power: move power supply drivers to power/supply

This moves all power supply drivers from drivers/power/
to drivers/power/supply/. The intention is a cleaner
source tree, since drivers/power/ also contains frameworks
unrelated to power supply, like adaptive voltage scaling.

Signed-off-by: Sebastian Reichel <sre@kernel.org>

1 files changed, 1162 insertions, 0 deletions

diff --git a/drivers/power/supply/twl4030_charger.c b/drivers/power/supply/twl4030_charger.c
new file mode 100644
index 000000000000..bcd4dc304f27
--- /dev/null
+++ b/drivers/power/supply/twl4030_charger.c
@@ -0,0 +1,1162 @@
+/*
+ * TWL4030/TPS65950 BCI (Battery Charger Interface) driver
+ *
+ * Copyright (C) 2010 Gražvydas Ignotas <notasas@gmail.com>
+ *
+ * based on twl4030_bci_battery.c by TI
+ * Copyright (C) 2008 Texas Instruments, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/i2c/twl.h>
+#include <linux/power_supply.h>
+#include <linux/notifier.h>
+#include <linux/usb/otg.h>
+#include <linux/iio/consumer.h>
+
+#define TWL4030_BCIMDEN		0x00
+#define TWL4030_BCIMDKEY	0x01
+#define TWL4030_BCIMSTATEC	0x02
+#define TWL4030_BCIICHG		0x08
+#define TWL4030_BCIVAC		0x0a
+#define TWL4030_BCIVBUS		0x0c
+#define TWL4030_BCIMFSTS3	0x0F
+#define TWL4030_BCIMFSTS4	0x10
+#define TWL4030_BCICTL1		0x23
+#define TWL4030_BB_CFG		0x12
+#define TWL4030_BCIIREF1	0x27
+#define TWL4030_BCIIREF2	0x28
+#define TWL4030_BCIMFKEY	0x11
+#define TWL4030_BCIMFEN3	0x14
+#define TWL4030_BCIMFTH8	0x1d
+#define TWL4030_BCIMFTH9	0x1e
+#define TWL4030_BCIWDKEY	0x21
+
+#define TWL4030_BCIMFSTS1	0x01
+
+#define TWL4030_BCIAUTOWEN	BIT(5)
+#define TWL4030_CONFIG_DONE	BIT(4)
+#define TWL4030_CVENAC		BIT(2)
+#define TWL4030_BCIAUTOUSB	BIT(1)
+#define TWL4030_BCIAUTOAC	BIT(0)
+#define TWL4030_CGAIN		BIT(5)
+#define TWL4030_USBFASTMCHG	BIT(2)
+#define TWL4030_STS_VBUS	BIT(7)
+#define TWL4030_STS_USB_ID	BIT(2)
+#define TWL4030_BBCHEN		BIT(4)
+#define TWL4030_BBSEL_MASK	0x0c
+#define TWL4030_BBSEL_2V5	0x00
+#define TWL4030_BBSEL_3V0	0x04
+#define TWL4030_BBSEL_3V1	0x08
+#define TWL4030_BBSEL_3V2	0x0c
+#define TWL4030_BBISEL_MASK	0x03
+#define TWL4030_BBISEL_25uA	0x00
+#define TWL4030_BBISEL_150uA	0x01
+#define TWL4030_BBISEL_500uA	0x02
+#define TWL4030_BBISEL_1000uA	0x03
+
+#define TWL4030_BATSTSPCHG	BIT(2)
+#define TWL4030_BATSTSMCHG	BIT(6)
+
+/* BCI interrupts */
+#define TWL4030_WOVF		BIT(0) /* Watchdog overflow */
+#define TWL4030_TMOVF		BIT(1) /* Timer overflow */
+#define TWL4030_ICHGHIGH	BIT(2) /* Battery charge current high */
+#define TWL4030_ICHGLOW		BIT(3) /* Battery cc. low / FSM state change */
+#define TWL4030_ICHGEOC		BIT(4) /* Battery current end-of-charge */
+#define TWL4030_TBATOR2		BIT(5) /* Battery temperature out of range 2 */
+#define TWL4030_TBATOR1		BIT(6) /* Battery temperature out of range 1 */
+#define TWL4030_BATSTS		BIT(7) /* Battery status */
+
+#define TWL4030_VBATLVL		BIT(0) /* VBAT level */
+#define TWL4030_VBATOV		BIT(1) /* VBAT overvoltage */
+#define TWL4030_VBUSOV		BIT(2) /* VBUS overvoltage */
+#define TWL4030_ACCHGOV		BIT(3) /* Ac charger overvoltage */
+
+#define TWL4030_MSTATEC_USB		BIT(4)
+#define TWL4030_MSTATEC_AC		BIT(5)
+#define TWL4030_MSTATEC_MASK		0x0f
+#define TWL4030_MSTATEC_QUICK1		0x02
+#define TWL4030_MSTATEC_QUICK7		0x07
+#define TWL4030_MSTATEC_COMPLETE1	0x0b
+#define TWL4030_MSTATEC_COMPLETE4	0x0e
+
+/*
+ * If AC (Accessory Charger) voltage exceeds 4.5V (MADC 11)
+ * then AC is available.
