[PATCHv2] power: supply: cpcap-battery: Add a battery driver

diff --git a/Documentation/devicetree/bindings/power/supply/cpcap-battery.txt b/Documentation/devicetree/bindings/power/supply/cpcap-battery.txt
new file mode 100644
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/supply/cpcap-battery.txt
@@ -0,0 +1,27 @@ 
+Motorola CPCAP PMIC battery driver binding
+
+Required properties:
+- compatible: Shall be "motorola,cpcap-battery"
+- interrupts: Interrupt specifier for each name in interrupt-names
+- interrupt-names: Should contain the following entries:
+		   "lowbph", "lowbpl", "chrgcurr1", "battdetb"
+- io-channels: IIO ADC channel specifier for each name in io-channel-names
+- io-channel-names: Should contain the following entries:
+		    "battdetb", "battp"
+
+Example:
+
+cpcap_battery: battery {
+	compatible = "motorola,cpcap-battery";
+	interrupts-extended = <
+		&cpcap 5 0 &cpcap 3 0
+		&cpcap 20 0 &cpcap 54 0
+	>;
+	interrupt-names =
+		"lowbph", "lowbpl",
+		"chrgcurr1", "battdetb";
+	io-channels = <&cpcap_adc 0 &cpcap_adc 1
+		       &cpcap_adc 5 &cpcap_adc 6>;
+	io-channel-names = "battdetb", "battp",
+			   "chg_isense", "batti";
+};
diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -82,6 +82,14 @@  config BATTERY_ACT8945A
 	  Say Y here to enable support for power supply provided by
 	  Active-semi ActivePath ACT8945A charger.
 
+config BATTERY_CPCAP
+	tristate "Motorola CPCAP PMIC battery driver"
+	depends on MFD_CPCAP && IIO
+	default MFD_CPCAP
+	help
+	  Say Y here to enable support for battery on Motorola
+	  phones and tablets such as droid 4.
+
 config BATTERY_DS2760
 	tristate "DS2760 battery driver (HP iPAQ & others)"
 	depends on W1 && W1_SLAVE_DS2760
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -20,6 +20,7 @@  obj-$(CONFIG_BATTERY_88PM860X)	+= 88pm860x_battery.o
 obj-$(CONFIG_BATTERY_ACT8945A)	+= act8945a_charger.o
 obj-$(CONFIG_BATTERY_AXP20X)	+= axp20x_battery.o
 obj-$(CONFIG_CHARGER_AXP20X)	+= axp20x_ac_power.o
+obj-$(CONFIG_BATTERY_CPCAP)	+= cpcap-battery.o
 obj-$(CONFIG_BATTERY_DS2760)	+= ds2760_battery.o
 obj-$(CONFIG_BATTERY_DS2780)	+= ds2780_battery.o
 obj-$(CONFIG_BATTERY_DS2781)	+= ds2781_battery.o
diff --git a/drivers/power/supply/cpcap-battery.c b/drivers/power/supply/cpcap-battery.c
new file mode 100644
--- /dev/null
+++ b/drivers/power/supply/cpcap-battery.c
@@ -0,0 +1,808 @@ 
+/*
+ * Battery driver for CPCAP PMIC
+ *
+ * Copyright (C) 2017 Tony Lindgren <tony@atomide.com>
+ *
+ * Some parts of the code based on earlie Motorola mapphone Linux kernel
+ * drivers:
+ *
+ * Copyright (C) 2009-2010 Motorola, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
+
+#include <linux/iio/consumer.h>
+#include <linux/iio/types.h>
+#include <linux/mfd/motorola-cpcap.h>
+
+#include <asm/div64.h>
+
+/*
+ * Register bit defines for CPCAP_REG_BPEOL. Some of these seem to
+ * map to MC13783UG.pdf "Table 5-19. Register 13, Power Control 0"
+ * to enable BATTDETEN, LOBAT and EOL features. We currently use
+ * LOBAT interrupts instead of EOL.
