ranges btemp_ranges;
    struct workqueue_struct *btemp_wq;
    struct delayed_work btemp_periodic_work;
};

/* BTEMP power supply properties */
static enum power_supply_property ab8500_btemp_props[] = {
    POWER_SUPPLY_PROP_PRESENT,
    POWER_SUPPLY_PROP_ONLINE,
    POWER_SUPPLY_PROP_TECHNOLOGY,
    POWER_SUPPLY_PROP_TEMP,
};

static LIST_HEAD(ab8500_btemp_list);

struct ab8500_btemp *ab8500_btemp_get(void)
{
    struct ab8500_btemp *btemp;
    btemp = list_first_entry(&ab8500_btemp_list, struct ab8500_btemp, node);

    return btemp;
}

static int ab8500_btemp_batctrl_volt_to_res(struct ab8500_btemp *di,
    int v_batctrl, int inst_curr)
{
    int rbs;

    if (is_ab8500_1p1_or_earlier(di->parent)) {
        /*
         * For ABB cut1.0 and 1.1 BAT_CTRL is internally
         * connected to 1.8V through a 450k resistor
         */
        return (450000 * (v_batctrl)) / (1800 - v_batctrl);
    }

    if (di->bat->adc_therm == ABx500_ADC_THERM_BATCTRL) {
        /*
         * If the battery has internal NTC, we use the current
         * source to calculate the resistance, 7uA or 20uA
         */
        rbs = (v_batctrl * 1000
               - di->bat->gnd_lift_resistance * inst_curr)
              / di->curr_source;
    } else {
        /*
         * BAT_CTRL is internally
         * connected to 1.8V through a 80k resistor
         */
        rbs = (80000 * (v_batctrl)) / (1800 - v_batctrl);
    }

    return rbs;
}

static int ab8500_btemp_read_batctrl_voltage(struct ab8500_btemp *di)
{
    int vbtemp;
    static int prev;

    vbtemp = ab8500_gpadc_convert(di->gpadc, BAT_CTRL);
    if (vbtemp < 0) {
        dev_err(di->dev,
            "%s gpadc conversion failed, using previous value",
            __func__);
        return prev;
    }
    prev = vbtemp;
    return vbtemp;
}

static int ab8500_btemp_curr_source_enable(struct ab8500_btemp *di,
    bool enable)
{
    int curr;
    int ret = 0;

    /*
     * BATCTRL current sources are included on AB8500 cut2.0
     * and future versions
     */
    if (is_ab8500_1p1_or_earlier(di->parent))
        return 0;

    /* Only do this for batteries with internal NTC */
    if (di->bat->adc_therm == ABx500_ADC_THERM_BATCTRL && enable) {
        if (di->curr_source == BTEMP_BATCTRL_CURR_SRC_7UA)
            curr = BAT_CTRL_7U_ENA;
        else
            curr = BAT_CTRL_20U_ENA;

        dev_dbg(di->dev, "Set BATCTRL %duA\n", di->curr_source);

        ret = abx500_mask_and_set_register_interruptible(di->dev,
            AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
            FORCE_BAT_CTRL_CMP_HIGH, FORCE_BAT_CTRL_CMP_HIGH);
        if (ret) {
            dev_err(di->dev, "%s failed setting cmp_force\n",
                __func__);
            return ret;
        }

        /*
         * We have to wait one 32kHz cycle before enabling
         * the current source, since ForceBatCtrlCmpHigh needs
         * to be written in a separate cycle
         */
        udelay(32);

        ret = abx500_set_register_interruptible(di->dev,
            AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
            FORCE_BAT_CTRL_CMP_HIGH | curr);
        if (ret) {
            dev_err(di->dev, "%s failed enabling current source\n",
                __func__);
            goto disable_curr_source;
        }
    } else if (di->bat->adc_therm == ABx500_ADC_THERM_BATCTRL && !enable) {
        dev_dbg(di->dev, "Disable BATCTRL curr source\n");

        /* Write 0 to the curr bits */
        ret = abx500_mask_and_set_register_interruptible(di->dev,
            AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
            BAT_CTRL_7U_ENA | BAT_CTRL_20U_ENA,
            ~(BAT_CTRL_7U_ENA | BAT_CTRL_20U_ENA));
        if (ret) {
            dev_err(di->dev, "%s failed disabling current source\n",
                __func__);
            goto disable_curr_source;
        }

