Added missing tegra files.HEADmaster

1 files changed, 810 insertions, 0 deletions

diff --git a/drivers/power/bq20z75.c b/drivers/power/bq20z75.c
new file mode 100644
index 00000000000..32e5a8c5c3d
--- /dev/null
+++ b/drivers/power/bq20z75.c
@@ -0,0 +1,810 @@
+/*
+ * Gas Gauge driver for TI's BQ20Z75
+ *
+ * Copyright (c) 2010, NVIDIA Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/power_supply.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+
+#include <linux/power/bq20z75.h>
+
+enum {
+        REG_MANUFACTURER_DATA,
+        REG_TEMPERATURE,
+        REG_VOLTAGE,
+        REG_CURRENT,
+        REG_CAPACITY,
+        REG_TIME_TO_EMPTY,
+        REG_TIME_TO_FULL,
+        REG_STATUS,
+        REG_CYCLE_COUNT,
+        REG_SERIAL_NUMBER,
+        REG_REMAINING_CAPACITY,
+        REG_REMAINING_CAPACITY_CHARGE,
+        REG_FULL_CHARGE_CAPACITY,
+        REG_FULL_CHARGE_CAPACITY_CHARGE,
+        REG_DESIGN_CAPACITY,
+        REG_DESIGN_CAPACITY_CHARGE,
+        REG_DESIGN_VOLTAGE,
+};
+
+/* Battery Mode defines */
+#define BATTERY_MODE_OFFSET             0x03
+#define BATTERY_MODE_MASK               0x8000
+enum bq20z75_battery_mode {
+        BATTERY_MODE_AMPS,
+        BATTERY_MODE_WATTS
+};
+
+/* manufacturer access defines */
+#define MANUFACTURER_ACCESS_STATUS      0x0006
+#define MANUFACTURER_ACCESS_SLEEP       0x0011
+
+/* battery status value bits */
+#define BATTERY_DISCHARGING             0x40
+#define BATTERY_FULL_CHARGED            0x20
+#define BATTERY_FULL_DISCHARGED         0x10
+
+#define BQ20Z75_DATA(_psp, _addr, _min_value, _max_value) { \
+        .psp = _psp, \
+        .addr = _addr, \
+        .min_value = _min_value, \
+        .max_value = _max_value, \
+}
+
+static const struct bq20z75_device_data {
+        enum power_supply_property psp;
+        u8 addr;
+        int min_value;
+        int max_value;
+} bq20z75_data[] = {
+        [REG_MANUFACTURER_DATA] =
+                BQ20Z75_DATA(POWER_SUPPLY_PROP_PRESENT, 0x00, 0, 65535),
+        [REG_TEMPERATURE] =
+                BQ20Z75_DATA(POWER_SUPPLY_PROP_TEMP, 0x08, 0, 65535),
+        [REG_VOLTAGE] =
+                BQ20Z75_DATA(POWER_SUPPLY_PROP_VOLTAGE_NOW, 0x09, 0, 20000),
+        [REG_CURRENT] =
+                BQ20Z75_DATA(POWER_SUPPLY_PROP_CURRENT_NOW, 0x0A, -32768,
+                        32767),
+        [REG_CAPACITY] =
+                BQ20Z75_DATA(POWER_SUPPLY_PROP_CAPACITY, 0x0E, 0, 100),
+        [REG_REMAINING_CAPACITY] =
+                BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_NOW, 0x0F, 0, 65535),
+        [REG_REMAINING_CAPACITY_CHARGE] =
+                BQ20Z75_DATA(POWER_SUPPLY_PROP_CHARGE_NOW, 0x0F, 0, 65535),
+        [REG_FULL_CHARGE_CAPACITY] =
+                BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_FULL, 0x10, 0, 65535),
+        [REG_FULL_CHARGE_CAPACITY_CHARGE] =
+                BQ20Z75_DATA(POWER_SUPPLY_PROP_CHARGE_FULL, 0x10, 0, 65535),
+        [REG_TIME_TO_EMPTY] =
+                BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, 0x12, 0,
+                        65535),
+        [REG_TIME_TO_FULL] =
+                BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_FULL_AVG, 0x13, 0,
+                        65535),
+        [REG_STATUS] =
+                BQ20Z75_DATA(POWER_SUPPLY_PROP_STATUS, 0x16, 0, 65535),
+        [REG_CYCLE_COUNT] =
+                BQ20Z75_DATA(POWER_SUPPLY_PROP_CYCLE_COUNT, 0x17, 0, 65535),
+        [REG_DESIGN_CAPACITY] =
+                BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN, 0x18, 0,
+                        65535),
+        [REG_DESIGN_CAPACITY_CHARGE] =
+                BQ20Z75_DATA(POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN, 0x18, 0,
+                        65535),
+        [REG_DESIGN_VOLTAGE] =
+                BQ20Z75_DATA(POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN, 0x19, 0,
+                        65535),
+        [REG_SERIAL_NUMBER] =
+                BQ20Z75_DATA(POWER_SUPPLY_PROP_SERIAL_NUMBER, 0x1C, 0, 65535),
