/*
   * Driver for LP8727 Micro/Mini USB IC with intergrated charger
   *
   *			Copyright (C) 2011 National Semiconductor
   *
   * 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/slab.h>
  #include <linux/interrupt.h>
  #include <linux/i2c.h>
  #include <linux/power_supply.h>
  #include <linux/lp8727.h>
  
  #define DEBOUNCE_MSEC	270
  
  /* Registers */
  #define CTRL1		0x1
  #define CTRL2		0x2
  #define	SWCTRL		0x3
  #define INT1		0x4
  #define INT2		0x5
  #define STATUS1		0x6
  #define STATUS2 	0x7
  #define CHGCTRL2	0x9
  
  /* CTRL1 register */
  #define CP_EN		(1 << 0)
  #define ADC_EN		(1 << 1)
  #define ID200_EN	(1 << 4)
  
  /* CTRL2 register */
  #define CHGDET_EN	(1 << 1)
  #define INT_EN		(1 << 6)
  
  /* SWCTRL register */
  #define SW_DM1_DM	(0x0 << 0)
  #define SW_DM1_U1	(0x1 << 0)
  #define SW_DM1_HiZ	(0x7 << 0)
  #define SW_DP2_DP	(0x0 << 3)
  #define SW_DP2_U2	(0x1 << 3)
  #define SW_DP2_HiZ	(0x7 << 3)
  
  /* INT1 register */
  #define IDNO		(0xF << 0)
  #define VBUS		(1 << 4)
  
  /* STATUS1 register */
  #define CHGSTAT		(3 << 4)
  #define CHPORT		(1 << 6)
  #define DCPORT		(1 << 7)
  
  /* STATUS2 register */
  #define TEMP_STAT	(3 << 5)
  
  enum lp8727_dev_id {
  	ID_NONE,
  	ID_TA,
  	ID_DEDICATED_CHG,
  	ID_USB_CHG,
  	ID_USB_DS,
  	ID_MAX,
  };
  
  enum lp8727_chg_stat {
  	PRECHG,
  	CC,
  	CV,
  	EOC,
  };
  
  struct lp8727_psy {
  	struct power_supply ac;
  	struct power_supply usb;
  	struct power_supply batt;
  };
  
  struct lp8727_chg {
  	struct device *dev;
  	struct i2c_client *client;
  	struct mutex xfer_lock;
  	struct delayed_work work;
  	struct workqueue_struct *irqthread;
  	struct lp8727_platform_data *pdata;
  	struct lp8727_psy *psy;
  	struct lp8727_chg_param *chg_parm;
  	enum lp8727_dev_id devid;
  };

  static int lp8727_i2c_read(struct lp8727_chg *pchg, u8 reg, u8 *data, u8 len)

  {
  	s32 ret;
  
  	mutex_lock(&pchg->xfer_lock);
  	ret = i2c_smbus_read_i2c_block_data(pchg->client, reg, len, data);
  	mutex_unlock(&pchg->xfer_lock);
  
  	return (ret != len) ? -EIO : 0;
  }

  static int lp8727_i2c_write(struct lp8727_chg *pchg, u8 reg, u8 *data, u8 len)

  {
  	s32 ret;
  
  	mutex_lock(&pchg->xfer_lock);
  	ret = i2c_smbus_write_i2c_block_data(pchg->client, reg, len, data);
  	mutex_unlock(&pchg->xfer_lock);
  
  	return ret;
  }
  
  static inline int lp8727_i2c_read_byte(struct lp8727_chg *pchg, u8 reg,

  				       u8 *data)

  {
  	return lp8727_i2c_read(pchg, reg, data, 1);
  }
  
  static inline int lp8727_i2c_write_byte(struct lp8727_chg *pchg, u8 reg,

  					u8 *data)

