/*

   *	iPAQ h1930/h1940/rx1950 battery controller driver

   *	Copyright (c) Vasily Khoruzhick
   *	Based on h1940_battery.c by Arnaud Patard
   *
   * This file is subject to the terms and conditions of the GNU General Public
   * License.  See the file COPYING in the main directory of this archive for
   * more details.
   *
   */
  
  #include <linux/interrupt.h>
  #include <linux/platform_device.h>
  #include <linux/power_supply.h>
  #include <linux/leds.h>
  #include <linux/gpio.h>
  #include <linux/err.h>
  #include <linux/timer.h>
  #include <linux/jiffies.h>
  #include <linux/s3c_adc_battery.h>
  #include <linux/errno.h>
  #include <linux/init.h>

  #include <linux/module.h>

  
  #include <plat/adc.h>
  
  #define BAT_POLL_INTERVAL		10000 /* ms */
  #define JITTER_DELAY			500 /* ms */
  
  struct s3c_adc_bat {

  	struct power_supply		*psy;

  	struct s3c_adc_client		*client;
  	struct s3c_adc_bat_pdata	*pdata;
  	int				volt_value;
  	int				cur_value;
  	unsigned int			timestamp;
  	int				level;
  	int				status;
  	int				cable_plugged:1;
  };
  
  static struct delayed_work bat_work;
  
  static void s3c_adc_bat_ext_power_changed(struct power_supply *psy)
  {
  	schedule_delayed_work(&bat_work,
  		msecs_to_jiffies(JITTER_DELAY));
  }

  static int gather_samples(struct s3c_adc_client *client, int num, int channel)
  {
  	int value, i;
  
  	/* default to 1 if nothing is set */
  	if (num < 1)
  		num = 1;
  
  	value = 0;
  	for (i = 0; i < num; i++)
  		value += s3c_adc_read(client, channel);
  	value /= num;
  
  	return value;
  }

  static enum power_supply_property s3c_adc_backup_bat_props[] = {
  	POWER_SUPPLY_PROP_VOLTAGE_NOW,
  	POWER_SUPPLY_PROP_VOLTAGE_MIN,
  	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
  };
  
  static int s3c_adc_backup_bat_get_property(struct power_supply *psy,
  				enum power_supply_property psp,
  				union power_supply_propval *val)
  {

  	struct s3c_adc_bat *bat = power_supply_get_drvdata(psy);

  
  	if (!bat) {

  		dev_err(&psy->dev, "%s: no battery infos ?!
  ", __func__);

  		return -EINVAL;
  	}
  
  	if (bat->volt_value < 0 ||
  		jiffies_to_msecs(jiffies - bat->timestamp) >
  			BAT_POLL_INTERVAL) {

  		bat->volt_value = gather_samples(bat->client,
  			bat->pdata->backup_volt_samples,

  			bat->pdata->backup_volt_channel);
  		bat->volt_value *= bat->pdata->backup_volt_mult;
  		bat->timestamp = jiffies;
  	}
  
  	switch (psp) {
  	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
  		val->intval = bat->volt_value;
  		return 0;
  	case POWER_SUPPLY_PROP_VOLTAGE_MIN:
  		val->intval = bat->pdata->backup_volt_min;
  		return 0;
  	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
  		val->intval = bat->pdata->backup_volt_max;
  		return 0;
  	default:
  		return -EINVAL;
  	}
  }

  static const struct power_supply_desc backup_bat_desc = {
  	.name		= "backup-battery",
  	.type		= POWER_SUPPLY_TYPE_BATTERY,
  	.properties	= s3c_adc_backup_bat_props,
  	.num_properties = ARRAY_SIZE(s3c_adc_backup_bat_props),
  	.get_property	= s3c_adc_backup_bat_get_property,
  	.use_for_apm	= 1,