+};
+
+static enum power_supply_property bq20z75_properties[] = {
+        POWER_SUPPLY_PROP_STATUS,
+        POWER_SUPPLY_PROP_HEALTH,
+        POWER_SUPPLY_PROP_PRESENT,
+        POWER_SUPPLY_PROP_TECHNOLOGY,
+        POWER_SUPPLY_PROP_CYCLE_COUNT,
+        POWER_SUPPLY_PROP_VOLTAGE_NOW,
+        POWER_SUPPLY_PROP_CURRENT_NOW,
+        POWER_SUPPLY_PROP_CAPACITY,
+        POWER_SUPPLY_PROP_TEMP,
+        POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
+        POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
+        POWER_SUPPLY_PROP_SERIAL_NUMBER,
+        POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
+        POWER_SUPPLY_PROP_ENERGY_NOW,
+        POWER_SUPPLY_PROP_ENERGY_FULL,
+        POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
+        POWER_SUPPLY_PROP_CHARGE_NOW,
+        POWER_SUPPLY_PROP_CHARGE_FULL,
+        POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
+};
+
+struct bq20z75_info {
+        struct i2c_client               *client;
+        struct power_supply             power_supply;
+        struct bq20z75_platform_data    plat_data;
+        bool                            is_present;
+        bool                            gpio_detect;
+        bool                            enable_detection;
+        int                             irq;
+        int                             last_state;
+        int                             poll_time;
+        struct delayed_work             work;
+        int                             ignore_changes;
+};
+
+static int bq20z75_read_word_data(struct i2c_client *client, u8 address)
+{
+        struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
+        s32 ret = 0;
+        int retries = 1;
+
+        retries = max(bq20z75_device->plat_data.i2c_retry_count + 1, 1);
+
+        while (retries > 0) {
+                ret = i2c_smbus_read_word_data(client, address);
+                if (ret >= 0)
+                        break;
+                retries--;
+        }
+
+        if (ret < 0) {
+                dev_dbg(&client->dev,
+                        "%s: i2c read at address 0x%x failed\n",
+                        __func__, address);
+                return ret;
+        }
+
+        return le16_to_cpu(ret);
+}
+
+static int bq20z75_write_word_data(struct i2c_client *client, u8 address,
+        u16 value)
+{
+        struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
+        s32 ret = 0;
+        int retries = 1;
+
+        retries = max(bq20z75_device->plat_data.i2c_retry_count + 1, 1);
+
+        while (retries > 0) {
+                ret = i2c_smbus_write_word_data(client, address,
+                        le16_to_cpu(value));
+                if (ret >= 0)
+                        break;
+                retries--;
+        }
+
+        if (ret < 0) {
+                dev_dbg(&client->dev,
+                        "%s: i2c write to address 0x%x failed\n",
+                        __func__, address);
+                return ret;
+        }
+
+        return 0;
+}
+
+static int bq20z75_get_battery_presence_and_health(
+        struct i2c_client *client, enum power_supply_property psp,
+        union power_supply_propval *val)
+{
+        s32 ret;
+        struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
+
+        if (psp == POWER_SUPPLY_PROP_PRESENT &&
+                bq20z75_device->gpio_detect) {
+                ret = gpio_get_value(
+                        bq20z75_device->plat_data.battery_detect);
+                if (ret == bq20z75_device->plat_data.battery_detect_present)
+                        val->intval = 1;
+                else
+                        val->intval = 0;
+                bq20z75_device->is_present = val->intval;
+                return ret;
+        }
+
+        /* Write to ManufacturerAccess with
+         * ManufacturerAccess command and then
+         * read the status */
+        ret = bq20z75_write_word_data(client,
+                bq20z75_data[REG_MANUFACTURER_DATA].addr,