  {
  	return lp8727_i2c_write(pchg, reg, data, 1);
  }
  
  static int lp8727_is_charger_attached(const char *name, int id)
  {
  	if (name) {
  		if (!strcmp(name, "ac"))
  			return (id == ID_TA || id == ID_DEDICATED_CHG) ? 1 : 0;
  		else if (!strcmp(name, "usb"))
  			return (id == ID_USB_CHG) ? 1 : 0;
  	}
  
  	return (id >= ID_TA && id <= ID_USB_CHG) ? 1 : 0;
  }
  
  static void lp8727_init_device(struct lp8727_chg *pchg)
  {
  	u8 val;
  
  	val = ID200_EN | ADC_EN | CP_EN;
  	if (lp8727_i2c_write_byte(pchg, CTRL1, &val))
  		dev_err(pchg->dev, "i2c write err : addr=0x%.2x
  ", CTRL1);
  
  	val = INT_EN | CHGDET_EN;
  	if (lp8727_i2c_write_byte(pchg, CTRL2, &val))
  		dev_err(pchg->dev, "i2c write err : addr=0x%.2x
  ", CTRL2);
  }
  
  static int lp8727_is_dedicated_charger(struct lp8727_chg *pchg)
  {
  	u8 val;

  	lp8727_i2c_read_byte(pchg, STATUS1, &val);

  	return (val & DCPORT);
  }
  
  static int lp8727_is_usb_charger(struct lp8727_chg *pchg)
  {
  	u8 val;

  	lp8727_i2c_read_byte(pchg, STATUS1, &val);

  	return (val & CHPORT);
  }
  
  static void lp8727_ctrl_switch(struct lp8727_chg *pchg, u8 sw)
  {
  	u8 val = sw;

  	lp8727_i2c_write_byte(pchg, SWCTRL, &val);

  }
  
  static void lp8727_id_detection(struct lp8727_chg *pchg, u8 id, int vbusin)
  {
  	u8 devid = ID_NONE;
  	u8 swctrl = SW_DM1_HiZ | SW_DP2_HiZ;
  
  	switch (id) {
  	case 0x5:
  		devid = ID_TA;
  		pchg->chg_parm = &pchg->pdata->ac;
  		break;
  	case 0xB:
  		if (lp8727_is_dedicated_charger(pchg)) {
  			pchg->chg_parm = &pchg->pdata->ac;
  			devid = ID_DEDICATED_CHG;
  		} else if (lp8727_is_usb_charger(pchg)) {
  			pchg->chg_parm = &pchg->pdata->usb;
  			devid = ID_USB_CHG;
  			swctrl = SW_DM1_DM | SW_DP2_DP;
  		} else if (vbusin) {
  			devid = ID_USB_DS;
  			swctrl = SW_DM1_DM | SW_DP2_DP;
  		}
  		break;
  	default:
  		devid = ID_NONE;
  		pchg->chg_parm = NULL;
  		break;
  	}
  
  	pchg->devid = devid;
  	lp8727_ctrl_switch(pchg, swctrl);
  }
  
  static void lp8727_enable_chgdet(struct lp8727_chg *pchg)
  {
  	u8 val;

  	lp8727_i2c_read_byte(pchg, CTRL2, &val);

  	val |= CHGDET_EN;

  	lp8727_i2c_write_byte(pchg, CTRL2, &val);

  }
  
  static void lp8727_delayed_func(struct work_struct *_work)
  {
  	u8 intstat[2], idno, vbus;
  	struct lp8727_chg *pchg =
  	    container_of(_work, struct lp8727_chg, work.work);
  
  	if (lp8727_i2c_read(pchg, INT1, intstat, 2)) {
  		dev_err(pchg->dev, "can not read INT registers
  ");
  		return;
  	}
  
  	idno = intstat[0] & IDNO;
  	vbus = intstat[0] & VBUS;
  
  	lp8727_id_detection(pchg, idno, vbus);
  	lp8727_enable_chgdet(pchg);
  
  	power_supply_changed(&pchg->psy->ac);
  	power_supply_changed(&pchg->psy->usb);
  	power_supply_changed(&pchg->psy->batt);
  }
  
  static irqreturn_t lp8727_isr_func(int irq, void *ptr)
  {
  	struct lp8727_chg *pchg = ptr;
  	unsigned long delay = msecs_to_jiffies(DEBOUNCE_MSEC);
  
  	queue_delayed_work(pchg->irqthread, &pchg->work, delay);
  
  	return IRQ_HANDLED;
  }
  
  static void lp8727_intr_config(struct lp8727_chg *pchg)
  {
  	INIT_DELAYED_WORK(&pchg->work, lp8727_delayed_func);
  
  	pchg->irqthread = create_singlethread_workqueue("lp8727-irqthd");
  	if (!pchg->irqthread)
  		dev_err(pchg->dev, "can not create thread for lp8727
  ");
  
