power: Add Qualcomm SMBB driver

Add the Qualcomm Switch-Mode Battery Charger and Boost driver, found in
pm8941.

Signed-off-by: Courtney Cavin <courtney.cavin@sonymobile.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

drivers/power/Kconfig

@@ -379,6 +379,18 @@ config CHARGER_MAX8998
 	  Say Y to enable support for the battery charger control sysfs and
 	  platform data of MAX8998/LP3974 PMICs.
 
+config CHARGER_QCOM_SMBB
+	tristate "Qualcomm Switch-Mode Battery Charger and Boost"
+	depends on MFD_SPMI_PMIC || COMPILE_TEST
+	depends on OF
+	help
+	  Say Y to include support for the Switch-Mode Battery Charger and
+	  Boost (SMBB) hardware found in Qualcomm PM8941 PMICs.  The charger
+	  is an integrated, single-cell lithium-ion battery charger.  DT
+	  configuration is required for loading, see the devicetree
+	  documentation for more detail.  The base name for this driver is
+	  'pm8941_charger'.
+
 config CHARGER_BQ2415X
 	tristate "TI BQ2415x battery charger driver"
 	depends on I2C

drivers/power/Makefile

@@ -58,6 +58,7 @@ obj-$(CONFIG_CHARGER_MAX14577)	+= max14577_charger.o
 obj-$(CONFIG_CHARGER_MAX77693)	+= max77693_charger.o
 obj-$(CONFIG_CHARGER_MAX8997)	+= max8997_charger.o
 obj-$(CONFIG_CHARGER_MAX8998)	+= max8998_charger.o
+obj-$(CONFIG_CHARGER_QCOM_SMBB)	+= qcom_smbb.o
 obj-$(CONFIG_CHARGER_BQ2415X)	+= bq2415x_charger.o
 obj-$(CONFIG_CHARGER_BQ24190)	+= bq24190_charger.o
 obj-$(CONFIG_CHARGER_BQ24257)	+= bq24257_charger.o

drivers/power/qcom_smbb.c

@@ -0,0 +1,951 @@
+/* Copyright (c) 2014, Sony Mobile Communications 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 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * This driver is for the multi-block Switch-Mode Battery Charger and Boost
+ * (SMBB) hardware, found in Qualcomm PM8941 PMICs.  The charger is an
+ * integrated, single-cell lithium-ion battery charger.
+ *
+ * Sub-components:
+ *  - Charger core
+ *  - Buck
+ *  - DC charge-path
+ *  - USB charge-path
+ *  - Battery interface
+ *  - Boost (not implemented)
+ *  - Misc
+ *  - HF-Buck
+ */
+
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define SMBB_CHG_VMAX		0x040
+#define SMBB_CHG_VSAFE		0x041
+#define SMBB_CHG_CFG		0x043
+#define SMBB_CHG_IMAX		0x044
+#define SMBB_CHG_ISAFE		0x045
+#define SMBB_CHG_VIN_MIN	0x047
+#define SMBB_CHG_CTRL		0x049
+#define CTRL_EN			BIT(7)
+#define SMBB_CHG_VBAT_WEAK	0x052
+#define SMBB_CHG_IBAT_TERM_CHG	0x05b
+#define IBAT_TERM_CHG_IEOC	BIT(7)
+#define IBAT_TERM_CHG_IEOC_BMS	BIT(7)
+#define IBAT_TERM_CHG_IEOC_CHG	0
+#define SMBB_CHG_VBAT_DET	0x05d
+#define SMBB_CHG_TCHG_MAX_EN	0x060
+#define TCHG_MAX_EN		BIT(7)
+#define SMBB_CHG_WDOG_TIME	0x062
+#define SMBB_CHG_WDOG_EN	0x065
+#define WDOG_EN			BIT(7)
+
+#define SMBB_BUCK_REG_MODE	0x174
+#define BUCK_REG_MODE		BIT(0)
+#define BUCK_REG_MODE_VBAT	BIT(0)
+#define BUCK_REG_MODE_VSYS	0
+
+#define SMBB_BAT_PRES_STATUS	0x208
+#define PRES_STATUS_BAT_PRES	BIT(7)
+#define SMBB_BAT_TEMP_STATUS	0x209
+#define TEMP_STATUS_OK		BIT(7)
+#define TEMP_STATUS_HOT		BIT(6)
+#define SMBB_BAT_BTC_CTRL	0x249
+#define BTC_CTRL_COMP_EN	BIT(7)
+#define BTC_CTRL_COLD_EXT	BIT(1)
+#define BTC_CTRL_HOT_EXT_N	BIT(0)
+
+#define SMBB_USB_IMAX		0x344
+#define SMBB_USB_ENUM_TIMER_STOP 0x34e
+#define ENUM_TIMER_STOP		BIT(0)
+#define SMBB_USB_SEC_ACCESS	0x3d0
+#define SEC_ACCESS_MAGIC	0xa5
+#define SMBB_USB_REV_BST	0x3ed
+#define REV_BST_CHG_GONE	BIT(7)