+ */
+#define CPCAP_REG_BPEOL_BIT_EOL9	BIT(9)	/* Set for EOL irq */
+#define CPCAP_REG_BPEOL_BIT_EOL8	BIT(8)	/* Set for EOL irq */
+#define CPCAP_REG_BPEOL_BIT_UNKNOWN7	BIT(7)
+#define CPCAP_REG_BPEOL_BIT_UNKNOWN6	BIT(6)
+#define CPCAP_REG_BPEOL_BIT_UNKNOWN5	BIT(5)
+#define CPCAP_REG_BPEOL_BIT_EOL_MULTI	BIT(4)	/* Set for multiple EOL irqs */
+#define CPCAP_REG_BPEOL_BIT_UNKNOWN3	BIT(3)
+#define CPCAP_REG_BPEOL_BIT_UNKNOWN2	BIT(2)
+#define CPCAP_REG_BPEOL_BIT_BATTDETEN	BIT(1)	/* Enable battery detect */
+#define CPCAP_REG_BPEOL_BIT_EOLSEL	BIT(0)	/* BPDET = 0, EOL = 1 */
+
+#define CPCAP_BATTERY_CC_SAMPLE_PERIOD_MS	250
+
+enum {
+	CPCAP_BATTERY_IIO_BATTDET,
+	CPCAP_BATTERY_IIO_VOLTAGE,
+	CPCAP_BATTERY_IIO_CHRG_CURRENT,
+	CPCAP_BATTERY_IIO_BATT_CURRENT,
+	CPCAP_BATTERY_IIO_NR,
+};
+
+enum cpcap_battery_irq_action {
+	CPCAP_BATTERY_IRQ_ACTION_NONE,
+	CPCAP_BATTERY_IRQ_ACTION_BATTERY_LOW,
+	CPCAP_BATTERY_IRQ_ACTION_POWEROFF,
+};
+
+struct cpcap_interrupt_desc {
+	const char *name;
+	struct list_head node;
+	int irq;
+	enum cpcap_battery_irq_action action;
+};
+
+struct cpcap_battery_config {
+	int ccm;
+	int cd_factor;
+	struct power_supply_info info;
+};
+
+struct cpcap_coulomb_counter_data {
+	s32 sample;		/* 24-bits */
+	s32 accumulator;
+	s16 offset;		/* 10-bits */
+};
+
+enum cpcap_battery_state {
+	CPCAP_BATTERY_STATE_PREVIOUS,
+	CPCAP_BATTERY_STATE_LATEST,
+	CPCAP_BATTERY_STATE_NR,
+};
+
+struct cpcap_battery_state_data {
+	int voltage;
+	int current_ua;
+	int counter_uah;
+	int temperature;
+	ktime_t time;
+	struct cpcap_coulomb_counter_data cc;
+};
+
+struct cpcap_battery_ddata {
+	struct device *dev;
+	struct regmap *reg;
+	struct list_head irq_list;
+	struct iio_channel *channels[CPCAP_BATTERY_IIO_NR];
+	struct power_supply *psy;
+	struct cpcap_battery_config config;
+	struct cpcap_battery_state_data state[CPCAP_BATTERY_STATE_NR];
+	atomic_t active;
+	int status;
+	u16 vendor;
+};
+
+#define CPCAP_NO_BATTERY	-400
+
+static struct cpcap_battery_state_data *
+cpcap_battery_get_state(struct cpcap_battery_ddata *ddata,
+			enum cpcap_battery_state state)
+{
+	if (state >= CPCAP_BATTERY_STATE_NR)
+		return NULL;
+
+	return &ddata->state[state];
+}
+
+static struct cpcap_battery_state_data *
+cpcap_battery_latest(struct cpcap_battery_ddata *ddata)
+{
+	return cpcap_battery_get_state(ddata, CPCAP_BATTERY_STATE_LATEST);
+}
+
+static struct cpcap_battery_state_data *
+cpcap_battery_previous(struct cpcap_battery_ddata *ddata)
+{
+	return cpcap_battery_get_state(ddata, CPCAP_BATTERY_STATE_PREVIOUS);
+}
+
+static int cpcap_charger_battery_temperature(struct cpcap_battery_ddata *ddata,
+					     int *value)
+{
+	struct iio_channel *channel;
+	int error;
+
+	channel = ddata->channels[CPCAP_BATTERY_IIO_BATTDET];
+	error = iio_read_channel_processed(channel, value);
+	if (error < 0) {
+		dev_warn(ddata->dev, "%s failed: %i\n", __func__, error);
+		*value = CPCAP_NO_BATTERY;
+
+		return error;
+	}
+
+	*value /= 100;
+
+	return 0;
+}
+
+static int cpcap_battery_get_voltage(struct cpcap_battery_ddata *ddata)
+{
+	struct iio_channel *channel;
+	int error, value = 0;
+
+	channel = ddata->channels[CPCAP_BATTERY_IIO_VOLTAGE];
+	error = iio_read_channel_processed(channel, &value);
