ab8500-fg: A8500 fuel gauge driver

This driver is responsible for provide battery parameters to user space via
sysfs by registers to power supply class. It uses fuel gauge and gpadc driver
in obtaining the battery parameters. These battery properties are used by
abx500 charging algorithm driver to monitor the battery.

Signed-off-by: Arun Murthy <arun.murthy@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>

1 files changed, 2636 insertions, 0 deletions

diff --git a/drivers/power/ab8500_fg.c b/drivers/power/ab8500_fg.c
new file mode 100644
index 00000000000..41ccb70d401
--- /dev/null
+++ b/drivers/power/ab8500_fg.c
@@ -0,0 +1,2636 @@
+/*
+ * Copyright (C) ST-Ericsson AB 2012
+ *
+ * Main and Back-up battery management driver.
+ *
+ * Note: Backup battery management is required in case of Li-Ion battery and not
+ * for capacitive battery. HREF boards have capacitive battery and hence backup
+ * battery management is not used and the supported code is available in this
+ * driver.
+ *
+ * License Terms: GNU General Public License v2
+ * Author:
+ *	Johan Palsson <johan.palsson@stericsson.com>
+ *	Karl Komierowski <karl.komierowski@stericsson.com>
+ *	Arun R Murthy <arun.murthy@stericsson.com>
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/kobject.h>
+#include <linux/mfd/abx500/ab8500.h>
+#include <linux/mfd/abx500.h>
+#include <linux/slab.h>
+#include <linux/mfd/abx500/ab8500-bm.h>
+#include <linux/delay.h>
+#include <linux/mfd/abx500/ab8500-gpadc.h>
+#include <linux/mfd/abx500.h>
+#include <linux/time.h>
+#include <linux/completion.h>
+
+#define MILLI_TO_MICRO			1000
+#define FG_LSB_IN_MA			1627
+#define QLSB_NANO_AMP_HOURS_X10		1129
+#define INS_CURR_TIMEOUT		(3 * HZ)
+
+#define SEC_TO_SAMPLE(S)		(S * 4)
+
+#define NBR_AVG_SAMPLES			20
+
+#define LOW_BAT_CHECK_INTERVAL		(2 * HZ)
+
+#define VALID_CAPACITY_SEC		(45 * 60) /* 45 minutes */
+#define BATT_OK_MIN			2360 /* mV */
+#define BATT_OK_INCREMENT		50 /* mV */
+#define BATT_OK_MAX_NR_INCREMENTS	0xE
+
+/* FG constants */
+#define BATT_OVV			0x01
+
+#define interpolate(x, x1, y1, x2, y2) \
+	((y1) + ((((y2) - (y1)) * ((x) - (x1))) / ((x2) - (x1))));
+
+#define to_ab8500_fg_device_info(x) container_of((x), \
+	struct ab8500_fg, fg_psy);
+
+/**
+ * struct ab8500_fg_interrupts - ab8500 fg interupts
+ * @name:	name of the interrupt
+ * @isr		function pointer to the isr
+ */
+struct ab8500_fg_interrupts {
+	char *name;
+	irqreturn_t (*isr)(int irq, void *data);
+};
+
+enum ab8500_fg_discharge_state {
+	AB8500_FG_DISCHARGE_INIT,
+	AB8500_FG_DISCHARGE_INITMEASURING,
+	AB8500_FG_DISCHARGE_INIT_RECOVERY,
+	AB8500_FG_DISCHARGE_RECOVERY,
+	AB8500_FG_DISCHARGE_READOUT_INIT,
+	AB8500_FG_DISCHARGE_READOUT,
+	AB8500_FG_DISCHARGE_WAKEUP,
+};
+
+static char *discharge_state[] = {
+	"DISCHARGE_INIT",
+	"DISCHARGE_INITMEASURING",
+	"DISCHARGE_INIT_RECOVERY",
+	"DISCHARGE_RECOVERY",
+	"DISCHARGE_READOUT_INIT",
+	"DISCHARGE_READOUT",
+	"DISCHARGE_WAKEUP",
+};
+
+enum ab8500_fg_charge_state {
+	AB8500_FG_CHARGE_INIT,
+	AB8500_FG_CHARGE_READOUT,
+};
+
+static char *charge_state[] = {
+	"CHARGE_INIT",
+	"CHARGE_READOUT",
+};
+
+enum ab8500_fg_calibration_state {
+	AB8500_FG_CALIB_INIT,
+	AB8500_FG_CALIB_WAIT,
+	AB8500_FG_CALIB_END,
+};
+
+struct ab8500_fg_avg_cap {
+	int avg;
+	int samples[NBR_AVG_SAMPLES];
+	__kernel_time_t time_stamps[NBR_AVG_SAMPLES];
+	int pos;
+	int nbr_samples;
+	int sum;
+};
+
+struct ab8500_fg_battery_capacity {
+	int max_mah_design;
+	int max_mah;
+	int mah;
+	int permille;
+	int level;
+	int prev_mah;
+	int prev_percent;
+	int prev_level;
+	int user_mah;
+};
+
+struct ab8500_fg_flags {
+	bool fg_enabled;
+	bool conv_done;
+	bool charging;
+	bool fully_charged;
+	bool force_full;
+	bool low_bat_delay;
+	bool low_bat;
+	bool bat_ovv;
+	bool batt_unknown;
+	bool calibrate;
+	bool user_cap;
+	bool batt_id_received;
+};
+
+struct inst_curr_result_list {
+	struct list_head list;
+	int *result;
+};
+
+/**