+ */
+static inline int ac_available(struct iio_channel *channel_vac)
+{
+	int val, err;
+
+	if (!channel_vac)
+		return 0;
+
+	err = iio_read_channel_processed(channel_vac, &val);
+	if (err < 0)
+		return 0;
+	return val > 4500;
+}
+
+static bool allow_usb;
+module_param(allow_usb, bool, 0644);
+MODULE_PARM_DESC(allow_usb, "Allow USB charge drawing default current");
+
+struct twl4030_bci {
+	struct device		*dev;
+	struct power_supply	*ac;
+	struct power_supply	*usb;
+	struct usb_phy		*transceiver;
+	struct notifier_block	usb_nb;
+	struct work_struct	work;
+	int			irq_chg;
+	int			irq_bci;
+	int			usb_enabled;
+
+	/*
+	 * ichg_* and *_cur values in uA. If any are 'large', we set
+	 * CGAIN to '1' which doubles the range for half the
+	 * precision.
+	 */
+	unsigned int		ichg_eoc, ichg_lo, ichg_hi;
+	unsigned int		usb_cur, ac_cur;
+	struct iio_channel	*channel_vac;
+	bool			ac_is_active;
+	int			usb_mode, ac_mode; /* charging mode requested */
+#define	CHARGE_OFF	0
+#define	CHARGE_AUTO	1
+#define	CHARGE_LINEAR	2
+
+	/* When setting the USB current we slowly increase the
+	 * requested current until target is reached or the voltage
+	 * drops below 4.75V.  In the latter case we step back one
+	 * step.
+	 */
+	unsigned int		usb_cur_target;
+	struct delayed_work	current_worker;
+#define	USB_CUR_STEP	20000	/* 20mA at a time */
+#define	USB_MIN_VOLT	4750000	/* 4.75V */
+#define	USB_CUR_DELAY	msecs_to_jiffies(100)
+#define	USB_MAX_CURRENT	1700000 /* TWL4030 caps at 1.7A */
+
+	unsigned long		event;
+};
+
+/* strings for 'usb_mode' values */
+static char *modes[] = { "off", "auto", "continuous" };
+
+/*
+ * clear and set bits on an given register on a given module
+ */
+static int twl4030_clear_set(u8 mod_no, u8 clear, u8 set, u8 reg)
+{
+	u8 val = 0;
+	int ret;
+
+	ret = twl_i2c_read_u8(mod_no, &val, reg);
+	if (ret)
+		return ret;
+
+	val &= ~clear;
+	val |= set;
+
+	return twl_i2c_write_u8(mod_no, val, reg);
+}
+
+static int twl4030_bci_read(u8 reg, u8 *val)
+{
+	return twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE, val, reg);
+}
+
+static int twl4030_clear_set_boot_bci(u8 clear, u8 set)
+{
+	return twl4030_clear_set(TWL_MODULE_PM_MASTER, clear,
+			TWL4030_CONFIG_DONE | TWL4030_BCIAUTOWEN | set,
+			TWL4030_PM_MASTER_BOOT_BCI);
+}
+
+static int twl4030bci_read_adc_val(u8 reg)
+{
+	int ret, temp;
+	u8 val;
+
+	/* read MSB */
+	ret = twl4030_bci_read(reg + 1, &val);
+	if (ret)
+		return ret;
+
+	temp = (int)(val & 0x03) << 8;
+
+	/* read LSB */
+	ret = twl4030_bci_read(reg, &val);
+	if (ret)
+		return ret;
+
+	return temp | val;
+}
+
+/*
+ * Check if Battery Pack was present
+ */
+static int twl4030_is_battery_present(struct twl4030_bci *bci)
+{
+	int ret;
+	u8 val = 0;
+
+	/* Battery presence in Main charge? */
+	ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE, &val, TWL4030_BCIMFSTS3);
+	if (ret)
+		return ret;
+	if (val & TWL4030_BATSTSMCHG)
+		return 0;
+
+	/*
+	 * OK, It could be that bootloader did not enable main charger,
+	 * pre-charge is h/w auto. So, Battery presence in Pre-charge?