+                MANUFACTURER_ACCESS_STATUS);
+        if (ret < 0) {
+                if (psp == POWER_SUPPLY_PROP_PRESENT)
+                        val->intval = 0; /* battery removed */
+                return ret;
+        }
+
+        ret = bq20z75_read_word_data(client,
+                bq20z75_data[REG_MANUFACTURER_DATA].addr);
+        if (ret < 0)
+                return ret;
+
+        if (ret < bq20z75_data[REG_MANUFACTURER_DATA].min_value ||
+            ret > bq20z75_data[REG_MANUFACTURER_DATA].max_value) {
+                val->intval = 0;
+                return 0;
+        }
+
+        /* Mask the upper nibble of 2nd byte and
+         * lower byte of response then
+         * shift the result by 8 to get status*/
+        ret &= 0x0F00;
+        ret >>= 8;
+        if (psp == POWER_SUPPLY_PROP_PRESENT) {
+                if (ret == 0x0F)
+                        /* battery removed */
+                        val->intval = 0;
+                else
+                        val->intval = 1;
+        } else if (psp == POWER_SUPPLY_PROP_HEALTH) {
+                if (ret == 0x09)
+                        val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+                else if (ret == 0x0B)
+                        val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
+                else if (ret == 0x0C)
+                        val->intval = POWER_SUPPLY_HEALTH_DEAD;
+                else
+                        val->intval = POWER_SUPPLY_HEALTH_GOOD;
+        }
+
+        return 0;
+}
+
+static int bq20z75_get_battery_property(struct i2c_client *client,
+        int reg_offset, enum power_supply_property psp,
+        union power_supply_propval *val)
+{
+        struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
+        s32 ret;
+
+        ret = bq20z75_read_word_data(client,
+                bq20z75_data[reg_offset].addr);
+        if (ret < 0)
+                return ret;
+
+        /* returned values are 16 bit */
+        if (bq20z75_data[reg_offset].min_value < 0)
+                ret = (s16)ret;
+
+        if (ret >= bq20z75_data[reg_offset].min_value &&
+            ret <= bq20z75_data[reg_offset].max_value) {
+                val->intval = ret;
+                if (psp != POWER_SUPPLY_PROP_STATUS)
+                        return 0;
+
+                if (ret & BATTERY_FULL_CHARGED)
+                        val->intval = POWER_SUPPLY_STATUS_FULL;
+                else if (ret & BATTERY_FULL_DISCHARGED)
+                        val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+                else if (ret & BATTERY_DISCHARGING)
+                        val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+                else
+                        val->intval = POWER_SUPPLY_STATUS_CHARGING;
+
+                if (bq20z75_device->poll_time == 0)
+                        bq20z75_device->last_state = val->intval;
+                else if (bq20z75_device->last_state != val->intval) {
+                        cancel_delayed_work_sync(&bq20z75_device->work);
+                        power_supply_changed(&bq20z75_device->power_supply);
+                        bq20z75_device->poll_time = 0;
+                }
+        } else {
+                if (psp == POWER_SUPPLY_PROP_STATUS)
+                        val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
+                else
+                        val->intval = 0;
+        }
+
+        return 0;
+}
+
+static void  bq20z75_unit_adjustment(struct i2c_client *client,
+        enum power_supply_property psp, union power_supply_propval *val)
+{
+#define BASE_UNIT_CONVERSION            1000
+#define BATTERY_MODE_CAP_MULT_WATT      (10 * BASE_UNIT_CONVERSION)
+#define TIME_UNIT_CONVERSION            60
+#define TEMP_KELVIN_TO_CELSIUS          2731
+        switch (psp) {
+        case POWER_SUPPLY_PROP_ENERGY_NOW:
+        case POWER_SUPPLY_PROP_ENERGY_FULL:
+        case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
+                /* bq20z75 provides energy in units of 10mWh.