+ * struct ab8500_fg - ab8500 FG device information
+ * @dev:		Pointer to the structure device
+ * @node:		a list of AB8500 FGs, hence prepared for reentrance
+ * @irq			holds the CCEOC interrupt number
+ * @vbat:		Battery voltage in mV
+ * @vbat_nom:		Nominal battery voltage in mV
+ * @inst_curr:		Instantenous battery current in mA
+ * @avg_curr:		Average battery current in mA
+ * @bat_temp		battery temperature
+ * @fg_samples:		Number of samples used in the FG accumulation
+ * @accu_charge:	Accumulated charge from the last conversion
+ * @recovery_cnt:	Counter for recovery mode
+ * @high_curr_cnt:	Counter for high current mode
+ * @init_cnt:		Counter for init mode
+ * @recovery_needed:	Indicate if recovery is needed
+ * @high_curr_mode:	Indicate if we're in high current mode
+ * @init_capacity:	Indicate if initial capacity measuring should be done
+ * @turn_off_fg:	True if fg was off before current measurement
+ * @calib_state		State during offset calibration
+ * @discharge_state:	Current discharge state
+ * @charge_state:	Current charge state
+ * @ab8500_fg_complete	Completion struct used for the instant current reading
+ * @flags:		Structure for information about events triggered
+ * @bat_cap:		Structure for battery capacity specific parameters
+ * @avg_cap:		Average capacity filter
+ * @parent:		Pointer to the struct ab8500
+ * @gpadc:		Pointer to the struct gpadc
+ * @pdata:		Pointer to the abx500_fg platform data
+ * @bat:		Pointer to the abx500_bm platform data
+ * @fg_psy:		Structure that holds the FG specific battery properties
+ * @fg_wq:		Work queue for running the FG algorithm
+ * @fg_periodic_work:	Work to run the FG algorithm periodically
+ * @fg_low_bat_work:	Work to check low bat condition
+ * @fg_reinit_work	Work used to reset and reinitialise the FG algorithm
+ * @fg_work:		Work to run the FG algorithm instantly
+ * @fg_acc_cur_work:	Work to read the FG accumulator
+ * @fg_check_hw_failure_work:	Work for checking HW state
+ * @cc_lock:		Mutex for locking the CC
+ * @fg_kobject:		Structure of type kobject
+ */
+struct ab8500_fg {
+	struct device *dev;
+	struct list_head node;
+	int irq;
+	int vbat;
+	int vbat_nom;
+	int inst_curr;
+	int avg_curr;
+	int bat_temp;
+	int fg_samples;
+	int accu_charge;
+	int recovery_cnt;
+	int high_curr_cnt;
+	int init_cnt;
+	bool recovery_needed;
+	bool high_curr_mode;
+	bool init_capacity;
+	bool turn_off_fg;
+	enum ab8500_fg_calibration_state calib_state;
+	enum ab8500_fg_discharge_state discharge_state;
+	enum ab8500_fg_charge_state charge_state;
+	struct completion ab8500_fg_complete;
+	struct ab8500_fg_flags flags;
+	struct ab8500_fg_battery_capacity bat_cap;
+	struct ab8500_fg_avg_cap avg_cap;
+	struct ab8500 *parent;
+	struct ab8500_gpadc *gpadc;
+	struct abx500_fg_platform_data *pdata;
+	struct abx500_bm_data *bat;
+	struct power_supply fg_psy;
+	struct workqueue_struct *fg_wq;
+	struct delayed_work fg_periodic_work;
+	struct delayed_work fg_low_bat_work;
+	struct delayed_work fg_reinit_work;
+	struct work_struct fg_work;
+	struct work_struct fg_acc_cur_work;
+	struct delayed_work fg_check_hw_failure_work;
+	struct mutex cc_lock;
+	struct kobject fg_kobject;
+};
+static LIST_HEAD(ab8500_fg_list);
+
+/**
+ * ab8500_fg_get() - returns a reference to the primary AB8500 fuel gauge
+ * (i.e. the first fuel gauge in the instance list)
+ */
+struct ab8500_fg *ab8500_fg_get(void)
+{
+	struct ab8500_fg *fg;
+
+	if (list_empty(&ab8500_fg_list))
+		return NULL;
+
+	fg = list_first_entry(&ab8500_fg_list, struct ab8500_fg, node);
+	return fg;
+}
+
+/* Main battery properties */
+static enum power_supply_property ab8500_fg_props[] = {
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_CURRENT_NOW,
+	POWER_SUPPLY_PROP_CURRENT_AVG,
+	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
+	POWER_SUPPLY_PROP_ENERGY_FULL,
+	POWER_SUPPLY_PROP_ENERGY_NOW,
+	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
+	POWER_SUPPLY_PROP_CHARGE_FULL,
+	POWER_SUPPLY_PROP_CHARGE_NOW,