+	 */
+	ret = twl_i2c_read_u8(TWL4030_MODULE_PRECHARGE, &val,
+			      TWL4030_BCIMFSTS1);
+	if (ret)
+		return ret;
+	if (val & TWL4030_BATSTSPCHG)
+		return 0;
+
+	return -ENODEV;
+}
+
+/*
+ * TI provided formulas:
+ * CGAIN == 0: ICHG = (BCIICHG * 1.7) / (2^10 - 1) - 0.85
+ * CGAIN == 1: ICHG = (BCIICHG * 3.4) / (2^10 - 1) - 1.7
+ * Here we use integer approximation of:
+ * CGAIN == 0: val * 1.6618 - 0.85 * 1000
+ * CGAIN == 1: (val * 1.6618 - 0.85 * 1000) * 2
+ */
+/*
+ * convert twl register value for currents into uA
+ */
+static int regval2ua(int regval, bool cgain)
+{
+	if (cgain)
+		return (regval * 16618 - 8500 * 1000) / 5;
+	else
+		return (regval * 16618 - 8500 * 1000) / 10;
+}
+
+/*
+ * convert uA currents into twl register value
+ */
+static int ua2regval(int ua, bool cgain)
+{
+	int ret;
+	if (cgain)
+		ua /= 2;
+	ret = (ua * 10 + 8500 * 1000) / 16618;
+	/* rounding problems */
+	if (ret < 512)
+		ret = 512;
+	return ret;
+}
+
+static int twl4030_charger_update_current(struct twl4030_bci *bci)
+{
+	int status;
+	int cur;
+	unsigned reg, cur_reg;
+	u8 bcictl1, oldreg, fullreg;
+	bool cgain = false;
+	u8 boot_bci;
+
+	/*
+	 * If AC (Accessory Charger) voltage exceeds 4.5V (MADC 11)
+	 * and AC is enabled, set current for 'ac'
+	 */
+	if (ac_available(bci->channel_vac)) {
+		cur = bci->ac_cur;
+		bci->ac_is_active = true;
+	} else {
+		cur = bci->usb_cur;
+		bci->ac_is_active = false;
+		if (cur > bci->usb_cur_target) {
+			cur = bci->usb_cur_target;
+			bci->usb_cur = cur;
+		}
+		if (cur < bci->usb_cur_target)
+			schedule_delayed_work(&bci->current_worker, USB_CUR_DELAY);
+	}
+
+	/* First, check thresholds and see if cgain is needed */
+	if (bci->ichg_eoc >= 200000)
+		cgain = true;
+	if (bci->ichg_lo >= 400000)
+		cgain = true;
+	if (bci->ichg_hi >= 820000)
+		cgain = true;
+	if (cur > 852000)
+		cgain = true;
+
+	status = twl4030_bci_read(TWL4030_BCICTL1, &bcictl1);
+	if (status < 0)
+		return status;
+	if (twl_i2c_read_u8(TWL_MODULE_PM_MASTER, &boot_bci,
+			    TWL4030_PM_MASTER_BOOT_BCI) < 0)
+		boot_bci = 0;
+	boot_bci &= 7;
+
+	if ((!!cgain) != !!(bcictl1 & TWL4030_CGAIN))
+		/* Need to turn for charging while we change the
+		 * CGAIN bit.  Leave it off while everything is
+		 * updated.
+		 */
+		twl4030_clear_set_boot_bci(boot_bci, 0);
+
+	/*
+	 * For ichg_eoc, the hardware only supports reg values matching
+	 * 100XXXX000, and requires the XXXX be stored in the high nibble
+	 * of TWL4030_BCIMFTH8.
+	 */
+	reg = ua2regval(bci->ichg_eoc, cgain);
+	if (reg > 0x278)
+		reg = 0x278;
+	if (reg < 0x200)
+		reg = 0x200;
+	reg = (reg >> 3) & 0xf;
+	fullreg = reg << 4;
+
+	/*
+	 * For ichg_lo, reg value must match 10XXXX0000.
+	 * XXXX is stored in low nibble of TWL4030_BCIMFTH8.
+	 */
+	reg = ua2regval(bci->ichg_lo, cgain);
+	if (reg > 0x2F0)
+		reg = 0x2F0;
+	if (reg < 0x200)
+		reg = 0x200;
+	reg = (reg >> 4) & 0xf;
+	fullreg |= reg;
+
+	/* ichg_eoc and ichg_lo live in same register */
+	status = twl4030_bci_read(TWL4030_BCIMFTH8, &oldreg);
+	if (status < 0)
+		return status;
+	if (oldreg != fullreg) {
+		status = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0xF4,
+					  TWL4030_BCIMFKEY);
+		if (status < 0)
+			return status;
+		twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
+				 fullreg, TWL4030_BCIMFTH8);
+	}
+
+	/* ichg_hi threshold must be 1XXXX01100 (I think) */
+	reg = ua2regval(bci->ichg_hi, cgain);
+	if (reg > 0x3E0)
+		reg = 0x3E0;
+	if (reg < 0x200)
+		reg = 0x200;
+	fullreg = (reg >> 5) & 0xF;
+	fullreg <<= 4;
+	status = twl4030_bci_read(TWL4030_BCIMFTH9, &oldreg);
+	if (status < 0)
+		return status;
+	if ((oldreg & 0xF0) != fullreg) {
+		fullreg |= (oldreg & 0x0F);
+		status = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0xE7,
+					  TWL4030_BCIMFKEY);
+		if (status < 0)
+			return status;
+		twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
+				 fullreg, TWL4030_BCIMFTH9);
+	}
+
+	/*
+	 * And finally, set the current.  This is stored in
+	 * two registers.