+                 * Convert to µWh
+                 */
+                val->intval *= BATTERY_MODE_CAP_MULT_WATT;
+                break;
+
+        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+        case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+        case POWER_SUPPLY_PROP_CURRENT_NOW:
+        case POWER_SUPPLY_PROP_CHARGE_NOW:
+        case POWER_SUPPLY_PROP_CHARGE_FULL:
+        case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
+                val->intval *= BASE_UNIT_CONVERSION;
+                break;
+
+        case POWER_SUPPLY_PROP_TEMP:
+                /* bq20z75 provides battery temperature in 0.1K
+                 * so convert it to 0.1°C
+                 */
+                val->intval -= TEMP_KELVIN_TO_CELSIUS;
+                break;
+
+        case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
+        case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
+                /* bq20z75 provides time to empty and time to full in minutes.
+                 * Convert to seconds
+                 */
+                val->intval *= TIME_UNIT_CONVERSION;
+                break;
+
+        default:
+                dev_dbg(&client->dev,
+                        "%s: no need for unit conversion %d\n", __func__, psp);
+        }
+}
+
+static enum bq20z75_battery_mode
+bq20z75_set_battery_mode(struct i2c_client *client,
+        enum bq20z75_battery_mode mode)
+{
+        int ret, original_val;
+
+        original_val = bq20z75_read_word_data(client, BATTERY_MODE_OFFSET);
+        if (original_val < 0)
+                return original_val;
+
+        if ((original_val & BATTERY_MODE_MASK) == mode)
+                return mode;
+
+        if (mode == BATTERY_MODE_AMPS)
+                ret = original_val & ~BATTERY_MODE_MASK;
+        else
+                ret = original_val | BATTERY_MODE_MASK;
+
+        ret = bq20z75_write_word_data(client, BATTERY_MODE_OFFSET, ret);
+        if (ret < 0)
+                return ret;
+
+        return original_val & BATTERY_MODE_MASK;
+}
+
+static int bq20z75_get_battery_capacity(struct i2c_client *client,
+        int reg_offset, enum power_supply_property psp,
+        union power_supply_propval *val)
+{
+        s32 ret;
+        enum bq20z75_battery_mode mode = BATTERY_MODE_WATTS;
+
+        if (power_supply_is_amp_property(psp))
+                mode = BATTERY_MODE_AMPS;
+
+        mode = bq20z75_set_battery_mode(client, mode);
+        if (mode < 0)
+                return mode;
+
+        ret = bq20z75_read_word_data(client, bq20z75_data[reg_offset].addr);
+        if (ret < 0)
+                return ret;
+
+        if (psp == POWER_SUPPLY_PROP_CAPACITY) {
+                /* bq20z75 spec says that this can be >100 %
+                * even if max value is 100 % */
+                val->intval = min(ret, 100);
+        } else
+                val->intval = ret;
+
+        ret = bq20z75_set_battery_mode(client, mode);
+        if (ret < 0)
+                return ret;
+
+        return 0;
+}
+
+static char bq20z75_serial[5];
+static int bq20z75_get_battery_serial_number(struct i2c_client *client,
+        union power_supply_propval *val)
+{
+        int ret;
+
+        ret = bq20z75_read_word_data(client,
+                bq20z75_data[REG_SERIAL_NUMBER].addr);
+        if (ret < 0)
+                return ret;
+
+        ret = sprintf(bq20z75_serial, "%04x", ret);
+        val->strval = bq20z75_serial;
+
+        return 0;
+}
+
+static int bq20z75_get_property_index(struct i2c_client *client,
+        enum power_supply_property psp)
+{
+        int count;
+        for (count = 0; count < ARRAY_SIZE(bq20z75_data); count++)
+                if (psp == bq20z75_data[count].psp)
+                        return count;
+
+        dev_warn(&client->dev,
+                "%s: Invalid Property - %d\n", __func__, psp);
+
+        return -EINVAL;
+}
+
+static int bq20z75_get_property(struct power_supply *psy,