+	if (error < 0) {
+		dev_warn(ddata->dev, "%s failed: %i\n", __func__, error);
+
+		return 0;
+	}
+
+	return value * 1000;
+}
+
+static int cpcap_battery_get_current(struct cpcap_battery_ddata *ddata)
+{
+	struct iio_channel *channel;
+	int error, value = 0;
+
+	channel = ddata->channels[CPCAP_BATTERY_IIO_BATT_CURRENT];
+	error = iio_read_channel_processed(channel, &value);
+	if (error < 0) {
+		dev_warn(ddata->dev, "%s failed: %i\n", __func__, error);
+
+		return 0;
+	}
+
+	return value * 1000;
+}
+
+/**
+ * cpcap_battery_cc_raw_div - calculate and divide coulomb counter μAms values
+ * @ddata: device driver data
+ * @sample: coulomb counter sample value
+ * @accumulator: coulomb counter integrator value
+ * @offset: coulomb counter offset value
+ * @divider: conversion divider
+ *
+ * Note that cc_lsb and cc_dur values are from Motorola Linux kernel
+ * function data_get_avg_curr_ua() and seem to be based on measured test
+ * results. It also has the following comment:
+ *
+ * Adjustment factors are applied here as a temp solution per the test
+ * results. Need to work out a formal solution for this adjustment.
+ *
+ * A coulomb counter for similar hardware seems to be documented in
+ * "TWL6030 Gas Gauging Basics (Rev. A)" swca095a.pdf in chapter
+ * "10 Calculating Accumulated Current". We however follow what the
+ * Motorola mapphone Linux kernel is doing as there may be either a
+ * TI or ST coulomb counter in the PMIC.
+ */
+static int cpcap_battery_cc_raw_div(struct cpcap_battery_ddata *ddata,
+				    u32 sample, s32 accumulator,
+				    s16 offset, u32 divider)
+{
+	s64 acc;
+	u64 tmp;
+	int avg_current;
+	u32 cc_lsb;
+
+	sample &= 0xffffff;		/* 24-bits, unsigned */
+	offset &= 0x7ff;		/* 10-bits, signed */
+
+	switch (ddata->vendor) {
+	case CPCAP_VENDOR_ST:
+		cc_lsb = 95374;		/* μAms per LSB */
+		break;
+	case CPCAP_VENDOR_TI:
+		cc_lsb = 91501;		/* μAms per LSB */
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	acc = accumulator;
+	acc = acc - ((s64)sample * offset);
+	cc_lsb = (cc_lsb * ddata->config.cd_factor) / 1000;
+
+	if (acc >=  0)
+		tmp = acc;
+	else
+		tmp = acc * -1;
+
+	tmp = tmp * cc_lsb;
+	do_div(tmp, divider);
+	avg_current = tmp;
+
+	if (acc >= 0)
+		return -avg_current;
+	else
+		return avg_current;
+}
+
+/* 3600000μAms = 1μAh */
+static int cpcap_battery_cc_to_uah(struct cpcap_battery_ddata *ddata,
+				   u32 sample, s32 accumulator,
+				   s16 offset)
+{
+	return cpcap_battery_cc_raw_div(ddata, sample,
+					accumulator, offset,
+					3600000);
+}
+
+static int cpcap_battery_cc_to_ua(struct cpcap_battery_ddata *ddata,
+				  u32 sample, s32 accumulator,
+				  s16 offset)
+{
+	return cpcap_battery_cc_raw_div(ddata, sample,
+					accumulator, offset,
+					sample *
+					CPCAP_BATTERY_CC_SAMPLE_PERIOD_MS);
+}
+
+/**
+ * cpcap_battery_read_accumulated - reads cpcap coulomb counter
+ * @ddata: device driver data
+ * @regs: coulomb counter values
+ *
+ * Based on Motorola mapphone kernel function data_read_regs().
+ * Looking at the registers, the coulomb counter seems similar to
+ * the coulomb counter in TWL6030. See "TWL6030 Gas Gauging Basics
+ * (Rev. A) swca095a.pdf for "10 Calculating Accumulated Current".