+
+#define SMBB_DC_IMAX		0x444
+
+#define SMBB_MISC_REV2		0x601
+#define SMBB_MISC_BOOT_DONE	0x642
+#define BOOT_DONE		BIT(7)
+
+#define STATUS_USBIN_VALID	BIT(0) /* USB connection is valid */
+#define STATUS_DCIN_VALID	BIT(1) /* DC connection is valid */
+#define STATUS_BAT_HOT		BIT(2) /* Battery temp 1=Hot, 0=Cold */
+#define STATUS_BAT_OK		BIT(3) /* Battery temp OK */
+#define STATUS_BAT_PRESENT	BIT(4) /* Battery is present */
+#define STATUS_CHG_DONE		BIT(5) /* Charge cycle is complete */
+#define STATUS_CHG_TRKL		BIT(6) /* Trickle charging */
+#define STATUS_CHG_FAST		BIT(7) /* Fast charging */
+#define STATUS_CHG_GONE		BIT(8) /* No charger is connected */
+
+enum smbb_attr {
+	ATTR_BAT_ISAFE,
+	ATTR_BAT_IMAX,
+	ATTR_USBIN_IMAX,
+	ATTR_DCIN_IMAX,
+	ATTR_BAT_VSAFE,
+	ATTR_BAT_VMAX,
+	ATTR_BAT_VMIN,
+	ATTR_CHG_VDET,
+	ATTR_VIN_MIN,
+	_ATTR_CNT,
+};
+
+struct smbb_charger {
+	unsigned int revision;
+	unsigned int addr;
+	struct device *dev;
+
+	bool dc_disabled;
+	bool jeita_ext_temp;
+	unsigned long status;
+	struct mutex statlock;
+
+	unsigned int attr[_ATTR_CNT];
+
+	struct power_supply *usb_psy;
+	struct power_supply *dc_psy;
+	struct power_supply *bat_psy;
+	struct regmap *regmap;
+};
+
+static int smbb_vbat_weak_fn(unsigned int index)
+{
+	return 2100000 + index * 100000;
+}
+
+static int smbb_vin_fn(unsigned int index)
+{
+	if (index > 42)
+		return 5600000 + (index - 43) * 200000;
+	return 3400000 + index * 50000;
+}
+
+static int smbb_vmax_fn(unsigned int index)
+{
+	return 3240000 + index * 10000;
+}
+
+static int smbb_vbat_det_fn(unsigned int index)
+{
+	return 3240000 + index * 20000;
+}
+
+static int smbb_imax_fn(unsigned int index)
+{
+	if (index < 2)
+		return 100000 + index * 50000;
+	return index * 100000;
+}
+
+static int smbb_bat_imax_fn(unsigned int index)
+{
+	return index * 50000;
+}
+
+static unsigned int smbb_hw_lookup(unsigned int val, int (*fn)(unsigned int))
+{
+	unsigned int widx;
+	unsigned int sel;
+
+	for (widx = sel = 0; (*fn)(widx) <= val; ++widx)
+		sel = widx;
+
+	return sel;
+}
+
+static const struct smbb_charger_attr {
+	const char *name;
+	unsigned int reg;
+	unsigned int safe_reg;
+	unsigned int max;
+	unsigned int min;
+	unsigned int fail_ok;
+	int (*hw_fn)(unsigned int);
+} smbb_charger_attrs[] = {
+	[ATTR_BAT_ISAFE] = {
+		.name = "qcom,fast-charge-safe-current",
+		.reg = SMBB_CHG_ISAFE,
+		.max = 3000000,
+		.min = 200000,
+		.hw_fn = smbb_bat_imax_fn,
+		.fail_ok = 1,
+	},
+	[ATTR_BAT_IMAX] = {
+		.name = "qcom,fast-charge-current-limit",
+		.reg = SMBB_CHG_IMAX,
+		.safe_reg = SMBB_CHG_ISAFE,
+		.max = 3000000,
+		.min = 200000,
+		.hw_fn = smbb_bat_imax_fn,
+	},
+	[ATTR_DCIN_IMAX] = {
+		.name = "qcom,dc-current-limit",
+		.reg = SMBB_DC_IMAX,
+		.max = 2500000,
+		.min = 100000,
+		.hw_fn = smbb_imax_fn,
+	},
+	[ATTR_BAT_VSAFE] = {
+		.name = "qcom,fast-charge-safe-voltage",
+		.reg = SMBB_CHG_VSAFE,
+		.max = 5000000,
+		.min = 3240000,
+		.hw_fn = smbb_vmax_fn,
+		.fail_ok = 1,
+	},
+	[ATTR_BAT_VMAX] = {
+		.name = "qcom,fast-charge-high-threshold-voltage",
+		.reg = SMBB_CHG_VMAX,
+		.safe_reg = SMBB_CHG_VSAFE,
+		.max = 5000000,
+		.min = 3240000,
+		.hw_fn = smbb_vmax_fn,
+	},
+	[ATTR_BAT_VMIN] = {
+		.name = "qcom,fast-charge-low-threshold-voltage",
+		.reg = SMBB_CHG_VBAT_WEAK,
+		.max = 3600000,
+		.min = 2100000,
+		.hw_fn = smbb_vbat_weak_fn,
+	},
+	[ATTR_CHG_VDET] = {