        /* Enable Pull-Up and comparator */
        ret = abx500_mask_and_set_register_interruptible(di->dev,
            AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
            BAT_CTRL_PULL_UP_ENA | BAT_CTRL_CMP_ENA,
            BAT_CTRL_PULL_UP_ENA | BAT_CTRL_CMP_ENA);
        if (ret) {
            dev_err(di->dev, "%s failed enabling PU and comp\n",
                __func__);
            goto enable_pu_comp;
        }

        /*
         * We have to wait one 32kHz cycle before disabling
         * ForceBatCtrlCmpHigh since this needs to be written
         * in a separate cycle
         */
        udelay(32);

        /* Disable 'force comparator' */
        ret = abx500_mask_and_set_register_interruptible(di->dev,
            AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
            FORCE_BAT_CTRL_CMP_HIGH, ~FORCE_BAT_CTRL_CMP_HIGH);
        if (ret) {
            dev_err(di->dev, "%s failed disabling force comp\n",
                __func__);
            goto disable_force_comp;
        }
    }
    return ret;

    /*
     * We have to try unsetting FORCE_BAT_CTRL_CMP_HIGH one more time
     * if we got an error above
     */
disable_curr_source:
    /* Write 0 to the curr bits */
    ret = abx500_mask_and_set_register_interruptible(di->dev,
            AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
            BAT_CTRL_7U_ENA | BAT_CTRL_20U_ENA,
            ~(BAT_CTRL_7U_ENA | BAT_CTRL_20U_ENA));
    if (ret) {
        dev_err(di->dev, "%s failed disabling current source\n",
            __func__);
        return ret;
    }
enable_pu_comp:
    /* Enable Pull-Up and comparator */
    ret = abx500_mask_and_set_register_interruptible(di->dev,
        AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
        BAT_CTRL_PULL_UP_ENA | BAT_CTRL_CMP_ENA,
        BAT_CTRL_PULL_UP_ENA | BAT_CTRL_CMP_ENA);
    if (ret) {
        dev_err(di->dev, "%s failed enabling PU and comp\n",
            __func__);
        return ret;
    }

disable_force_comp:
    /*
     * We have to wait one 32kHz cycle before disabling
     * ForceBatCtrlCmpHigh since this needs to be written
     * in a separate cycle
     */
    udelay(32);

    /* Disable 'force comparator' */
    ret = abx500_mask_and_set_register_interruptible(di->dev,
        AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
        FORCE_BAT_CTRL_CMP_HIGH, ~FORCE_BAT_CTRL_CMP_HIGH);
    if (ret) {
        dev_err(di->dev, "%s failed disabling force comp\n",
            __func__);
        return ret;
    }

    return ret;
}

static int ab8500_btemp_get_batctrl_res(struct ab8500_btemp *di)
{
    int ret;
    int batctrl = 0;
    int res;
    int inst_curr;
    int i;

    /*
     * BATCTRL current sources are included on AB8500 cut2.0
     * and future versions
     */
    ret = ab8500_btemp_curr_source_enable(di, true);
    if (ret) {
        dev_err(di->dev, "%s curr source enabled failed\n", __func__);
        return ret;
    }

    if (!di->fg)
        di->fg = ab8500_fg_get();
    if (!di->fg) {
        dev_err(di->dev, "No fg found\n");
        return -EINVAL;
    }

    ret = ab8500_fg_inst_curr_start(di->fg);

    if (ret) {
        dev_err(di->dev, "Failed to start current measurement\n");
        return ret;
    }