  };

  static struct s3c_adc_bat backup_bat;

  static enum power_supply_property s3c_adc_main_bat_props[] = {
  	POWER_SUPPLY_PROP_STATUS,
  	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
  	POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN,
  	POWER_SUPPLY_PROP_CHARGE_NOW,
  	POWER_SUPPLY_PROP_VOLTAGE_NOW,
  	POWER_SUPPLY_PROP_CURRENT_NOW,
  };
  
  static int calc_full_volt(int volt_val, int cur_val, int impedance)
  {
  	return volt_val + cur_val * impedance / 1000;
  }

  static int charge_finished(struct s3c_adc_bat *bat)
  {
  	return bat->pdata->gpio_inverted ?
  		!gpio_get_value(bat->pdata->gpio_charge_finished) :
  		gpio_get_value(bat->pdata->gpio_charge_finished);
  }

  static int s3c_adc_bat_get_property(struct power_supply *psy,
  				    enum power_supply_property psp,
  				    union power_supply_propval *val)
  {

  	struct s3c_adc_bat *bat = power_supply_get_drvdata(psy);

  
  	int new_level;
  	int full_volt;

  	const struct s3c_adc_bat_thresh *lut;
  	unsigned int lut_size;

  
  	if (!bat) {

  		dev_err(&psy->dev, "no battery infos ?!
  ");

  		return -EINVAL;
  	}

  	lut = bat->pdata->lut_noac;
  	lut_size = bat->pdata->lut_noac_cnt;

  	if (bat->volt_value < 0 || bat->cur_value < 0 ||
  		jiffies_to_msecs(jiffies - bat->timestamp) >
  			BAT_POLL_INTERVAL) {

  		bat->volt_value = gather_samples(bat->client,
  			bat->pdata->volt_samples,

  			bat->pdata->volt_channel) * bat->pdata->volt_mult;

  		bat->cur_value = gather_samples(bat->client,
  			bat->pdata->current_samples,

  			bat->pdata->current_channel) * bat->pdata->current_mult;
  		bat->timestamp = jiffies;
  	}
  
  	if (bat->cable_plugged &&
  		((bat->pdata->gpio_charge_finished < 0) ||

  		!charge_finished(bat))) {

  		lut = bat->pdata->lut_acin;
  		lut_size = bat->pdata->lut_acin_cnt;
  	}
  
  	new_level = 100000;
  	full_volt = calc_full_volt((bat->volt_value / 1000),
  		(bat->cur_value / 1000), bat->pdata->internal_impedance);
  
  	if (full_volt < calc_full_volt(lut->volt, lut->cur,
  		bat->pdata->internal_impedance)) {
  		lut_size--;
  		while (lut_size--) {
  			int lut_volt1;
  			int lut_volt2;
  
  			lut_volt1 = calc_full_volt(lut[0].volt, lut[0].cur,
  				bat->pdata->internal_impedance);
  			lut_volt2 = calc_full_volt(lut[1].volt, lut[1].cur,
  				bat->pdata->internal_impedance);
  			if (full_volt < lut_volt1 && full_volt >= lut_volt2) {
  				new_level = (lut[1].level +
  					(lut[0].level - lut[1].level) *
  					(full_volt - lut_volt2) /
  					(lut_volt1 - lut_volt2)) * 1000;
  				break;
  			}
  			new_level = lut[1].level * 1000;
  			lut++;
  		}
  	}
  
  	bat->level = new_level;
  
  	switch (psp) {
  	case POWER_SUPPLY_PROP_STATUS:
  		if (bat->pdata->gpio_charge_finished < 0)
  			val->intval = bat->level == 100000 ?
  				POWER_SUPPLY_STATUS_FULL : bat->status;
  		else
  			val->intval = bat->status;
  		return 0;
  	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
  		val->intval = 100000;
  		return 0;
  	case POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN:
  		val->intval = 0;
  		return 0;
  	case POWER_SUPPLY_PROP_CHARGE_NOW:
  		val->intval = bat->level;
  		return 0;
  	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
  		val->intval = bat->volt_value;
  		return 0;
  	case POWER_SUPPLY_PROP_CURRENT_NOW:
  		val->intval = bat->cur_value;
  		return 0;
  	default:
  		return -EINVAL;
  	}
  }

  static const struct power_supply_desc main_bat_desc = {
  	.name			= "main-battery",
  	.type			= POWER_SUPPLY_TYPE_BATTERY,
  	.properties		= s3c_adc_main_bat_props,
  	.num_properties		= ARRAY_SIZE(s3c_adc_main_bat_props),
  	.get_property		= s3c_adc_bat_get_property,
  	.external_power_changed = s3c_adc_bat_ext_power_changed,
  	.use_for_apm		= 1,