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
+};
+
+/*
+ * This array maps the raw hex value to lowbat voltage used by the AB8500
+ * Values taken from the UM0836
+ */
+static int ab8500_fg_lowbat_voltage_map[] = {
+	2300 ,
+	2325 ,
+	2350 ,
+	2375 ,
+	2400 ,
+	2425 ,
+	2450 ,
+	2475 ,
+	2500 ,
+	2525 ,
+	2550 ,
+	2575 ,
+	2600 ,
+	2625 ,
+	2650 ,
+	2675 ,
+	2700 ,
+	2725 ,
+	2750 ,
+	2775 ,
+	2800 ,
+	2825 ,
+	2850 ,
+	2875 ,
+	2900 ,
+	2925 ,
+	2950 ,
+	2975 ,
+	3000 ,
+	3025 ,
+	3050 ,
+	3075 ,
+	3100 ,
+	3125 ,
+	3150 ,
+	3175 ,
+	3200 ,
+	3225 ,
+	3250 ,
+	3275 ,
+	3300 ,
+	3325 ,
+	3350 ,
+	3375 ,
+	3400 ,
+	3425 ,
+	3450 ,
+	3475 ,
+	3500 ,
+	3525 ,
+	3550 ,
+	3575 ,
+	3600 ,
+	3625 ,
+	3650 ,
+	3675 ,
+	3700 ,
+	3725 ,
+	3750 ,
+	3775 ,
+	3800 ,
+	3825 ,
+	3850 ,
+	3850 ,
+};
+
+static u8 ab8500_volt_to_regval(int voltage)
+{
+	int i;
+
+	if (voltage < ab8500_fg_lowbat_voltage_map[0])
+		return 0;
+
+	for (i = 0; i < ARRAY_SIZE(ab8500_fg_lowbat_voltage_map); i++) {
+		if (voltage < ab8500_fg_lowbat_voltage_map[i])
+			return (u8) i - 1;
+	}
+
+	/* If not captured above, return index of last element */
+	return (u8) ARRAY_SIZE(ab8500_fg_lowbat_voltage_map) - 1;
+}
+
+/**
+ * ab8500_fg_is_low_curr() - Low or high current mode
+ * @di:		pointer to the ab8500_fg structure
+ * @curr:	the current to base or our decision on
+ *
+ * Low current mode if the current consumption is below a certain threshold
+ */
+static int ab8500_fg_is_low_curr(struct ab8500_fg *di, int curr)
+{
+	/*
+	 * We want to know if we're in low current mode
+	 */
+	if (curr > -di->bat->fg_params->high_curr_threshold)
+		return true;
+	else
+		return false;
+}
+
+/**
+ * ab8500_fg_add_cap_sample() - Add capacity to average filter
+ * @di:		pointer to the ab8500_fg structure
+ * @sample:	the capacity in mAh to add to the filter
+ *
+ * A capacity is added to the filter and a new mean capacity is calculated and
+ * returned
+ */
+static int ab8500_fg_add_cap_sample(struct ab8500_fg *di, int sample)
+{
+	struct timespec ts;
+	struct ab8500_fg_avg_cap *avg = &di->avg_cap;
+
+	getnstimeofday(&ts);
+
+	do {
+		avg->sum += sample - avg->samples[avg->pos];
+		avg->samples[avg->pos] = sample;
+		avg->time_stamps[avg->pos] = ts.tv_sec;
+		avg->pos++;
+
+		if (avg->pos == NBR_AVG_SAMPLES)
+			avg->pos = 0;
+
+		if (avg->nbr_samples < NBR_AVG_SAMPLES)
+			avg->nbr_samples++;
+
+		/*
+		 * Check the time stamp for each sample. If too old,
+		 * replace with latest sample
+		 */
+	} while (ts.tv_sec - VALID_CAPACITY_SEC > avg->time_stamps[avg->pos]);
+
+	avg->avg = avg->sum / avg->nbr_samples;
+
+	return avg->avg;
+}
+
+/**
+ * ab8500_fg_clear_cap_samples() - Clear average filter
+ * @di:		pointer to the ab8500_fg structure
+ *
+ * The capacity filter is is reset to zero.
+ */
+static void ab8500_fg_clear_cap_samples(struct ab8500_fg *di)
+{
+	int i;
+	struct ab8500_fg_avg_cap *avg = &di->avg_cap;
+
+	avg->pos = 0;
+	avg->nbr_samples = 0;
+	avg->sum = 0;
+	avg->avg = 0;
+
+	for (i = 0; i < NBR_AVG_SAMPLES; i++) {
+		avg->samples[i] = 0;
+		avg->time_stamps[i] = 0;
+	}
+}
+
+/**
+ * ab8500_fg_fill_cap_sample() - Fill average filter
+ * @di:		pointer to the ab8500_fg structure
+ * @sample:	the capacity in mAh to fill the filter with
+ *
+ * The capacity filter is filled with a capacity in mAh
+ */
+static void ab8500_fg_fill_cap_sample(struct ab8500_fg *di, int sample)
+{
+	int i;
+	struct timespec ts;
+	struct ab8500_fg_avg_cap *avg = &di->avg_cap;
+
+	getnstimeofday(&ts);
+
+	for (i = 0; i < NBR_AVG_SAMPLES; i++) {
+		avg->samples[i] = sample;
+		avg->time_stamps[i] = ts.tv_sec;
+	}
+
+	avg->pos = 0;
+	avg->nbr_samples = NBR_AVG_SAMPLES;
+	avg->sum = sample * NBR_AVG_SAMPLES;
+	avg->avg = sample;
+}
+
+/**
+ * ab8500_fg_coulomb_counter() - enable coulomb counter
+ * @di:		pointer to the ab8500_fg structure
+ * @enable:	enable/disable
+ *
+ * Enable/Disable coulomb counter.
+ * On failure returns negative value.