+ *
+ * Note that swca095a.pdf instructs to stop the coulomb counter
+ * before reading to avoid values changing. Motorola mapphone
+ * Linux kernel does not do it, so let's assume they've verified
+ * the data produced is correct.
+ */
+static int
+cpcap_battery_read_accumulated(struct cpcap_battery_ddata *ddata,
+			       struct cpcap_coulomb_counter_data *ccd)
+{
+	u16 buf[7];	/* CPCAP_REG_CC1 to CCI */
+	int error;
+
+	ccd->sample = 0;
+	ccd->accumulator = 0;
+	ccd->offset = 0;
+
+	/* Read coulomb counter register range */
+	error = regmap_bulk_read(ddata->reg, CPCAP_REG_CCS1,
+				 buf, ARRAY_SIZE(buf));
+	if (error)
+		return 0;
+
+	/* Sample value CPCAP_REG_CCS1 & 2 */
+	ccd->sample = (buf[1] & 0x0fff) << 16;
+	ccd->sample |= buf[0];
+
+	/* Accumulator value CPCAP_REG_CCA1 & 2 */
+	ccd->accumulator = ((s16)buf[3]) << 16;
+	ccd->accumulator |= buf[2];
+
+	/* Offset value CPCAP_REG_CCO */
+	ccd->offset = buf[5];
+
+	/* Adjust offset based on mode value CPCAP_REG_CCM? */
+	if (buf[4] >= 0x200)
+		ccd->offset |= 0xfc00;
+
+	return cpcap_battery_cc_to_uah(ddata,
+				       ccd->sample,
+				       ccd->accumulator,
+				       ccd->offset);
+}
+
+/**
+ * cpcap_battery_cc_get_avg_current - read cpcap coulumb counter
+ * @ddata: cpcap battery driver device data
+ */
+static int cpcap_battery_cc_get_avg_current(struct cpcap_battery_ddata *ddata)
+{
+	int value, acc, error;
+	s32 sample = 1;
+	s16 offset;
+
+	if (ddata->vendor == CPCAP_VENDOR_ST)
+		sample = 4;
+
+	/* Coulomb counter integrator */
+	error = regmap_read(ddata->reg, CPCAP_REG_CCI, &value);
+	if (error)
+		return error;
+
+	if ((ddata->vendor == CPCAP_VENDOR_TI) && (value > 0x2000))
+		value = value | 0xc000;
+
+	acc = (s16)value;
+
+	/* Coulomb counter sample time */
+	error = regmap_read(ddata->reg, CPCAP_REG_CCM, &value);
+	if (error)
+		return error;
+
+	if (value < 0x200)
+		offset = value;
+	else
+		offset = value | 0xfc00;
+
+	return cpcap_battery_cc_to_ua(ddata, sample, acc, offset);
+}
+
+static bool cpcap_battery_full(struct cpcap_battery_ddata *ddata)
+{
+	struct cpcap_battery_state_data *state = cpcap_battery_latest(ddata);
+
+	/* Basically anything that measures above 4347000 is full */
+	if (state->voltage >= (ddata->config.info.voltage_max_design - 4000))
+		return true;
+
+	return false;
+}
+
+static int cpcap_battery_update_status(struct cpcap_battery_ddata *ddata)
+{
+	struct cpcap_battery_state_data state, *latest, *previous;
+	ktime_t now;
+	int error;
+
+	memset(&state, 0, sizeof(state));
+	now = ktime_get();
+
+	latest = cpcap_battery_latest(ddata);
+	if (latest) {
+		s64 delta_ms = ktime_to_ms(ktime_sub(now, latest->time));
+
+		if (delta_ms < CPCAP_BATTERY_CC_SAMPLE_PERIOD_MS)
+			return delta_ms;
+	}
+
+	state.time = now;
+	state.voltage = cpcap_battery_get_voltage(ddata);
+	state.current_ua = cpcap_battery_get_current(ddata);
+	state.counter_uah = cpcap_battery_read_accumulated(ddata, &state.cc);
+
+	error = cpcap_charger_battery_temperature(ddata,
+						  &state.temperature);
+	if (error)
+		return error;
+
+	previous = cpcap_battery_previous(ddata);
+	memcpy(previous, latest, sizeof(*previous));
+	memcpy(latest, &state, sizeof(*latest));
+
+	return 0;
+}
+
+static enum power_supply_property cpcap_battery_props[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_TECHNOLOGY,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
+	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
+	POWER_SUPPLY_PROP_CURRENT_AVG,
+	POWER_SUPPLY_PROP_CURRENT_NOW,
+	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