    /*
     * Since there is no interrupt when current measurement is done,
     * loop for over 250ms (250ms is one sample conversion time
     * with 32.768 Khz RTC clock). Note that a stop time must be set
     * since the ab8500_btemp_read_batctrl_voltage call can block and
     * take an unknown amount of time to complete.
     */
    i = 0;

    do {
        batctrl += ab8500_btemp_read_batctrl_voltage(di);
        i++;
        msleep(20);
    } while (!ab8500_fg_inst_curr_done(di->fg));
    batctrl /= i;

    ret = ab8500_fg_inst_curr_finalize(di->fg, &inst_curr);
    if (ret) {
        dev_err(di->dev, "Failed to finalize current measurement\n");
        return ret;
    }

    res = ab8500_btemp_batctrl_volt_to_res(di, batctrl, inst_curr);

    ret = ab8500_btemp_curr_source_enable(di, false);
    if (ret) {
        dev_err(di->dev, "%s curr source disable failed\n", __func__);
        return ret;
    }

    dev_dbg(di->dev, "%s batctrl: %d res: %d inst_curr: %d samples: %d\n",
        __func__, batctrl, res, inst_curr, i);

    return res;
}

static int ab8500_btemp_res_to_temp(struct ab8500_btemp *di,
    const struct abx500_res_to_temp *tbl, int tbl_size, int res)
{
    int i, temp;
    /*
     * Calculate the formula for the straight line
     * Simple interpolation if we are within
     * the resistance table limits, extrapolate
     * if resistance is outside the limits.
     */
    if (res > tbl[0].resist)
        i = 0;
    else if (res <= tbl[tbl_size - 1].resist)
        i = tbl_size - 2;
    else {
        i = 0;
        while (!(res <= tbl[i].resist &&
            res > tbl[i + 1].resist))
            i++;
    }

    temp = tbl[i].temp + ((tbl[i + 1].temp - tbl[i].temp) *
        (res - tbl[i].resist)) / (tbl[i + 1].resist - tbl[i].resist);
    return temp;
}

static int ab8500_btemp_measure_temp(struct ab8500_btemp *di)
{
    int temp;
    static int prev;
    int rbat, rntc, vntc;
    u8 id;

    id = di->bat->batt_id;

    if (di->bat->adc_therm == ABx500_ADC_THERM_BATCTRL &&
            id != BATTERY_UNKNOWN) {

        rbat = ab8500_btemp_get_batctrl_res(di);
        if (rbat < 0) {
            dev_err(di->dev, "%s get batctrl res failed\n",
                __func__);
            /*
             * Return out-of-range temperature so that
             * charging is stopped
             */
            return BTEMP_THERMAL_LOW_LIMIT;
        }

        temp = ab8500_btemp_res_to_temp(di,
            di->bat->bat_type[id].r_to_t_tbl,
            di->bat->bat_type[id].n_temp_tbl_elements, rbat);
    } else {
        vntc = ab8500_gpadc_convert(di->gpadc, BTEMP_BALL);
        if (vntc < 0) {
            dev_err(di->dev,
                "%s gpadc conversion failed,"
                " using previous value\n", __func__);
            return prev;
        }
        /*
         * The PCB NTC is sourced from VTVOUT via a 230kOhm
         * resistor.
         */
        rntc = 230000 * vntc / (VTVOUT_V - vntc);

        temp = ab8500_btemp_res_to_temp(di,
            di->bat->bat_type[id].r_to_t_tbl,
            di->bat->bat_type[id].n_temp_tbl_elements, rntc);
        prev = temp;
    }
    dev_dbg(di->dev, "Battery temperature is %d\n", temp);
    return temp;
}

static int ab8500_btemp_id(struct ab8500_btemp *di)
{
    int res;
    u8 i;

    di->curr_source = BTEMP_BATCTRL_CURR_SRC_7UA;
    di->bat->batt_id = BATTERY_UNKNOWN;

    res =  ab8500_btemp_get_batctrl_res(di);
    if (res < 0) {
        dev_err(di->dev, "%s get batctrl res failed\n", __func__);
        return -ENXIO;
    }

    /* BATTERY_UNKNOWN is defined on position 0, skip it! */
    for (i = BATTERY_UNKNOWN + 1; i < di->bat->n_btypes; i++) {
        if ((res <= di->bat->bat_type[i].resis_high) &&
            (res >= di->bat->bat_type[i].resis_low)) {
            dev_dbg(di->dev, "Battery detected on %s"
                " low %d < res %d < high: %d"
                " index: %d\n",
                di->bat->adc_therm == ABx500_ADC_THERM_BATCTRL ?
                "BATCTRL" : "BATTEMP",
                di->bat->bat_type[i].resis_low, res,
                di->bat->bat_type[i].resis_high, i);

            di->bat->batt_id = i;
            break;
        }
    }

    if (di->bat->batt_id == BATTERY_UNKNOWN) {
        dev_warn(di->dev, "Battery identified as unknown"
            ", resistance %d Ohm\n", res);
        return -ENXIO;
    }