+ */
+static int ab8500_fg_coulomb_counter(struct ab8500_fg *di, bool enable)
+{
+	int ret = 0;
+	mutex_lock(&di->cc_lock);
+	if (enable) {
+		/* To be able to reprogram the number of samples, we have to
+		 * first stop the CC and then enable it again */
+		ret = abx500_set_register_interruptible(di->dev, AB8500_RTC,
+			AB8500_RTC_CC_CONF_REG, 0x00);
+		if (ret)
+			goto cc_err;
+
+		/* Program the samples */
+		ret = abx500_set_register_interruptible(di->dev,
+			AB8500_GAS_GAUGE, AB8500_GASG_CC_NCOV_ACCU,
+			di->fg_samples);
+		if (ret)
+			goto cc_err;
+
+		/* Start the CC */
+		ret = abx500_set_register_interruptible(di->dev, AB8500_RTC,
+			AB8500_RTC_CC_CONF_REG,
+			(CC_DEEP_SLEEP_ENA | CC_PWR_UP_ENA));
+		if (ret)
+			goto cc_err;
+
+		di->flags.fg_enabled = true;
+	} else {
+		/* Clear any pending read requests */
+		ret = abx500_set_register_interruptible(di->dev,
+			AB8500_GAS_GAUGE, AB8500_GASG_CC_CTRL_REG, 0);
+		if (ret)
+			goto cc_err;
+
+		ret = abx500_set_register_interruptible(di->dev,
+			AB8500_GAS_GAUGE, AB8500_GASG_CC_NCOV_ACCU_CTRL, 0);
+		if (ret)
+			goto cc_err;
+
+		/* Stop the CC */
+		ret = abx500_set_register_interruptible(di->dev, AB8500_RTC,
+			AB8500_RTC_CC_CONF_REG, 0);
+		if (ret)
+			goto cc_err;
+
+		di->flags.fg_enabled = false;
+
+	}
+	dev_dbg(di->dev, " CC enabled: %d Samples: %d\n",
+		enable, di->fg_samples);
+
+	mutex_unlock(&di->cc_lock);
+
+	return ret;
+cc_err:
+	dev_err(di->dev, "%s Enabling coulomb counter failed\n", __func__);
+	mutex_unlock(&di->cc_lock);
+	return ret;
+}
+
+/**
+ * ab8500_fg_inst_curr_start() - start battery instantaneous current
+ * @di:         pointer to the ab8500_fg structure
+ *
+ * Returns 0 or error code
+ * Note: This is part "one" and has to be called before
+ * ab8500_fg_inst_curr_finalize()
+ */
+ int ab8500_fg_inst_curr_start(struct ab8500_fg *di)
+{
+	u8 reg_val;
+	int ret;
+
+	mutex_lock(&di->cc_lock);
+
+	ret = abx500_get_register_interruptible(di->dev, AB8500_RTC,
+		AB8500_RTC_CC_CONF_REG, &reg_val);
+	if (ret < 0)
+		goto fail;
+
+	if (!(reg_val & CC_PWR_UP_ENA)) {
+		dev_dbg(di->dev, "%s Enable FG\n", __func__);
+		di->turn_off_fg = true;
+
+		/* Program the samples */
+		ret = abx500_set_register_interruptible(di->dev,
+			AB8500_GAS_GAUGE, AB8500_GASG_CC_NCOV_ACCU,
+			SEC_TO_SAMPLE(10));
+		if (ret)
+			goto fail;
+
+		/* Start the CC */
+		ret = abx500_set_register_interruptible(di->dev, AB8500_RTC,
+			AB8500_RTC_CC_CONF_REG,
+			(CC_DEEP_SLEEP_ENA | CC_PWR_UP_ENA));
+		if (ret)
+			goto fail;
+	} else {
+		di->turn_off_fg = false;
+	}
+
+	/* Return and WFI */
+	INIT_COMPLETION(di->ab8500_fg_complete);
+	enable_irq(di->irq);
+
+	/* Note: cc_lock is still locked */
+	return 0;
+fail:
+	mutex_unlock(&di->cc_lock);
+	return ret;
+}
+
+/**
+ * ab8500_fg_inst_curr_done() - check if fg conversion is done
+ * @di:         pointer to the ab8500_fg structure
+ *
+ * Returns 1 if conversion done, 0 if still waiting
+ */
+int ab8500_fg_inst_curr_done(struct ab8500_fg *di)
+{
+	return completion_done(&di->ab8500_fg_complete);
+}
+
+/**
+ * ab8500_fg_inst_curr_finalize() - battery instantaneous current
+ * @di:         pointer to the ab8500_fg structure
+ * @res:	battery instantenous current(on success)
+ *
+ * Returns 0 or an error code
+ * Note: This is part "two" and has to be called at earliest 250 ms
+ * after ab8500_fg_inst_curr_start()
+ */
+int ab8500_fg_inst_curr_finalize(struct ab8500_fg *di, int *res)
+{
+	u8 low, high;
+	int val;
+	int ret;
+	int timeout;
+
+	if (!completion_done(&di->ab8500_fg_complete)) {
+		timeout = wait_for_completion_timeout(&di->ab8500_fg_complete,
+			INS_CURR_TIMEOUT);
+		dev_dbg(di->dev, "Finalize time: %d ms\n",
+			((INS_CURR_TIMEOUT - timeout) * 1000) / HZ);
