/*
   * Copyright (C) ST-Ericsson SA 2010
   * Author: Mattias Nilsson <mattias.i.nilsson@stericsson.com> for ST Ericsson.
   * License terms: GNU General Public License (GPL) version 2
   */
  
  #include <linux/err.h>
  #include <linux/module.h>
  #include <linux/platform_device.h>
  #include <linux/pm.h>
  #include <linux/reboot.h>
  #include <linux/signal.h>
  #include <linux/power_supply.h>
  #include <linux/mfd/abx500.h>
  #include <linux/mfd/abx500/ab8500.h>
  #include <linux/mfd/abx500/ab8500-sysctrl.h>
  
  /* RtcCtrl bits */
  #define AB8500_ALARM_MIN_LOW  0x08
  #define AB8500_ALARM_MIN_MID 0x09
  #define RTC_CTRL 0x0B
  #define RTC_ALARM_ENABLE 0x4
  
  static struct device *sysctrl_dev;
  
  static void ab8500_power_off(void)
  {
  	sigset_t old;
  	sigset_t all;
  	static char *pss[] = {"ab8500_ac", "pm2301", "ab8500_usb"};
  	int i;
  	bool charger_present = false;
  	union power_supply_propval val;
  	struct power_supply *psy;
  	int ret;
  
  	if (sysctrl_dev == NULL) {
  		pr_err("%s: sysctrl not initialized
  ", __func__);
  		return;
  	}
  
  	/*
  	 * If we have a charger connected and we're powering off,
  	 * reboot into charge-only mode.
  	 */
  
  	for (i = 0; i < ARRAY_SIZE(pss); i++) {
  		psy = power_supply_get_by_name(pss[i]);
  		if (!psy)
  			continue;
  
  		ret = psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &val);
  
  		if (!ret && val.intval) {
  			charger_present = true;
  			break;
  		}
  	}
  
  	if (!charger_present)
  		goto shutdown;
  
  	/* Check if battery is known */
  	psy = power_supply_get_by_name("ab8500_btemp");
  	if (psy) {
  		ret = psy->get_property(psy, POWER_SUPPLY_PROP_TECHNOLOGY,
  					&val);
  		if (!ret && val.intval != POWER_SUPPLY_TECHNOLOGY_UNKNOWN) {
  			printk(KERN_INFO
  			       "Charger \"%s\" is connected with known battery."
  			       " Rebooting.
  ",
  			       pss[i]);
  			machine_restart("charging");
  		}
  	}
  
  shutdown:
  	sigfillset(&all);
  
  	if (!sigprocmask(SIG_BLOCK, &all, &old)) {
  		(void)ab8500_sysctrl_set(AB8500_STW4500CTRL1,
  					 AB8500_STW4500CTRL1_SWOFF |
  					 AB8500_STW4500CTRL1_SWRESET4500N);
  		(void)sigprocmask(SIG_SETMASK, &old, NULL);
  	}
  }
  
  /*
   * Use the AB WD to reset the platform. It will perform a hard
   * reset instead of a soft reset. Write the reset reason to
   * the AB before reset, which can be read upon restart.
   */
  void ab8500_restart(char mode, const char *cmd)
  {
  	struct ab8500_platform_data *plat;
  	struct ab8500_sysctrl_platform_data *pdata;
  	u16 reason = 0;
  	u8 val;
  
  	if (sysctrl_dev == NULL) {
  		pr_err("%s: sysctrl not initialized
  ", __func__);
  		return;
  	}
  
  	plat = dev_get_platdata(sysctrl_dev->parent);
  	pdata = plat->sysctrl;
  	if (pdata && pdata->reboot_reason_code)
  		reason = pdata->reboot_reason_code(cmd);
  	else
  		pr_warn("[%s] No reboot reason set. Default reason %d
  ",
  			__func__, reason);
  
