power: supply: cpcap-battery: Add a battery driver

On the CPCAP PMIC we can use the ADCs for monitoring the battery,
and there is also a coulomb counter. So let's add basic support for
the battery driver.

I did not add any capacity prediction as that should probably be
done in the user space. Or at least user space should tell the kernel
some battery statistics and then the kernel driver could display the
capacity based on that.

Cc: devicetree@vger.kernel.org
Cc: Marcel Partap <mpartap@gmx.net>
Cc: Michael Scott <michael.scott@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

3 files changed, 817 insertions, 0 deletions

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index 30598aa05e21..f04c44c6c3f3 100644
--- 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
index c5e576f0f0ee..a41f40957847 100644
--- 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
index 000000000000..ee71a2b37b12
--- /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");