power_supply: Add driver for the PMU on WM831x PMICs

The WM831x PMICs provide power path management from three sources:
a wall supply, USB and a battery with integrated charger. They also
provide an additional backup supply with integrated for maintaining
always on functionality such as the RTC and monitoring of power
switches.

After some initial configuration at startup the device operates
autonomously, the driver simply provides reporting of the current
state.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>

1 files changed, 779 insertions, 0 deletions

diff --git a/drivers/power/wm831x_power.c b/drivers/power/wm831x_power.c
new file mode 100644
index 00000000000..2a4c8b0b829
--- /dev/null
+++ b/drivers/power/wm831x_power.c
@@ -0,0 +1,779 @@
+/*
+ * PMU driver for Wolfson Microelectronics wm831x PMICs
+ *
+ * Copyright 2009 Wolfson Microelectronics PLC.
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+
+#include <linux/mfd/wm831x/core.h>
+#include <linux/mfd/wm831x/auxadc.h>
+#include <linux/mfd/wm831x/pmu.h>
+#include <linux/mfd/wm831x/pdata.h>
+
+struct wm831x_power {
+	struct wm831x *wm831x;
+	struct power_supply wall;
+	struct power_supply backup;
+	struct power_supply usb;
+	struct power_supply battery;
+};
+
+static int wm831x_power_check_online(struct wm831x *wm831x, int supply,
+				     union power_supply_propval *val)
+{
+	int ret;
+
+	ret = wm831x_reg_read(wm831x, WM831X_SYSTEM_STATUS);
+	if (ret < 0)
+		return ret;
+
+	if (ret & supply)
+		val->intval = 1;
+	else
+		val->intval = 0;
+
+	return 0;
+}
+
+static int wm831x_power_read_voltage(struct wm831x *wm831x,
+				     enum wm831x_auxadc src,
+				     union power_supply_propval *val)
+{
+	int ret;
+
+	ret = wm831x_auxadc_read_uv(wm831x, src);
+	if (ret >= 0)
+		val->intval = ret;
+
+	return ret;
+}
+
+/*********************************************************************
+ *		WALL Power
+ *********************************************************************/
+static int wm831x_wall_get_prop(struct power_supply *psy,
+				enum power_supply_property psp,
+				union power_supply_propval *val)
+{
+	struct wm831x_power *wm831x_power = dev_get_drvdata(psy->dev->parent);
+	struct wm831x *wm831x = wm831x_power->wm831x;
+	int ret = 0;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_ONLINE:
+		ret = wm831x_power_check_online(wm831x, WM831X_PWR_WALL, val);
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		ret = wm831x_power_read_voltage(wm831x, WM831X_AUX_WALL, val);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+static enum power_supply_property wm831x_wall_props[] = {
+	POWER_SUPPLY_PROP_ONLINE,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+};
+
+/*********************************************************************
+ *		USB Power
+ *********************************************************************/
+static int wm831x_usb_get_prop(struct power_supply *psy,
+			       enum power_supply_property psp,
+			       union power_supply_propval *val)
+{