  };

  static struct s3c_adc_bat main_bat;

  static void s3c_adc_bat_work(struct work_struct *work)
  {
  	struct s3c_adc_bat *bat = &main_bat;
  	int is_charged;
  	int is_plugged;
  	static int was_plugged;

  	is_plugged = power_supply_am_i_supplied(bat->psy);

  	bat->cable_plugged = is_plugged;
  	if (is_plugged != was_plugged) {
  		was_plugged = is_plugged;
  		if (is_plugged) {
  			if (bat->pdata->enable_charger)
  				bat->pdata->enable_charger();
  			bat->status = POWER_SUPPLY_STATUS_CHARGING;
  		} else {
  			if (bat->pdata->disable_charger)
  				bat->pdata->disable_charger();
  			bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
  		}
  	} else {
  		if ((bat->pdata->gpio_charge_finished >= 0) && is_plugged) {

  			is_charged = charge_finished(&main_bat);

  			if (is_charged) {
  				if (bat->pdata->disable_charger)
  					bat->pdata->disable_charger();
  				bat->status = POWER_SUPPLY_STATUS_FULL;
  			} else {
  				if (bat->pdata->enable_charger)
  					bat->pdata->enable_charger();
  				bat->status = POWER_SUPPLY_STATUS_CHARGING;
  			}
  		}
  	}

  	power_supply_changed(bat->psy);

  }
  
  static irqreturn_t s3c_adc_bat_charged(int irq, void *dev_id)
  {
  	schedule_delayed_work(&bat_work,
  		msecs_to_jiffies(JITTER_DELAY));
  	return IRQ_HANDLED;
  }

  static int s3c_adc_bat_probe(struct platform_device *pdev)

  {
  	struct s3c_adc_client	*client;
  	struct s3c_adc_bat_pdata *pdata = pdev->dev.platform_data;
  	int ret;
  
  	client = s3c_adc_register(pdev, NULL, NULL, 0);
  	if (IS_ERR(client)) {
  		dev_err(&pdev->dev, "cannot register adc
  ");
  		return PTR_ERR(client);
  	}
  
  	platform_set_drvdata(pdev, client);
  
  	main_bat.client = client;
  	main_bat.pdata = pdata;
  	main_bat.volt_value = -1;
  	main_bat.cur_value = -1;
  	main_bat.cable_plugged = 0;
  	main_bat.status = POWER_SUPPLY_STATUS_DISCHARGING;

  	main_bat.psy = power_supply_register(&pdev->dev, &main_bat_desc, NULL);
  	if (IS_ERR(main_bat.psy)) {
  		ret = PTR_ERR(main_bat.psy);

  		goto err_reg_main;

  	}

  	if (pdata->backup_volt_mult) {

  		const struct power_supply_config psy_cfg
  						= { .drv_data = &backup_bat, };

  		backup_bat.client = client;
  		backup_bat.pdata = pdev->dev.platform_data;
  		backup_bat.volt_value = -1;

  		backup_bat.psy = power_supply_register(&pdev->dev,
  						       &backup_bat_desc,
  						       &psy_cfg);
  		if (IS_ERR(backup_bat.psy)) {
  			ret = PTR_ERR(backup_bat.psy);

  			goto err_reg_backup;

