power: move power supply drivers to power/supply

This moves all power supply drivers from drivers/power/
to drivers/power/supply/. The intention is a cleaner
source tree, since drivers/power/ also contains frameworks
unrelated to power supply, like adaptive voltage scaling.

Signed-off-by: Sebastian Reichel <sre@kernel.org>

1 files changed, 998 insertions, 0 deletions

diff --git a/drivers/power/supply/sbs-battery.c b/drivers/power/supply/sbs-battery.c
new file mode 100644
index 000000000000..768b9fcb58ea
--- /dev/null
+++ b/drivers/power/supply/sbs-battery.c
@@ -0,0 +1,998 @@
+/*
+ * Gas Gauge driver for SBS Compliant Batteries
+ *
+ * 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/of.h>
+#include <linux/stat.h>
+
+#include <linux/power/sbs-battery.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_MIN,
+	REG_DESIGN_VOLTAGE_MAX,
+	REG_MANUFACTURER,
+	REG_MODEL_NAME,
+};
+
+/* Battery Mode defines */
+#define BATTERY_MODE_OFFSET		0x03
+#define BATTERY_MODE_MASK		0x8000
+enum sbs_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
+
+/* min_value and max_value are only valid for numerical data */
+#define SBS_DATA(_psp, _addr, _min_value, _max_value) { \
+	.psp = _psp, \
+	.addr = _addr, \
+	.min_value = _min_value, \
+	.max_value = _max_value, \
+}
+
+static const struct chip_data {
+	enum power_supply_property psp;
+	u8 addr;
+	int min_value;
+	int max_value;
+} sbs_data[] = {
+	[REG_MANUFACTURER_DATA] =
+		SBS_DATA(POWER_SUPPLY_PROP_PRESENT, 0x00, 0, 65535),
+	[REG_TEMPERATURE] =
+		SBS_DATA(POWER_SUPPLY_PROP_TEMP, 0x08, 0, 65535),
+	[REG_VOLTAGE] =
+		SBS_DATA(POWER_SUPPLY_PROP_VOLTAGE_NOW, 0x09, 0, 20000),
+	[REG_CURRENT] =
+		SBS_DATA(POWER_SUPPLY_PROP_CURRENT_NOW, 0x0A, -32768, 32767),
+	[REG_CAPACITY] =
+		SBS_DATA(POWER_SUPPLY_PROP_CAPACITY, 0x0D, 0, 100),
+	[REG_REMAINING_CAPACITY] =
+		SBS_DATA(POWER_SUPPLY_PROP_ENERGY_NOW, 0x0F, 0, 65535),
+	[REG_REMAINING_CAPACITY_CHARGE] =
+		SBS_DATA(POWER_SUPPLY_PROP_CHARGE_NOW, 0x0F, 0, 65535),
+	[REG_FULL_CHARGE_CAPACITY] =
+		SBS_DATA(POWER_SUPPLY_PROP_ENERGY_FULL, 0x10, 0, 65535),
+	[REG_FULL_CHARGE_CAPACITY_CHARGE] =
+		SBS_DATA(POWER_SUPPLY_PROP_CHARGE_FULL, 0x10, 0, 65535),
+	[REG_TIME_TO_EMPTY] =
+		SBS_DATA(POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, 0x12, 0, 65535),
+	[REG_TIME_TO_FULL] =
+		SBS_DATA(POWER_SUPPLY_PROP_TIME_TO_FULL_AVG, 0x13, 0, 65535),
+	[REG_STATUS] =
+		SBS_DATA(POWER_SUPPLY_PROP_STATUS, 0x16, 0, 65535),
+	[REG_CYCLE_COUNT] =
+		SBS_DATA(POWER_SUPPLY_PROP_CYCLE_COUNT, 0x17, 0, 65535),
+	[REG_DESIGN_CAPACITY] =
+		SBS_DATA(POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN, 0x18, 0, 65535),
+	[REG_DESIGN_CAPACITY_CHARGE] =
+		SBS_DATA(POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN, 0x18, 0, 65535),
+	[REG_DESIGN_VOLTAGE_MIN] =
+		SBS_DATA(POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN, 0x19, 0, 65535),
+	[REG_DESIGN_VOLTAGE_MAX] =
+		SBS_DATA(POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN, 0x19, 0, 65535),
+	[REG_SERIAL_NUMBER] =
+		SBS_DATA(POWER_SUPPLY_PROP_SERIAL_NUMBER, 0x1C, 0, 65535),
+	/* Properties of type `const char *' */
+	[REG_MANUFACTURER] =
+		SBS_DATA(POWER_SUPPLY_PROP_MANUFACTURER, 0x20, 0, 65535),
+	[REG_MODEL_NAME] =
+		SBS_DATA(POWER_SUPPLY_PROP_MODEL_NAME, 0x21, 0, 65535)
+};
+
+static enum power_supply_property sbs_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_MIN_DESIGN,
+	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,
+	/* Properties of type `const char *' */
+	POWER_SUPPLY_PROP_MANUFACTURER,
+	POWER_SUPPLY_PROP_MODEL_NAME
+};
+
+struct sbs_info {
+	struct i2c_client		*client;
+	struct power_supply		*power_supply;