+	POWER_SUPPLY_PROP_CHARGE_COUNTER,
+	POWER_SUPPLY_PROP_POWER_NOW,
+	POWER_SUPPLY_PROP_POWER_AVG,
+	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
+	POWER_SUPPLY_PROP_SCOPE,
+	POWER_SUPPLY_PROP_TEMP,
+};
+
+static int cpcap_battery_get_property(struct power_supply *psy,
+				      enum power_supply_property psp,
+				      union power_supply_propval *val)
+{
+	struct cpcap_battery_ddata *ddata = power_supply_get_drvdata(psy);
+	struct cpcap_battery_state_data *latest, *previous;
+	u32 sample;
+	s32 accumulator;
+	int cached;
+	s64 tmp;
+
+	cached = cpcap_battery_update_status(ddata);
+	if (cached < 0)
+		return cached;
+
+	latest = cpcap_battery_latest(ddata);
+	previous = cpcap_battery_previous(ddata);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_PRESENT:
+		if (latest->temperature > CPCAP_NO_BATTERY)
+			val->intval = 1;
+		else
+			val->intval = 0;
+		break;
+	case POWER_SUPPLY_PROP_STATUS:
+		if (cpcap_battery_full(ddata)) {
+			val->intval = POWER_SUPPLY_STATUS_FULL;
+			break;
+		}
+		if (cpcap_battery_cc_get_avg_current(ddata) < 0)
+			val->intval = POWER_SUPPLY_STATUS_CHARGING;
+		else
+			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+		break;
+	case POWER_SUPPLY_PROP_TECHNOLOGY:
+		val->intval = ddata->config.info.technology;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		val->intval = cpcap_battery_get_voltage(ddata);
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+		val->intval = ddata->config.info.voltage_max_design;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
+		val->intval = ddata->config.info.voltage_min_design;
+		break;
+	case POWER_SUPPLY_PROP_CURRENT_AVG:
+		if (cached) {
+			val->intval = cpcap_battery_cc_get_avg_current(ddata);
+			break;
+		}
+		sample = latest->cc.sample - previous->cc.sample;
+		accumulator = latest->cc.accumulator - previous->cc.accumulator;
+		val->intval = cpcap_battery_cc_to_ua(ddata, sample,
+						     accumulator,
+						     latest->cc.offset);
+		break;
+	case POWER_SUPPLY_PROP_CURRENT_NOW:
+		val->intval = latest->current_ua;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
+		val->intval = latest->counter_uah;
+		break;
+	case POWER_SUPPLY_PROP_POWER_NOW:
+		tmp = (latest->voltage / 10000) * latest->current_ua;
+		val->intval = div64_s64(tmp, 100);
+		break;
+	case POWER_SUPPLY_PROP_POWER_AVG:
+		if (cached) {
+			tmp = cpcap_battery_cc_get_avg_current(ddata);
+			tmp *= (latest->voltage / 10000);
+			val->intval = div64_s64(tmp, 100);
+			break;
+		}
+		sample = latest->cc.sample - previous->cc.sample;
+		accumulator = latest->cc.accumulator - previous->cc.accumulator;
+		tmp = cpcap_battery_cc_to_ua(ddata, sample, accumulator,
+					     latest->cc.offset);
+		tmp *= ((latest->voltage + previous->voltage) / 20000);
+		val->intval = div64_s64(tmp, 100);
+		break;
+	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
+		if (cpcap_battery_full(ddata))
+			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
+		else if (latest->voltage >= 3750000)
+			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_HIGH;
+		else if (latest->voltage >= 3300000)
+			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
+		else if (latest->voltage > 3100000)
+			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
+		else if (latest->voltage <= 3100000)
+			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
+		else
+			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_UNKNOWN;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
+		val->intval = ddata->config.info.charge_full_design;