+		if (!timeout) {
+			ret = -ETIME;
+			disable_irq(di->irq);
+			dev_err(di->dev, "completion timed out [%d]\n",
+				__LINE__);
+			goto fail;
+		}
+	}
+
+	disable_irq(di->irq);
+
+	ret = abx500_mask_and_set_register_interruptible(di->dev,
+			AB8500_GAS_GAUGE, AB8500_GASG_CC_CTRL_REG,
+			READ_REQ, READ_REQ);
+
+	/* 100uS between read request and read is needed */
+	usleep_range(100, 100);
+
+	/* Read CC Sample conversion value Low and high */
+	ret = abx500_get_register_interruptible(di->dev, AB8500_GAS_GAUGE,
+		AB8500_GASG_CC_SMPL_CNVL_REG,  &low);
+	if (ret < 0)
+		goto fail;
+
+	ret = abx500_get_register_interruptible(di->dev, AB8500_GAS_GAUGE,
+		AB8500_GASG_CC_SMPL_CNVH_REG,  &high);
+	if (ret < 0)
+		goto fail;
+
+	/*
+	 * negative value for Discharging
+	 * convert 2's compliment into decimal
+	 */
+	if (high & 0x10)
+		val = (low | (high << 8) | 0xFFFFE000);
+	else
+		val = (low | (high << 8));
+
+	/*
+	 * Convert to unit value in mA
+	 * Full scale input voltage is
+	 * 66.660mV => LSB = 66.660mV/(4096*res) = 1.627mA
+	 * Given a 250ms conversion cycle time the LSB corresponds
+	 * to 112.9 nAh. Convert to current by dividing by the conversion
+	 * time in hours (250ms = 1 / (3600 * 4)h)
+	 * 112.9nAh assumes 10mOhm, but fg_res is in 0.1mOhm
+	 */
+	val = (val * QLSB_NANO_AMP_HOURS_X10 * 36 * 4) /
+		(1000 * di->bat->fg_res);
+
+	if (di->turn_off_fg) {
+		dev_dbg(di->dev, "%s Disable FG\n", __func__);
+
+		/* Clear any pending read requests */
+		ret = abx500_set_register_interruptible(di->dev,
+			AB8500_GAS_GAUGE, AB8500_GASG_CC_CTRL_REG, 0);
+		if (ret)
+			goto fail;
+
+		/* Stop the CC */
+		ret = abx500_set_register_interruptible(di->dev, AB8500_RTC,
+			AB8500_RTC_CC_CONF_REG, 0);
+		if (ret)
+			goto fail;
+	}
+	mutex_unlock(&di->cc_lock);
+	(*res) = val;
+
+	return 0;
+fail:
+	mutex_unlock(&di->cc_lock);
+	return ret;
+}
+
+/**
+ * ab8500_fg_inst_curr_blocking() - battery instantaneous current
+ * @di:         pointer to the ab8500_fg structure
+ * @res:	battery instantenous current(on success)
+ *
+ * Returns 0 else error code
+ */
+int ab8500_fg_inst_curr_blocking(struct ab8500_fg *di)
+{
+	int ret;
+	int res = 0;
+
+	ret = ab8500_fg_inst_curr_start(di);
+	if (ret) {
+		dev_err(di->dev, "Failed to initialize fg_inst\n");
+		return 0;
+	}
+
+	ret = ab8500_fg_inst_curr_finalize(di, &res);
+	if (ret) {
+		dev_err(di->dev, "Failed to finalize fg_inst\n");
+		return 0;
+	}
+
+	return res;
+}
+
+/**
+ * ab8500_fg_acc_cur_work() - average battery current
+ * @work:	pointer to the work_struct structure
+ *
+ * Updated the average battery current obtained from the
+ * coulomb counter.
+ */
+static void ab8500_fg_acc_cur_work(struct work_struct *work)
+{
+	int val;
+	int ret;
+	u8 low, med, high;
+
+	struct ab8500_fg *di = container_of(work,
+		struct ab8500_fg, fg_acc_cur_work);
+
+	mutex_lock(&di->cc_lock);
+	ret = abx500_set_register_interruptible(di->dev, AB8500_GAS_GAUGE,
+		AB8500_GASG_CC_NCOV_ACCU_CTRL, RD_NCONV_ACCU_REQ);
+	if (ret)
+		goto exit;
+
+	ret = abx500_get_register_interruptible(di->dev, AB8500_GAS_GAUGE,
+		AB8500_GASG_CC_NCOV_ACCU_LOW,  &low);
+	if (ret < 0)
+		goto exit;
+
+	ret = abx500_get_register_interruptible(di->dev, AB8500_GAS_GAUGE,
+		AB8500_GASG_CC_NCOV_ACCU_MED,  &med);
+	if (ret < 0)
+		goto exit;
+
+	ret = abx500_get_register_interruptible(di->dev, AB8500_GAS_GAUGE,
+		AB8500_GASG_CC_NCOV_ACCU_HIGH, &high);
+	if (ret < 0)
+		goto exit;
+
+	/* Check for sign bit in case of negative value, 2's compliment */
+	if (high & 0x10)
+		val = (low | (med << 8) | (high << 16) | 0xFFE00000);
+	else
+		val = (low | (med << 8) | (high << 16));
+
+	/*
+	 * Convert to uAh
+	 * Given a 250ms conversion cycle time the LSB corresponds
+	 * to 112.9 nAh.