+	struct wm831x_power *wm831x_power = dev_get_drvdata(psy->dev->parent);
+	struct wm831x *wm831x = wm831x_power->wm831x;
+	int ret = 0;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_ONLINE:
+		ret = wm831x_power_check_online(wm831x, WM831X_PWR_USB, val);
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		ret = wm831x_power_read_voltage(wm831x, WM831X_AUX_USB, val);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+static enum power_supply_property wm831x_usb_props[] = {
+	POWER_SUPPLY_PROP_ONLINE,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+};
+
+/*********************************************************************
+ *		Battery properties
+ *********************************************************************/
+
+struct chg_map {
+	int val;
+	int reg_val;
+};
+
+static struct chg_map trickle_ilims[] = {
+	{  50, 0 << WM831X_CHG_TRKL_ILIM_SHIFT },
+	{ 100, 1 << WM831X_CHG_TRKL_ILIM_SHIFT },
+	{ 150, 2 << WM831X_CHG_TRKL_ILIM_SHIFT },
+	{ 200, 3 << WM831X_CHG_TRKL_ILIM_SHIFT },
+};
+
+static struct chg_map vsels[] = {
+	{ 4050, 0 << WM831X_CHG_VSEL_SHIFT },
+	{ 4100, 1 << WM831X_CHG_VSEL_SHIFT },
+	{ 4150, 2 << WM831X_CHG_VSEL_SHIFT },
+	{ 4200, 3 << WM831X_CHG_VSEL_SHIFT },
+};
+
+static struct chg_map fast_ilims[] = {
+	{    0,  0 << WM831X_CHG_FAST_ILIM_SHIFT },
+	{   50,  1 << WM831X_CHG_FAST_ILIM_SHIFT },
+	{  100,  2 << WM831X_CHG_FAST_ILIM_SHIFT },
+	{  150,  3 << WM831X_CHG_FAST_ILIM_SHIFT },
+	{  200,  4 << WM831X_CHG_FAST_ILIM_SHIFT },
+	{  250,  5 << WM831X_CHG_FAST_ILIM_SHIFT },
+	{  300,  6 << WM831X_CHG_FAST_ILIM_SHIFT },
+	{  350,  7 << WM831X_CHG_FAST_ILIM_SHIFT },
+	{  400,  8 << WM831X_CHG_FAST_ILIM_SHIFT },
+	{  450,  9 << WM831X_CHG_FAST_ILIM_SHIFT },
+	{  500, 10 << WM831X_CHG_FAST_ILIM_SHIFT },
+	{  600, 11 << WM831X_CHG_FAST_ILIM_SHIFT },
+	{  700, 12 << WM831X_CHG_FAST_ILIM_SHIFT },
+	{  800, 13 << WM831X_CHG_FAST_ILIM_SHIFT },
+	{  900, 14 << WM831X_CHG_FAST_ILIM_SHIFT },
+	{ 1000, 15 << WM831X_CHG_FAST_ILIM_SHIFT },
+};
+
+static struct chg_map eoc_iterms[] = {
+	{ 20, 0 << WM831X_CHG_ITERM_SHIFT },
+	{ 30, 1 << WM831X_CHG_ITERM_SHIFT },
+	{ 40, 2 << WM831X_CHG_ITERM_SHIFT },
+	{ 50, 3 << WM831X_CHG_ITERM_SHIFT },
+	{ 60, 4 << WM831X_CHG_ITERM_SHIFT },
+	{ 70, 5 << WM831X_CHG_ITERM_SHIFT },
+	{ 80, 6 << WM831X_CHG_ITERM_SHIFT },
+	{ 90, 7 << WM831X_CHG_ITERM_SHIFT },
+};
+
+static struct chg_map chg_times[] = {
+	{  60,  0 << WM831X_CHG_TIME_SHIFT },
+	{  90,  1 << WM831X_CHG_TIME_SHIFT },
+	{ 120,  2 << WM831X_CHG_TIME_SHIFT },
+	{ 150,  3 << WM831X_CHG_TIME_SHIFT },
+	{ 180,  4 << WM831X_CHG_TIME_SHIFT },
+	{ 210,  5 << WM831X_CHG_TIME_SHIFT },
+	{ 240,  6 << WM831X_CHG_TIME_SHIFT },
+	{ 270,  7 << WM831X_CHG_TIME_SHIFT },
+	{ 300,  8 << WM831X_CHG_TIME_SHIFT },
+	{ 330,  9 << WM831X_CHG_TIME_SHIFT },
+	{ 360, 10 << WM831X_CHG_TIME_SHIFT },
+	{ 390, 11 << WM831X_CHG_TIME_SHIFT },
+	{ 420, 12 << WM831X_CHG_TIME_SHIFT },
+	{ 450, 13 << WM831X_CHG_TIME_SHIFT },
+	{ 480, 14 << WM831X_CHG_TIME_SHIFT },
+	{ 510, 15 << WM831X_CHG_TIME_SHIFT },