+		break;
+	case POWER_SUPPLY_PROP_SCOPE:
+		val->intval = POWER_SUPPLY_SCOPE_SYSTEM;
+		break;
+	case POWER_SUPPLY_PROP_TEMP:
+		val->intval = latest->temperature;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static irqreturn_t cpcap_battery_irq_thread(int irq, void *data)
+{
+	struct cpcap_battery_ddata *ddata = data;
+	struct cpcap_battery_state_data *latest;
+	struct cpcap_interrupt_desc *d;
+
+	if (!atomic_read(&ddata->active))
+		return IRQ_NONE;
+
+	list_for_each_entry(d, &ddata->irq_list, node) {
+		if (irq == d->irq)
+			break;
+	}
+
+	if (!d)
+		return IRQ_NONE;
+
+	latest = cpcap_battery_latest(ddata);
+
+	switch (d->action) {
+	case CPCAP_BATTERY_IRQ_ACTION_BATTERY_LOW:
+		if (latest->counter_uah >= 0)
+			dev_warn(ddata->dev, "Battery low at 3.3V!\n");
+		break;
+	case CPCAP_BATTERY_IRQ_ACTION_POWEROFF:
+		if (latest->counter_uah >= 0) {
+			dev_emerg(ddata->dev,
+				  "Battery empty at 3.1V, powering off\n");
+			orderly_poweroff(true);
+		}
+		break;
+	default:
+		break;
+	}
+
+	power_supply_changed(ddata->psy);
+
+	return IRQ_HANDLED;
+}
+
+static int cpcap_battery_init_irq(struct platform_device *pdev,
+				  struct cpcap_battery_ddata *ddata,
+				  const char *name)
+{
+	struct cpcap_interrupt_desc *d;
+	int irq, error;
+
+	irq = platform_get_irq_byname(pdev, name);
+	if (!irq)
+		return -ENODEV;
+
+	error = devm_request_threaded_irq(ddata->dev, irq, NULL,
+					  cpcap_battery_irq_thread,
+					  IRQF_SHARED,
+					  name, ddata);
+	if (error) {
+		dev_err(ddata->dev, "could not get irq %s: %i\n",
+			name, error);
+
+		return error;
+	}
+
+	d = devm_kzalloc(ddata->dev, sizeof(*d), GFP_KERNEL);
+	if (!d)
+		return -ENOMEM;
+
+	d->name = name;
+	d->irq = irq;
+
+	if (!strncmp(name, "lowbph", 6))
+		d->action = CPCAP_BATTERY_IRQ_ACTION_BATTERY_LOW;
+	else if (!strncmp(name, "lowbpl", 6))
+		d->action = CPCAP_BATTERY_IRQ_ACTION_POWEROFF;
+
+	list_add(&d->node, &ddata->irq_list);
+
+	return 0;
+}
+
+static int cpcap_battery_init_interrupts(struct platform_device *pdev,
+					 struct cpcap_battery_ddata *ddata)
+{
+	const char * const cpcap_battery_irqs[] = {
+		"eol", "lowbph", "lowbpl",
+		"chrgcurr1", "battdetb"
+	};
+	int i, error;
+
+	for (i = 0; i < ARRAY_SIZE(cpcap_battery_irqs); i++) {
+		error = cpcap_battery_init_irq(pdev, ddata,
+					       cpcap_battery_irqs[i]);
+		if (error)
+			return error;
+	}
+
+	/* Enable low battery interrupts for 3.3V high and 3.1V low */
+	error = regmap_update_bits(ddata->reg, CPCAP_REG_BPEOL,
+				   0xffff,
+				   CPCAP_REG_BPEOL_BIT_BATTDETEN);
+	if (error)
+		return error;
+
+	return 0;
+}
+
+static int cpcap_battery_init_iio(struct cpcap_battery_ddata *ddata)
+{
+	const char * const names[CPCAP_BATTERY_IIO_NR] = {
+		"battdetb", "battp", "chg_isense", "batti",
+	};
+	int error, i;
+
+	for (i = 0; i < CPCAP_BATTERY_IIO_NR; i++) {
+		ddata->channels[i] = devm_iio_channel_get(ddata->dev,
+							  names[i]);
+		if (IS_ERR(ddata->channels[i])) {
+			error = PTR_ERR(ddata->channels[i]);
+			goto out_err;
+		}
+
+		if (!ddata->channels[i]->indio_dev) {
+			error = -ENXIO;
+			goto out_err;
+		}
+	}
+
+	return 0;
+
+out_err:
+	dev_err(ddata->dev, "could not initialize VBUS or ID IIO: %i\n",
+		error);
+
+	return error;
+}
+
+/*
+ * Based on the values from Motorola mapphone Linux kernel. In the
+ * the Motorola mapphone Linux kernel tree the value for pm_cd_factor
+ * is passed to the kernel via device tree. If it turns out to be
+ * something device specific we can consider that too later.
