/*
   * Battery and Power Management code for the Sharp SL-5x00
   *
   * Copyright (C) 2009 Thomas Kunze
   *
   * based on tosa_battery.c
   *
   * 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/kernel.h>
  #include <linux/module.h>
  #include <linux/power_supply.h>
  #include <linux/delay.h>
  #include <linux/spinlock.h>
  #include <linux/interrupt.h>
  #include <linux/gpio.h>
  #include <linux/mfd/ucb1x00.h>
  
  #include <asm/mach/sharpsl_param.h>
  #include <asm/mach-types.h>
  #include <mach/collie.h>
  
  static DEFINE_MUTEX(bat_lock); /* protects gpio pins */
  static struct work_struct bat_work;
  static struct ucb1x00 *ucb;

  static int wakeup_enabled;

  
  struct collie_bat {
  	int status;

  	struct power_supply *psy;

  	int full_chrg;
  
  	struct mutex work_lock; /* protects data */
  
  	bool (*is_present)(struct collie_bat *bat);
  	int gpio_full;
  	int gpio_charge_on;
  
  	int technology;
  
  	int gpio_bat;
  	int adc_bat;
  	int adc_bat_divider;
  	int bat_max;
  	int bat_min;
  
  	int gpio_temp;
  	int adc_temp;
  	int adc_temp_divider;
  };
  
  static struct collie_bat collie_bat_main;
  
  static unsigned long collie_read_bat(struct collie_bat *bat)
  {
  	unsigned long value = 0;
  
  	if (bat->gpio_bat < 0 || bat->adc_bat < 0)
  		return 0;
  	mutex_lock(&bat_lock);
  	gpio_set_value(bat->gpio_bat, 1);
  	msleep(5);
  	ucb1x00_adc_enable(ucb);
  	value = ucb1x00_adc_read(ucb, bat->adc_bat, UCB_SYNC);
  	ucb1x00_adc_disable(ucb);
  	gpio_set_value(bat->gpio_bat, 0);
  	mutex_unlock(&bat_lock);
  	value = value * 1000000 / bat->adc_bat_divider;
  
  	return value;
  }
  
  static unsigned long collie_read_temp(struct collie_bat *bat)
  {
  	unsigned long value = 0;
  	if (bat->gpio_temp < 0 || bat->adc_temp < 0)
  		return 0;
  
  	mutex_lock(&bat_lock);
  	gpio_set_value(bat->gpio_temp, 1);
  	msleep(5);
  	ucb1x00_adc_enable(ucb);
  	value = ucb1x00_adc_read(ucb, bat->adc_temp, UCB_SYNC);
  	ucb1x00_adc_disable(ucb);
  	gpio_set_value(bat->gpio_temp, 0);
  	mutex_unlock(&bat_lock);
  
  	value = value * 10000 / bat->adc_temp_divider;
  
  	return value;
  }
  
  static int collie_bat_get_property(struct power_supply *psy,
  			    enum power_supply_property psp,
  			    union power_supply_propval *val)
  {
  	int ret = 0;

  	struct collie_bat *bat = power_supply_get_drvdata(psy);

  
  	if (bat->is_present && !bat->is_present(bat)
  			&& psp != POWER_SUPPLY_PROP_PRESENT) {
  		return -ENODEV;
  	}
  
  	switch (psp) {
  	case POWER_SUPPLY_PROP_STATUS:
  		val->intval = bat->status;
  		break;
  	case POWER_SUPPLY_PROP_TECHNOLOGY:
  		val->intval = bat->technology;
  		break;
  	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
  		val->intval = collie_read_bat(bat);
  		break;
  	case POWER_SUPPLY_PROP_VOLTAGE_MAX:
  		if (bat->full_chrg == -1)
  			val->intval = bat->bat_max;
  		else
  			val->intval = bat->full_chrg;
  		break;
  	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
  		val->intval = bat->bat_max;
  		break;
  	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
  		val->intval = bat->bat_min;
  		break;
  	case POWER_SUPPLY_PROP_TEMP:
  		val->intval = collie_read_temp(bat);
  		break;
  	case POWER_SUPPLY_PROP_PRESENT:
  		val->intval = bat->is_present ? bat->is_present(bat) : 1;
  		break;
  	default:
  		ret = -EINVAL;
  		break;
  	}
  	return ret;
  }
  
  static void collie_bat_external_power_changed(struct power_supply *psy)
  {
  	schedule_work(&bat_work);
  }
  
  static irqreturn_t collie_bat_gpio_isr(int irq, void *data)
  {

  	pr_info("collie_bat_gpio irq
  ");

  	schedule_work(&bat_work);
  	return IRQ_HANDLED;
  }
  
  static void collie_bat_update(struct collie_bat *bat)
  {
  	int old;

  	struct power_supply *psy = bat->psy;

  
  	mutex_lock(&bat->work_lock);
  
  	old = bat->status;
  
  	if (bat->is_present && !bat->is_present(bat)) {

  		printk(KERN_NOTICE "%s not present
  ", psy->desc->name);

