/*
   * 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/slab.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 usb;
  	struct power_supply battery;

  	char wall_name[20];
  	char usb_name[20];
  	char battery_name[20];

  	bool have_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
  ",
  			name, val, units);
  	} else {
  		*reg |= map[i].reg_val;
  		dev_dbg(wm831x->dev, "Set %s of %d%s
  ", 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
  ");
  		return;
  	}
  
  	pdata = wm831x_pdata->battery;
  
  	reg1 = 0;
  	reg2 = 0;
  
  	if (!pdata->enable) {
  		dev_info(wm831x->dev, "Battery charger disabled
  ");
  		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
  ", ret);
  		return;
  	}
  
  	ret = wm831x_set_bits(wm831x, WM831X_CHARGER_CONTROL_1,
  			      WM831X_CHG_ENA_MASK |
  			      WM831X_CHG_FAST_MASK |

  			      WM831X_CHG_ITERM_MASK,
  			      reg1);
  	if (ret != 0)
  		dev_err(wm831x->dev, "Failed to set charger control 1: %d
  ",
  			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
  ",
  			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
  ", irq);
  
  	/* The battery charger is autonomous so we don't need to do
  	 * anything except kick user space */

  	if (wm831x_power->have_battery)
  		power_supply_changed(&wm831x_power->battery);

  
  	return IRQ_HANDLED;
  }
  
  
  /*********************************************************************

   *		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
  ");
  
  	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
  ");

  	/* Just notify for everything - little harm in overnotifying. */

  	if (wm831x_power->have_battery)
  		power_supply_changed(&wm831x_power->battery);

  	power_supply_changed(&wm831x_power->usb);
  	power_supply_changed(&wm831x_power->wall);
  
  	return IRQ_HANDLED;
  }

  static int wm831x_power_probe(struct platform_device *pdev)

  {
  	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);

  	struct wm831x_pdata *wm831x_pdata = wm831x->dev->platform_data;

  	struct wm831x_power *power;
  	struct power_supply *usb;
  	struct power_supply *battery;
  	struct power_supply *wall;

  	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;

  	if (wm831x_pdata && wm831x_pdata->wm831x_num) {
  		snprintf(power->wall_name, sizeof(power->wall_name),
  			 "wm831x-wall.%d", wm831x_pdata->wm831x_num);
  		snprintf(power->battery_name, sizeof(power->wall_name),
  			 "wm831x-battery.%d", wm831x_pdata->wm831x_num);
  		snprintf(power->usb_name, sizeof(power->wall_name),
  			 "wm831x-usb.%d", wm831x_pdata->wm831x_num);
  	} else {
  		snprintf(power->wall_name, sizeof(power->wall_name),
  			 "wm831x-wall");
  		snprintf(power->battery_name, sizeof(power->wall_name),
  			 "wm831x-battery");
  		snprintf(power->usb_name, sizeof(power->wall_name),
  			 "wm831x-usb");
  	}

  	/* We ignore configuration failures since we can still read back

  	 * the status without enabling the charger.

  	 */
  	wm831x_config_battery(wm831x);

  	wall->name = power->wall_name;

  	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;

  	usb->name = power->usb_name,

  	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_wall;
  
  	ret = wm831x_reg_read(wm831x, WM831X_CHARGER_CONTROL_1);
  	if (ret < 0)
  		goto err_wall;
  	power->have_battery = ret & WM831X_CHG_ENA;
  
  	if (power->have_battery) {
  		    battery->name = power->battery_name;
  		    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_usb;
  	}

  	irq = wm831x_irq(wm831x, platform_get_irq_byname(pdev, "SYSLO"));

  	ret = request_threaded_irq(irq, NULL, wm831x_syslo_irq,
  				   IRQF_TRIGGER_RISING, "System power low",
  				   power);

  	if (ret != 0) {
  		dev_err(&pdev->dev, "Failed to request SYSLO IRQ %d: %d
  ",
  			irq, ret);

  		goto err_battery;

  	}

  	irq = wm831x_irq(wm831x, platform_get_irq_byname(pdev, "PWR SRC"));

  	ret = request_threaded_irq(irq, NULL, 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
  ",
  			irq, ret);
  		goto err_syslo;
  	}
  
  	for (i = 0; i < ARRAY_SIZE(wm831x_bat_irqs); i++) {

  		irq = wm831x_irq(wm831x,
  				 platform_get_irq_byname(pdev,
  							 wm831x_bat_irqs[i]));

  		ret = request_threaded_irq(irq, NULL, 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
  ",
  				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]);

  		free_irq(irq, power);

  	}

  	irq = wm831x_irq(wm831x, platform_get_irq_byname(pdev, "PWR SRC"));

  	free_irq(irq, power);

  err_syslo:

  	irq = wm831x_irq(wm831x, platform_get_irq_byname(pdev, "SYSLO"));

  	free_irq(irq, power);

  err_battery:
  	if (power->have_battery)
  		power_supply_unregister(battery);

  err_usb:
  	power_supply_unregister(usb);

  err_wall:
  	power_supply_unregister(wall);
  err_kmalloc:
  	kfree(power);
  	return ret;
  }

  static 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 = wm831x_irq(wm831x, 
  				 platform_get_irq_byname(pdev,
  							 wm831x_bat_irqs[i]));

  		free_irq(irq, wm831x_power);

  	}

  	irq = wm831x_irq(wm831x, platform_get_irq_byname(pdev, "PWR SRC"));

  	free_irq(irq, wm831x_power);

  	irq = wm831x_irq(wm831x, platform_get_irq_byname(pdev, "SYSLO"));

  	free_irq(irq, wm831x_power);

  	if (wm831x_power->have_battery)
  		power_supply_unregister(&wm831x_power->battery);

  	power_supply_unregister(&wm831x_power->wall);
  	power_supply_unregister(&wm831x_power->usb);

  	kfree(wm831x_power);

  	return 0;
  }
  
  static struct platform_driver wm831x_power_driver = {
  	.probe = wm831x_power_probe,

  	.remove = wm831x_power_remove,

  	.driver = {
  		.name = "wm831x-power",
  	},
  };

  module_platform_driver(wm831x_power_driver);

  
  MODULE_DESCRIPTION("Power supply driver for WM831x PMICs");
  MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:wm831x-power");