+	 */
+	reg = ua2regval(cur, cgain);
+	/* we have only 10 bits */
+	if (reg > 0x3ff)
+		reg = 0x3ff;
+	status = twl4030_bci_read(TWL4030_BCIIREF1, &oldreg);
+	if (status < 0)
+		return status;
+	cur_reg = oldreg;
+	status = twl4030_bci_read(TWL4030_BCIIREF2, &oldreg);
+	if (status < 0)
+		return status;
+	cur_reg |= oldreg << 8;
+	if (reg != oldreg) {
+		/* disable write protection for one write access for
+		 * BCIIREF */
+		status = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0xE7,
+					  TWL4030_BCIMFKEY);
+		if (status < 0)
+			return status;
+		status = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
+					  (reg & 0x100) ? 3 : 2,
+					  TWL4030_BCIIREF2);
+		if (status < 0)
+			return status;
+		/* disable write protection for one write access for
+		 * BCIIREF */
+		status = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0xE7,
+					  TWL4030_BCIMFKEY);
+		if (status < 0)
+			return status;
+		status = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
+					  reg & 0xff,
+					  TWL4030_BCIIREF1);
+	}
+	if ((!!cgain) != !!(bcictl1 & TWL4030_CGAIN)) {
+		/* Flip CGAIN and re-enable charging */
+		bcictl1 ^= TWL4030_CGAIN;
+		twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
+				 bcictl1, TWL4030_BCICTL1);
+		twl4030_clear_set_boot_bci(0, boot_bci);
+	}
+	return 0;
+}
+
+static int twl4030_charger_get_current(void);
+
+static void twl4030_current_worker(struct work_struct *data)
+{
+	int v, curr;
+	int res;
+	struct twl4030_bci *bci = container_of(data, struct twl4030_bci,
+					       current_worker.work);
+
+	res = twl4030bci_read_adc_val(TWL4030_BCIVBUS);
+	if (res < 0)
+		v = 0;
+	else
+		/* BCIVBUS uses ADCIN8, 7/1023 V/step */
+		v = res * 6843;
+	curr = twl4030_charger_get_current();
+
+	dev_dbg(bci->dev, "v=%d cur=%d limit=%d target=%d\n", v, curr,
+		bci->usb_cur, bci->usb_cur_target);
+
+	if (v < USB_MIN_VOLT) {
+		/* Back up and stop adjusting. */
+		bci->usb_cur -= USB_CUR_STEP;
+		bci->usb_cur_target = bci->usb_cur;
+	} else if (bci->usb_cur >= bci->usb_cur_target ||
+		   bci->usb_cur + USB_CUR_STEP > USB_MAX_CURRENT) {
+		/* Reached target and voltage is OK - stop */
+		return;
+	} else {
+		bci->usb_cur += USB_CUR_STEP;
+		schedule_delayed_work(&bci->current_worker, USB_CUR_DELAY);
+	}
+	twl4030_charger_update_current(bci);
+}
+
+/*
+ * Enable/Disable USB Charge functionality.
+ */
+static int twl4030_charger_enable_usb(struct twl4030_bci *bci, bool enable)
+{
+	int ret;
+
+	if (bci->usb_mode == CHARGE_OFF)
+		enable = false;
+	if (enable && !IS_ERR_OR_NULL(bci->transceiver)) {
+
+		twl4030_charger_update_current(bci);
+
+		/* Need to keep phy powered */
+		if (!bci->usb_enabled) {
+			pm_runtime_get_sync(bci->transceiver->dev);
+			bci->usb_enabled = 1;
+		}
+
+		if (bci->usb_mode == CHARGE_AUTO)
+			/* forcing the field BCIAUTOUSB (BOOT_BCI[1]) to 1 */
+			ret = twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOUSB);
+
+		/* forcing USBFASTMCHG(BCIMFSTS4[2]) to 1 */
+		ret = twl4030_clear_set(TWL_MODULE_MAIN_CHARGE, 0,
+			TWL4030_USBFASTMCHG, TWL4030_BCIMFSTS4);
+		if (bci->usb_mode == CHARGE_LINEAR) {
+			twl4030_clear_set_boot_bci(TWL4030_BCIAUTOAC|TWL4030_CVENAC, 0);
+			/* Watch dog key: WOVF acknowledge */
+			ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0x33,
+					       TWL4030_BCIWDKEY);
+			/* 0x24 + EKEY6: off mode */
+			ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0x2a,
+					       TWL4030_BCIMDKEY);
+			/* EKEY2: Linear charge: USB path */
+			ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0x26,
+					       TWL4030_BCIMDKEY);
+			/* WDKEY5: stop watchdog count */
+			ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0xf3,
+					       TWL4030_BCIWDKEY);
+			/* enable MFEN3 access */
+			ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0x9c,
+					       TWL4030_BCIMFKEY);
+			 /* ICHGEOCEN - end-of-charge monitor (current < 80mA)
+			  *                      (charging continues)
+			  * ICHGLOWEN - current level monitor (charge continues)
+			  * don't monitor over-current or heat save
+			  */
+			ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0xf0,
+					       TWL4030_BCIMFEN3);
+		}
+	} else {
+		ret = twl4030_clear_set_boot_bci(TWL4030_BCIAUTOUSB, 0);
+		ret |= twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0x2a,
+					TWL4030_BCIMDKEY);
+		if (bci->usb_enabled) {
+			pm_runtime_mark_last_busy(bci->transceiver->dev);
+			pm_runtime_put_autosuspend(bci->transceiver->dev);
+			bci->usb_enabled = 0;
+		}
+		bci->usb_cur = 0;
+	}
+
+	return ret;
+}
+
+/*
+ * Enable/Disable AC Charge funtionality.
+ */
+static int twl4030_charger_enable_ac(struct twl4030_bci *bci, bool enable)
+{
+	int ret;
+
+	if (bci->ac_mode == CHARGE_OFF)
+		enable = false;
+
+	if (enable)
+		ret = twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOAC);
+	else
+		ret = twl4030_clear_set_boot_bci(TWL4030_BCIAUTOAC, 0);
+
+	return ret;
+}
+
+/*
+ * Enable/Disable charging of Backup Battery.
