/*
   * Batttery Driver for Dialog DA9052 PMICs
   *
   * Copyright(c) 2011 Dialog Semiconductor Ltd.
   *
   * Author: David Dajun Chen <dchen@diasemi.com>
   *
   * 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/delay.h>
  #include <linux/freezer.h>
  #include <linux/fs.h>
  #include <linux/jiffies.h>
  #include <linux/module.h>
  #include <linux/timer.h>
  #include <linux/uaccess.h>
  #include <linux/platform_device.h>
  #include <linux/power_supply.h>
  
  #include <linux/mfd/da9052/da9052.h>
  #include <linux/mfd/da9052/pdata.h>
  #include <linux/mfd/da9052/reg.h>
  
  /* STATIC CONFIGURATION */
  #define DA9052_BAT_CUTOFF_VOLT		2800
  #define DA9052_BAT_TSH			62000
  #define DA9052_BAT_LOW_CAP		4
  #define DA9052_AVG_SZ			4
  #define DA9052_VC_TBL_SZ		68
  #define DA9052_VC_TBL_REF_SZ		3
  
  #define DA9052_ISET_USB_MASK		0x0F
  #define DA9052_CHG_USB_ILIM_MASK	0x40
  #define DA9052_CHG_LIM_COLS		16
  
  #define DA9052_MEAN(x, y)		((x + y) / 2)
  
  enum charger_type_enum {
  	DA9052_NOCHARGER = 1,
  	DA9052_CHARGER,
  };
  
  static const u16 da9052_chg_current_lim[2][DA9052_CHG_LIM_COLS] = {
  	{70,  80,  90,  100, 110, 120, 400,  450,
  	 500, 550, 600, 650, 700, 900, 1100, 1300},
  	{80,  90,  100, 110,  120,  400,  450,  500,
  	 550, 600, 800, 1000, 1200, 1400, 1600, 1800},
  };
  