+		.name = "qcom,auto-recharge-threshold-voltage",
+		.reg = SMBB_CHG_VBAT_DET,
+		.max = 5000000,
+		.min = 3240000,
+		.hw_fn = smbb_vbat_det_fn,
+	},
+	[ATTR_VIN_MIN] = {
+		.name = "qcom,minimum-input-voltage",
+		.reg = SMBB_CHG_VIN_MIN,
+		.max = 9600000,
+		.min = 4200000,
+		.hw_fn = smbb_vin_fn,
+	},
+	[ATTR_USBIN_IMAX] = {
+		.name = "usb-charge-current-limit",
+		.reg = SMBB_USB_IMAX,
+		.max = 2500000,
+		.min = 100000,
+		.hw_fn = smbb_imax_fn,
+	},
+};
+
+static int smbb_charger_attr_write(struct smbb_charger *chg,
+		enum smbb_attr which, unsigned int val)
+{
+	const struct smbb_charger_attr *prop;
+	unsigned int wval;
+	unsigned int out;
+	int rc;
+
+	prop = &smbb_charger_attrs[which];
+
+	if (val > prop->max || val < prop->min) {
+		dev_err(chg->dev, "value out of range for %s [%u:%u]\n",
+			prop->name, prop->min, prop->max);
+		return -EINVAL;
+	}
+
+	if (prop->safe_reg) {
+		rc = regmap_read(chg->regmap,
+				chg->addr + prop->safe_reg, &wval);
+		if (rc) {
+			dev_err(chg->dev,
+				"unable to read safe value for '%s'\n",
+				prop->name);
+			return rc;
+		}
+
+		wval = prop->hw_fn(wval);
+
+		if (val > wval) {
+			dev_warn(chg->dev,
+				"%s above safe value, clamping at %u\n",
+				prop->name, wval);
+			val = wval;
+		}
+	}
+
+	wval = smbb_hw_lookup(val, prop->hw_fn);
+
+	rc = regmap_write(chg->regmap, chg->addr + prop->reg, wval);
+	if (rc) {
+		dev_err(chg->dev, "unable to update %s", prop->name);
+		return rc;
+	}
+	out = prop->hw_fn(wval);
+	if (out != val) {
+		dev_warn(chg->dev,
+			"%s inaccurate, rounded to %u\n",
+			prop->name, out);
+	}
+
+	dev_dbg(chg->dev, "%s <= %d\n", prop->name, out);
+
+	chg->attr[which] = out;
+
+	return 0;
+}
+
+static int smbb_charger_attr_read(struct smbb_charger *chg,
+		enum smbb_attr which)
+{
+	const struct smbb_charger_attr *prop;
+	unsigned int val;
+	int rc;
+
+	prop = &smbb_charger_attrs[which];
+
+	rc = regmap_read(chg->regmap, chg->addr + prop->reg, &val);
+	if (rc) {
+		dev_err(chg->dev, "failed to read %s\n", prop->name);
+		return rc;
+	}
+	val = prop->hw_fn(val);
+	dev_dbg(chg->dev, "%s => %d\n", prop->name, val);
+
+	chg->attr[which] = val;
+
+	return 0;
+}
+
+static int smbb_charger_attr_parse(struct smbb_charger *chg,
+		enum smbb_attr which)
+{
+	const struct smbb_charger_attr *prop;
+	unsigned int val;
+	int rc;
+
+	prop = &smbb_charger_attrs[which];
+
+	rc = of_property_read_u32(chg->dev->of_node, prop->name, &val);
+	if (rc == 0) {
+		rc = smbb_charger_attr_write(chg, which, val);
+		if (!rc || !prop->fail_ok)
+			return rc;
+	}
+	return smbb_charger_attr_read(chg, which);
+}
+
+static void smbb_set_line_flag(struct smbb_charger *chg, int irq, int flag)
+{
+	bool state;
+	int ret;
+
+	ret = irq_get_irqchip_state(irq, IRQCHIP_STATE_LINE_LEVEL, &state);
+	if (state < 0) {
+		dev_err(chg->dev, "failed to read irq line\n");
+		return;
+	}
+
+	mutex_lock(&chg->statlock);
+	if (state)
+		chg->status |= flag;
+	else
+		chg->status &= ~flag;
+	mutex_unlock(&chg->statlock);
+
+	dev_dbg(chg->dev, "status = %03lx\n", chg->status);
+}
+
+static irqreturn_t smbb_usb_valid_handler(int irq, void *_data)
+{
+	struct smbb_charger *chg = _data;
+
+	smbb_set_line_flag(chg, irq, STATUS_USBIN_VALID);
+	power_supply_changed(chg->usb_psy);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t smbb_dc_valid_handler(int irq, void *_data)
+{
+	struct smbb_charger *chg = _data;
+
