Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / power / ab8500_btemp.c
diff --git a/kernel/drivers/power/ab8500_btemp.c b/kernel/drivers/power/ab8500_btemp.c
new file mode 100644 (file)
index 0000000..8f8044e
--- /dev/null
@@ -0,0 +1,1217 @@
+/*
+ * 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/jiffies.h>
+#include <linux/of.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/abx500.h>
+#include <linux/mfd/abx500/ab8500.h>
+#include <linux/mfd/abx500/ab8500-bm.h>
+#include <linux/mfd/abx500/ab8500-gpadc.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 BTEMP_BATCTRL_CURR_SRC_16UA    16
+#define BTEMP_BATCTRL_CURR_SRC_18UA    18
+
+#define BTEMP_BATCTRL_CURR_SRC_60UA    60
+#define BTEMP_BATCTRL_CURR_SRC_120UA   120
+
+/**
+ * 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:          Dispatched battery temperature in degree Celcius
+ * @prev_bat_temp      Last measured battery temperature in degree Celcius
+ * @parent:            Pointer to the struct ab8500
+ * @gpadc:             Pointer to the struct gpadc
+ * @fg:                        Pointer to the struct fg
+ * @bm:                Platform specific battery management information
+ * @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
+ * @initialized:       True if battery id read.
+ */
+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_bm_data *bm;
+       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;
+       bool initialized;
+};
+
+/* 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;
+}
+EXPORT_SYMBOL(ab8500_btemp_get);
+
+/**
+ * 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->bm->adc_therm == ABx500_ADC_THERM_BATCTRL) {
+               /*
+                * If the battery has internal NTC, we use the current
+                * source to calculate the resistance.
+                */
+               rbs = (v_batctrl * 1000
+                      - di->bm->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->bm->adc_therm == ABx500_ADC_THERM_BATCTRL && enable) {
+
+               if (is_ab8540(di->parent)) {
+                       if (di->curr_source == BTEMP_BATCTRL_CURR_SRC_60UA)
+                               curr = BAT_CTRL_60U_ENA;
+                       else
+                               curr = BAT_CTRL_120U_ENA;
+               } else if (is_ab9540(di->parent) || is_ab8505(di->parent)) {
+                       if (di->curr_source == BTEMP_BATCTRL_CURR_SRC_16UA)
+                               curr = BAT_CTRL_16U_ENA;
+                       else
+                               curr = BAT_CTRL_18U_ENA;
+               } else {
+                       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->bm->adc_therm == ABx500_ADC_THERM_BATCTRL && !enable) {
+               dev_dbg(di->dev, "Disable BATCTRL curr source\n");
+
+               if (is_ab8540(di->parent)) {
+                       /* Write 0 to the curr bits */
+                       ret = abx500_mask_and_set_register_interruptible(
+                               di->dev,
+                               AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
+                               BAT_CTRL_60U_ENA | BAT_CTRL_120U_ENA,
+                               ~(BAT_CTRL_60U_ENA | BAT_CTRL_120U_ENA));
+               } else if (is_ab9540(di->parent) || is_ab8505(di->parent)) {
+                       /* Write 0 to the curr bits */
+                       ret = abx500_mask_and_set_register_interruptible(
+                               di->dev,
+                               AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
+                               BAT_CTRL_16U_ENA | BAT_CTRL_18U_ENA,
+                               ~(BAT_CTRL_16U_ENA | BAT_CTRL_18U_ENA));
+               } else {
+                       /* 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:
+       if (is_ab8540(di->parent)) {
+               /* Write 0 to the curr bits */
+               ret = abx500_mask_and_set_register_interruptible(di->dev,
+                       AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
+                       BAT_CTRL_60U_ENA | BAT_CTRL_120U_ENA,
+                       ~(BAT_CTRL_60U_ENA | BAT_CTRL_120U_ENA));