+	struct sbs_platform_data	*pdata;
+	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 char model_name[I2C_SMBUS_BLOCK_MAX + 1];
+static char manufacturer[I2C_SMBUS_BLOCK_MAX + 1];
+static bool force_load;
+
+static int sbs_read_word_data(struct i2c_client *client, u8 address)
+{
+	struct sbs_info *chip = i2c_get_clientdata(client);
+	s32 ret = 0;
+	int retries = 1;
+
+	if (chip->pdata)
+		retries = max(chip->pdata->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 sbs_read_string_data(struct i2c_client *client, u8 address,
+				char *values)
+{
+	struct sbs_info *chip = i2c_get_clientdata(client);
+	s32 ret = 0, block_length = 0;
+	int retries_length = 1, retries_block = 1;
+	u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
+
+	if (chip->pdata) {
+		retries_length = max(chip->pdata->i2c_retry_count + 1, 1);
+		retries_block = max(chip->pdata->i2c_retry_count + 1, 1);
+	}
+
+	/* Adapter needs to support these two functions */
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_BYTE_DATA |
+				     I2C_FUNC_SMBUS_I2C_BLOCK)){
+		return -ENODEV;
+	}
+
+	/* Get the length of block data */
+	while (retries_length > 0) {
+		ret = i2c_smbus_read_byte_data(client, address);
+		if (ret >= 0)
+			break;
+		retries_length--;
+	}
+
+	if (ret < 0) {
+		dev_dbg(&client->dev,
+			"%s: i2c read at address 0x%x failed\n",
+			__func__, address);
+		return ret;
+	}
+
+	/* block_length does not include NULL terminator */
+	block_length = ret;
+	if (block_length > I2C_SMBUS_BLOCK_MAX) {
+		dev_err(&client->dev,
+			"%s: Returned block_length is longer than 0x%x\n",
+			__func__, I2C_SMBUS_BLOCK_MAX);
+		return -EINVAL;
+	}
+
+	/* Get the block data */
+	while (retries_block > 0) {
+		ret = i2c_smbus_read_i2c_block_data(
+				client, address,
+				block_length + 1, block_buffer);
+		if (ret >= 0)
+			break;
+		retries_block--;
+	}
+
+	if (ret < 0) {
+		dev_dbg(&client->dev,
+			"%s: i2c read at address 0x%x failed\n",
+			__func__, address);
+		return ret;
+	}
+
+	/* block_buffer[0] == block_length */
+	memcpy(values, block_buffer + 1, block_length);
+	values[block_length] = '\0';
+
+	return le16_to_cpu(ret);
+}
+
+static int sbs_write_word_data(struct i2c_client *client, u8 address,
+	u16 value)
+{
+	struct sbs_info *chip = i2c_get_clientdata(client);
+	s32 ret = 0;
+	int retries = 1;
+
+	if (chip->pdata)
+		retries = max(chip->pdata->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 sbs_get_battery_presence_and_health(
+	struct i2c_client *client, enum power_supply_property psp,
+	union power_supply_propval *val)
+{
+	s32 ret;
+	struct sbs_info *chip = i2c_get_clientdata(client);
+
+	if (psp == POWER_SUPPLY_PROP_PRESENT &&
+		chip->gpio_detect) {
+		ret = gpio_get_value(chip->pdata->battery_detect);
+		if (ret == chip->pdata->battery_detect_present)
+			val->intval = 1;
+		else
+			val->intval = 0;
+		chip->is_present = val->intval;
+		return ret;
+	}
+
+	/* Write to ManufacturerAccess with
+	 * ManufacturerAccess command and then
+	 * read the status */
+	ret = sbs_write_word_data(client, sbs_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 = sbs_read_word_data(client, sbs_data[REG_MANUFACTURER_DATA].addr);
+	if (ret < 0)
+		return ret;
+
+	if (ret < sbs_data[REG_MANUFACTURER_DATA].min_value ||
+	    ret > sbs_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 sbs_get_battery_property(struct i2c_client *client,
+	int reg_offset, enum power_supply_property psp,
+	union power_supply_propval *val)
+{
+	struct sbs_info *chip = i2c_get_clientdata(client);
+	s32 ret;
+
+	ret = sbs_read_word_data(client, sbs_data[reg_offset].addr);
+	if (ret < 0)
+		return ret;
+
+	/* returned values are 16 bit */