  static const u16 vc_tbl_ref[3] = {10, 25, 40};
  /* Lookup table for voltage vs capacity */
  static u32 const vc_tbl[3][68][2] = {
  	/* For temperature 10 degree Celsius */
  	{
  	{4082, 100}, {4036, 98},
  	{4020, 96}, {4008, 95},
  	{3997, 93}, {3983, 91},
  	{3964, 90}, {3943, 88},
  	{3926, 87}, {3912, 85},
  	{3900, 84}, {3890, 82},
  	{3881, 80}, {3873, 79},
  	{3865, 77}, {3857, 76},
  	{3848, 74}, {3839, 73},
  	{3829, 71}, {3820, 70},
  	{3811, 68}, {3802, 67},
  	{3794, 65}, {3785, 64},
  	{3778, 62}, {3770, 61},
  	{3763, 59}, {3756, 58},
  	{3750, 56}, {3744, 55},
  	{3738, 53}, {3732, 52},
  	{3727, 50}, {3722, 49},
  	{3717, 47}, {3712, 46},
  	{3708, 44}, {3703, 43},
  	{3700, 41}, {3696, 40},
  	{3693, 38}, {3691, 37},
  	{3688, 35}, {3686, 34},
  	{3683, 32}, {3681, 31},
  	{3678, 29}, {3675, 28},
  	{3672, 26}, {3669, 25},
  	{3665, 23}, {3661, 22},
  	{3656, 21}, {3651, 19},
  	{3645, 18}, {3639, 16},
  	{3631, 15}, {3622, 13},
  	{3611, 12}, {3600, 10},
  	{3587, 9}, {3572, 7},
  	{3548, 6}, {3503, 5},
  	{3420, 3}, {3268, 2},
  	{2992, 1}, {2746, 0}
  	},
  	/* For temperature 25 degree Celsius */
  	{
  	{4102, 100}, {4065, 98},
  	{4048, 96}, {4034, 95},
  	{4021, 93}, {4011, 92},
  	{4001, 90}, {3986, 88},
  	{3968, 87}, {3952, 85},
  	{3938, 84}, {3926, 82},
  	{3916, 81}, {3908, 79},
  	{3900, 77}, {3892, 76},
  	{3883, 74}, {3874, 73},
  	{3864, 71}, {3855, 70},
  	{3846, 68}, {3836, 67},
  	{3827, 65}, {3819, 64},
  	{3810, 62}, {3801, 61},
  	{3793, 59}, {3786, 58},
  	{3778, 56}, {3772, 55},
  	{3765, 53}, {3759, 52},
  	{3754, 50}, {3748, 49},
  	{3743, 47}, {3738, 46},
  	{3733, 44}, {3728, 43},
  	{3724, 41}, {3720, 40},
  	{3716, 38}, {3712, 37},
  	{3709, 35}, {3706, 34},
  	{3703, 33}, {3701, 31},
  	{3698, 30}, {3696, 28},
  	{3693, 27}, {3690, 25},
  	{3687, 24}, {3683, 22},
  	{3680, 21}, {3675, 19},
  	{3671, 18}, {3666, 17},
  	{3660, 15}, {3654, 14},
  	{3647, 12}, {3639, 11},
  	{3630, 9}, {3621, 8},
  	{3613, 6}, {3606, 5},
  	{3597, 4}, {3582, 2},
  	{3546, 1}, {2747, 0}
  	},
  	/* For temperature 40 degree Celsius */
  	{
  	{4114, 100}, {4081, 98},
  	{4065, 96}, {4050, 95},
  	{4036, 93}, {4024, 92},
  	{4013, 90}, {4002, 88},
  	{3990, 87}, {3976, 85},
  	{3962, 84}, {3950, 82},
  	{3939, 81}, {3930, 79},
  	{3921, 77}, {3912, 76},
  	{3902, 74}, {3893, 73},
  	{3883, 71}, {3874, 70},
  	{3865, 68}, {3856, 67},
  	{3847, 65}, {3838, 64},
  	{3829, 62}, {3820, 61},
  	{3812, 59}, {3803, 58},
  	{3795, 56}, {3787, 55},
  	{3780, 53}, {3773, 52},
  	{3767, 50}, {3761, 49},
  	{3756, 47}, {3751, 46},
  	{3746, 44}, {3741, 43},
  	{3736, 41}, {3732, 40},
  	{3728, 38}, {3724, 37},
  	{3720, 35}, {3716, 34},
  	{3713, 33}, {3710, 31},
  	{3707, 30}, {3704, 28},
  	{3701, 27}, {3698, 25},
  	{3695, 24}, {3691, 22},
  	{3686, 21}, {3681, 19},
  	{3676, 18}, {3671, 17},
  	{3666, 15}, {3661, 14},
  	{3655, 12}, {3648, 11},
  	{3640, 9}, {3632, 8},
  	{3622, 6}, {3616, 5},
  	{3611, 4}, {3604, 2},
  	{3594, 1}, {2747, 0}
  	}
  };
  
  struct da9052_battery {
  	struct da9052 *da9052;
  	struct power_supply psy;
  	struct notifier_block nb;
  	int charger_type;
  	int status;
  	int health;
  };
  
  static inline int volt_reg_to_mV(int value)
  {
  	return ((value * 1000) / 512) + 2500;
  }
  
  static inline int ichg_reg_to_mA(int value)
  {
  	return (value * 3900) / 1000;
  }
  
  static int da9052_read_chgend_current(struct da9052_battery *bat,
  				       int *current_mA)
  {
  	int ret;
  
  	if (bat->status == POWER_SUPPLY_STATUS_DISCHARGING)
  		return -EINVAL;
  
  	ret = da9052_reg_read(bat->da9052, DA9052_ICHG_END_REG);
  	if (ret < 0)
  		return ret;
  
  	*current_mA = ichg_reg_to_mA(ret & DA9052_ICHGEND_ICHGEND);
  
  	return 0;
  }
  
  static int da9052_read_chg_current(struct da9052_battery *bat, int *current_mA)
  {
  	int ret;
  
  	if (bat->status == POWER_SUPPLY_STATUS_DISCHARGING)
  		return -EINVAL;
  
  	ret = da9052_reg_read(bat->da9052, DA9052_ICHG_AV_REG);
  	if (ret < 0)
  		return ret;
  