+};
+
+static void wm831x_battey_apply_config(struct wm831x *wm831x,
+				       struct chg_map *map, int count, int val,
+				       int *reg, const char *name,
+				       const char *units)
+{
+	int i;
+
+	for (i = 0; i < count; i++)
+		if (val == map[i].val)
+			break;
+	if (i == count) {
+		dev_err(wm831x->dev, "Invalid %s %d%s\n",
+			name, val, units);
+	} else {
+		*reg |= map[i].reg_val;
+		dev_dbg(wm831x->dev, "Set %s of %d%s\n", name, val, units);
+	}
+}
+
+static void wm831x_config_battery(struct wm831x *wm831x)
+{
+	struct wm831x_pdata *wm831x_pdata = wm831x->dev->platform_data;
+	struct wm831x_battery_pdata *pdata;
+	int ret, reg1, reg2;
+
+	if (!wm831x_pdata || !wm831x_pdata->battery) {
+		dev_warn(wm831x->dev,
+			 "No battery charger configuration\n");
+		return;
+	}
+
+	pdata = wm831x_pdata->battery;
+
+	reg1 = 0;
+	reg2 = 0;
+
+	if (!pdata->enable) {
+		dev_info(wm831x->dev, "Battery charger disabled\n");
+		return;
+	}
+
+	reg1 |= WM831X_CHG_ENA;
+	if (pdata->off_mask)
+		reg2 |= WM831X_CHG_OFF_MSK;
+	if (pdata->fast_enable)
+		reg1 |= WM831X_CHG_FAST;
+
+	wm831x_battey_apply_config(wm831x, trickle_ilims,
+				   ARRAY_SIZE(trickle_ilims),
+				   pdata->trickle_ilim, &reg2,
+				   "trickle charge current limit", "mA");
+
+	wm831x_battey_apply_config(wm831x, vsels, ARRAY_SIZE(vsels),
+				   pdata->vsel, &reg2,
+				   "target voltage", "mV");
+
+	wm831x_battey_apply_config(wm831x, fast_ilims, ARRAY_SIZE(fast_ilims),
+				   pdata->fast_ilim, &reg2,
+				   "fast charge current limit", "mA");
+
+	wm831x_battey_apply_config(wm831x, eoc_iterms, ARRAY_SIZE(eoc_iterms),
+				   pdata->eoc_iterm, &reg1,
+				   "end of charge current threshold", "mA");
+
+	wm831x_battey_apply_config(wm831x, chg_times, ARRAY_SIZE(chg_times),
+				   pdata->timeout, &reg2,
+				   "charger timeout", "min");
+
+	ret = wm831x_reg_unlock(wm831x);
+	if (ret != 0) {
+		dev_err(wm831x->dev, "Failed to unlock registers: %d\n", ret);
+		return;
+	}
+
+	ret = wm831x_set_bits(wm831x, WM831X_CHARGER_CONTROL_1,
+			      WM831X_CHG_ENA_MASK |
+			      WM831X_CHG_FAST_MASK |
+			      WM831X_CHG_ITERM_MASK |
+			      WM831X_CHG_ITERM_MASK,
+			      reg1);
+	if (ret != 0)
+		dev_err(wm831x->dev, "Failed to set charger control 1: %d\n",
+			ret);
+
+	ret = wm831x_set_bits(wm831x, WM831X_CHARGER_CONTROL_2,
+			      WM831X_CHG_OFF_MSK |
+			      WM831X_CHG_TIME_MASK |
+			      WM831X_CHG_FAST_ILIM_MASK |
+			      WM831X_CHG_TRKL_ILIM_MASK |
+			      WM831X_CHG_VSEL_MASK,
+			      reg2);
+	if (ret != 0)
+		dev_err(wm831x->dev, "Failed to set charger control 2: %d\n",
+			ret);
+
+	wm831x_reg_lock(wm831x);
+}
+
+static int wm831x_bat_check_status(struct wm831x *wm831x, int *status)
+{
+	int ret;
+
+	ret = wm831x_reg_read(wm831x, WM831X_SYSTEM_STATUS);
+	if (ret < 0)
+		return ret;
+
+	if (ret & WM831X_PWR_SRC_BATT) {
+		*status = POWER_SUPPLY_STATUS_DISCHARGING;
+		return 0;
+	}
+
+	ret = wm831x_reg_read(wm831x, WM831X_CHARGER_STATUS);
+	if (ret < 0)
+		return ret;
+