+        enum power_supply_property psp,
+        union power_supply_propval *val)
+{
+        int ret = 0;
+        struct bq20z75_info *bq20z75_device = container_of(psy,
+                                struct bq20z75_info, power_supply);
+        struct i2c_client *client = bq20z75_device->client;
+
+        switch (psp) {
+        case POWER_SUPPLY_PROP_PRESENT:
+        case POWER_SUPPLY_PROP_HEALTH:
+                ret = bq20z75_get_battery_presence_and_health(client, psp, val);
+                if (psp == POWER_SUPPLY_PROP_PRESENT)
+                        return 0;
+                break;
+
+        case POWER_SUPPLY_PROP_TECHNOLOGY:
+                val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
+                break;
+
+        case POWER_SUPPLY_PROP_ENERGY_NOW:
+        case POWER_SUPPLY_PROP_ENERGY_FULL:
+        case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
+        case POWER_SUPPLY_PROP_CHARGE_NOW:
+        case POWER_SUPPLY_PROP_CHARGE_FULL:
+        case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
+        case POWER_SUPPLY_PROP_CAPACITY:
+                ret = bq20z75_get_property_index(client, psp);
+                if (ret < 0)
+                        break;
+
+                ret = bq20z75_get_battery_capacity(client, ret, psp, val);
+                break;
+
+        case POWER_SUPPLY_PROP_SERIAL_NUMBER:
+                ret = bq20z75_get_battery_serial_number(client, val);
+                break;
+
+        case POWER_SUPPLY_PROP_STATUS:
+        case POWER_SUPPLY_PROP_CYCLE_COUNT:
+        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+        case POWER_SUPPLY_PROP_CURRENT_NOW:
+        case POWER_SUPPLY_PROP_TEMP:
+        case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
+        case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
+        case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+                ret = bq20z75_get_property_index(client, psp);
+                if (ret < 0)
+                        break;
+
+                ret = bq20z75_get_battery_property(client, ret, psp, val);
+                break;
+
+        default:
+                dev_err(&client->dev,
+                        "%s: INVALID property\n", __func__);
+                return -EINVAL;
+        }
+
+        if (!bq20z75_device->enable_detection)
+                goto done;
+
+        if (!bq20z75_device->gpio_detect &&
+                bq20z75_device->is_present != (ret >= 0)) {
+                bq20z75_device->is_present = (ret >= 0);
+                power_supply_changed(&bq20z75_device->power_supply);
+        }
+
+done:
+        if (!ret) {
+                /* Convert units to match requirements for power supply class */
+                bq20z75_unit_adjustment(client, psp, val);
+        }
+
+        dev_dbg(&client->dev,
+                "%s: property = %d, value = %x\n", __func__, psp, val->intval);
+
+        if (ret && bq20z75_device->is_present)
+                return ret;
+
+        /* battery not present, so return NODATA for properties */
+        if (ret)
+                return -ENODATA;
+
+        return 0;
+}
+
+static irqreturn_t bq20z75_irq(int irq, void *devid)
+{
+        struct power_supply *battery = devid;
+
+        power_supply_changed(battery);
+
+        return IRQ_HANDLED;
+}
+
+static void bq20z75_external_power_changed(struct power_supply *psy)
+{
+        struct bq20z75_info *bq20z75_device;
+
+        bq20z75_device = container_of(psy, struct bq20z75_info, power_supply);
+
+        if (bq20z75_device->ignore_changes > 0) {
+                bq20z75_device->ignore_changes--;
+                return;
+        }
+
+        /* cancel outstanding work */
+        cancel_delayed_work_sync(&bq20z75_device->work);
+
+        schedule_delayed_work(&bq20z75_device->work, HZ);
+        bq20z75_device->poll_time = bq20z75_device->plat_data.poll_retry_count;
+}