  	*current_mA = ichg_reg_to_mA(ret & DA9052_ICHGAV_ICHGAV);
  
  	return 0;
  }
  
  static int da9052_bat_check_status(struct da9052_battery *bat, int *status)
  {
  	u8 v[2] = {0, 0};
  	u8 bat_status;
  	u8 chg_end;
  	int ret;
  	int chg_current;
  	int chg_end_current;
  	bool dcinsel;
  	bool dcindet;
  	bool vbussel;
  	bool vbusdet;
  	bool dc;
  	bool vbus;
  
  	ret = da9052_group_read(bat->da9052, DA9052_STATUS_A_REG, 2, v);
  	if (ret < 0)
  		return ret;
  
  	bat_status = v[0];
  	chg_end = v[1];
  
  	dcinsel = bat_status & DA9052_STATUSA_DCINSEL;
  	dcindet = bat_status & DA9052_STATUSA_DCINDET;
  	vbussel = bat_status & DA9052_STATUSA_VBUSSEL;
  	vbusdet = bat_status & DA9052_STATUSA_VBUSDET;
  	dc = dcinsel && dcindet;
  	vbus = vbussel && vbusdet;
  
  	/* Preference to WALL(DCIN) charger unit */
  	if (dc || vbus) {
  		bat->charger_type = DA9052_CHARGER;
  
  		/* If charging end flag is set and Charging current is greater
  		 * than charging end limit then battery is charging
  		*/
  		if ((chg_end & DA9052_STATUSB_CHGEND) != 0) {
  			ret = da9052_read_chg_current(bat, &chg_current);
  			if (ret < 0)
  				return ret;
  			ret = da9052_read_chgend_current(bat, &chg_end_current);
  			if (ret < 0)
  				return ret;
  
  			if (chg_current >= chg_end_current)
  				bat->status = POWER_SUPPLY_STATUS_CHARGING;
  			else
  				bat->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
  		} else {
  			/* If Charging end flag is cleared then battery is
  			 * charging
  			*/
  			bat->status = POWER_SUPPLY_STATUS_CHARGING;
  		}
  	} else if (dcindet || vbusdet) {
  			bat->charger_type = DA9052_CHARGER;
  			bat->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
  	} else {
  		bat->charger_type = DA9052_NOCHARGER;
  		bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
  	}
  
  	if (status != NULL)
  		*status = bat->status;
  	return 0;
  }
  
  static int da9052_bat_read_volt(struct da9052_battery *bat, int *volt_mV)
  {
  	int volt;
  
  	volt = da9052_adc_manual_read(bat->da9052, DA9052_ADC_MAN_MUXSEL_VBAT);
  	if (volt < 0)
  		return volt;
  
  	*volt_mV = volt_reg_to_mV(volt);
  
  	return 0;
  }
  
  static int da9052_bat_check_presence(struct da9052_battery *bat, int *illegal)
  {
  	int bat_temp;
  
  	bat_temp = da9052_adc_read_temp(bat->da9052);
  	if (bat_temp < 0)
  		return bat_temp;
  
  	if (bat_temp > DA9052_BAT_TSH)
  		*illegal = 1;
  	else
  		*illegal = 0;
  
  	return 0;
  }
  
  static int da9052_bat_interpolate(int vbat_lower, int  vbat_upper,
  				   int level_lower, int level_upper,
  				   int bat_voltage)
  {
  	int tmp;
  
  	tmp = ((level_upper - level_lower) * 1000) / (vbat_upper - vbat_lower);
  	tmp = level_lower + (((bat_voltage - vbat_lower) * tmp) / 1000);
  
  	return tmp;
  }
  
  static unsigned char da9052_determine_vc_tbl_index(unsigned char adc_temp)
  {
  	int i;
  
  	if (adc_temp <= vc_tbl_ref[0])
  		return 0;
  