+	if (sbs_data[reg_offset].min_value < 0)
+		ret = (s16)ret;
+
+	if (ret >= sbs_data[reg_offset].min_value &&
+	    ret <= sbs_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_DISCHARGING)
+			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+		else
+			val->intval = POWER_SUPPLY_STATUS_CHARGING;
+
+		if (chip->poll_time == 0)
+			chip->last_state = val->intval;
+		else if (chip->last_state != val->intval) {
+			cancel_delayed_work_sync(&chip->work);
+			power_supply_changed(chip->power_supply);
+			chip->poll_time = 0;
+		}
+	} else {
+		if (psp == POWER_SUPPLY_PROP_STATUS)
+			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
+		else
+			val->intval = 0;
+	}
+
+	return 0;
+}
+
+static int sbs_get_battery_string_property(struct i2c_client *client,
+	int reg_offset, enum power_supply_property psp, char *val)
+{
+	s32 ret;
+
+	ret = sbs_read_string_data(client, sbs_data[reg_offset].addr, val);
+
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static void  sbs_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:
+		/* sbs 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_MIN_DESIGN:
+	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:
+		/* sbs 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:
+		/* sbs 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 sbs_battery_mode sbs_set_battery_mode(struct i2c_client *client,
+	enum sbs_battery_mode mode)
+{
+	int ret, original_val;
+
+	original_val = sbs_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 = sbs_write_word_data(client, BATTERY_MODE_OFFSET, ret);
+	if (ret < 0)
+		return ret;
+
+	return original_val & BATTERY_MODE_MASK;
+}
+
+static int sbs_get_battery_capacity(struct i2c_client *client,
+	int reg_offset, enum power_supply_property psp,
+	union power_supply_propval *val)
+{
+	s32 ret;
+	enum sbs_battery_mode mode = BATTERY_MODE_WATTS;
+
+	if (power_supply_is_amp_property(psp))
+		mode = BATTERY_MODE_AMPS;
+
+	mode = sbs_set_battery_mode(client, mode);
+	if (mode < 0)
+		return mode;
+
+	ret = sbs_read_word_data(client, sbs_data[reg_offset].addr);
+	if (ret < 0)
+		return ret;
+
+	if (psp == POWER_SUPPLY_PROP_CAPACITY) {
+		/* sbs spec says that this can be >100 %
+		* even if max value is 100 % */
+		val->intval = min(ret, 100);
+	} else
+		val->intval = ret;
+
+	ret = sbs_set_battery_mode(client, mode);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static char sbs_serial[5];
+static int sbs_get_battery_serial_number(struct i2c_client *client,
+	union power_supply_propval *val)
+{
+	int ret;
+
+	ret = sbs_read_word_data(client, sbs_data[REG_SERIAL_NUMBER].addr);
+	if (ret < 0)
+		return ret;
+
+	ret = sprintf(sbs_serial, "%04x", ret);
+	val->strval = sbs_serial;
+
+	return 0;
+}
+
+static int sbs_get_property_index(struct i2c_client *client,
+	enum power_supply_property psp)
+{
+	int count;
+	for (count = 0; count < ARRAY_SIZE(sbs_data); count++)
+		if (psp == sbs_data[count].psp)
+			return count;
+
+	dev_warn(&client->dev,
+		"%s: Invalid Property - %d\n", __func__, psp);
+
+	return -EINVAL;
+}
+
+static int sbs_get_property(struct power_supply *psy,
+	enum power_supply_property psp,
+	union power_supply_propval *val)
+{
+	int ret = 0;
+	struct sbs_info *chip = power_supply_get_drvdata(psy);
+	struct i2c_client *client = chip->client;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_PRESENT:
+	case POWER_SUPPLY_PROP_HEALTH:
+		ret = sbs_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;
+		goto done; /* don't trigger power_supply_changed()! */
+
+	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 = sbs_get_property_index(client, psp);
+		if (ret < 0)
+			break;
+