+	smbb_set_line_flag(chg, irq, STATUS_DCIN_VALID);
+	if (!chg->dc_disabled)
+		power_supply_changed(chg->dc_psy);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t smbb_bat_temp_handler(int irq, void *_data)
+{
+	struct smbb_charger *chg = _data;
+	unsigned int val;
+	int rc;
+
+	rc = regmap_read(chg->regmap, chg->addr + SMBB_BAT_TEMP_STATUS, &val);
+	if (rc)
+		return IRQ_HANDLED;
+
+	mutex_lock(&chg->statlock);
+	if (val & TEMP_STATUS_OK) {
+		chg->status |= STATUS_BAT_OK;
+	} else {
+		chg->status &= ~STATUS_BAT_OK;
+		if (val & TEMP_STATUS_HOT)
+			chg->status |= STATUS_BAT_HOT;
+	}
+	mutex_unlock(&chg->statlock);
+
+	power_supply_changed(chg->bat_psy);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t smbb_bat_present_handler(int irq, void *_data)
+{
+	struct smbb_charger *chg = _data;
+
+	smbb_set_line_flag(chg, irq, STATUS_BAT_PRESENT);
+	power_supply_changed(chg->bat_psy);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t smbb_chg_done_handler(int irq, void *_data)
+{
+	struct smbb_charger *chg = _data;
+
+	smbb_set_line_flag(chg, irq, STATUS_CHG_DONE);
+	power_supply_changed(chg->bat_psy);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t smbb_chg_gone_handler(int irq, void *_data)
+{
+	struct smbb_charger *chg = _data;
+
+	smbb_set_line_flag(chg, irq, STATUS_CHG_GONE);
+	power_supply_changed(chg->bat_psy);
+	power_supply_changed(chg->usb_psy);
+	if (!chg->dc_disabled)
+		power_supply_changed(chg->dc_psy);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t smbb_chg_fast_handler(int irq, void *_data)
+{
+	struct smbb_charger *chg = _data;
+
+	smbb_set_line_flag(chg, irq, STATUS_CHG_FAST);
+	power_supply_changed(chg->bat_psy);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t smbb_chg_trkl_handler(int irq, void *_data)
+{
+	struct smbb_charger *chg = _data;
+
+	smbb_set_line_flag(chg, irq, STATUS_CHG_TRKL);
+	power_supply_changed(chg->bat_psy);
+
+	return IRQ_HANDLED;
+}
+
+static const struct smbb_irq {
+	const char *name;
+	irqreturn_t (*handler)(int, void *);
+} smbb_charger_irqs[] = {
+	{ "chg-done", smbb_chg_done_handler },
+	{ "chg-fast", smbb_chg_fast_handler },
+	{ "chg-trkl", smbb_chg_trkl_handler },
+	{ "bat-temp-ok", smbb_bat_temp_handler },
+	{ "bat-present", smbb_bat_present_handler },
+	{ "chg-gone", smbb_chg_gone_handler },
+	{ "usb-valid", smbb_usb_valid_handler },
+	{ "dc-valid", smbb_dc_valid_handler },
+};
+
+static int smbb_usbin_get_property(struct power_supply *psy,
+		enum power_supply_property psp,
+		union power_supply_propval *val)
+{
+	struct smbb_charger *chg = power_supply_get_drvdata(psy);
+	int rc = 0;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_ONLINE:
+		mutex_lock(&chg->statlock);
+		val->intval = !(chg->status & STATUS_CHG_GONE) &&
+				(chg->status & STATUS_USBIN_VALID);
+		mutex_unlock(&chg->statlock);
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT:
+		val->intval = chg->attr[ATTR_USBIN_IMAX];
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX:
+		val->intval = 2500000;
+		break;
+	default:
+		rc = -EINVAL;
+		break;
+	}
+
+	return rc;
+}
+
+static int smbb_usbin_set_property(struct power_supply *psy,
+		enum power_supply_property psp,
+		const union power_supply_propval *val)
+{
+	struct smbb_charger *chg = power_supply_get_drvdata(psy);
+	int rc;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT:
+		rc = smbb_charger_attr_write(chg, ATTR_USBIN_IMAX,
+				val->intval);