+ */
+static int twl4030_charger_enable_backup(int uvolt, int uamp)
+{
+	int ret;
+	u8 flags;
+
+	if (uvolt < 2500000 ||
+	    uamp < 25) {
+		/* disable charging of backup battery */
+		ret = twl4030_clear_set(TWL_MODULE_PM_RECEIVER,
+					TWL4030_BBCHEN, 0, TWL4030_BB_CFG);
+		return ret;
+	}
+
+	flags = TWL4030_BBCHEN;
+	if (uvolt >= 3200000)
+		flags |= TWL4030_BBSEL_3V2;
+	else if (uvolt >= 3100000)
+		flags |= TWL4030_BBSEL_3V1;
+	else if (uvolt >= 3000000)
+		flags |= TWL4030_BBSEL_3V0;
+	else
+		flags |= TWL4030_BBSEL_2V5;
+
+	if (uamp >= 1000)
+		flags |= TWL4030_BBISEL_1000uA;
+	else if (uamp >= 500)
+		flags |= TWL4030_BBISEL_500uA;
+	else if (uamp >= 150)
+		flags |= TWL4030_BBISEL_150uA;
+	else
+		flags |= TWL4030_BBISEL_25uA;
+
+	ret = twl4030_clear_set(TWL_MODULE_PM_RECEIVER,
+				TWL4030_BBSEL_MASK | TWL4030_BBISEL_MASK,
+				flags,
+				TWL4030_BB_CFG);
+
+	return ret;
+}
+
+/*
+ * TWL4030 CHG_PRES (AC charger presence) events
+ */
+static irqreturn_t twl4030_charger_interrupt(int irq, void *arg)
+{
+	struct twl4030_bci *bci = arg;
+
+	dev_dbg(bci->dev, "CHG_PRES irq\n");
+	/* reset current on each 'plug' event */
+	bci->ac_cur = 500000;
+	twl4030_charger_update_current(bci);
+	power_supply_changed(bci->ac);
+	power_supply_changed(bci->usb);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * TWL4030 BCI monitoring events
+ */
+static irqreturn_t twl4030_bci_interrupt(int irq, void *arg)
+{
+	struct twl4030_bci *bci = arg;
+	u8 irqs1, irqs2;
+	int ret;
+
+	ret = twl_i2c_read_u8(TWL4030_MODULE_INTERRUPTS, &irqs1,
+			      TWL4030_INTERRUPTS_BCIISR1A);
+	if (ret < 0)
+		return IRQ_HANDLED;
+
+	ret = twl_i2c_read_u8(TWL4030_MODULE_INTERRUPTS, &irqs2,
+			      TWL4030_INTERRUPTS_BCIISR2A);
+	if (ret < 0)
+		return IRQ_HANDLED;
+
+	dev_dbg(bci->dev, "BCI irq %02x %02x\n", irqs2, irqs1);
+
+	if (irqs1 & (TWL4030_ICHGLOW | TWL4030_ICHGEOC)) {
+		/* charger state change, inform the core */
+		power_supply_changed(bci->ac);
+		power_supply_changed(bci->usb);
+	}
+	twl4030_charger_update_current(bci);
+
+	/* various monitoring events, for now we just log them here */
+	if (irqs1 & (TWL4030_TBATOR2 | TWL4030_TBATOR1))
+		dev_warn(bci->dev, "battery temperature out of range\n");
+
+	if (irqs1 & TWL4030_BATSTS)
+		dev_crit(bci->dev, "battery disconnected\n");
+
+	if (irqs2 & TWL4030_VBATOV)
+		dev_crit(bci->dev, "VBAT overvoltage\n");
+
+	if (irqs2 & TWL4030_VBUSOV)
+		dev_crit(bci->dev, "VBUS overvoltage\n");
+
+	if (irqs2 & TWL4030_ACCHGOV)
+		dev_crit(bci->dev, "Ac charger overvoltage\n");
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * Provide "max_current" attribute in sysfs.
+ */
+static ssize_t
+twl4030_bci_max_current_store(struct device *dev, struct device_attribute *attr,
+	const char *buf, size_t n)
+{
+	struct twl4030_bci *bci = dev_get_drvdata(dev->parent);
+	int cur = 0;
+	int status = 0;
+	status = kstrtoint(buf, 10, &cur);
+	if (status)
+		return status;
+	if (cur < 0)
+		return -EINVAL;
+	if (dev == &bci->ac->dev)
+		bci->ac_cur = cur;
+	else
+		bci->usb_cur_target = cur;
+
+	twl4030_charger_update_current(bci);
+	return n;
+}
+
+/*
+ * sysfs max_current show
+ */
+static ssize_t twl4030_bci_max_current_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	int status = 0;
+	int cur = -1;
+	u8 bcictl1;
+	struct twl4030_bci *bci = dev_get_drvdata(dev->parent);
+
+	if (dev == &bci->ac->dev) {
+		if (!bci->ac_is_active)
+			cur = bci->ac_cur;
+	} else {
+		if (bci->ac_is_active)
+			cur = bci->usb_cur_target;
+	}
+	if (cur < 0) {
+		cur = twl4030bci_read_adc_val(TWL4030_BCIIREF1);
+		if (cur < 0)
+			return cur;
+		status = twl4030_bci_read(TWL4030_BCICTL1, &bcictl1);
+		if (status < 0)
+			return status;
+		cur = regval2ua(cur, bcictl1 & TWL4030_CGAIN);
+	}
+	return scnprintf(buf, PAGE_SIZE, "%u\n", cur);
+}
+
+static DEVICE_ATTR(max_current, 0644, twl4030_bci_max_current_show,
+			twl4030_bci_max_current_store);
+
+static void twl4030_bci_usb_work(struct work_struct *data)
+{