  	if (request_threaded_irq(pchg->client->irq,
  				 NULL,
  				 lp8727_isr_func,
  				 IRQF_TRIGGER_FALLING, "lp8727_irq", pchg)) {
  		dev_err(pchg->dev, "lp8727 irq can not be registered
  ");
  	}
  }
  
  static enum power_supply_property lp8727_charger_prop[] = {
  	POWER_SUPPLY_PROP_ONLINE,
  };
  
  static enum power_supply_property lp8727_battery_prop[] = {
  	POWER_SUPPLY_PROP_STATUS,
  	POWER_SUPPLY_PROP_HEALTH,
  	POWER_SUPPLY_PROP_PRESENT,
  	POWER_SUPPLY_PROP_VOLTAGE_NOW,
  	POWER_SUPPLY_PROP_CAPACITY,
  	POWER_SUPPLY_PROP_TEMP,
  };
  
  static char *battery_supplied_to[] = {
  	"main_batt",
  };
  
  static int lp8727_charger_get_property(struct power_supply *psy,
  				       enum power_supply_property psp,
  				       union power_supply_propval *val)
  {
  	struct lp8727_chg *pchg = dev_get_drvdata(psy->dev->parent);

  	if (psp == POWER_SUPPLY_PROP_ONLINE)

  		val->intval = lp8727_is_charger_attached(psy->name,
  							 pchg->devid);

  
  	return 0;
  }
  
  static int lp8727_battery_get_property(struct power_supply *psy,
  				       enum power_supply_property psp,
  				       union power_supply_propval *val)
  {
  	struct lp8727_chg *pchg = dev_get_drvdata(psy->dev->parent);
  	u8 read;
  
  	switch (psp) {
  	case POWER_SUPPLY_PROP_STATUS:
  		if (lp8727_is_charger_attached(psy->name, pchg->devid)) {

  			lp8727_i2c_read_byte(pchg, STATUS1, &read);

  			if (((read & CHGSTAT) >> 4) == EOC)
  				val->intval = POWER_SUPPLY_STATUS_FULL;
  			else
  				val->intval = POWER_SUPPLY_STATUS_CHARGING;
  		} else {
  			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
  		}
  		break;
  	case POWER_SUPPLY_PROP_HEALTH:

  		lp8727_i2c_read_byte(pchg, STATUS2, &read);

  		read = (read & TEMP_STAT) >> 5;
  		if (read >= 0x1 && read <= 0x3)
  			val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
  		else
  			val->intval = POWER_SUPPLY_HEALTH_GOOD;
  		break;
  	case POWER_SUPPLY_PROP_PRESENT:
  		if (pchg->pdata->get_batt_present)
  			val->intval = pchg->pdata->get_batt_present();
  		break;
  	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
  		if (pchg->pdata->get_batt_level)
  			val->intval = pchg->pdata->get_batt_level();
  		break;
  	case POWER_SUPPLY_PROP_CAPACITY:
  		if (pchg->pdata->get_batt_capacity)
  			val->intval = pchg->pdata->get_batt_capacity();
  		break;
  	case POWER_SUPPLY_PROP_TEMP:
  		if (pchg->pdata->get_batt_temp)
  			val->intval = pchg->pdata->get_batt_temp();
  		break;
  	default:
  		break;
  	}
  
  	return 0;
  }
  
  static void lp8727_charger_changed(struct power_supply *psy)
  {
  	struct lp8727_chg *pchg = dev_get_drvdata(psy->dev->parent);
  	u8 val;
  	u8 eoc_level, ichg;
  
  	if (lp8727_is_charger_attached(psy->name, pchg->devid)) {
  		if (pchg->chg_parm) {
  			eoc_level = pchg->chg_parm->eoc_level;
  			ichg = pchg->chg_parm->ichg;
  			val = (ichg << 4) | eoc_level;

  			lp8727_i2c_write_byte(pchg, CHGCTRL2, &val);