    /*
     * We only have to change current source if the
     * detected type is Type 1, else we use the 7uA source
     */
    if (di->bat->adc_therm == ABx500_ADC_THERM_BATCTRL &&
            di->bat->batt_id == 1) {
        dev_dbg(di->dev, "Set BATCTRL current source to 20uA\n");
        di->curr_source = BTEMP_BATCTRL_CURR_SRC_20UA;
    }

    return di->bat->batt_id;
}

static void ab8500_btemp_periodic_work(struct work_struct *work)
{
    int interval;
    struct ab8500_btemp *di = container_of(work,
        struct ab8500_btemp, btemp_periodic_work.work);

    di->bat_temp = ab8500_btemp_measure_temp(di);

    if (di->bat_temp != di->prev_bat_temp) {
        di->prev_bat_temp = di->bat_temp;
        power_supply_changed(&di->btemp_psy);
    }

    if (di->events.ac_conn || di->events.usb_conn)
        interval = di->bat->temp_interval_chg;
    else
        interval = di->bat->temp_interval_nochg;

    /* Schedule a new measurement */
    queue_delayed_work(di->btemp_wq,
        &di->btemp_periodic_work,
        round_jiffies(interval * HZ));
}

static irqreturn_t ab8500_btemp_batctrlindb_handler(int irq, void *_di)
{
    struct ab8500_btemp *di = _di;
    dev_err(di->dev, "Battery removal detected!\n");

    di->events.batt_rem = true;
    power_supply_changed(&di->btemp_psy);

    return IRQ_HANDLED;
}

static irqreturn_t ab8500_btemp_templow_handler(int irq, void *_di)
{
    struct ab8500_btemp *di = _di;

    if (is_ab8500_2p0_or_earlier(di->parent)) {
        dev_dbg(di->dev, "Ignore false btemp low irq"
            " for ABB cut 1.0, 1.1 and 2.0\n");
    } else {
        dev_crit(di->dev, "Battery temperature lower than -10deg c\n");

        di->events.btemp_low = true;
        di->events.btemp_high = false;
        di->events.btemp_medhigh = false;
        di->events.btemp_lowmed = false;
        power_supply_changed(&di->btemp_psy);
    }

    return IRQ_HANDLED;
}

static irqreturn_t ab8500_btemp_temphigh_handler(int irq, void *_di)
{
    struct ab8500_btemp *di = _di;

    dev_crit(di->dev, "Battery temperature is higher than MAX temp\n");

    di->events.btemp_high = true;
    di->events.btemp_medhigh = false;
    di->events.btemp_lowmed = false;
    di->events.btemp_low = false;
    power_supply_changed(&di->btemp_psy);

    return IRQ_HANDLED;
}

static irqreturn_t ab8500_btemp_lowmed_handler(int irq, void *_di)
{
    struct ab8500_btemp *di = _di;

    dev_dbg(di->dev, "Battery temperature is between low and medium\n");

    di->events.btemp_lowmed = true;
    di->events.btemp_medhigh = false;
    di->events.btemp_high = false;
    di->events.btemp_low = false;
    power_supply_changed(&di->btemp_psy);

    return IRQ_HANDLED;
}

static irqreturn_t ab8500_btemp_medhigh_handler(int irq, void *_di)
{
    struct ab8500_btemp *di = _di;

    dev_dbg(di->dev, "Battery temperature is between medium and high\n");

    di->events.btemp_medhigh = true;
    di->events.btemp_lowmed = false;
    di->events.btemp_high = false;
    di->events.btemp_low = false;
    power_supply_changed(&di->btemp_psy);

    return IRQ_HANDLED;
}

static void ab8500_btemp_periodic(struct ab8500_btemp *di,
    bool enable)
{
    dev_dbg(di->dev, "Enable periodic temperature measurements: %d\n",
        enable);
    /*
     * Make sure a new measurement is done directly by cancelling
     * any pending work
     */
    cancel_delayed_work_sync(&di->btemp_periodic_work);

    if (enable)
        queue_delayed_work(di->btemp_wq, &di->btemp_periodic_work, 0);
}

static int ab8500_btemp_get_temp(struct ab8500_btemp *di)
{
    int temp = 0;