  	if (adc_temp > vc_tbl_ref[DA9052_VC_TBL_REF_SZ - 1])
  		return DA9052_VC_TBL_REF_SZ - 1;
  
  	for (i = 0; i < DA9052_VC_TBL_REF_SZ - 1; i++) {
  		if ((adc_temp > vc_tbl_ref[i]) &&
  		    (adc_temp <= DA9052_MEAN(vc_tbl_ref[i], vc_tbl_ref[i + 1])))
  				return i;
  		if ((adc_temp > DA9052_MEAN(vc_tbl_ref[i], vc_tbl_ref[i + 1]))
  		     && (adc_temp <= vc_tbl_ref[i]))
  				return i + 1;
  	}
  	/*
  	 * For some reason authors of the driver didn't presume that we can
  	 * end up here. It might be OK, but might be not, no one knows for
  	 * sure. Go check your battery, is it on fire?
  	 */
  	WARN_ON(1);
  	return 0;
  }
  
  static int da9052_bat_read_capacity(struct da9052_battery *bat, int *capacity)
  {
  	int adc_temp;
  	int bat_voltage;
  	int vbat_lower;
  	int vbat_upper;
  	int level_upper;
  	int level_lower;
  	int ret;
  	int flag;
  	int i = 0;
  	int j;
  
  	ret = da9052_bat_read_volt(bat, &bat_voltage);
  	if (ret < 0)
  		return ret;
  
  	adc_temp = da9052_adc_read_temp(bat->da9052);
  	if (adc_temp < 0)
  		return adc_temp;
  
  	i = da9052_determine_vc_tbl_index(adc_temp);
  
  	if (bat_voltage >= vc_tbl[i][0][0]) {
  		*capacity = 100;
  		return 0;
  	}
  	if (bat_voltage <= vc_tbl[i][DA9052_VC_TBL_SZ - 1][0]) {
  		*capacity = 0;
  		return 0;
  	}
  	flag = 0;
  
  	for (j = 0; j < (DA9052_VC_TBL_SZ-1); j++) {
  		if ((bat_voltage <= vc_tbl[i][j][0]) &&
  		    (bat_voltage >= vc_tbl[i][j + 1][0])) {
  			vbat_upper = vc_tbl[i][j][0];
  			vbat_lower = vc_tbl[i][j + 1][0];
  			level_upper = vc_tbl[i][j][1];
  			level_lower = vc_tbl[i][j + 1][1];
  			flag = 1;
  			break;
  		}
  	}
  	if (!flag)
  		return -EIO;
  
  	*capacity = da9052_bat_interpolate(vbat_lower, vbat_upper, level_lower,
  					   level_upper, bat_voltage);
  
  	return 0;
  }
  
  static int da9052_bat_check_health(struct da9052_battery *bat, int *health)
  {
  	int ret;
  	int bat_illegal;
  	int capacity;
  
  	ret = da9052_bat_check_presence(bat, &bat_illegal);
  	if (ret < 0)
  		return ret;
  
  	if (bat_illegal) {
  		bat->health = POWER_SUPPLY_HEALTH_UNKNOWN;
  		return 0;
  	}
  
  	if (bat->health != POWER_SUPPLY_HEALTH_OVERHEAT) {
  		ret = da9052_bat_read_capacity(bat, &capacity);
  		if (ret < 0)
  			return ret;
  		if (capacity < DA9052_BAT_LOW_CAP)
  			bat->health = POWER_SUPPLY_HEALTH_DEAD;
  		else
  			bat->health = POWER_SUPPLY_HEALTH_GOOD;
  	}
  