+		ret = sbs_get_battery_capacity(client, ret, psp, val);
+		break;
+
+	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
+		ret = sbs_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_MIN_DESIGN:
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+		ret = sbs_get_property_index(client, psp);
+		if (ret < 0)
+			break;
+
+		ret = sbs_get_battery_property(client, ret, psp, val);
+		break;
+
+	case POWER_SUPPLY_PROP_MODEL_NAME:
+		ret = sbs_get_property_index(client, psp);
+		if (ret < 0)
+			break;
+
+		ret = sbs_get_battery_string_property(client, ret, psp,
+						      model_name);
+		val->strval = model_name;
+		break;
+
+	case POWER_SUPPLY_PROP_MANUFACTURER:
+		ret = sbs_get_property_index(client, psp);
+		if (ret < 0)
+			break;
+
+		ret = sbs_get_battery_string_property(client, ret, psp,
+						      manufacturer);
+		val->strval = manufacturer;
+		break;
+
+	default:
+		dev_err(&client->dev,
+			"%s: INVALID property\n", __func__);
+		return -EINVAL;
+	}
+
+	if (!chip->enable_detection)
+		goto done;
+
+	if (!chip->gpio_detect &&
+		chip->is_present != (ret >= 0)) {
+		chip->is_present = (ret >= 0);
+		power_supply_changed(chip->power_supply);
+	}
+
+done:
+	if (!ret) {
+		/* Convert units to match requirements for power supply class */
+		sbs_unit_adjustment(client, psp, val);
+	}
+
+	dev_dbg(&client->dev,
+		"%s: property = %d, value = %x\n", __func__, psp, val->intval);
+
+	if (ret && chip->is_present)
+		return ret;
+
+	/* battery not present, so return NODATA for properties */
+	if (ret)
+		return -ENODATA;
+
+	return 0;
+}
+
+static irqreturn_t sbs_irq(int irq, void *devid)
+{
+	struct power_supply *battery = devid;
+
+	power_supply_changed(battery);
+
+	return IRQ_HANDLED;
+}
+
+static void sbs_external_power_changed(struct power_supply *psy)
+{
+	struct sbs_info *chip = power_supply_get_drvdata(psy);
+
+	if (chip->ignore_changes > 0) {
+		chip->ignore_changes--;
+		return;
+	}
+
+	/* cancel outstanding work */
+	cancel_delayed_work_sync(&chip->work);
+
+	schedule_delayed_work(&chip->work, HZ);
+	chip->poll_time = chip->pdata->poll_retry_count;
+}
+
+static void sbs_delayed_work(struct work_struct *work)
+{
+	struct sbs_info *chip;
+	s32 ret;
+
+	chip = container_of(work, struct sbs_info, work.work);
+
+	ret = sbs_read_word_data(chip->client, sbs_data[REG_STATUS].addr);
+	/* if the read failed, give up on this work */
+	if (ret < 0) {
+		chip->poll_time = 0;
+		return;
+	}
+
+	if (ret & BATTERY_FULL_CHARGED)
+		ret = POWER_SUPPLY_STATUS_FULL;
+	else if (ret & BATTERY_DISCHARGING)
+		ret = POWER_SUPPLY_STATUS_DISCHARGING;
+	else
+		ret = POWER_SUPPLY_STATUS_CHARGING;
+
+	if (chip->last_state != ret) {
+		chip->poll_time = 0;
+		power_supply_changed(chip->power_supply);
+		return;
+	}
+	if (chip->poll_time > 0) {
+		schedule_delayed_work(&chip->work, HZ);
+		chip->poll_time--;
+		return;
+	}
+}
+
+#if defined(CONFIG_OF)
+
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+
+static const struct of_device_id sbs_dt_ids[] = {
+	{ .compatible = "sbs,sbs-battery" },
+	{ .compatible = "ti,bq20z75" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sbs_dt_ids);
+
+static struct sbs_platform_data *sbs_of_populate_pdata(
+		struct i2c_client *client)
+{
+	struct device_node *of_node = client->dev.of_node;
+	struct sbs_platform_data *pdata = client->dev.platform_data;
+	enum of_gpio_flags gpio_flags;
+	int rc;
+	u32 prop;
+
+	/* verify this driver matches this device */
+	if (!of_node)
+		return NULL;
+
+	/* if platform data is set, honor it */
+	if (pdata)
+		return pdata;
+
+	/* first make sure at least one property is set, otherwise
+	 * it won't change behavior from running without pdata.