    /*
     * The BTEMP events are not reliabe on AB8500 cut2.0
     * and prior versions
     */
    if (is_ab8500_2p0_or_earlier(di->parent)) {
        temp = di->bat_temp * 10;
    } else {
        if (di->events.btemp_low) {
            if (temp > di->btemp_ranges.btemp_low_limit)
                temp = di->btemp_ranges.btemp_low_limit;
            else
                temp = di->bat_temp * 10;
        } else if (di->events.btemp_high) {
            if (temp < di->btemp_ranges.btemp_high_limit)
                temp = di->btemp_ranges.btemp_high_limit;
            else
                temp = di->bat_temp * 10;
        } else if (di->events.btemp_lowmed) {
            if (temp > di->btemp_ranges.btemp_med_limit)
                temp = di->btemp_ranges.btemp_med_limit;
            else
                temp = di->bat_temp * 10;
        } else if (di->events.btemp_medhigh) {
            if (temp < di->btemp_ranges.btemp_med_limit)
                temp = di->btemp_ranges.btemp_med_limit;
            else
                temp = di->bat_temp * 10;
        } else
            temp = di->bat_temp * 10;
    }
    return temp;
}

int ab8500_btemp_get_batctrl_temp(struct ab8500_btemp *btemp)
{
    return btemp->bat_temp * 1000;
}

static int ab8500_btemp_get_property(struct power_supply *psy,
    enum power_supply_property psp,
    union power_supply_propval *val)
{
    struct ab8500_btemp *di;

    di = to_ab8500_btemp_device_info(psy);

    switch (psp) {
    case POWER_SUPPLY_PROP_PRESENT:
    case POWER_SUPPLY_PROP_ONLINE:
        if (di->events.batt_rem)
            val->intval = 0;
        else
            val->intval = 1;
        break;
    case POWER_SUPPLY_PROP_TECHNOLOGY:
        val->intval = di->bat->bat_type[di->bat->batt_id].name;
        break;
    case POWER_SUPPLY_PROP_TEMP:
        val->intval = ab8500_btemp_get_temp(di);
        break;
    default:
        return -EINVAL;
    }
    return 0;
}

static int ab8500_btemp_get_ext_psy_data(struct device *dev, void *data)
{
    struct power_supply *psy;
    struct power_supply *ext;
    struct ab8500_btemp *di;
    union power_supply_propval ret;
    int i, j;
    bool psy_found = false;

    psy = (struct power_supply *)data;
    ext = dev_get_drvdata(dev);
    di = to_ab8500_btemp_device_info(psy);

    /*
     * For all psy where the name of your driver
     * appears in any supplied_to
     */
    for (i = 0; i < ext->num_supplicants; i++) {
        if (!strcmp(ext->supplied_to[i], psy->name))
            psy_found = true;
    }

    if (!psy_found)
        return 0;

    /* Go through all properties for the psy */
    for (j = 0; j < ext->num_properties; j++) {
        enum power_supply_property prop;
        prop = ext->properties[j];

        if (ext->get_property(ext, prop, &ret))
            continue;

        switch (prop) {
        case POWER_SUPPLY_PROP_PRESENT:
            switch (ext->type) {
            case POWER_SUPPLY_TYPE_MAINS:
                /* AC disconnected */
                if (!ret.intval && di->events.ac_conn) {
                    di->events.ac_conn = false;
                }
                /* AC connected */
                else if (ret.intval && !di->events.ac_conn) {
                    di->events.ac_conn = true;
                    if (!di->events.usb_conn)
                        ab8500_btemp_periodic(di, true);
                }
                break;
            case POWER_SUPPLY_TYPE_USB:
                /* USB disconnected */
                if (!ret.intval && di->events.usb_conn) {
                    di->events.usb_conn = false;
                }
                /* USB connected */
                else if (ret.intval && !di->events.usb_conn) {
                    di->events.usb_conn = true;
                    if (!di->events.ac_conn)
                        ab8500_btemp_periodic(di, true);
                }
                break;
            default:
                break;
            }
            break;
        default:
            break;
        }
    }
    return 0;
}

static void ab8500_btemp_external_power_changed(struct power_supply *psy)
{
    struct ab8500_btemp *di = to_ab8500_btemp_device_info(psy);

    class_for_each_device(power_supply_class, NULL,
        &di->btemp_psy, ab8500_btemp_get_ext_psy_data);
}