  	*health = bat->health;
  
  	return 0;
  }
  
  static irqreturn_t da9052_bat_irq(int irq, void *data)
  {
  	struct da9052_battery *bat = data;
  	int virq;
  
  	virq = regmap_irq_get_virq(bat->da9052->irq_data, irq);
  	irq -= virq;
  
  	if (irq == DA9052_IRQ_CHGEND)
  		bat->status = POWER_SUPPLY_STATUS_FULL;
  	else
  		da9052_bat_check_status(bat, NULL);
  
  	if (irq == DA9052_IRQ_CHGEND || irq == DA9052_IRQ_DCIN ||
  	    irq == DA9052_IRQ_VBUS || irq == DA9052_IRQ_TBAT) {
  		power_supply_changed(&bat->psy);
  	}
  
  	return IRQ_HANDLED;
  }
  
  static int da9052_USB_current_notifier(struct notifier_block *nb,
  					unsigned long events, void *data)
  {
  	u8 row;
  	u8 col;
  	int *current_mA = data;
  	int ret;
  	struct da9052_battery *bat = container_of(nb, struct da9052_battery,
  						  nb);
  
  	if (bat->status == POWER_SUPPLY_STATUS_DISCHARGING)
  		return -EPERM;
  
  	ret = da9052_reg_read(bat->da9052, DA9052_CHGBUCK_REG);
  	if (ret & DA9052_CHG_USB_ILIM_MASK)
  		return -EPERM;
  
  	if (bat->da9052->chip_id == DA9052)
  		row = 0;
  	else
  		row = 1;
  
  	if (*current_mA < da9052_chg_current_lim[row][0] ||
  	    *current_mA > da9052_chg_current_lim[row][DA9052_CHG_LIM_COLS - 1])
  		return -EINVAL;
  
  	for (col = 0; col <= DA9052_CHG_LIM_COLS - 1 ; col++) {
  		if (*current_mA <= da9052_chg_current_lim[row][col])
  			break;
  	}
  
  	return da9052_reg_update(bat->da9052, DA9052_ISET_REG,
  				 DA9052_ISET_USB_MASK, col);
  }
  
  static int da9052_bat_get_property(struct power_supply *psy,
  				    enum power_supply_property psp,
  				    union power_supply_propval *val)
  {
  	int ret;
  	int illegal;
  	struct da9052_battery *bat = container_of(psy, struct da9052_battery,
  						  psy);
  
  	ret = da9052_bat_check_presence(bat, &illegal);
  	if (ret < 0)
  		return ret;
  
  	if (illegal && psp != POWER_SUPPLY_PROP_PRESENT)
  		return -ENODEV;
  
  	switch (psp) {
  	case POWER_SUPPLY_PROP_STATUS:
  		ret = da9052_bat_check_status(bat, &val->intval);
  		break;
  	case POWER_SUPPLY_PROP_ONLINE:
  		val->intval =
  			(bat->charger_type == DA9052_NOCHARGER) ? 0 : 1;
  		break;
  	case POWER_SUPPLY_PROP_PRESENT:
  		ret = da9052_bat_check_presence(bat, &val->intval);
  		break;
  	case POWER_SUPPLY_PROP_HEALTH:
  		ret = da9052_bat_check_health(bat, &val->intval);
  		break;
  	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
  		val->intval = DA9052_BAT_CUTOFF_VOLT * 1000;
  		break;
  	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
  		ret = da9052_bat_read_volt(bat, &val->intval);
  		break;
  	case POWER_SUPPLY_PROP_CURRENT_AVG:
  		ret = da9052_read_chg_current(bat, &val->intval);
  		break;
  	case POWER_SUPPLY_PROP_CAPACITY:
  		ret = da9052_bat_read_capacity(bat, &val->intval);
  		break;
  	case POWER_SUPPLY_PROP_TEMP:
  		val->intval = da9052_adc_read_temp(bat->da9052);
  		ret = val->intval;
  		break;
  	case POWER_SUPPLY_PROP_TECHNOLOGY:
  		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
  		break;
  	default:
  		return -EINVAL;
  	}
  	return ret;
  }
  