+		break;
+	default:
+		rc = -EINVAL;
+		break;
+	}
+
+	return rc;
+}
+
+static int smbb_dcin_get_property(struct power_supply *psy,
+		enum power_supply_property psp,
+		union power_supply_propval *val)
+{
+	struct smbb_charger *chg = power_supply_get_drvdata(psy);
+	int rc = 0;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_ONLINE:
+		mutex_lock(&chg->statlock);
+		val->intval = !(chg->status & STATUS_CHG_GONE) &&
+				(chg->status & STATUS_DCIN_VALID);
+		mutex_unlock(&chg->statlock);
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT:
+		val->intval = chg->attr[ATTR_DCIN_IMAX];
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX:
+		val->intval = 2500000;
+		break;
+	default:
+		rc = -EINVAL;
+		break;
+	}
+
+	return rc;
+}
+
+static int smbb_dcin_set_property(struct power_supply *psy,
+		enum power_supply_property psp,
+		const union power_supply_propval *val)
+{
+	struct smbb_charger *chg = power_supply_get_drvdata(psy);
+	int rc;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT:
+		rc = smbb_charger_attr_write(chg, ATTR_DCIN_IMAX,
+				val->intval);
+		break;
+	default:
+		rc = -EINVAL;
+		break;
+	}
+
+	return rc;
+}
+
+static int smbb_charger_writable_property(struct power_supply *psy,
+		enum power_supply_property psp)
+{
+	return psp == POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT;
+}
+
+static int smbb_battery_get_property(struct power_supply *psy,
+		enum power_supply_property psp,
+		union power_supply_propval *val)
+{
+	struct smbb_charger *chg = power_supply_get_drvdata(psy);
+	unsigned long status;
+	int rc = 0;
+
+	mutex_lock(&chg->statlock);
+	status = chg->status;
+	mutex_unlock(&chg->statlock);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		if (status & STATUS_CHG_GONE)
+			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+		else if (!(status & (STATUS_DCIN_VALID | STATUS_USBIN_VALID)))
+			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+		else if (status & STATUS_CHG_DONE)
+			val->intval = POWER_SUPPLY_STATUS_FULL;
+		else if (!(status & STATUS_BAT_OK))
+			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+		else if (status & (STATUS_CHG_FAST | STATUS_CHG_TRKL))
+			val->intval = POWER_SUPPLY_STATUS_CHARGING;
+		else /* everything is ok for charging, but we are not... */
+			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+		break;
+	case POWER_SUPPLY_PROP_HEALTH:
+		if (status & STATUS_BAT_OK)
+			val->intval = POWER_SUPPLY_HEALTH_GOOD;
+		else if (status & STATUS_BAT_HOT)
+			val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
+		else
+			val->intval = POWER_SUPPLY_HEALTH_COLD;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_TYPE:
+		if (status & STATUS_CHG_FAST)
+			val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
+		else if (status & STATUS_CHG_TRKL)
+			val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
+		else
+			val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
+		break;
+	case POWER_SUPPLY_PROP_PRESENT:
+		val->intval = !!(status & STATUS_BAT_PRESENT);
+		break;
+	case POWER_SUPPLY_PROP_CURRENT_MAX:
+		val->intval = chg->attr[ATTR_BAT_IMAX];
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX:
+		val->intval = chg->attr[ATTR_BAT_VMAX];
+		break;
+	case POWER_SUPPLY_PROP_TECHNOLOGY:
+		/* this charger is a single-cell lithium-ion battery charger
+		* only.  If you hook up some other technology, there will be
+		* fireworks.