+	struct twl4030_bci *bci = container_of(data, struct twl4030_bci, work);
+
+	switch (bci->event) {
+	case USB_EVENT_VBUS:
+	case USB_EVENT_CHARGER:
+		twl4030_charger_enable_usb(bci, true);
+		break;
+	case USB_EVENT_NONE:
+		twl4030_charger_enable_usb(bci, false);
+		break;
+	}
+}
+
+static int twl4030_bci_usb_ncb(struct notifier_block *nb, unsigned long val,
+			       void *priv)
+{
+	struct twl4030_bci *bci = container_of(nb, struct twl4030_bci, usb_nb);
+
+	dev_dbg(bci->dev, "OTG notify %lu\n", val);
+
+	/* reset current on each 'plug' event */
+	if (allow_usb)
+		bci->usb_cur_target = 500000;
+	else
+		bci->usb_cur_target = 100000;
+
+	bci->event = val;
+	schedule_work(&bci->work);
+
+	return NOTIFY_OK;
+}
+
+/*
+ * sysfs charger enabled store
+ */
+static ssize_t
+twl4030_bci_mode_store(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t n)
+{
+	struct twl4030_bci *bci = dev_get_drvdata(dev->parent);
+	int mode;
+	int status;
+
+	if (sysfs_streq(buf, modes[0]))
+		mode = 0;
+	else if (sysfs_streq(buf, modes[1]))
+		mode = 1;
+	else if (sysfs_streq(buf, modes[2]))
+		mode = 2;
+	else
+		return -EINVAL;
+	if (dev == &bci->ac->dev) {
+		if (mode == 2)
+			return -EINVAL;
+		twl4030_charger_enable_ac(bci, false);
+		bci->ac_mode = mode;
+		status = twl4030_charger_enable_ac(bci, true);
+	} else {
+		twl4030_charger_enable_usb(bci, false);
+		bci->usb_mode = mode;
+		status = twl4030_charger_enable_usb(bci, true);
+	}
+	return (status == 0) ? n : status;
+}
+
+/*
+ * sysfs charger enabled show
+ */
+static ssize_t
+twl4030_bci_mode_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct twl4030_bci *bci = dev_get_drvdata(dev->parent);
+	int len = 0;
+	int i;
+	int mode = bci->usb_mode;
+
+	if (dev == &bci->ac->dev)
+		mode = bci->ac_mode;
+
+	for (i = 0; i < ARRAY_SIZE(modes); i++)
+		if (mode == i)
+			len += snprintf(buf+len, PAGE_SIZE-len,
+					"[%s] ", modes[i]);
+		else
+			len += snprintf(buf+len, PAGE_SIZE-len,
+					"%s ", modes[i]);
+	buf[len-1] = '\n';
+	return len;
+}
+static DEVICE_ATTR(mode, 0644, twl4030_bci_mode_show,
+		   twl4030_bci_mode_store);
+
+static int twl4030_charger_get_current(void)
+{
+	int curr;
+	int ret;
+	u8 bcictl1;
+
+	curr = twl4030bci_read_adc_val(TWL4030_BCIICHG);
+	if (curr < 0)
+		return curr;
+
+	ret = twl4030_bci_read(TWL4030_BCICTL1, &bcictl1);
+	if (ret)
+		return ret;
+
+	return regval2ua(curr, bcictl1 & TWL4030_CGAIN);
+}
+
+/*
+ * Returns the main charge FSM state
+ * Or < 0 on failure.
+ */
+static int twl4030bci_state(struct twl4030_bci *bci)
+{
+	int ret;
+	u8 state;
+
+	ret = twl4030_bci_read(TWL4030_BCIMSTATEC, &state);
+	if (ret) {
+		pr_err("twl4030_bci: error reading BCIMSTATEC\n");
+		return ret;
+	}
+
+	dev_dbg(bci->dev, "state: %02x\n", state);
+
+	return state;
+}
+
+static int twl4030_bci_state_to_status(int state)
+{
+	state &= TWL4030_MSTATEC_MASK;
+	if (TWL4030_MSTATEC_QUICK1 <= state && state <= TWL4030_MSTATEC_QUICK7)
+		return POWER_SUPPLY_STATUS_CHARGING;
+	else if (TWL4030_MSTATEC_COMPLETE1 <= state &&
+					state <= TWL4030_MSTATEC_COMPLETE4)
+		return POWER_SUPPLY_STATUS_FULL;
+	else
+		return POWER_SUPPLY_STATUS_NOT_CHARGING;
+}
+
+static int twl4030_bci_get_property(struct power_supply *psy,
+				    enum power_supply_property psp,
+				    union power_supply_propval *val)
+{
+	struct twl4030_bci *bci = dev_get_drvdata(psy->dev.parent);
+	int is_charging;
+	int state;
+	int ret;
+
+	state = twl4030bci_state(bci);
+	if (state < 0)
+		return state;
+
+	if (psy->desc->type == POWER_SUPPLY_TYPE_USB)
+		is_charging = state & TWL4030_MSTATEC_USB;
+	else
+		is_charging = state & TWL4030_MSTATEC_AC;
+	if (!is_charging) {
+		u8 s;
+		twl4030_bci_read(TWL4030_BCIMDEN, &s);
+		if (psy->desc->type == POWER_SUPPLY_TYPE_USB)
+			is_charging = s & 1;
+		else
+			is_charging = s & 2;
+		if (is_charging)
+			/* A little white lie */
+			state = TWL4030_MSTATEC_QUICK1;
+	}
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		if (is_charging)
+			val->intval = twl4030_bci_state_to_status(state);