+
+static void bq20z75_delayed_work(struct work_struct *work)
+{
+        struct bq20z75_info *bq20z75_device;
+        s32 ret;
+
+        bq20z75_device = container_of(work, struct bq20z75_info, work.work);
+
+        ret = bq20z75_read_word_data(bq20z75_device->client,
+                                     bq20z75_data[REG_STATUS].addr);
+        /* if the read failed, give up on this work */
+        if (ret < 0) {
+                bq20z75_device->poll_time = 0;
+                return;
+        }
+
+        if (ret & BATTERY_FULL_CHARGED)
+                ret = POWER_SUPPLY_STATUS_FULL;
+        else if (ret & BATTERY_FULL_DISCHARGED)
+                ret = POWER_SUPPLY_STATUS_NOT_CHARGING;
+        else if (ret & BATTERY_DISCHARGING)
+                ret = POWER_SUPPLY_STATUS_DISCHARGING;
+        else
+                ret = POWER_SUPPLY_STATUS_CHARGING;
+
+        if (bq20z75_device->last_state != ret) {
+                bq20z75_device->poll_time = 0;
+                power_supply_changed(&bq20z75_device->power_supply);
+                return;
+        }
+        if (bq20z75_device->poll_time > 0) {
+                schedule_delayed_work(&bq20z75_device->work, HZ);
+                bq20z75_device->poll_time--;
+                return;
+        }
+}
+
+static int __devinit bq20z75_probe(struct i2c_client *client,
+        const struct i2c_device_id *id)
+{
+        struct bq20z75_info *bq20z75_device;
+        struct bq20z75_platform_data *pdata = client->dev.platform_data;
+        int rc;
+        int irq;
+
+        bq20z75_device = kzalloc(sizeof(struct bq20z75_info), GFP_KERNEL);
+        if (!bq20z75_device)
+                return -ENOMEM;
+
+        bq20z75_device->client = client;
+        bq20z75_device->enable_detection = false;
+        bq20z75_device->gpio_detect = false;
+        bq20z75_device->power_supply.name = "battery";
+        bq20z75_device->power_supply.type = POWER_SUPPLY_TYPE_BATTERY;
+        bq20z75_device->power_supply.properties = bq20z75_properties;
+        bq20z75_device->power_supply.num_properties =
+                ARRAY_SIZE(bq20z75_properties);
+        bq20z75_device->power_supply.get_property = bq20z75_get_property;
+        /* ignore first notification of external change, it is generated
+         * from the power_supply_register call back
+         */
+        bq20z75_device->ignore_changes = 1;
+        bq20z75_device->last_state = POWER_SUPPLY_STATUS_UNKNOWN;
+        bq20z75_device->power_supply.external_power_changed =
+                bq20z75_external_power_changed;
+
+        if (pdata) {
+                bq20z75_device->gpio_detect =
+                        gpio_is_valid(pdata->battery_detect);
+                memcpy(&bq20z75_device->plat_data, pdata, sizeof(struct bq20z75_platform_data));
+        }
+
+        i2c_set_clientdata(client, bq20z75_device);
+
+        /* Probing for the presence of the bq20z75 */
+        rc = bq20z75_read_word_data(client,
+                bq20z75_data[REG_SERIAL_NUMBER].addr);
+
+        if (rc < 0) {
+                dev_err(&client->dev,
+                        "%s: bq20z75 is not responding\n", __func__);
+                rc = -ENODEV;
+                goto exit_mem_free;
+        }
+
+        if (!bq20z75_device->gpio_detect)
+                goto skip_gpio;
+
+        rc = gpio_request(pdata->battery_detect, dev_name(&client->dev));
+        if (rc) {
+                dev_warn(&client->dev, "Failed to request gpio: %d\n", rc);
+                bq20z75_device->gpio_detect = false;
+                goto skip_gpio;
+        }
+
+        rc = gpio_direction_input(pdata->battery_detect);
+        if (rc) {
+                dev_warn(&client->dev, "Failed to get gpio as input: %d\n", rc);
+                gpio_free(pdata->battery_detect);
+                bq20z75_device->gpio_detect = false;
+                goto skip_gpio;
+        }
+
+        irq = gpio_to_irq(pdata->battery_detect);