/* ab8500 btemp driver interrupts and their respective isr */
static struct ab8500_btemp_interrupts ab8500_btemp_irq[] = {
    {"BAT_CTRL_INDB", ab8500_btemp_batctrlindb_handler},
    {"BTEMP_LOW", ab8500_btemp_templow_handler},
    {"BTEMP_HIGH", ab8500_btemp_temphigh_handler},
    {"BTEMP_LOW_MEDIUM", ab8500_btemp_lowmed_handler},
    {"BTEMP_MEDIUM_HIGH", ab8500_btemp_medhigh_handler},
};

#if defined(CONFIG_PM)
static int ab8500_btemp_resume(struct platform_device *pdev)
{
    struct ab8500_btemp *di = platform_get_drvdata(pdev);

    ab8500_btemp_periodic(di, true);

    return 0;
}

static int ab8500_btemp_suspend(struct platform_device *pdev,
    pm_message_t state)
{
    struct ab8500_btemp *di = platform_get_drvdata(pdev);

    ab8500_btemp_periodic(di, false);

    return 0;
}
#else
#define ab8500_btemp_suspend      NULL
#define ab8500_btemp_resume       NULL
#endif

static int __devexit ab8500_btemp_remove(struct platform_device *pdev)
{
    struct ab8500_btemp *di = platform_get_drvdata(pdev);
    int i, irq;

    /* Disable interrupts */
    for (i = 0; i < ARRAY_SIZE(ab8500_btemp_irq); i++) {
        irq = platform_get_irq_byname(pdev, ab8500_btemp_irq[i].name);
        free_irq(irq, di);
    }

    /* Delete the work queue */
    destroy_workqueue(di->btemp_wq);

    flush_scheduled_work();
    power_supply_unregister(&di->btemp_psy);
    platform_set_drvdata(pdev, NULL);
    kfree(di);

    return 0;
}

static int __devinit ab8500_btemp_probe(struct platform_device *pdev)
{
    int irq, i, ret = 0;
    u8 val;
    struct abx500_bm_plat_data *plat_data = pdev->dev.platform_data;
    struct ab8500_btemp *di;

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

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

    /* get parent data */
    di->dev = &pdev->dev;
    di->parent = dev_get_drvdata(pdev->dev.parent);
    di->gpadc = ab8500_gpadc_get("ab8500-gpadc.0");

    /* get btemp specific platform data */
    di->pdata = plat_data->btemp;
    if (!di->pdata) {
        dev_err(di->dev, "no btemp platform data supplied\n");
        ret = -EINVAL;
        goto free_device_info;
    }

    /* get battery specific platform data */
    di->bat = plat_data->battery;
    if (!di->bat) {
        dev_err(di->dev, "no battery platform data supplied\n");
        ret = -EINVAL;
        goto free_device_info;
    }

    /* BTEMP supply */
    di->btemp_psy.name = "ab8500_btemp";
    di->btemp_psy.type = POWER_SUPPLY_TYPE_BATTERY;
    di->btemp_psy.properties = ab8500_btemp_props;
    di->btemp_psy.num_properties = ARRAY_SIZE(ab8500_btemp_props);
    di->btemp_psy.get_property = ab8500_btemp_get_property;
    di->btemp_psy.supplied_to = di->pdata->supplied_to;
    di->btemp_psy.num_supplicants = di->pdata->num_supplicants;
    di->btemp_psy.external_power_changed =
        ab8500_btemp_external_power_changed;


    /* Create a work queue for the btemp */
    di->btemp_wq =
        create_singlethread_workqueue("ab8500_btemp_wq");
    if (di->btemp_wq == NULL) {
        dev_err(di->dev, "failed to create work queue\n");
        ret = -ENOMEM;
        goto free_device_info;
    }