+		else
+			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		/* charging must be active for meaningful result */
+		if (!is_charging)
+			return -ENODATA;
+		if (psy->desc->type == POWER_SUPPLY_TYPE_USB) {
+			ret = twl4030bci_read_adc_val(TWL4030_BCIVBUS);
+			if (ret < 0)
+				return ret;
+			/* BCIVBUS uses ADCIN8, 7/1023 V/step */
+			val->intval = ret * 6843;
+		} else {
+			ret = twl4030bci_read_adc_val(TWL4030_BCIVAC);
+			if (ret < 0)
+				return ret;
+			/* BCIVAC uses ADCIN11, 10/1023 V/step */
+			val->intval = ret * 9775;
+		}
+		break;
+	case POWER_SUPPLY_PROP_CURRENT_NOW:
+		if (!is_charging)
+			return -ENODATA;
+		/* current measurement is shared between AC and USB */
+		ret = twl4030_charger_get_current();
+		if (ret < 0)
+			return ret;
+		val->intval = ret;
+		break;
+	case POWER_SUPPLY_PROP_ONLINE:
+		val->intval = is_charging &&
+			twl4030_bci_state_to_status(state) !=
+				POWER_SUPPLY_STATUS_NOT_CHARGING;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static enum power_supply_property twl4030_charger_props[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_ONLINE,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_CURRENT_NOW,
+};
+
+#ifdef CONFIG_OF
+static const struct twl4030_bci_platform_data *
+twl4030_bci_parse_dt(struct device *dev)
+{
+	struct device_node *np = dev->of_node;
+	struct twl4030_bci_platform_data *pdata;
+	u32 num;
+
+	if (!np)
+		return NULL;
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return pdata;
+
+	if (of_property_read_u32(np, "ti,bb-uvolt", &num) == 0)
+		pdata->bb_uvolt = num;
+	if (of_property_read_u32(np, "ti,bb-uamp", &num) == 0)
+		pdata->bb_uamp = num;
+	return pdata;
+}
+#else
+static inline const struct twl4030_bci_platform_data *
+twl4030_bci_parse_dt(struct device *dev)
+{
+	return NULL;
+}
+#endif
+
+static const struct power_supply_desc twl4030_bci_ac_desc = {
+	.name		= "twl4030_ac",
+	.type		= POWER_SUPPLY_TYPE_MAINS,
+	.properties	= twl4030_charger_props,
+	.num_properties	= ARRAY_SIZE(twl4030_charger_props),
+	.get_property	= twl4030_bci_get_property,
+};
+
+static const struct power_supply_desc twl4030_bci_usb_desc = {
+	.name		= "twl4030_usb",
+	.type		= POWER_SUPPLY_TYPE_USB,
+	.properties	= twl4030_charger_props,
+	.num_properties	= ARRAY_SIZE(twl4030_charger_props),
+	.get_property	= twl4030_bci_get_property,
+};
+
+static int twl4030_bci_probe(struct platform_device *pdev)
+{
+	struct twl4030_bci *bci;
+	const struct twl4030_bci_platform_data *pdata = pdev->dev.platform_data;
+	int ret;
+	u32 reg;
+
+	bci = devm_kzalloc(&pdev->dev, sizeof(*bci), GFP_KERNEL);
+	if (bci == NULL)
+		return -ENOMEM;
+
+	if (!pdata)
+		pdata = twl4030_bci_parse_dt(&pdev->dev);
+
+	bci->ichg_eoc = 80100; /* Stop charging when current drops to here */
+	bci->ichg_lo = 241000; /* Low threshold */
+	bci->ichg_hi = 500000; /* High threshold */
+	bci->ac_cur = 500000; /* 500mA */
+	if (allow_usb)
+		bci->usb_cur_target = 500000;  /* 500mA */
+	else
+		bci->usb_cur_target = 100000;  /* 100mA */
+	bci->usb_mode = CHARGE_AUTO;
+	bci->ac_mode = CHARGE_AUTO;
+
+	bci->dev = &pdev->dev;
+	bci->irq_chg = platform_get_irq(pdev, 0);
+	bci->irq_bci = platform_get_irq(pdev, 1);
+
+	/* Only proceed further *IF* battery is physically present */
+	ret = twl4030_is_battery_present(bci);
+	if  (ret) {
+		dev_crit(&pdev->dev, "Battery was not detected:%d\n", ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, bci);
+
+	bci->ac = devm_power_supply_register(&pdev->dev, &twl4030_bci_ac_desc,
+					     NULL);
+	if (IS_ERR(bci->ac)) {
+		ret = PTR_ERR(bci->ac);
+		dev_err(&pdev->dev, "failed to register ac: %d\n", ret);
+		return ret;
+	}
+
+	bci->usb = devm_power_supply_register(&pdev->dev, &twl4030_bci_usb_desc,
+					      NULL);
+	if (IS_ERR(bci->usb)) {
+		ret = PTR_ERR(bci->usb);
+		dev_err(&pdev->dev, "failed to register usb: %d\n", ret);
+		return ret;
+	}
+
+	ret = devm_request_threaded_irq(&pdev->dev, bci->irq_chg, NULL,
+			twl4030_charger_interrupt, IRQF_ONESHOT, pdev->name,