+ *
+ * And looking at the battery full and shutdown values for the stock
+ * kernel on droid 4, full is 4351000 and software initiates shutdown
+ * at 3078000. The device will die around 2743000.
+ */
+static const struct cpcap_battery_config cpcap_battery_default_data = {
+	.ccm = 0x3ff,
+	.cd_factor = 0x3cc,
+	.info.technology = POWER_SUPPLY_TECHNOLOGY_LION,
+	.info.voltage_max_design = 4351000,
+	.info.voltage_min_design = 3100000,
+	.info.charge_full_design = 1740000,
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id cpcap_battery_id_table[] = {
+	{
+		.compatible = "motorola,cpcap-battery",
+		.data = &cpcap_battery_default_data,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, cpcap_battery_id_table);
+#endif
+
+static int cpcap_battery_probe(struct platform_device *pdev)
+{
+	struct power_supply_desc *psy_desc;
+	struct cpcap_battery_ddata *ddata;
+	const struct of_device_id *match;
+	struct power_supply_config psy_cfg = {};
+	int error;
+
+	match = of_match_device(of_match_ptr(cpcap_battery_id_table),
+				&pdev->dev);
+	if (!match)
+		return -EINVAL;
+
+	if (!match->data) {
+		dev_err(&pdev->dev, "no configuration data found\n");
+
+		return -ENODEV;
+	}
+
+	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
+	if (!ddata)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&ddata->irq_list);
+	ddata->dev = &pdev->dev;
+	memcpy(&ddata->config, match->data, sizeof(ddata->config));
+
+	ddata->reg = dev_get_regmap(ddata->dev->parent, NULL);
+	if (!ddata->reg)
+		return -ENODEV;
+
+	error = cpcap_get_vendor(ddata->dev, ddata->reg, &ddata->vendor);
+	if (error)
+		return error;
+
+	platform_set_drvdata(pdev, ddata);
+
+	error = regmap_update_bits(ddata->reg, CPCAP_REG_CCM,
+				   0xffff, ddata->config.ccm);
+	if (error)
+		return error;
+
+	error = cpcap_battery_init_interrupts(pdev, ddata);
+	if (error)
+		return error;
+
+	error = cpcap_battery_init_iio(ddata);
+	if (error)
+		return error;
+
+	psy_desc = devm_kzalloc(ddata->dev, sizeof(*psy_desc), GFP_KERNEL);
+	if (!psy_desc)
+		return -ENOMEM;
+
+	psy_desc->name = "battery",
+	psy_desc->type = POWER_SUPPLY_TYPE_BATTERY,
+	psy_desc->properties = cpcap_battery_props,
+	psy_desc->num_properties = ARRAY_SIZE(cpcap_battery_props),
+	psy_desc->get_property = cpcap_battery_get_property,
+
+	psy_cfg.of_node = pdev->dev.of_node;
+	psy_cfg.drv_data = ddata;
+
+	ddata->psy = devm_power_supply_register(ddata->dev, psy_desc,
+						&psy_cfg);
+	error = PTR_ERR_OR_ZERO(ddata->psy);
+	if (error) {
+		dev_err(ddata->dev, "failed to register power supply\n");
+		return error;
+	}
+
+	atomic_set(&ddata->active, 1);
+
+	return 0;
+}
+
+static int cpcap_battery_remove(struct platform_device *pdev)
+{
+	struct cpcap_battery_ddata *ddata = platform_get_drvdata(pdev);
+	int error;
+
+	atomic_set(&ddata->active, 0);
+	error = regmap_update_bits(ddata->reg, CPCAP_REG_BPEOL,
+				   0xffff, 0);
+	if (error)
+		dev_err(&pdev->dev, "could not disable: %i\n", error);
+
+	return 0;
+}
+
+static struct platform_driver cpcap_battery_driver = {
+	.driver	= {
+		.name		= "cpcap_battery",
+		.of_match_table = of_match_ptr(cpcap_battery_id_table),
+	},
+	.probe	= cpcap_battery_probe,
+	.remove = cpcap_battery_remove,
+};
+module_platform_driver(cpcap_battery_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>");
+MODULE_DESCRIPTION("CPCAP PMIC Battery Driver");