+		*/
+		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
+		val->intval = 3000000; /* single-cell li-ion low end */
+		break;
+	default:
+		rc = -EINVAL;
+		break;
+	}
+
+	return rc;
+}
+
+static int smbb_battery_set_property(struct power_supply *psy,
+		enum power_supply_property psp,
+		const union power_supply_propval *val)
+{
+	struct smbb_charger *chg = power_supply_get_drvdata(psy);
+	int rc;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CURRENT_MAX:
+		rc = smbb_charger_attr_write(chg, ATTR_BAT_IMAX, val->intval);
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX:
+		rc = smbb_charger_attr_write(chg, ATTR_BAT_VMAX, val->intval);
+		break;
+	default:
+		rc = -EINVAL;
+		break;
+	}
+
+	return rc;
+}
+
+static int smbb_battery_writable_property(struct power_supply *psy,
+		enum power_supply_property psp)
+{
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CURRENT_MAX:
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX:
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+static enum power_supply_property smbb_charger_properties[] = {
+	POWER_SUPPLY_PROP_ONLINE,
+	POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT,
+	POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX,
+};
+
+static enum power_supply_property smbb_battery_properties[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_HEALTH,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_CHARGE_TYPE,
+	POWER_SUPPLY_PROP_CURRENT_MAX,
+	POWER_SUPPLY_PROP_VOLTAGE_MAX,
+	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
+	POWER_SUPPLY_PROP_TECHNOLOGY,
+};
+
+static const struct reg_off_mask_default {
+	unsigned int offset;
+	unsigned int mask;
+	unsigned int value;
+	unsigned int rev_mask;
+} smbb_charger_setup[] = {
+	/* The bootloader is supposed to set this... make sure anyway. */
+	{ SMBB_MISC_BOOT_DONE, BOOT_DONE, BOOT_DONE },
+
+	/* Disable software timer */
+	{ SMBB_CHG_TCHG_MAX_EN, TCHG_MAX_EN, 0 },
+
+	/* Clear and disable watchdog */
+	{ SMBB_CHG_WDOG_TIME, 0xff, 160 },
+	{ SMBB_CHG_WDOG_EN, WDOG_EN, 0 },
+
+	/* Use charger based EoC detection */
+	{ SMBB_CHG_IBAT_TERM_CHG, IBAT_TERM_CHG_IEOC, IBAT_TERM_CHG_IEOC_CHG },
+
+	/* Disable GSM PA load adjustment.
+	* The PA signal is incorrectly connected on v2.