+			bci);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "could not request irq %d, status %d\n",
+			bci->irq_chg, ret);
+		return ret;
+	}
+
+	ret = devm_request_threaded_irq(&pdev->dev, bci->irq_bci, NULL,
+			twl4030_bci_interrupt, IRQF_ONESHOT, pdev->name, bci);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "could not request irq %d, status %d\n",
+			bci->irq_bci, ret);
+		return ret;
+	}
+
+	bci->channel_vac = iio_channel_get(&pdev->dev, "vac");
+	if (IS_ERR(bci->channel_vac)) {
+		bci->channel_vac = NULL;
+		dev_warn(&pdev->dev, "could not request vac iio channel");
+	}
+
+	INIT_WORK(&bci->work, twl4030_bci_usb_work);
+	INIT_DELAYED_WORK(&bci->current_worker, twl4030_current_worker);
+
+	bci->usb_nb.notifier_call = twl4030_bci_usb_ncb;
+	if (bci->dev->of_node) {
+		struct device_node *phynode;
+
+		phynode = of_find_compatible_node(bci->dev->of_node->parent,
+						  NULL, "ti,twl4030-usb");
+		if (phynode)
+			bci->transceiver = devm_usb_get_phy_by_node(
+				bci->dev, phynode, &bci->usb_nb);
+	}
+
+	/* Enable interrupts now. */
+	reg = ~(u32)(TWL4030_ICHGLOW | TWL4030_ICHGEOC | TWL4030_TBATOR2 |
+		TWL4030_TBATOR1 | TWL4030_BATSTS);
+	ret = twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, reg,
+			       TWL4030_INTERRUPTS_BCIIMR1A);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to unmask interrupts: %d\n", ret);
+		goto fail;
+	}
+
+	reg = ~(u32)(TWL4030_VBATOV | TWL4030_VBUSOV | TWL4030_ACCHGOV);
+	ret = twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, reg,
+			       TWL4030_INTERRUPTS_BCIIMR2A);
+	if (ret < 0)
+		dev_warn(&pdev->dev, "failed to unmask interrupts: %d\n", ret);
+
+	twl4030_charger_update_current(bci);
+	if (device_create_file(&bci->usb->dev, &dev_attr_max_current))
+		dev_warn(&pdev->dev, "could not create sysfs file\n");
+	if (device_create_file(&bci->usb->dev, &dev_attr_mode))
+		dev_warn(&pdev->dev, "could not create sysfs file\n");
+	if (device_create_file(&bci->ac->dev, &dev_attr_mode))
+		dev_warn(&pdev->dev, "could not create sysfs file\n");
+	if (device_create_file(&bci->ac->dev, &dev_attr_max_current))
+		dev_warn(&pdev->dev, "could not create sysfs file\n");
+
+	twl4030_charger_enable_ac(bci, true);
+	if (!IS_ERR_OR_NULL(bci->transceiver))
+		twl4030_bci_usb_ncb(&bci->usb_nb,
+				    bci->transceiver->last_event,
+				    NULL);
+	else
+		twl4030_charger_enable_usb(bci, false);
+	if (pdata)
+		twl4030_charger_enable_backup(pdata->bb_uvolt,
+					      pdata->bb_uamp);
+	else
+		twl4030_charger_enable_backup(0, 0);
+
+	return 0;
+fail:
+	iio_channel_release(bci->channel_vac);
+
+	return ret;
+}
+
+static int __exit twl4030_bci_remove(struct platform_device *pdev)
+{
+	struct twl4030_bci *bci = platform_get_drvdata(pdev);
+
+	twl4030_charger_enable_ac(bci, false);
+	twl4030_charger_enable_usb(bci, false);
+	twl4030_charger_enable_backup(0, 0);
+
+	iio_channel_release(bci->channel_vac);
+
+	device_remove_file(&bci->usb->dev, &dev_attr_max_current);
+	device_remove_file(&bci->usb->dev, &dev_attr_mode);
+	device_remove_file(&bci->ac->dev, &dev_attr_max_current);
+	device_remove_file(&bci->ac->dev, &dev_attr_mode);
+	/* mask interrupts */
+	twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xff,
+			 TWL4030_INTERRUPTS_BCIIMR1A);
+	twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xff,
+			 TWL4030_INTERRUPTS_BCIIMR2A);
+
+	return 0;
+}
+
+static const struct of_device_id twl_bci_of_match[] = {
+	{.compatible = "ti,twl4030-bci", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, twl_bci_of_match);
+
+static struct platform_driver twl4030_bci_driver = {
+	.probe = twl4030_bci_probe,
+	.driver	= {
+		.name	= "twl4030_bci",
+		.of_match_table = of_match_ptr(twl_bci_of_match),
+	},
+	.remove	= __exit_p(twl4030_bci_remove),
+};
+module_platform_driver(twl4030_bci_driver);
+
+MODULE_AUTHOR("Gražvydas Ignotas");
+MODULE_DESCRIPTION("TWL4030 Battery Charger Interface driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:twl4030_bci");