+	switch (ret & WM831X_CHG_STATE_MASK) {
+	case WM831X_CHG_STATE_OFF:
+		*status = POWER_SUPPLY_STATUS_NOT_CHARGING;
+		break;
+	case WM831X_CHG_STATE_TRICKLE:
+	case WM831X_CHG_STATE_FAST:
+		*status = POWER_SUPPLY_STATUS_CHARGING;
+		break;
+
+	default:
+		*status = POWER_SUPPLY_STATUS_UNKNOWN;
+		break;
+	}
+
+	return 0;
+}
+
+static int wm831x_bat_check_type(struct wm831x *wm831x, int *type)
+{
+	int ret;
+
+	ret = wm831x_reg_read(wm831x, WM831X_CHARGER_STATUS);
+	if (ret < 0)
+		return ret;
+
+	switch (ret & WM831X_CHG_STATE_MASK) {
+	case WM831X_CHG_STATE_TRICKLE:
+	case WM831X_CHG_STATE_TRICKLE_OT:
+		*type = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
+		break;
+	case WM831X_CHG_STATE_FAST:
+	case WM831X_CHG_STATE_FAST_OT:
+		*type = POWER_SUPPLY_CHARGE_TYPE_FAST;
+		break;
+	default:
+		*type = POWER_SUPPLY_CHARGE_TYPE_NONE;
+		break;
+	}
+
+	return 0;
+}
+
+static int wm831x_bat_check_health(struct wm831x *wm831x, int *health)
+{
+	int ret;
+
+	ret = wm831x_reg_read(wm831x, WM831X_CHARGER_STATUS);
+	if (ret < 0)
+		return ret;
+
+	if (ret & WM831X_BATT_HOT_STS) {
+		*health = POWER_SUPPLY_HEALTH_OVERHEAT;
+		return 0;
+	}
+
+	if (ret & WM831X_BATT_COLD_STS) {
+		*health = POWER_SUPPLY_HEALTH_COLD;
+		return 0;
+	}
+
+	if (ret & WM831X_BATT_OV_STS) {
+		*health = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
+		return 0;
+	}
+
+	switch (ret & WM831X_CHG_STATE_MASK) {
+	case WM831X_CHG_STATE_TRICKLE_OT:
+	case WM831X_CHG_STATE_FAST_OT:
+		*health = POWER_SUPPLY_HEALTH_OVERHEAT;
+		break;
+	case WM831X_CHG_STATE_DEFECTIVE:
+		*health = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+		break;
+	default:
+		*health = POWER_SUPPLY_HEALTH_GOOD;
+		break;
+	}
+
+	return 0;
+}
+
+static int wm831x_bat_get_prop(struct power_supply *psy,
+			       enum power_supply_property psp,
+			       union power_supply_propval *val)
+{
+	struct wm831x_power *wm831x_power = dev_get_drvdata(psy->dev->parent);
+	struct wm831x *wm831x = wm831x_power->wm831x;
+	int ret = 0;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		ret = wm831x_bat_check_status(wm831x, &val->intval);
+		break;
+	case POWER_SUPPLY_PROP_ONLINE:
+		ret = wm831x_power_check_online(wm831x, WM831X_PWR_SRC_BATT,
+						val);
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		ret = wm831x_power_read_voltage(wm831x, WM831X_AUX_BATT, val);
+		break;
+	case POWER_SUPPLY_PROP_HEALTH:
+		ret = wm831x_bat_check_health(wm831x, &val->intval);
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_TYPE:
+		ret = wm831x_bat_check_type(wm831x, &val->intval);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+static enum power_supply_property wm831x_bat_props[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_ONLINE,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_HEALTH,
+	POWER_SUPPLY_PROP_CHARGE_TYPE,
+};
+
+static const char *wm831x_bat_irqs[] = {
+	"BATT HOT",
+	"BATT COLD",
+	"BATT FAIL",
+	"OV",
+	"END",
+	"TO",
+	"MODE",
+	"START",
+};
+
+static irqreturn_t wm831x_bat_irq(int irq, void *data)
