ab8500-btemp: AB8500 battery temperature driver

This driver is responsible for battery detection, obtaining battery
temperature and monitor the battery temperature by taking precautionary
measurements when battery temperature goes beyond or below the thresholds.

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, 1123 insertions, 0 deletions

diff --git a/drivers/power/ab8500_btemp.c b/drivers/power/ab8500_btemp.c
new file mode 100644
index 000000000000..443bc7db30a0
--- /dev/null
+++ b/drivers/power/ab8500_btemp.c
@@ -0,0 +1,1123 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2012
+ *
+ * Battery temperature driver for AB8500
+ *
+ * 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/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 - ab8500 interrupts
+ * @name:	name of the interrupt
+ * @isr		function pointer to the isr
+ */
+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 - ab8500 BTEMP device information
+ * @dev:		Pointer to the structure device
+ * @node:		List of AB8500 BTEMPs, hence prepared for reentrance
+ * @curr_source:	What current source we use, in uA
+ * @bat_temp:		Battery temperature in degree Celcius
+ * @prev_bat_temp	Last dispatched battery temperature
+ * @parent:		Pointer to the struct ab8500
+ * @gpadc:		Pointer to the struct gpadc
+ * @fg:			Pointer to the struct fg
+ * @pdata:		Pointer to the abx500_btemp platform data
+ * @bat:		Pointer to the abx500_bm platform data
+ * @btemp_psy:		Structure for BTEMP specific battery properties
+ * @events:		Structure for information about events triggered
+ * @btemp_ranges:	Battery temperature range structure
+ * @btemp_wq:		Work queue for measuring the temperature periodically
+ * @btemp_periodic_work:	Work for measuring the temperature periodically
+ */
+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);
+
+/**
+ * ab8500_btemp_get() - returns a reference to the primary AB8500 BTEMP
+ * (i.e. the first BTEMP in the instance 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;
+}
+
+/**
+ * ab8500_btemp_batctrl_volt_to_res() - convert batctrl voltage to resistance
+ * @di:		pointer to the ab8500_btemp structure
+ * @v_batctrl:	measured batctrl voltage
+ * @inst_curr:	measured instant current
+ *
+ * This function returns the battery resistance that is
+ * derived from the BATCTRL voltage.
+ * Returns value in Ohms.
+ */
+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 == 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;
+}
+
+/**
+ * ab8500_btemp_read_batctrl_voltage() - measure batctrl voltage
+ * @di:		pointer to the ab8500_btemp structure
+ *
+ * This function returns the voltage on BATCTRL. Returns value in mV.
+ */
+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;
+}
+
+/**
+ * ab8500_btemp_curr_source_enable() - enable/disable batctrl current source
+ * @di:		pointer to the ab8500_btemp structure
+ * @enable:	enable or disable the current source
+ *
+ * Enable or disable the current sources for the BatCtrl AD channel
+ */
+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 == 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 == 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;
+}
+
+/**
+ * ab8500_btemp_get_batctrl_res() - get battery resistance
+ * @di:		pointer to the ab8500_btemp structure
+ *
+ * This function returns the battery pack identification resistance.
+ * Returns value in Ohms.
+ */
+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;
+}
+
+/**
+ * ab8500_btemp_res_to_temp() - resistance to temperature
+ * @di:		pointer to the ab8500_btemp structure
+ * @tbl:	pointer to the resiatance to temperature table
+ * @tbl_size:	size of the resistance to temperature table
+ * @res:	resistance to calculate the temperature from
+ *
+ * This function returns the battery temperature in degrees Celcius
+ * based on the NTC resistance.
+ */
+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;
+}
+
+/**
+ * ab8500_btemp_measure_temp() - measure battery temperature
+ * @di:		pointer to the ab8500_btemp structure
+ *
+ * Returns battery temperature (on success) else the previous temperature
+ */
+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 == 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;
+}
+
+/**
+ * ab8500_btemp_id() - Identify the connected battery