  static enum power_supply_property da9052_bat_props[] = {
  	POWER_SUPPLY_PROP_STATUS,
  	POWER_SUPPLY_PROP_ONLINE,
  	POWER_SUPPLY_PROP_PRESENT,
  	POWER_SUPPLY_PROP_HEALTH,
  	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
  	POWER_SUPPLY_PROP_VOLTAGE_AVG,
  	POWER_SUPPLY_PROP_CURRENT_AVG,
  	POWER_SUPPLY_PROP_CAPACITY,
  	POWER_SUPPLY_PROP_TEMP,
  	POWER_SUPPLY_PROP_TECHNOLOGY,
  };
  
  static struct power_supply template_battery = {
  	.name		= "da9052-bat",
  	.type		= POWER_SUPPLY_TYPE_BATTERY,
  	.properties	= da9052_bat_props,
  	.num_properties	= ARRAY_SIZE(da9052_bat_props),
  	.get_property	= da9052_bat_get_property,
  };
  
  static char *da9052_bat_irqs[] = {
  	"BATT TEMP",
  	"DCIN DET",
  	"DCIN REM",
  	"VBUS DET",
  	"VBUS REM",
  	"CHG END",
  };
  
  static int da9052_bat_irq_bits[] = {
  	DA9052_IRQ_TBAT,
  	DA9052_IRQ_DCIN,
  	DA9052_IRQ_DCINREM,
  	DA9052_IRQ_VBUS,
  	DA9052_IRQ_VBUSREM,
  	DA9052_IRQ_CHGEND,
  };
  
  static s32 da9052_bat_probe(struct platform_device *pdev)
  {
  	struct da9052_pdata *pdata;
  	struct da9052_battery *bat;
  	int ret;
  	int i;
  
  	bat = devm_kzalloc(&pdev->dev, sizeof(struct da9052_battery),
  				GFP_KERNEL);
  	if (!bat)
  		return -ENOMEM;
  
  	bat->da9052 = dev_get_drvdata(pdev->dev.parent);
  	bat->psy = template_battery;
  	bat->charger_type = DA9052_NOCHARGER;
  	bat->status = POWER_SUPPLY_STATUS_UNKNOWN;
  	bat->health = POWER_SUPPLY_HEALTH_UNKNOWN;
  	bat->nb.notifier_call = da9052_USB_current_notifier;
  
  	pdata = bat->da9052->dev->platform_data;
  	if (pdata != NULL && pdata->use_for_apm)
  		bat->psy.use_for_apm = pdata->use_for_apm;
  	else
  		bat->psy.use_for_apm = 1;
  
  	for (i = 0; i < ARRAY_SIZE(da9052_bat_irqs); i++) {
  		ret = da9052_request_irq(bat->da9052,
  				da9052_bat_irq_bits[i], da9052_bat_irqs[i],
  				da9052_bat_irq, bat);
  
  		if (ret != 0) {
  			dev_err(bat->da9052->dev,
  				"DA9052 failed to request %s IRQ: %d
  ",
  				da9052_bat_irqs[i], ret);
  			goto err;
  		}
  	}
  
  	ret = power_supply_register(&pdev->dev, &bat->psy);
  	 if (ret)
  		goto err;
  
  	platform_set_drvdata(pdev, bat);
  	return 0;
  
  err:
  	while (--i >= 0)
  		da9052_free_irq(bat->da9052, da9052_bat_irq_bits[i], bat);
  
  	return ret;
  }
  static int da9052_bat_remove(struct platform_device *pdev)
  {
  	int i;
  	struct da9052_battery *bat = platform_get_drvdata(pdev);
  
  	for (i = 0; i < ARRAY_SIZE(da9052_bat_irqs); i++)
  		da9052_free_irq(bat->da9052, da9052_bat_irq_bits[i], bat);
  
  	power_supply_unregister(&bat->psy);
  
  	return 0;
  }
  
  static struct platform_driver da9052_bat_driver = {
  	.probe = da9052_bat_probe,
  	.remove = da9052_bat_remove,
  	.driver = {
  		.name = "da9052-bat",
  		.owner = THIS_MODULE,
  	},
  };
  module_platform_driver(da9052_bat_driver);
  
  MODULE_DESCRIPTION("DA9052 BAT Device Driver");
  MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:da9052-bat");