+	*/
+	{ SMBB_CHG_CFG, 0xff, 0x00, BIT(3) },
+
+	/* Use VBAT (not VSYS) to compensate for IR drop during fast charging */
+	{ SMBB_BUCK_REG_MODE, BUCK_REG_MODE, BUCK_REG_MODE_VBAT },
+
+	/* Enable battery temperature comparators */
+	{ SMBB_BAT_BTC_CTRL, BTC_CTRL_COMP_EN, BTC_CTRL_COMP_EN },
+
+	/* Stop USB enumeration timer */
+	{ SMBB_USB_ENUM_TIMER_STOP, ENUM_TIMER_STOP, ENUM_TIMER_STOP },
+
+#if 0 /* FIXME supposedly only to disable hardware ARB termination */
+	{ SMBB_USB_SEC_ACCESS, SEC_ACCESS_MAGIC },
+	{ SMBB_USB_REV_BST, 0xff, REV_BST_CHG_GONE },
+#endif
+
+	/* Stop USB enumeration timer, again */
+	{ SMBB_USB_ENUM_TIMER_STOP, ENUM_TIMER_STOP, ENUM_TIMER_STOP },
+
+	/* Enable charging */
+	{ SMBB_CHG_CTRL, CTRL_EN, CTRL_EN },
+};
+
+static char *smbb_bif[] = { "smbb-bif" };
+
+static const struct power_supply_desc bat_psy_desc = {
+	.name = "smbb-bif",
+	.type = POWER_SUPPLY_TYPE_BATTERY,
+	.properties = smbb_battery_properties,
+	.num_properties = ARRAY_SIZE(smbb_battery_properties),
+	.get_property = smbb_battery_get_property,
+	.set_property = smbb_battery_set_property,
+	.property_is_writeable = smbb_battery_writable_property,
+};
+
+static const struct power_supply_desc usb_psy_desc = {
+	.name = "smbb-usbin",
+	.type = POWER_SUPPLY_TYPE_USB,
+	.properties = smbb_charger_properties,
+	.num_properties = ARRAY_SIZE(smbb_charger_properties),
+	.get_property = smbb_usbin_get_property,
+	.set_property = smbb_usbin_set_property,
+	.property_is_writeable = smbb_charger_writable_property,
+};
+
+static const struct power_supply_desc dc_psy_desc = {
+	.name = "smbb-dcin",
+	.type = POWER_SUPPLY_TYPE_MAINS,
+	.properties = smbb_charger_properties,
+	.num_properties = ARRAY_SIZE(smbb_charger_properties),
+	.get_property = smbb_dcin_get_property,
+	.set_property = smbb_dcin_set_property,
+	.property_is_writeable = smbb_charger_writable_property,
+};
+
+static int smbb_charger_probe(struct platform_device *pdev)
+{
+	struct power_supply_config bat_cfg = {};
+	struct power_supply_config usb_cfg = {};
+	struct power_supply_config dc_cfg = {};
+	struct smbb_charger *chg;
+	int rc, i;
+
+	chg = devm_kzalloc(&pdev->dev, sizeof(*chg), GFP_KERNEL);
+	if (!chg)
+		return -ENOMEM;
+
+	chg->dev = &pdev->dev;
+	mutex_init(&chg->statlock);
+
+	chg->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	if (!chg->regmap) {
+		dev_err(&pdev->dev, "failed to locate regmap\n");
+		return -ENODEV;
+	}
+
+	rc = of_property_read_u32(pdev->dev.of_node, "reg", &chg->addr);
+	if (rc) {
+		dev_err(&pdev->dev, "missing or invalid 'reg' property\n");
+		return rc;
+	}
+
+	rc = regmap_read(chg->regmap, chg->addr + SMBB_MISC_REV2, &chg->revision);
+	if (rc) {
+		dev_err(&pdev->dev, "unable to read revision\n");
+		return rc;
+	}
+
+	chg->revision += 1;
+	if (chg->revision != 2 && chg->revision != 3) {
+		dev_err(&pdev->dev, "v1 hardware not supported\n");
+		return -ENODEV;
+	}
+	dev_info(&pdev->dev, "Initializing SMBB rev %u", chg->revision);
+
+	chg->dc_disabled = of_property_read_bool(pdev->dev.of_node, "qcom,disable-dc");
+
+	for (i = 0; i < _ATTR_CNT; ++i) {
+		rc = smbb_charger_attr_parse(chg, i);
+		if (rc) {
+			dev_err(&pdev->dev, "failed to parse/apply settings\n");
+			return rc;
+		}
+	}
+
+	bat_cfg.drv_data = chg;
+	bat_cfg.of_node = pdev->dev.of_node;