    /* Init work for measuring temperature periodically */
    INIT_DEFERRABLE_WORK(&di->btemp_periodic_work,
        ab8500_btemp_periodic_work);

    /* Identify the battery */
    if (ab8500_btemp_id(di) < 0)
        dev_warn(di->dev, "failed to identify the battery\n");

    /* Set BTEMP thermal limits. Low and Med are fixed */
    di->btemp_ranges.btemp_low_limit = BTEMP_THERMAL_LOW_LIMIT;
    di->btemp_ranges.btemp_med_limit = BTEMP_THERMAL_MED_LIMIT;

    ret = abx500_get_register_interruptible(di->dev, AB8500_CHARGER,
        AB8500_BTEMP_HIGH_TH, &val);
    if (ret < 0) {
        dev_err(di->dev, "%s ab8500 read failed\n", __func__);
        goto free_btemp_wq;
    }
    switch (val) {
    case BTEMP_HIGH_TH_57_0:
    case BTEMP_HIGH_TH_57_1:
        di->btemp_ranges.btemp_high_limit =
            BTEMP_THERMAL_HIGH_LIMIT_57;
        break;
    case BTEMP_HIGH_TH_52:
        di->btemp_ranges.btemp_high_limit =
            BTEMP_THERMAL_HIGH_LIMIT_52;
        break;
    case BTEMP_HIGH_TH_62:
        di->btemp_ranges.btemp_high_limit =
            BTEMP_THERMAL_HIGH_LIMIT_62;
        break;
    }

    /* Register BTEMP power supply class */
    ret = power_supply_register(di->dev, &di->btemp_psy);
    if (ret) {
        dev_err(di->dev, "failed to register BTEMP psy\n");
        goto free_btemp_wq;
    }

    /* Register interrupts */
    for (i = 0; i < ARRAY_SIZE(ab8500_btemp_irq); i++) {
        irq = platform_get_irq_byname(pdev, ab8500_btemp_irq[i].name);
        ret = request_threaded_irq(irq, NULL, ab8500_btemp_irq[i].isr,
            IRQF_SHARED | IRQF_NO_SUSPEND,
            ab8500_btemp_irq[i].name, di);

        if (ret) {
            dev_err(di->dev, "failed to request %s IRQ %d: %d\n"
                , ab8500_btemp_irq[i].name, irq, ret);
            goto free_irq;
        }
        dev_dbg(di->dev, "Requested %s IRQ %d: %d\n",
            ab8500_btemp_irq[i].name, irq, ret);
    }

    platform_set_drvdata(pdev, di);

    /* Kick off periodic temperature measurements */
    ab8500_btemp_periodic(di, true);
    list_add_tail(&di->node, &ab8500_btemp_list);

    return ret;

free_irq:
    power_supply_unregister(&di->btemp_psy);

    /* We also have to free all successfully registered irqs */
    for (i = i - 1; i >= 0; i--) {
        irq = platform_get_irq_byname(pdev, ab8500_btemp_irq[i].name);
        free_irq(irq, di);
    }
free_btemp_wq:
    destroy_workqueue(di->btemp_wq);
free_device_info:
    kfree(di);

    return ret;
}

static struct platform_driver ab8500_btemp_driver = {
    .probe = ab8500_btemp_probe,
    .remove = __devexit_p(ab8500_btemp_remove),
    .suspend = ab8500_btemp_suspend,
    .resume = ab8500_btemp_resume,
    .driver = {
        .name = "ab8500-btemp",
        .owner = THIS_MODULE,
    },
};

static int __init ab8500_btemp_init(void)
{
    return platform_driver_register(&ab8500_btemp_driver);
}

static void __exit ab8500_btemp_exit(void)
{
    platform_driver_unregister(&ab8500_btemp_driver);
}

subsys_initcall_sync(ab8500_btemp_init);
module_exit(ab8500_btemp_exit);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Johan Palsson, Karl Komierowski, Arun R Murthy");
MODULE_ALIAS("platform:ab8500-btemp");
MODULE_DESCRIPTION("AB8500 battery temperature driver");