+        if (irq <= 0) {
+                dev_warn(&client->dev, "Failed to get gpio as irq: %d\n", irq);
+                gpio_free(pdata->battery_detect);
+                bq20z75_device->gpio_detect = false;
+                goto skip_gpio;
+        }
+
+        rc = request_irq(irq, bq20z75_irq,
+                IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+                dev_name(&client->dev), &bq20z75_device->power_supply);
+        if (rc) {
+                dev_warn(&client->dev, "Failed to request irq: %d\n", rc);
+                gpio_free(pdata->battery_detect);
+                bq20z75_device->gpio_detect = false;
+                goto skip_gpio;
+        }
+
+        bq20z75_device->irq = irq;
+
+skip_gpio:
+        rc = power_supply_register(&client->dev, &bq20z75_device->power_supply);
+        if (rc) {
+                dev_err(&client->dev,
+                        "%s: Failed to register power supply\n", __func__);
+                goto exit_psupply;
+        }
+
+        dev_info(&client->dev,
+                "%s: battery gas gauge device registered\n", client->name);
+
+        INIT_DELAYED_WORK(&bq20z75_device->work, bq20z75_delayed_work);
+
+        bq20z75_device->enable_detection = true;
+
+        return 0;
+
+exit_psupply:
+        if (bq20z75_device->irq)
+                free_irq(bq20z75_device->irq, &bq20z75_device->power_supply);
+        if (bq20z75_device->gpio_detect)
+                gpio_free(pdata->battery_detect);
+
+exit_mem_free:
+        kfree(bq20z75_device);
+
+        return rc;
+}
+
+static int __devexit bq20z75_remove(struct i2c_client *client)
+{
+        struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
+
+        if (bq20z75_device->irq)
+                free_irq(bq20z75_device->irq, &bq20z75_device->power_supply);
+        if (bq20z75_device->gpio_detect)
+                gpio_free(bq20z75_device->plat_data.battery_detect);
+
+        power_supply_unregister(&bq20z75_device->power_supply);
+
+        cancel_delayed_work_sync(&bq20z75_device->work);
+
+        kfree(bq20z75_device);
+        bq20z75_device = NULL;
+
+        return 0;
+}
+
+#if defined CONFIG_PM
+static int bq20z75_suspend(struct i2c_client *client,
+        pm_message_t state)
+{
+        struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
+        s32 ret;
+
+        if (bq20z75_device->poll_time > 0)
+                cancel_delayed_work_sync(&bq20z75_device->work);
+
+        /* write to manufacturer access with sleep command */
+        ret = bq20z75_write_word_data(client,
+                bq20z75_data[REG_MANUFACTURER_DATA].addr,
+                MANUFACTURER_ACCESS_SLEEP);
+        if (bq20z75_device->is_present && ret < 0)
+                return ret;
+
+        return 0;
+}
+
+static int bq20z75_resume(struct i2c_client *client)
+{
+        struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
+
+        schedule_delayed_work(&bq20z75_device->work, HZ);
+        return 0;
+}
+#else
+#define bq20z75_suspend         NULL
+#define bq20z75_resume          NULL
+#endif
+
+static const struct i2c_device_id bq20z75_id[] = {
+        { "bq20z75", 0 },
+        {}
+};
+MODULE_DEVICE_TABLE(i2c, bq20z75_id);
+
+static struct i2c_driver bq20z75_battery_driver = {
+        .probe          = bq20z75_probe,
+        .remove         = __devexit_p(bq20z75_remove),
+        .suspend        = bq20z75_suspend,
+        .resume         = bq20z75_resume,
+        .id_table       = bq20z75_id,
+        .driver = {
+                .name   = "bq20z75-battery",
+        },
+};
+
+static int __init bq20z75_battery_init(void)
+{
+        return i2c_add_driver(&bq20z75_battery_driver);
+}
+module_init(bq20z75_battery_init);
+
+static void __exit bq20z75_battery_exit(void)
+{
+        i2c_del_driver(&bq20z75_battery_driver);
+}
+module_exit(bq20z75_battery_exit);
+
+MODULE_DESCRIPTION("BQ20z75 battery monitor driver");
+MODULE_LICENSE("GPL");