+	 */
+	if (!of_get_property(of_node, "sbs,i2c-retry-count", NULL) &&
+		!of_get_property(of_node, "sbs,poll-retry-count", NULL) &&
+		!of_get_property(of_node, "sbs,battery-detect-gpios", NULL))
+		goto of_out;
+
+	pdata = devm_kzalloc(&client->dev, sizeof(struct sbs_platform_data),
+				GFP_KERNEL);
+	if (!pdata)
+		goto of_out;
+
+	rc = of_property_read_u32(of_node, "sbs,i2c-retry-count", &prop);
+	if (!rc)
+		pdata->i2c_retry_count = prop;
+
+	rc = of_property_read_u32(of_node, "sbs,poll-retry-count", &prop);
+	if (!rc)
+		pdata->poll_retry_count = prop;
+
+	if (!of_get_property(of_node, "sbs,battery-detect-gpios", NULL)) {
+		pdata->battery_detect = -1;
+		goto of_out;
+	}
+
+	pdata->battery_detect = of_get_named_gpio_flags(of_node,
+			"sbs,battery-detect-gpios", 0, &gpio_flags);
+
+	if (gpio_flags & OF_GPIO_ACTIVE_LOW)
+		pdata->battery_detect_present = 0;
+	else
+		pdata->battery_detect_present = 1;
+
+of_out:
+	return pdata;
+}
+#else
+static struct sbs_platform_data *sbs_of_populate_pdata(
+	struct i2c_client *client)
+{
+	return client->dev.platform_data;
+}
+#endif
+
+static const struct power_supply_desc sbs_default_desc = {
+	.type = POWER_SUPPLY_TYPE_BATTERY,
+	.properties = sbs_properties,
+	.num_properties = ARRAY_SIZE(sbs_properties),
+	.get_property = sbs_get_property,
+	.external_power_changed = sbs_external_power_changed,
+};
+
+static int sbs_probe(struct i2c_client *client,
+	const struct i2c_device_id *id)
+{
+	struct sbs_info *chip;
+	struct power_supply_desc *sbs_desc;
+	struct sbs_platform_data *pdata = client->dev.platform_data;
+	struct power_supply_config psy_cfg = {};
+	int rc;
+	int irq;
+
+	sbs_desc = devm_kmemdup(&client->dev, &sbs_default_desc,
+			sizeof(*sbs_desc), GFP_KERNEL);
+	if (!sbs_desc)
+		return -ENOMEM;
+
+	sbs_desc->name = devm_kasprintf(&client->dev, GFP_KERNEL, "sbs-%s",
+			dev_name(&client->dev));
+	if (!sbs_desc->name)
+		return -ENOMEM;
+
+	chip = kzalloc(sizeof(struct sbs_info), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->client = client;
+	chip->enable_detection = false;
+	chip->gpio_detect = false;
+	psy_cfg.of_node = client->dev.of_node;
+	psy_cfg.drv_data = chip;
+	/* ignore first notification of external change, it is generated
+	 * from the power_supply_register call back
+	 */
+	chip->ignore_changes = 1;
+	chip->last_state = POWER_SUPPLY_STATUS_UNKNOWN;
+
+	pdata = sbs_of_populate_pdata(client);
+
+	if (pdata) {
+		chip->gpio_detect = gpio_is_valid(pdata->battery_detect);
+		chip->pdata = pdata;
+	}
+
+	i2c_set_clientdata(client, chip);
+
+	if (!chip->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);
+		chip->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);
+		chip->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);
+		chip->gpio_detect = false;
+		goto skip_gpio;
+	}
+
+	rc = request_irq(irq, sbs_irq,
+		IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+		dev_name(&client->dev), chip->power_supply);
+	if (rc) {
+		dev_warn(&client->dev, "Failed to request irq: %d\n", rc);
+		gpio_free(pdata->battery_detect);
+		chip->gpio_detect = false;
+		goto skip_gpio;
+	}
+
+	chip->irq = irq;
+
+skip_gpio:
+	/*
+	 * Before we register, we might need to make sure we can actually talk
+	 * to the battery.