+       } else if (is_ab9540(di->parent) || is_ab8505(di->parent)) {
+               /* Write 0 to the curr bits */
+               ret = abx500_mask_and_set_register_interruptible(di->dev,
+                       AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
+                       BAT_CTRL_16U_ENA | BAT_CTRL_18U_ENA,
+                       ~(BAT_CTRL_16U_ENA | BAT_CTRL_18U_ENA));
+       } else {
+               /* 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;
+       }
+
+       do {
+               msleep(20);
+       } while (!ab8500_fg_inst_curr_started(di->fg));
+
+       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->bm->batt_id;
+
+       if (di->bm->adc_therm == ABx500_ADC_THERM_BATCTRL &&
+                       id != BATTERY_UNKNOWN) {
+
+               rbat = ab8500_btemp_get_batctrl_res(di);
+               if (rbat < 0) {
+                       dev_err(di->dev, "%s get batctrl res failed\n",
+                               __func__);
+                       /*
+                        * Return out-of-range temperature so that
+                        * charging is stopped
+                        */
+                       return BTEMP_THERMAL_LOW_LIMIT;
+               }
+
+               temp = ab8500_btemp_res_to_temp(di,
+                       di->bm->bat_type[id].r_to_t_tbl,
+                       di->bm->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->bm->bat_type[id].r_to_t_tbl,
+                       di->bm->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;
+       if (is_ab8540(di->parent))
+               di->curr_source = BTEMP_BATCTRL_CURR_SRC_60UA;
+       else if (is_ab9540(di->parent) || is_ab8505(di->parent))
+               di->curr_source = BTEMP_BATCTRL_CURR_SRC_16UA;
+       else
+               di->curr_source = BTEMP_BATCTRL_CURR_SRC_7UA;
+
+       di->bm->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->bm->n_btypes; i++) {
+               if ((res <= di->bm->bat_type[i].resis_high) &&
+                       (res >= di->bm->bat_type[i].resis_low)) {
+                       dev_dbg(di->dev, "Battery detected on %s"
+                               " low %d < res %d < high: %d"
+                               " index: %d\n",
+                               di->bm->adc_therm == ABx500_ADC_THERM_BATCTRL ?
+                               "BATCTRL" : "BATTEMP",
+                               di->bm->bat_type[i].resis_low, res,
+                               di->bm->bat_type[i].resis_high, i);
+
+                       di->bm->batt_id = i;
+                       break;
+               }
+       }
+
+       if (di->bm->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.
+        */
+       if (di->bm->adc_therm == ABx500_ADC_THERM_BATCTRL &&
+           di->bm->batt_id == 1) {
+               if (is_ab8540(di->parent)) {
+                       dev_dbg(di->dev,
+                               "Set BATCTRL current source to 60uA\n");
+                       di->curr_source = BTEMP_BATCTRL_CURR_SRC_60UA;
+               } else if (is_ab9540(di->parent) || is_ab8505(di->parent)) {
+                       dev_dbg(di->dev,
+                               "Set BATCTRL current source to 16uA\n");
+                       di->curr_source = BTEMP_BATCTRL_CURR_SRC_16UA;
+               } else {
+                       dev_dbg(di->dev, "Set BATCTRL current source to 20uA\n");
+                       di->curr_source = BTEMP_BATCTRL_CURR_SRC_20UA;
+               }
+       }
+
+       return di->bm->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;
+       int bat_temp;
+       struct ab8500_btemp *di = container_of(work,
+               struct ab8500_btemp, btemp_periodic_work.work);
+
+       if (!di->initialized) {
+               /* Identify the battery */
+               if (ab8500_btemp_id(di) < 0)
+                       dev_warn(di->dev, "failed to identify the battery\n");
+       }
+
+       bat_temp = ab8500_btemp_measure_temp(di);
+       /*
+        * Filter battery temperature.
+        * Allow direct updates on temperature only if two samples result in
+        * same temperature. Else only allow 1 degree change from previous
+        * reported value in the direction of the new measurement.