+{
+	struct wm831x_power *wm831x_power = data;
+	struct wm831x *wm831x = wm831x_power->wm831x;
+
+	dev_dbg(wm831x->dev, "Battery status changed: %d\n", irq);
+
+	/* The battery charger is autonomous so we don't need to do
+	 * anything except kick user space */
+	power_supply_changed(&wm831x_power->battery);
+
+	return IRQ_HANDLED;
+}
+
+
+/*********************************************************************
+ *		Backup supply properties
+ *********************************************************************/
+
+static void wm831x_config_backup(struct wm831x *wm831x)
+{
+	struct wm831x_pdata *wm831x_pdata = wm831x->dev->platform_data;
+	struct wm831x_backup_pdata *pdata;
+	int ret, reg;
+
+	if (!wm831x_pdata || !wm831x_pdata->backup) {
+		dev_warn(wm831x->dev,
+			 "No backup battery charger configuration\n");
+		return;
+	}
+
+	pdata = wm831x_pdata->backup;
+
+	reg = 0;
+
+	if (pdata->charger_enable)
+		reg |= WM831X_BKUP_CHG_ENA | WM831X_BKUP_BATT_DET_ENA;
+	if (pdata->no_constant_voltage)
+		reg |= WM831X_BKUP_CHG_MODE;
+
+	switch (pdata->vlim) {
+	case 2500:
+		break;
+	case 3100:
+		reg |= WM831X_BKUP_CHG_VLIM;
+		break;
+	default:
+		dev_err(wm831x->dev, "Invalid backup voltage limit %dmV\n",
+			pdata->vlim);
+	}
+
+	switch (pdata->ilim) {
+	case 100:
+		break;
+	case 200:
+		reg |= 1;
+		break;
+	case 300:
+		reg |= 2;
+		break;
+	case 400:
+		reg |= 3;
+		break;
+	default:
+		dev_err(wm831x->dev, "Invalid backup current limit %duA\n",
+			pdata->ilim);
+	}
+
+	ret = wm831x_reg_unlock(wm831x);
+	if (ret != 0) {
+		dev_err(wm831x->dev, "Failed to unlock registers: %d\n", ret);
+		return;
+	}
+
+	ret = wm831x_set_bits(wm831x, WM831X_BACKUP_CHARGER_CONTROL,
+			      WM831X_BKUP_CHG_ENA_MASK |
+			      WM831X_BKUP_CHG_MODE_MASK |
+			      WM831X_BKUP_BATT_DET_ENA_MASK |
+			      WM831X_BKUP_CHG_VLIM_MASK |
+			      WM831X_BKUP_CHG_ILIM_MASK,
+			      reg);
+	if (ret != 0)
+		dev_err(wm831x->dev,
+			"Failed to set backup charger config: %d\n", ret);
+
+	wm831x_reg_lock(wm831x);
+}
+
+static int wm831x_backup_get_prop(struct power_supply *psy,
+				  enum power_supply_property psp,
+				  union power_supply_propval *val)
+{
+	struct wm831x_power *wm831x_power = dev_get_drvdata(psy->dev->parent);
+	struct wm831x *wm831x = wm831x_power->wm831x;
+	int ret = 0;
+
+	ret = wm831x_reg_read(wm831x, WM831X_BACKUP_CHARGER_CONTROL);
+	if (ret < 0)
+		return ret;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		if (ret & WM831X_BKUP_CHG_STS)
+			val->intval = POWER_SUPPLY_STATUS_CHARGING;
+		else
+			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+		break;
+
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		ret = wm831x_power_read_voltage(wm831x, WM831X_AUX_BKUP_BATT,
+						val);
+		break;
+
+	case POWER_SUPPLY_PROP_PRESENT:
+		if (ret & WM831X_BKUP_CHG_STS)
+			val->intval = 1;
+		else
+			val->intval = 0;
+		break;
+
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+static enum power_supply_property wm831x_backup_props[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_PRESENT,