+	 * 112.9nAh assumes 10mOhm, but fg_res is in 0.1mOhm
+	 */
+	di->accu_charge = (val * QLSB_NANO_AMP_HOURS_X10) /
+		(100 * di->bat->fg_res);
+
+	/*
+	 * Convert to unit value in mA
+	 * Full scale input voltage is
+	 * 66.660mV => LSB = 66.660mV/(4096*res) = 1.627mA
+	 * Given a 250ms conversion cycle time the LSB corresponds
+	 * to 112.9 nAh. Convert to current by dividing by the conversion
+	 * time in hours (= samples / (3600 * 4)h)
+	 * 112.9nAh assumes 10mOhm, but fg_res is in 0.1mOhm
+	 */
+	di->avg_curr = (val * QLSB_NANO_AMP_HOURS_X10 * 36) /
+		(1000 * di->bat->fg_res * (di->fg_samples / 4));
+
+	di->flags.conv_done = true;
+
+	mutex_unlock(&di->cc_lock);
+
+	queue_work(di->fg_wq, &di->fg_work);
+
+	return;
+exit:
+	dev_err(di->dev,
+		"Failed to read or write gas gauge registers\n");
+	mutex_unlock(&di->cc_lock);
+	queue_work(di->fg_wq, &di->fg_work);
+}
+
+/**
+ * ab8500_fg_bat_voltage() - get battery voltage
+ * @di:		pointer to the ab8500_fg structure
+ *
+ * Returns battery voltage(on success) else error code
+ */
+static int ab8500_fg_bat_voltage(struct ab8500_fg *di)
+{
+	int vbat;
+	static int prev;
+
+	vbat = ab8500_gpadc_convert(di->gpadc, MAIN_BAT_V);
+	if (vbat < 0) {
+		dev_err(di->dev,
+			"%s gpadc conversion failed, using previous value\n",
+			__func__);
+		return prev;
+	}
+
+	prev = vbat;
+	return vbat;
+}
+
+/**
+ * ab8500_fg_volt_to_capacity() - Voltage based capacity
+ * @di:		pointer to the ab8500_fg structure
+ * @voltage:	The voltage to convert to a capacity
+ *
+ * Returns battery capacity in per mille based on voltage
+ */
+static int ab8500_fg_volt_to_capacity(struct ab8500_fg *di, int voltage)
+{
+	int i, tbl_size;
+	struct v_to_cap *tbl;
+	int cap = 0;
+
+	tbl = di->bat->bat_type[di->bat->batt_id].v_to_cap_tbl,
+	tbl_size = di->bat->bat_type[di->bat->batt_id].n_v_cap_tbl_elements;
+
+	for (i = 0; i < tbl_size; ++i) {
+		if (voltage > tbl[i].voltage)
+			break;
+	}
+
+	if ((i > 0) && (i < tbl_size)) {
+		cap = interpolate(voltage,
+			tbl[i].voltage,
+			tbl[i].capacity * 10,
+			tbl[i-1].voltage,
+			tbl[i-1].capacity * 10);
+	} else if (i == 0) {
+		cap = 1000;
+	} else {
+		cap = 0;
+	}
+
+	dev_dbg(di->dev, "%s Vbat: %d, Cap: %d per mille",
+		__func__, voltage, cap);
+
+	return cap;
+}
+
+/**
+ * ab8500_fg_uncomp_volt_to_capacity() - Uncompensated voltage based capacity
+ * @di:		pointer to the ab8500_fg structure
+ *
+ * Returns battery capacity based on battery voltage that is not compensated
+ * for the voltage drop due to the load
+ */
+static int ab8500_fg_uncomp_volt_to_capacity(struct ab8500_fg *di)
+{
+	di->vbat = ab8500_fg_bat_voltage(di);
+	return ab8500_fg_volt_to_capacity(di, di->vbat);
+}
+
+/**
+ * ab8500_fg_battery_resistance() - Returns the battery inner resistance
+ * @di:		pointer to the ab8500_fg structure
+ *
+ * Returns battery inner resistance added with the fuel gauge resistor value
+ * to get the total resistance in the whole link from gnd to bat+ node.