+        */
+       if ((bat_temp == di->prev_bat_temp) || !di->initialized) {
+               if ((di->bat_temp != di->prev_bat_temp) || !di->initialized) {
+                       di->initialized = true;
+                       di->bat_temp = bat_temp;
+                       power_supply_changed(di->btemp_psy);
+               }
+       } else if (bat_temp < di->prev_bat_temp) {
+               di->bat_temp--;
+               power_supply_changed(di->btemp_psy);
+       } else if (bat_temp > di->prev_bat_temp) {
+               di->bat_temp++;
+               power_supply_changed(di->btemp_psy);
+       }
+       di->prev_bat_temp = bat_temp;
+
+       if (di->events.ac_conn || di->events.usb_conn)
+               interval = di->bm->temp_interval_chg;
+       else
+               interval = di->bm->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_3p3_or_earlier(di->parent)) {
+               dev_dbg(di->dev, "Ignore false btemp low irq"
+                       " for ABB cut 1.0, 1.1, 2.0 and 3.3\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
+ */
+int ab8500_btemp_get_temp(struct ab8500_btemp *di)
+{
+       int temp = 0;
+
+       /*
+        * The BTEMP events are not reliabe on AB8500 cut3.3
+        * and prior versions
+        */
+       if (is_ab8500_3p3_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 * 10;
+                       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 * 10;
+                       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 * 10;
+                       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 * 10;
+                       else
+                               temp = di->bat_temp * 10;
+               } else
+                       temp = di->bat_temp * 10;
+       }
+       return temp;
+}
+EXPORT_SYMBOL(ab8500_btemp_get_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;
+}
+EXPORT_SYMBOL(ab8500_btemp_get_batctrl_temp);
+
+/**
+ * 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 = power_supply_get_drvdata(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->bm->bat_type[di->bm->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 = power_supply_get_drvdata(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->desc->name))
+                       psy_found = true;
+       }
+
+       if (!psy_found)
+               return 0;
+
+       /* Go through all properties for the psy */
+       for (j = 0; j < ext->desc->num_properties; j++) {
+               enum power_supply_property prop;
+               prop = ext->desc->properties[j];
+
+               if (power_supply_get_property(ext, prop, &ret))
+                       continue;
+
+               switch (prop) {
+               case POWER_SUPPLY_PROP_PRESENT:
+                       switch (ext->desc->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 = power_supply_get_drvdata(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 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);
+
+       return 0;
+}
+
+static char *supply_interface[] = {
+       "ab8500_chargalg",
+       "ab8500_fg",
+};
+
+static const struct power_supply_desc ab8500_btemp_desc = {
+       .name                   = "ab8500_btemp",
+       .type                   = POWER_SUPPLY_TYPE_BATTERY,
+       .properties             = ab8500_btemp_props,
+       .num_properties         = ARRAY_SIZE(ab8500_btemp_props),
+       .get_property           = ab8500_btemp_get_property,
+       .external_power_changed = ab8500_btemp_external_power_changed,
+};
+
+static int ab8500_btemp_probe(struct platform_device *pdev)
+{
+       struct device_node *np = pdev->dev.of_node;
+       struct abx500_bm_data *plat = pdev->dev.platform_data;
+       struct power_supply_config psy_cfg = {};
+       struct ab8500_btemp *di;
+       int irq, i, ret = 0;
+       u8 val;
+
+       di = devm_kzalloc(&pdev->dev, sizeof(*di), GFP_KERNEL);
+       if (!di) {
+               dev_err(&pdev->dev, "%s no mem for ab8500_btemp\n", __func__);
+               return -ENOMEM;
+       }
+
+       if (!plat) {
+               dev_err(&pdev->dev, "no battery management data supplied\n");
+               return -EINVAL;
+       }
+       di->bm = plat;
+
+       if (np) {
+               ret = ab8500_bm_of_probe(&pdev->dev, np, di->bm);
+               if (ret) {
+                       dev_err(&pdev->dev, "failed to get battery information\n");
+                       return ret;
+               }
+       }
+
+       /* get parent data */
+       di->dev = &pdev->dev;
+       di->parent = dev_get_drvdata(pdev->dev.parent);
+       di->gpadc = ab8500_gpadc_get("ab8500-gpadc.0");
+
+       di->initialized = false;
+
+       psy_cfg.supplied_to = supply_interface;
+       psy_cfg.num_supplicants = ARRAY_SIZE(supply_interface);
+       psy_cfg.drv_data = di;
+
+       /* 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");
+               return -ENOMEM;
+       }
+
+       /* Init work for measuring temperature periodically */
+       INIT_DEFERRABLE_WORK(&di->btemp_periodic_work,
+               ab8500_btemp_periodic_work);
+
+       /* 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 */
+       di->btemp_psy = power_supply_register(di->dev, &ab8500_btemp_desc,
+                                             &psy_cfg);
+       if (IS_ERR(di->btemp_psy)) {
+               dev_err(di->dev, "failed to register BTEMP psy\n");
+               ret = PTR_ERR(di->btemp_psy);
+               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);
+       return ret;
+}
+
+static const struct of_device_id ab8500_btemp_match[] = {
+       { .compatible = "stericsson,ab8500-btemp", },
+       { },
+};
+
+static struct platform_driver ab8500_btemp_driver = {
+       .probe = ab8500_btemp_probe,
+       .remove = ab8500_btemp_remove,
+       .suspend = ab8500_btemp_suspend,
+       .resume = ab8500_btemp_resume,
+       .driver = {
+               .name = "ab8500-btemp",
+               .of_match_table = ab8500_btemp_match,
+       },
+};
+
+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);
+}
+
+device_initcall(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");