+};
+
+/*********************************************************************
+ *		Initialisation
+ *********************************************************************/
+
+static irqreturn_t wm831x_syslo_irq(int irq, void *data)
+{
+	struct wm831x_power *wm831x_power = data;
+	struct wm831x *wm831x = wm831x_power->wm831x;
+
+	/* Not much we can actually *do* but tell people for
+	 * posterity, we're probably about to run out of power. */
+	dev_crit(wm831x->dev, "SYSVDD under voltage\n");
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t wm831x_pwr_src_irq(int irq, void *data)
+{
+	struct wm831x_power *wm831x_power = data;
+	struct wm831x *wm831x = wm831x_power->wm831x;
+
+	dev_dbg(wm831x->dev, "Power source changed\n");
+
+	/* Just notify for everything - little harm in overnotifying.
+	 * The backup battery is not a power source while the system
+	 * is running so skip that.
+	 */
+	power_supply_changed(&wm831x_power->battery);
+	power_supply_changed(&wm831x_power->usb);
+	power_supply_changed(&wm831x_power->wall);
+
+	return IRQ_HANDLED;
+}
+
+static __devinit int wm831x_power_probe(struct platform_device *pdev)
+{
+	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
+	struct wm831x_power *power;
+	struct power_supply *usb;
+	struct power_supply *battery;
+	struct power_supply *wall;
+	struct power_supply *backup;
+	int ret, irq, i;
+
+	power = kzalloc(sizeof(struct wm831x_power), GFP_KERNEL);
+	if (power == NULL)
+		return -ENOMEM;
+
+	power->wm831x = wm831x;
+	platform_set_drvdata(pdev, power);
+
+	usb = &power->usb;
+	battery = &power->battery;
+	wall = &power->wall;
+	backup = &power->backup;
+
+	/* We ignore configuration failures since we can still read back
+	 * the status without enabling either of the chargers.
+	 */
+	wm831x_config_battery(wm831x);
+	wm831x_config_backup(wm831x);
+
+	wall->name = "wm831x-wall";
+	wall->type = POWER_SUPPLY_TYPE_MAINS;
+	wall->properties = wm831x_wall_props;
+	wall->num_properties = ARRAY_SIZE(wm831x_wall_props);
+	wall->get_property = wm831x_wall_get_prop;
+	ret = power_supply_register(&pdev->dev, wall);
+	if (ret)
+		goto err_kmalloc;
+
+	battery->name = "wm831x-battery";
+	battery->properties = wm831x_bat_props;
+	battery->num_properties = ARRAY_SIZE(wm831x_bat_props);
+	battery->get_property = wm831x_bat_get_prop;
+	battery->use_for_apm = 1;
+	ret = power_supply_register(&pdev->dev, battery);
+	if (ret)
+		goto err_wall;
+
+	usb->name = "wm831x-usb",
+	usb->type = POWER_SUPPLY_TYPE_USB;
+	usb->properties = wm831x_usb_props;
+	usb->num_properties = ARRAY_SIZE(wm831x_usb_props);
+	usb->get_property = wm831x_usb_get_prop;
+	ret = power_supply_register(&pdev->dev, usb);
+	if (ret)
+		goto err_battery;
+
+	backup->name = "wm831x-backup";
+	backup->type = POWER_SUPPLY_TYPE_BATTERY;
+	backup->properties = wm831x_backup_props;
+	backup->num_properties = ARRAY_SIZE(wm831x_backup_props);
+	backup->get_property = wm831x_backup_get_prop;