  		bat->status = POWER_SUPPLY_STATUS_UNKNOWN;
  		bat->full_chrg = -1;
  	} else if (power_supply_am_i_supplied(psy)) {
  		if (bat->status == POWER_SUPPLY_STATUS_DISCHARGING) {
  			gpio_set_value(bat->gpio_charge_on, 1);
  			mdelay(15);
  		}
  
  		if (gpio_get_value(bat->gpio_full)) {
  			if (old == POWER_SUPPLY_STATUS_CHARGING ||
  					bat->full_chrg == -1)
  				bat->full_chrg = collie_read_bat(bat);
  
  			gpio_set_value(bat->gpio_charge_on, 0);
  			bat->status = POWER_SUPPLY_STATUS_FULL;
  		} else {
  			gpio_set_value(bat->gpio_charge_on, 1);
  			bat->status = POWER_SUPPLY_STATUS_CHARGING;
  		}
  	} else {
  		gpio_set_value(bat->gpio_charge_on, 0);
  		bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
  	}
  
  	if (old != bat->status)
  		power_supply_changed(psy);
  
  	mutex_unlock(&bat->work_lock);
  }
  
  static void collie_bat_work(struct work_struct *work)
  {
  	collie_bat_update(&collie_bat_main);
  }
  
  
  static enum power_supply_property collie_bat_main_props[] = {
  	POWER_SUPPLY_PROP_STATUS,
  	POWER_SUPPLY_PROP_TECHNOLOGY,
  	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
  	POWER_SUPPLY_PROP_VOLTAGE_NOW,
  	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
  	POWER_SUPPLY_PROP_VOLTAGE_MAX,
  	POWER_SUPPLY_PROP_PRESENT,
  	POWER_SUPPLY_PROP_TEMP,
  };
  
  static enum power_supply_property collie_bat_bu_props[] = {
  	POWER_SUPPLY_PROP_STATUS,
  	POWER_SUPPLY_PROP_TECHNOLOGY,
  	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
  	POWER_SUPPLY_PROP_VOLTAGE_NOW,
  	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
  	POWER_SUPPLY_PROP_VOLTAGE_MAX,
  	POWER_SUPPLY_PROP_PRESENT,
  };

  static const struct power_supply_desc collie_bat_main_desc = {
  	.name		= "main-battery",
  	.type		= POWER_SUPPLY_TYPE_BATTERY,
  	.properties	= collie_bat_main_props,
  	.num_properties	= ARRAY_SIZE(collie_bat_main_props),
  	.get_property	= collie_bat_get_property,
  	.external_power_changed = collie_bat_external_power_changed,
  	.use_for_apm	= 1,
  };

  static struct collie_bat collie_bat_main = {
  	.status = POWER_SUPPLY_STATUS_DISCHARGING,
  	.full_chrg = -1,

  	.psy = NULL,

  
  	.gpio_full = COLLIE_GPIO_CO,
  	.gpio_charge_on = COLLIE_GPIO_CHARGE_ON,
  
  	.technology = POWER_SUPPLY_TECHNOLOGY_LIPO,
  
  	.gpio_bat = COLLIE_GPIO_MBAT_ON,
  	.adc_bat = UCB_ADC_INP_AD1,
  	.adc_bat_divider = 155,
  	.bat_max = 4310000,
  	.bat_min = 1551 * 1000000 / 414,
  
  	.gpio_temp = COLLIE_GPIO_TMP_ON,
  	.adc_temp = UCB_ADC_INP_AD0,
  	.adc_temp_divider = 10000,
  };

  static const struct power_supply_desc collie_bat_bu_desc = {
  	.name		= "backup-battery",
  	.type		= POWER_SUPPLY_TYPE_BATTERY,
  	.properties	= collie_bat_bu_props,
  	.num_properties	= ARRAY_SIZE(collie_bat_bu_props),
  	.get_property	= collie_bat_get_property,
  	.external_power_changed = collie_bat_external_power_changed,
  };

  static struct collie_bat collie_bat_bu = {
  	.status = POWER_SUPPLY_STATUS_UNKNOWN,
  	.full_chrg = -1,

  	.psy = NULL,

  
  	.gpio_full = -1,
  	.gpio_charge_on = -1,
  
  	.technology = POWER_SUPPLY_TECHNOLOGY_LiMn,
  
  	.gpio_bat = COLLIE_GPIO_BBAT_ON,
  	.adc_bat = UCB_ADC_INP_AD1,
  	.adc_bat_divider = 155,
  	.bat_max = 3000000,
  	.bat_min = 1900000,
  