  		}

  	}
  
  	INIT_DELAYED_WORK(&bat_work, s3c_adc_bat_work);
  
  	if (pdata->gpio_charge_finished >= 0) {
  		ret = gpio_request(pdata->gpio_charge_finished, "charged");
  		if (ret)
  			goto err_gpio;
  
  		ret = request_irq(gpio_to_irq(pdata->gpio_charge_finished),
  				s3c_adc_bat_charged,
  				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
  				"battery charged", NULL);
  		if (ret)
  			goto err_irq;
  	}
  
  	if (pdata->init) {
  		ret = pdata->init();
  		if (ret)
  			goto err_platform;
  	}
  
  	dev_info(&pdev->dev, "successfully loaded
  ");
  	device_init_wakeup(&pdev->dev, 1);
  
  	/* Schedule timer to check current status */
  	schedule_delayed_work(&bat_work,
  		msecs_to_jiffies(JITTER_DELAY));
  
  	return 0;
  
  err_platform:
  	if (pdata->gpio_charge_finished >= 0)
  		free_irq(gpio_to_irq(pdata->gpio_charge_finished), NULL);
  err_irq:
  	if (pdata->gpio_charge_finished >= 0)
  		gpio_free(pdata->gpio_charge_finished);
  err_gpio:
  	if (pdata->backup_volt_mult)

  		power_supply_unregister(backup_bat.psy);

  err_reg_backup:

  	power_supply_unregister(main_bat.psy);

  err_reg_main:
  	return ret;
  }
  
  static int s3c_adc_bat_remove(struct platform_device *pdev)
  {
  	struct s3c_adc_client *client = platform_get_drvdata(pdev);
  	struct s3c_adc_bat_pdata *pdata = pdev->dev.platform_data;

  	power_supply_unregister(main_bat.psy);

  	if (pdata->backup_volt_mult)

  		power_supply_unregister(backup_bat.psy);

  
  	s3c_adc_release(client);
  
  	if (pdata->gpio_charge_finished >= 0) {
  		free_irq(gpio_to_irq(pdata->gpio_charge_finished), NULL);
  		gpio_free(pdata->gpio_charge_finished);
  	}
  
  	cancel_delayed_work(&bat_work);
  
  	if (pdata->exit)
  		pdata->exit();
  
  	return 0;
  }
  
  #ifdef CONFIG_PM
  static int s3c_adc_bat_suspend(struct platform_device *pdev,
  	pm_message_t state)
  {
  	struct s3c_adc_bat_pdata *pdata = pdev->dev.platform_data;
  
  	if (pdata->gpio_charge_finished >= 0) {
  		if (device_may_wakeup(&pdev->dev))
  			enable_irq_wake(
  				gpio_to_irq(pdata->gpio_charge_finished));
  		else {
  			disable_irq(gpio_to_irq(pdata->gpio_charge_finished));
  			main_bat.pdata->disable_charger();
  		}
  	}
  
  	return 0;
  }
  
  static int s3c_adc_bat_resume(struct platform_device *pdev)
  {
  	struct s3c_adc_bat_pdata *pdata = pdev->dev.platform_data;
  
  	if (pdata->gpio_charge_finished >= 0) {
  		if (device_may_wakeup(&pdev->dev))
  			disable_irq_wake(
  				gpio_to_irq(pdata->gpio_charge_finished));
  		else
  			enable_irq(gpio_to_irq(pdata->gpio_charge_finished));
  	}
  
  	/* Schedule timer to check current status */
  	schedule_delayed_work(&bat_work,
  		msecs_to_jiffies(JITTER_DELAY));
  
  	return 0;
  }
  #else

  #define s3c_adc_bat_suspend NULL
  #define s3c_adc_bat_resume NULL

  #endif
  
  static struct platform_driver s3c_adc_bat_driver = {
  	.driver		= {
  		.name	= "s3c-adc-battery",
  	},
  	.probe		= s3c_adc_bat_probe,
  	.remove		= s3c_adc_bat_remove,
  	.suspend	= s3c_adc_bat_suspend,
  	.resume		= s3c_adc_bat_resume,
  };

  module_platform_driver(s3c_adc_bat_driver);

  
  MODULE_AUTHOR("Vasily Khoruzhick <anarsoul@gmail.com>");

  MODULE_DESCRIPTION("iPAQ H1930/H1940/RX1950 battery controller driver");

  MODULE_LICENSE("GPL");