  		}
  	}
  }
  
  static int lp8727_register_psy(struct lp8727_chg *pchg)
  {
  	struct lp8727_psy *psy;
  
  	psy = kzalloc(sizeof(*psy), GFP_KERNEL);
  	if (!psy)
  		goto err_mem;
  
  	pchg->psy = psy;
  
  	psy->ac.name = "ac";
  	psy->ac.type = POWER_SUPPLY_TYPE_MAINS;
  	psy->ac.properties = lp8727_charger_prop;
  	psy->ac.num_properties = ARRAY_SIZE(lp8727_charger_prop);
  	psy->ac.get_property = lp8727_charger_get_property;
  	psy->ac.supplied_to = battery_supplied_to;
  	psy->ac.num_supplicants = ARRAY_SIZE(battery_supplied_to);
  
  	if (power_supply_register(pchg->dev, &psy->ac))
  		goto err_psy;
  
  	psy->usb.name = "usb";
  	psy->usb.type = POWER_SUPPLY_TYPE_USB;
  	psy->usb.properties = lp8727_charger_prop;
  	psy->usb.num_properties = ARRAY_SIZE(lp8727_charger_prop);
  	psy->usb.get_property = lp8727_charger_get_property;
  	psy->usb.supplied_to = battery_supplied_to;
  	psy->usb.num_supplicants = ARRAY_SIZE(battery_supplied_to);
  
  	if (power_supply_register(pchg->dev, &psy->usb))
  		goto err_psy;
  
  	psy->batt.name = "main_batt";
  	psy->batt.type = POWER_SUPPLY_TYPE_BATTERY;
  	psy->batt.properties = lp8727_battery_prop;
  	psy->batt.num_properties = ARRAY_SIZE(lp8727_battery_prop);
  	psy->batt.get_property = lp8727_battery_get_property;
  	psy->batt.external_power_changed = lp8727_charger_changed;
  
  	if (power_supply_register(pchg->dev, &psy->batt))
  		goto err_psy;
  
  	return 0;
  
  err_mem:
  	return -ENOMEM;
  err_psy:
  	kfree(psy);
  	return -EPERM;
  }
  
  static void lp8727_unregister_psy(struct lp8727_chg *pchg)
  {
  	struct lp8727_psy *psy = pchg->psy;

  	if (!psy)
  		return;
  
  	power_supply_unregister(&psy->ac);
  	power_supply_unregister(&psy->usb);
  	power_supply_unregister(&psy->batt);
  	kfree(psy);

  }
  
  static int lp8727_probe(struct i2c_client *cl, const struct i2c_device_id *id)
  {
  	struct lp8727_chg *pchg;
  	int ret;

  	if (!i2c_check_functionality(cl->adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
  		return -EIO;

  	pchg = kzalloc(sizeof(*pchg), GFP_KERNEL);
  	if (!pchg)
  		return -ENOMEM;
  
  	pchg->client = cl;
  	pchg->dev = &cl->dev;
  	pchg->pdata = cl->dev.platform_data;
  	i2c_set_clientdata(cl, pchg);
  
  	mutex_init(&pchg->xfer_lock);
  
  	lp8727_init_device(pchg);
  	lp8727_intr_config(pchg);
  
  	ret = lp8727_register_psy(pchg);

  	if (ret)

  		dev_err(pchg->dev,
  			"can not register power supplies. err=%d", ret);

  
  	return 0;
  }
  
  static int __devexit lp8727_remove(struct i2c_client *cl)
  {
  	struct lp8727_chg *pchg = i2c_get_clientdata(cl);
  
  	lp8727_unregister_psy(pchg);
  	free_irq(pchg->client->irq, pchg);
  	flush_workqueue(pchg->irqthread);
  	destroy_workqueue(pchg->irqthread);
  	kfree(pchg);
  	return 0;
  }
  
  static const struct i2c_device_id lp8727_ids[] = {
  	{"lp8727", 0},
  };
  
  static struct i2c_driver lp8727_driver = {
  	.driver = {
  		   .name = "lp8727",
  		   },
  	.probe = lp8727_probe,
  	.remove = __devexit_p(lp8727_remove),
  	.id_table = lp8727_ids,
  };
  
  static int __init lp8727_init(void)
  {
  	return i2c_add_driver(&lp8727_driver);
  }

  static void __exit lp8727_exit(void)

  {
  	i2c_del_driver(&lp8727_driver);
  }
  
  module_init(lp8727_init);

  module_exit(lp8727_exit);

  
  MODULE_DESCRIPTION("National Semiconductor LP8727 charger driver");

  MODULE_AUTHOR
      ("Woogyom Kim <milo.kim@ti.com>, Daniel Jeong <daniel.jeong@ti.com>");

  MODULE_LICENSE("GPL");