+	chg->bat_psy = devm_power_supply_register(&pdev->dev,
+						  &bat_psy_desc,
+						  &bat_cfg);
+	if (IS_ERR(chg->bat_psy)) {
+		dev_err(&pdev->dev, "failed to register battery\n");
+		return PTR_ERR(chg->bat_psy);
+	}
+
+	usb_cfg.drv_data = chg;
+	usb_cfg.supplied_to = smbb_bif;
+	usb_cfg.num_supplicants = ARRAY_SIZE(smbb_bif);
+	chg->usb_psy = devm_power_supply_register(&pdev->dev,
+						  &usb_psy_desc,
+						  &usb_cfg);
+	if (IS_ERR(chg->usb_psy)) {
+		dev_err(&pdev->dev, "failed to register USB power supply\n");
+		return PTR_ERR(chg->usb_psy);
+	}
+
+	if (!chg->dc_disabled) {
+		dc_cfg.drv_data = chg;
+		dc_cfg.supplied_to = smbb_bif;
+		dc_cfg.num_supplicants = ARRAY_SIZE(smbb_bif);
+		chg->dc_psy = devm_power_supply_register(&pdev->dev,
+							 &dc_psy_desc,
+							 &dc_cfg);
+		if (IS_ERR(chg->dc_psy)) {
+			dev_err(&pdev->dev, "failed to register DC power supply\n");
+			return PTR_ERR(chg->dc_psy);
+		}
+	}
+
+	for (i = 0; i < ARRAY_SIZE(smbb_charger_irqs); ++i) {
+		int irq;
+
+		irq = platform_get_irq_byname(pdev, smbb_charger_irqs[i].name);
+		if (irq < 0) {
+			dev_err(&pdev->dev, "failed to get irq '%s'\n",
+				smbb_charger_irqs[i].name);
+			return irq;
+		}
+
+		smbb_charger_irqs[i].handler(irq, chg);
+
+		rc = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+				smbb_charger_irqs[i].handler, IRQF_ONESHOT,
+				smbb_charger_irqs[i].name, chg);
+		if (rc) {
+			dev_err(&pdev->dev, "failed to request irq '%s'\n",
+				smbb_charger_irqs[i].name);
+			return rc;
+		}
+	}
+
+	chg->jeita_ext_temp = of_property_read_bool(pdev->dev.of_node,
+			"qcom,jeita-extended-temp-range");
+
+	/* Set temperature range to [35%:70%] or [25%:80%] accordingly */
+	rc = regmap_update_bits(chg->regmap, chg->addr + SMBB_BAT_BTC_CTRL,
+			BTC_CTRL_COLD_EXT | BTC_CTRL_HOT_EXT_N,
+			chg->jeita_ext_temp ?
+				BTC_CTRL_COLD_EXT :
+				BTC_CTRL_HOT_EXT_N);
+	if (rc) {
+		dev_err(&pdev->dev,
+			"unable to set %s temperature range\n",
+			chg->jeita_ext_temp ? "JEITA extended" : "normal");
+		return rc;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(smbb_charger_setup); ++i) {
+		const struct reg_off_mask_default *r = &smbb_charger_setup[i];
+
+		if (r->rev_mask & BIT(chg->revision))
+			continue;
+
+		rc = regmap_update_bits(chg->regmap, chg->addr + r->offset,
+				r->mask, r->value);
+		if (rc) {
+			dev_err(&pdev->dev,
+				"unable to initializing charging, bailing\n");
+			return rc;
+		}
+	}
+
+	platform_set_drvdata(pdev, chg);
+
+	return 0;
+}
+
+static int smbb_charger_remove(struct platform_device *pdev)
+{
+	struct smbb_charger *chg;
+
+	chg = platform_get_drvdata(pdev);
+
+	regmap_update_bits(chg->regmap, chg->addr + SMBB_CHG_CTRL, CTRL_EN, 0);
+
+	return 0;
+}
+
+static const struct of_device_id smbb_charger_id_table[] = {
+	{ .compatible = "qcom,pm8941-charger" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, smbb_charger_id_table);
+
+static struct platform_driver smbb_charger_driver = {
+	.probe	  = smbb_charger_probe,
+	.remove	 = smbb_charger_remove,
+	.driver	 = {
+		.name   = "qcom-smbb",
+		.of_match_table = smbb_charger_id_table,
+	},
+};
+module_platform_driver(smbb_charger_driver);
+
+MODULE_DESCRIPTION("Qualcomm Switch-Mode Battery Charger and Boost driver");
+MODULE_LICENSE("GPL v2");