  	.gpio_temp = -1,
  	.adc_temp = -1,
  	.adc_temp_divider = -1,
  };

  static struct gpio collie_batt_gpios[] = {
  	{ COLLIE_GPIO_CO,	    GPIOF_IN,		"main battery full" },
  	{ COLLIE_GPIO_MAIN_BAT_LOW, GPIOF_IN,		"main battery low" },
  	{ COLLIE_GPIO_CHARGE_ON,    GPIOF_OUT_INIT_LOW,	"main charge on" },
  	{ COLLIE_GPIO_MBAT_ON,	    GPIOF_OUT_INIT_LOW,	"main battery" },
  	{ COLLIE_GPIO_TMP_ON,	    GPIOF_OUT_INIT_LOW,	"main battery temp" },
  	{ COLLIE_GPIO_BBAT_ON,	    GPIOF_OUT_INIT_LOW,	"backup battery" },

  };
  
  #ifdef CONFIG_PM

  static int collie_bat_suspend(struct ucb1x00_dev *dev)

  {
  	/* flush all pending status updates */

  	flush_work(&bat_work);

  
  	if (device_may_wakeup(&dev->ucb->dev) &&
  	    collie_bat_main.status == POWER_SUPPLY_STATUS_CHARGING)
  		wakeup_enabled = !enable_irq_wake(gpio_to_irq(COLLIE_GPIO_CO));
  	else
  		wakeup_enabled = 0;

  	return 0;
  }
  
  static int collie_bat_resume(struct ucb1x00_dev *dev)
  {

  	if (wakeup_enabled)
  		disable_irq_wake(gpio_to_irq(COLLIE_GPIO_CO));

  	/* things may have changed while we were away */
  	schedule_work(&bat_work);
  	return 0;
  }
  #else
  #define collie_bat_suspend NULL
  #define collie_bat_resume NULL
  #endif

  static int collie_bat_probe(struct ucb1x00_dev *dev)

  {
  	int ret;

  	struct power_supply_config psy_main_cfg = {}, psy_bu_cfg = {};

  
  	if (!machine_is_collie())
  		return -ENODEV;
  
  	ucb = dev->ucb;

  	ret = gpio_request_array(collie_batt_gpios,
  				 ARRAY_SIZE(collie_batt_gpios));
  	if (ret)
  		return ret;

  
  	mutex_init(&collie_bat_main.work_lock);
  
  	INIT_WORK(&bat_work, collie_bat_work);

  	psy_main_cfg.drv_data = &collie_bat_main;
  	collie_bat_main.psy = power_supply_register(&dev->ucb->dev,
  						    &collie_bat_main_desc,
  						    &psy_main_cfg);
  	if (IS_ERR(collie_bat_main.psy)) {
  		ret = PTR_ERR(collie_bat_main.psy);

  		goto err_psy_reg_main;

  	}
  
  	psy_main_cfg.drv_data = &collie_bat_bu;
  	collie_bat_bu.psy = power_supply_register(&dev->ucb->dev,
  						  &collie_bat_bu_desc,
  						  &psy_bu_cfg);
  	if (IS_ERR(collie_bat_bu.psy)) {
  		ret = PTR_ERR(collie_bat_bu.psy);

  		goto err_psy_reg_bu;

  	}

  
  	ret = request_irq(gpio_to_irq(COLLIE_GPIO_CO),
  				collie_bat_gpio_isr,
  				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
  				"main full", &collie_bat_main);

  	if (ret)
  		goto err_irq;
  
  	device_init_wakeup(&ucb->dev, 1);
  	schedule_work(&bat_work);
  
  	return 0;
  
  err_irq:

  	power_supply_unregister(collie_bat_bu.psy);

  err_psy_reg_bu:

  	power_supply_unregister(collie_bat_main.psy);

  err_psy_reg_main:
  
  	/* see comment in collie_bat_remove */

  	cancel_work_sync(&bat_work);

  	gpio_free_array(collie_batt_gpios, ARRAY_SIZE(collie_batt_gpios));

  	return ret;
  }

  static void collie_bat_remove(struct ucb1x00_dev *dev)

  {

  	free_irq(gpio_to_irq(COLLIE_GPIO_CO), &collie_bat_main);

  	power_supply_unregister(collie_bat_bu.psy);
  	power_supply_unregister(collie_bat_main.psy);

  
  	/*

  	 * Now cancel the bat_work.  We won't get any more schedules,
  	 * since all sources (isr and external_power_changed) are
  	 * unregistered now.

  	 */

  	cancel_work_sync(&bat_work);

  	gpio_free_array(collie_batt_gpios, ARRAY_SIZE(collie_batt_gpios));

  }
  
  static struct ucb1x00_driver collie_bat_driver = {
  	.add		= collie_bat_probe,

  	.remove		= collie_bat_remove,

  	.suspend	= collie_bat_suspend,
  	.resume		= collie_bat_resume,
  };
  
  static int __init collie_bat_init(void)
  {
  	return ucb1x00_register_driver(&collie_bat_driver);
  }
  
  static void __exit collie_bat_exit(void)
  {
  	ucb1x00_unregister_driver(&collie_bat_driver);
  }
  
  module_init(collie_bat_init);
  module_exit(collie_bat_exit);
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Thomas Kunze");
  MODULE_DESCRIPTION("Collie battery driver");