+ * @di:		pointer to the ab8500_btemp structure
+ *
+ * This function will try to identify the battery by reading the ID
+ * resistor. Some brands use a combined ID resistor with a NTC resistor to
+ * both be able to identify and to read the temperature of it.
+ */
+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 == 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 == 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;
+}
+
+/**
+ * ab8500_btemp_periodic_work() - Measuring the temperature periodically
+ * @work:	pointer to the work_struct structure
+ *
+ * Work function for measuring the temperature periodically
+ */
+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));
+}
+
+/**
+ * ab8500_btemp_batctrlindb_handler() - battery removal detected
+ * @irq:       interrupt number
+ * @_di:       void pointer that has to address of ab8500_btemp
+ *
+ * Returns IRQ status(IRQ_HANDLED)
+ */
+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;
+}
+
+/**
+ * ab8500_btemp_templow_handler() - battery temp lower than 10 degrees
+ * @irq:       interrupt number
+ * @_di:       void pointer that has to address of ab8500_btemp
+ *
+ * Returns IRQ status(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;
+}
+
+/**
+ * ab8500_btemp_temphigh_handler() - battery temp higher than max temp
+ * @irq:       interrupt number
+ * @_di:       void pointer that has to address of ab8500_btemp
+ *
+ * Returns IRQ status(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;
+}
+
+/**
+ * ab8500_btemp_lowmed_handler() - battery temp between low and medium
+ * @irq:       interrupt number
+ * @_di:       void pointer that has to address of ab8500_btemp
+ *
+ * Returns IRQ status(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;
+}
+
+/**
+ * ab8500_btemp_medhigh_handler() - battery temp between medium and high
+ * @irq:       interrupt number
+ * @_di:       void pointer that has to address of ab8500_btemp
+ *
+ * Returns IRQ status(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;
+}
+
+/**
+ * ab8500_btemp_periodic() - Periodic temperature measurements
+ * @di:		pointer to the ab8500_btemp structure
+ * @enable:	enable or disable periodic temperature measurements
+ *
+ * Starts of stops periodic temperature measurements. Periodic measurements
+ * should only be done when a charger is connected.
+ */
+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);
+}
+
+/**
+ * ab8500_btemp_get_temp() - get battery temperature
+ * @di:		pointer to the ab8500_btemp structure
+ *
+ * Returns battery temperature
+ */
+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;
+}
+
+/**
+ * ab8500_btemp_get_batctrl_temp() - get the temperature
+ * @btemp:      pointer to the btemp structure
+ *
+ * Returns the batctrl temperature in millidegrees
+ */
+int ab8500_btemp_get_batctrl_temp(struct ab8500_btemp *btemp)
+{
+	return btemp->bat_temp * 1000;
+}
+
+/**
+ * ab8500_btemp_get_property() - get the btemp properties
+ * @psy:        pointer to the power_supply structure
+ * @psp:        pointer to the power_supply_property structure
+ * @val:        pointer to the power_supply_propval union
+ *
+ * This function gets called when an application tries to get the btemp
+ * properties by reading the sysfs files.
+ * online:	presence of the battery
+ * present:	presence of the battery
+ * technology:	battery technology
+ * temp:	battery temperature
+ * Returns error code in case of failure else 0(on success)
+ */
+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;
+}
+
+/**
+ * ab8500_btemp_external_power_changed() - callback for power supply changes
+ * @psy:       pointer to the structure power_supply
+ *
+ * This function is pointing to the function pointer external_power_changed
+ * of the structure power_supply.
+ * This function gets executed when there is a change in the external power
+ * supply to the btemp.
+ */
+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;
+
+	struct ab8500_btemp *di =
+		kzalloc(sizeof(struct ab8500_btemp), 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 */
+	plat_data = pdev->dev.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");
+		goto free_device_info;
+	}
+
+	/* Init work for measuring temperature periodically */
+	INIT_DELAYED_WORK_DEFERRABLE(&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");