+ */
+static int ab8500_fg_battery_resistance(struct ab8500_fg *di)
+{
+	int i, tbl_size;
+	struct batres_vs_temp *tbl;
+	int resist = 0;
+
+	tbl = di->bat->bat_type[di->bat->batt_id].batres_tbl;
+	tbl_size = di->bat->bat_type[di->bat->batt_id].n_batres_tbl_elements;
+
+	for (i = 0; i < tbl_size; ++i) {
+		if (di->bat_temp / 10 > tbl[i].temp)
+			break;
+	}
+
+	if ((i > 0) && (i < tbl_size)) {
+		resist = interpolate(di->bat_temp / 10,
+			tbl[i].temp,
+			tbl[i].resist,
+			tbl[i-1].temp,
+			tbl[i-1].resist);
+	} else if (i == 0) {
+		resist = tbl[0].resist;
+	} else {
+		resist = tbl[tbl_size - 1].resist;
+	}
+
+	dev_dbg(di->dev, "%s Temp: %d battery internal resistance: %d"
+	    " fg resistance %d, total: %d (mOhm)\n",
+		__func__, di->bat_temp, resist, di->bat->fg_res / 10,
+		(di->bat->fg_res / 10) + resist);
+
+	/* fg_res variable is in 0.1mOhm */
+	resist += di->bat->fg_res / 10;
+
+	return resist;
+}
+
+/**
+ * ab8500_fg_load_comp_volt_to_capacity() - Load compensated voltage based capacity
+ * @di:		pointer to the ab8500_fg structure
+ *
+ * Returns battery capacity based on battery voltage that is load compensated
+ * for the voltage drop
+ */
+static int ab8500_fg_load_comp_volt_to_capacity(struct ab8500_fg *di)
+{
+	int vbat_comp, res;
+	int i = 0;
+	int vbat = 0;
+
+	ab8500_fg_inst_curr_start(di);
+
+	do {
+		vbat += ab8500_fg_bat_voltage(di);
+		i++;
+		msleep(5);
+	} while (!ab8500_fg_inst_curr_done(di));
+
+	ab8500_fg_inst_curr_finalize(di, &di->inst_curr);
+
+	di->vbat = vbat / i;
+	res = ab8500_fg_battery_resistance(di);
+
+	/* Use Ohms law to get the load compensated voltage */
+	vbat_comp = di->vbat - (di->inst_curr * res) / 1000;
+
+	dev_dbg(di->dev, "%s Measured Vbat: %dmV,Compensated Vbat %dmV, "
+		"R: %dmOhm, Current: %dmA Vbat Samples: %d\n",
+		__func__, di->vbat, vbat_comp, res, di->inst_curr, i);
+
+	return ab8500_fg_volt_to_capacity(di, vbat_comp);
+}
+
+/**
+ * ab8500_fg_convert_mah_to_permille() - Capacity in mAh to permille
+ * @di:		pointer to the ab8500_fg structure
+ * @cap_mah:	capacity in mAh
+ *
+ * Converts capacity in mAh to capacity in permille
+ */
+static int ab8500_fg_convert_mah_to_permille(struct ab8500_fg *di, int cap_mah)
+{
+	return (cap_mah * 1000) / di->bat_cap.max_mah_design;
+}
+
+/**
+ * ab8500_fg_convert_permille_to_mah() - Capacity in permille to mAh
+ * @di:		pointer to the ab8500_fg structure
+ * @cap_pm:	capacity in permille
+ *
+ * Converts capacity in permille to capacity in mAh
+ */
+static int ab8500_fg_convert_permille_to_mah(struct ab8500_fg *di, int cap_pm)
+{
+	return cap_pm * di->bat_cap.max_mah_design / 1000;
+}
+
+/**
+ * ab8500_fg_convert_mah_to_uwh() - Capacity in mAh to uWh
+ * @di:		pointer to the ab8500_fg structure
+ * @cap_mah:	capacity in mAh
+ *
+ * Converts capacity in mAh to capacity in uWh
+ */
+static int ab8500_fg_convert_mah_to_uwh(struct ab8500_fg *di, int cap_mah)
+{
+	u64 div_res;
+	u32 div_rem;
+
+	div_res = ((u64) cap_mah) * ((u64) di->vbat_nom);
+	div_rem = do_div(div_res, 1000);
+
+	/* Make sure to round upwards if necessary */
+	if (div_rem >= 1000 / 2)
+		div_res++;
+
+	return (int) div_res;
+}
+
+/**
+ * ab8500_fg_calc_cap_charging() - Calculate remaining capacity while charging
+ * @di:		pointer to the ab8500_fg structure
+ *
+ * Return the capacity in mAh based on previous calculated capcity and the FG
+ * accumulator register value. The filter is filled with this capacity
+ */
+static int ab8500_fg_calc_cap_charging(struct ab8500_fg *di)
+{
+	dev_dbg(di->dev, "%s cap_mah %d accu_charge %d\n",
+		__func__,
+		di->bat_cap.mah,
+		di->accu_charge);
+
+	/* Capacity should not be less than 0 */
+	if (di->bat_cap.mah + di->accu_charge > 0)
+		di->bat_cap.mah += di->accu_charge;
+	else
+		di->bat_cap.mah = 0;
+	/*
+	 * We force capacity to 100% once when the algorithm
+	 * reports that it's full.
+	 */
+	if (di->bat_cap.mah >= di->bat_cap.max_mah_design ||
+		di->flags.force_full) {
+		di->bat_cap.mah = di->bat_cap.max_mah_design;
+	}
+
+	ab8500_fg_fill_cap_sample(di, di->bat_cap.mah);
+	di->bat_cap.permille =
+		ab8500_fg_convert_mah_to_permille(di, di->bat_cap.mah);
+
+	/* We need to update battery voltage and inst current when charging */
+	di->vbat = ab8500_fg_bat_voltage(di);
+	di->inst_curr = ab8500_fg_inst_curr_blocking(di);
+
+	return di->bat_cap.mah;
+}
+
+/**
+ * ab8500_fg_calc_cap_discharge_voltage() - Capacity in discharge with voltage
+ * @di:		pointer to the ab8500_fg structure
+ * @comp:	if voltage should be load compensated before capacity calc
+ *
+ * Return the capacity in mAh based on the battery voltage. The voltage can
+ * either be load compensated or not. This value is added to the filter and a
+ * new mean value is calculated and returned.
+ */
+static int ab8500_fg_calc_cap_discharge_voltage(struct ab8500_fg *di, bool comp)
+{
+	int permille, mah;
+
+	if (comp)
+		permille = ab8500_fg_load_comp_volt_to_capacity(di);
+	else
+		permille = ab8500_fg_uncomp_volt_to_capacity(di);
+
+	mah = ab8500_fg_convert_permille_to_mah(di, permille);
+
+	di->bat_cap.mah = ab8500_fg_add_cap_sample(di, mah);
+	di->bat_cap.permille =
+		ab8500_fg_convert_mah_to_permille(di, di->bat_cap.mah);
+
+	return di->bat_cap.mah;
+}
+
+/**
+ * ab8500_fg_calc_cap_discharge_fg() - Capacity in discharge with FG
+ * @di:		pointer to the ab8500_fg structure
+ *
+ * Return the capacity in mAh based on previous calculated capcity and the FG
+ * accumulator register value. This value is added to the filter and a
+ * new mean value is calculated and returned.