+	 */
+	if (!force_load) {
+		rc = sbs_read_word_data(client, sbs_data[REG_STATUS].addr);
+
+		if (rc < 0) {
+			dev_err(&client->dev, "%s: Failed to get device status\n",
+				__func__);
+			goto exit_psupply;
+		}
+	}
+
+	chip->power_supply = power_supply_register(&client->dev, sbs_desc,
+						   &psy_cfg);
+	if (IS_ERR(chip->power_supply)) {
+		dev_err(&client->dev,
+			"%s: Failed to register power supply\n", __func__);
+		rc = PTR_ERR(chip->power_supply);
+		goto exit_psupply;
+	}
+
+	dev_info(&client->dev,
+		"%s: battery gas gauge device registered\n", client->name);
+
+	INIT_DELAYED_WORK(&chip->work, sbs_delayed_work);
+
+	chip->enable_detection = true;
+
+	return 0;
+
+exit_psupply:
+	if (chip->irq)
+		free_irq(chip->irq, chip->power_supply);
+	if (chip->gpio_detect)
+		gpio_free(pdata->battery_detect);
+
+	kfree(chip);
+
+	return rc;
+}
+
+static int sbs_remove(struct i2c_client *client)
+{
+	struct sbs_info *chip = i2c_get_clientdata(client);
+
+	if (chip->irq)
+		free_irq(chip->irq, chip->power_supply);
+	if (chip->gpio_detect)
+		gpio_free(chip->pdata->battery_detect);
+
+	power_supply_unregister(chip->power_supply);
+
+	cancel_delayed_work_sync(&chip->work);
+
+	kfree(chip);
+	chip = NULL;
+
+	return 0;
+}
+
+#if defined CONFIG_PM_SLEEP
+
+static int sbs_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct sbs_info *chip = i2c_get_clientdata(client);
+	s32 ret;
+
+	if (chip->poll_time > 0)
+		cancel_delayed_work_sync(&chip->work);
+
+	/* write to manufacturer access with sleep command */
+	ret = sbs_write_word_data(client, sbs_data[REG_MANUFACTURER_DATA].addr,
+		MANUFACTURER_ACCESS_SLEEP);
+	if (chip->is_present && ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(sbs_pm_ops, sbs_suspend, NULL);
+#define SBS_PM_OPS (&sbs_pm_ops)
+
+#else
+#define SBS_PM_OPS NULL
+#endif
+
+static const struct i2c_device_id sbs_id[] = {
+	{ "bq20z75", 0 },
+	{ "sbs-battery", 1 },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, sbs_id);
+
+static struct i2c_driver sbs_battery_driver = {
+	.probe		= sbs_probe,
+	.remove		= sbs_remove,
+	.id_table	= sbs_id,
+	.driver = {
+		.name	= "sbs-battery",
+		.of_match_table = of_match_ptr(sbs_dt_ids),
+		.pm	= SBS_PM_OPS,
+	},
+};
+module_i2c_driver(sbs_battery_driver);
+
+MODULE_DESCRIPTION("SBS battery monitor driver");
+MODULE_LICENSE("GPL");
+
+module_param(force_load, bool, S_IRUSR | S_IRGRP | S_IROTH);
+MODULE_PARM_DESC(force_load,
+		 "Attempt to load the driver even if no battery is connected");