+	ret = power_supply_register(&pdev->dev, backup);
+	if (ret)
+		goto err_usb;
+
+	irq = platform_get_irq_byname(pdev, "SYSLO");
+	ret = wm831x_request_irq(wm831x, irq, wm831x_syslo_irq,
+				 IRQF_TRIGGER_RISING, "SYSLO",
+				 power);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "Failed to request SYSLO IRQ %d: %d\n",
+			irq, ret);
+		goto err_backup;
+	}
+
+	irq = platform_get_irq_byname(pdev, "PWR SRC");
+	ret = wm831x_request_irq(wm831x, irq, wm831x_pwr_src_irq,
+				 IRQF_TRIGGER_RISING, "Power source",
+				 power);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "Failed to request PWR SRC IRQ %d: %d\n",
+			irq, ret);
+		goto err_syslo;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(wm831x_bat_irqs); i++) {
+		irq = platform_get_irq_byname(pdev, wm831x_bat_irqs[i]);
+		ret = wm831x_request_irq(wm831x, irq, wm831x_bat_irq,
+					 IRQF_TRIGGER_RISING,
+					 wm831x_bat_irqs[i],
+					 power);
+		if (ret != 0) {
+			dev_err(&pdev->dev,
+				"Failed to request %s IRQ %d: %d\n",
+				wm831x_bat_irqs[i], irq, ret);
+			goto err_bat_irq;
+		}
+	}
+
+	return ret;
+
+err_bat_irq:
+	for (; i >= 0; i--) {
+		irq = platform_get_irq_byname(pdev, wm831x_bat_irqs[i]);
+		wm831x_free_irq(wm831x, irq, power);
+	}
+	irq = platform_get_irq_byname(pdev, "PWR SRC");
+	wm831x_free_irq(wm831x, irq, power);
+err_syslo:
+	irq = platform_get_irq_byname(pdev, "SYSLO");
+	wm831x_free_irq(wm831x, irq, power);
+err_backup:
+	power_supply_unregister(backup);
+err_usb:
+	power_supply_unregister(usb);
+err_battery:
+	power_supply_unregister(battery);
+err_wall:
+	power_supply_unregister(wall);
+err_kmalloc:
+	kfree(power);
+	return ret;
+}
+
+static __devexit int wm831x_power_remove(struct platform_device *pdev)
+{
+	struct wm831x_power *wm831x_power = platform_get_drvdata(pdev);
+	struct wm831x *wm831x = wm831x_power->wm831x;
+	int irq, i;
+
+	for (i = 0; i < ARRAY_SIZE(wm831x_bat_irqs); i++) {
+		irq = platform_get_irq_byname(pdev, wm831x_bat_irqs[i]);
+		wm831x_free_irq(wm831x, irq, wm831x_power);
+	}
+
+	irq = platform_get_irq_byname(pdev, "PWR SRC");
+	wm831x_free_irq(wm831x, irq, wm831x_power);
+
+	irq = platform_get_irq_byname(pdev, "SYSLO");
+	wm831x_free_irq(wm831x, irq, wm831x_power);
+
+	power_supply_unregister(&wm831x_power->backup);
+	power_supply_unregister(&wm831x_power->battery);
+	power_supply_unregister(&wm831x_power->wall);
+	power_supply_unregister(&wm831x_power->usb);
+	return 0;
+}
+
+static struct platform_driver wm831x_power_driver = {
+	.probe = wm831x_power_probe,
+	.remove = __devexit_p(wm831x_power_remove),
+	.driver = {
+		.name = "wm831x-power",
+	},
+};
+
+static int __init wm831x_power_init(void)
+{
+	return platform_driver_register(&wm831x_power_driver);
+}
+module_init(wm831x_power_init);
+
+static void __exit wm831x_power_exit(void)
+{
+	platform_driver_unregister(&wm831x_power_driver);
+}
+module_exit(wm831x_power_exit);
+
+MODULE_DESCRIPTION("Power supply driver for WM831x PMICs");
+MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:wm831x-power");