+ */
+static int ab8500_fg_calc_cap_discharge_fg(struct ab8500_fg *di)
+{
+	int permille_volt, permille;
+
+	dev_dbg(di->dev, "%s cap_mah %d accu_charge %d\n",
+		__func__,
+		di->bat_cap.mah,
+		di->accu_charge);
+
+	/* Capacity should not be less than 0 */
+	if (di->bat_cap.mah + di->accu_charge > 0)
+		di->bat_cap.mah += di->accu_charge;
+	else
+		di->bat_cap.mah = 0;
+
+	if (di->bat_cap.mah >= di->bat_cap.max_mah_design)
+		di->bat_cap.mah = di->bat_cap.max_mah_design;
+
+	/*
+	 * Check against voltage based capacity. It can not be lower
+	 * than what the uncompensated voltage says
+	 */
+	permille = ab8500_fg_convert_mah_to_permille(di, di->bat_cap.mah);
+	permille_volt = ab8500_fg_uncomp_volt_to_capacity(di);
+
+	if (permille < permille_volt) {
+		di->bat_cap.permille = permille_volt;
+		di->bat_cap.mah = ab8500_fg_convert_permille_to_mah(di,
+			di->bat_cap.permille);
+
+		dev_dbg(di->dev, "%s voltage based: perm %d perm_volt %d\n",
+			__func__,
+			permille,
+			permille_volt);
+
+		ab8500_fg_fill_cap_sample(di, di->bat_cap.mah);
+	} else {
+		ab8500_fg_fill_cap_sample(di, di->bat_cap.mah);
+		di->bat_cap.permille =
+			ab8500_fg_convert_mah_to_permille(di, di->bat_cap.mah);
+	}
+
+	return di->bat_cap.mah;
+}
+
+/**
+ * ab8500_fg_capacity_level() - Get the battery capacity level
+ * @di:		pointer to the ab8500_fg structure
+ *
+ * Get the battery capacity level based on the capacity in percent
+ */
+static int ab8500_fg_capacity_level(struct ab8500_fg *di)
+{
+	int ret, percent;
+
+	percent = di->bat_cap.permille / 10;
+
+	if (percent <= di->bat->cap_levels->critical ||
+		di->flags.low_bat)
+		ret = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
+	else if (percent <= di->bat->cap_levels->low)
+		ret = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
+	else if (percent <= di->bat->cap_levels->normal)
+		ret = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
+	else if (percent <= di->bat->cap_levels->high)
+		ret = POWER_SUPPLY_CAPACITY_LEVEL_HIGH;
+	else
+		ret = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
+
+	return ret;
+}
+
+/**
+ * ab8500_fg_check_capacity_limits() - Check if capacity has changed
+ * @di:		pointer to the ab8500_fg structure
+ * @init:	capacity is allowed to go up in init mode
+ *
+ * Check if capacity or capacity limit has changed and notify the system
+ * about it using the power_supply framework
+ */
+static void ab8500_fg_check_capacity_limits(struct ab8500_fg *di, bool init)
+{
+	bool changed = false;
+
+	di->bat_cap.level = ab8500_fg_capacity_level(di);
+
+	if (di->bat_cap.level != di->bat_cap.prev_level) {
+		/*
+		 * We do not allow reported capacity level to go up
+		 * unless we're charging or if we're in init
+		 */
+		if (!(!di->flags.charging && di->bat_cap.level >
+			di->bat_cap.prev_level) || init) {
+			dev_dbg(di->dev, "level changed from %d to %d\n",
+				di->bat_cap.prev_level,
+				di->bat_cap.level);
+			di->bat_cap.prev_level = di->bat_cap.level;
+			changed = true;
+		} else {
+			dev_dbg(di->dev, "level not allowed to go up "
+				"since no charger is connected: %d to %d\n",
+				di->bat_cap.prev_level,
+				di->bat_cap.level);
+		}
+	}
+
+	/*
+	 * If we have received the LOW_BAT IRQ, set capacity to 0 to initiate
+	 * shutdown
+	 */
+	if (di->flags.low_bat) {
+		dev_dbg(di->dev, "Battery low, set capacity to 0\n");
+		di->bat_cap.prev_percent = 0;
+		di->bat_cap.permille = 0;
+		di->bat_cap.prev_mah = 0;
+		di->bat_cap.mah = 0;
+		changed = true;
+	} else if (di->flags.fully_charged) {
+		/*
+		 * We report 100% if algorithm reported fully charged
+		 * unless capacity drops too much
+		 */
+		if (di->flags.force_full) {
+			di->bat_cap.prev_percent = di->bat_cap.permille / 10;
+			di->bat_cap.prev_mah = di->bat_cap.mah;
+		} else if (!di->flags.force_full &&
+			di->bat_cap.prev_percent !=
+			(di->bat_cap.permille) / 10 &&
+			(di->bat_cap.permille / 10) <
+			di->bat->fg_params->maint_thres) {
+			dev_dbg(di->dev,
+