  	/*
  	 * Disable RTC alarm, just a precaution so that no alarm
  	 * is running when WD reset is executed.
  	 */
  	abx500_get_register_interruptible(sysctrl_dev, AB8500_RTC,
  		RTC_CTRL , &val);
  	abx500_set_register_interruptible(sysctrl_dev, AB8500_RTC,
  		RTC_CTRL , (val & ~RTC_ALARM_ENABLE));
  
  	/*
  	 * Android is not using the RTC alarm registers during reboot
  	 * so we borrow them for writing the reason of reset
  	 */
  
  	/* reason[8 LSB] */
  	val = reason & 0xFF;
  	abx500_set_register_interruptible(sysctrl_dev, AB8500_RTC,
  		AB8500_ALARM_MIN_LOW , val);
  
  	/* reason[8 MSB] */
  	val = (reason>>8) & 0xFF;
  	abx500_set_register_interruptible(sysctrl_dev, AB8500_RTC,
  		AB8500_ALARM_MIN_MID , val);
  
  	/* Setting WD timeout to 0 */
  	ab8500_sysctrl_write(AB8500_MAINWDOGTIMER, 0xFF, 0x0);
  
  	/* Setting the parameters to AB8500 WD*/
  	ab8500_sysctrl_write(AB8500_MAINWDOGCTRL, 0xFF, (AB8500_ENABLE_WD |
  		AB8500_WD_RESTART_ON_EXPIRE | AB8500_KICK_WD));
  }
  
  static inline bool valid_bank(u8 bank)
  {
  	return ((bank == AB8500_SYS_CTRL1_BLOCK) ||
  		(bank == AB8500_SYS_CTRL2_BLOCK));
  }
  
  int ab8500_sysctrl_read(u16 reg, u8 *value)
  {
  	u8 bank;
  
  	if (sysctrl_dev == NULL)
  		return -EINVAL;
  
  	bank = (reg >> 8);
  	if (!valid_bank(bank))
  		return -EINVAL;
  
  	return abx500_get_register_interruptible(sysctrl_dev, bank,
  		(u8)(reg & 0xFF), value);
  }
  EXPORT_SYMBOL(ab8500_sysctrl_read);
  
  int ab8500_sysctrl_write(u16 reg, u8 mask, u8 value)
  {
  	u8 bank;
  
  	if (sysctrl_dev == NULL)
  		return -EINVAL;
  
  	bank = (reg >> 8);
  	if (!valid_bank(bank))
  		return -EINVAL;
  
  	return abx500_mask_and_set_register_interruptible(sysctrl_dev, bank,
  		(u8)(reg & 0xFF), mask, value);
  }
  EXPORT_SYMBOL(ab8500_sysctrl_write);
  
  static int ab8500_sysctrl_probe(struct platform_device *pdev)
  {
  	struct ab8500 *ab8500 = dev_get_drvdata(pdev->dev.parent);
  	struct ab8500_platform_data *plat;
  	struct ab8500_sysctrl_platform_data *pdata;
  
  	plat = dev_get_platdata(pdev->dev.parent);
  
  	if (!plat)
  		return -EINVAL;
  
  	sysctrl_dev = &pdev->dev;
  
  	if (!pm_power_off)
  		pm_power_off = ab8500_power_off;
  
  	pdata = plat->sysctrl;
  	if (pdata) {
  		int last, ret, i, j;
  
  		if (is_ab8505(ab8500))
  			last = AB8500_SYSCLKREQ4RFCLKBUF;
  		else
  			last = AB8500_SYSCLKREQ8RFCLKBUF;
  
  		for (i = AB8500_SYSCLKREQ1RFCLKBUF; i <= last; i++) {
  			j = i - AB8500_SYSCLKREQ1RFCLKBUF;
  			ret = ab8500_sysctrl_write(i, 0xff,
  					pdata->initial_req_buf_config[j]);
  			dev_dbg(&pdev->dev,
  					"Setting SysClkReq%dRfClkBuf 0x%X
  ",
  					j + 1,
  					pdata->initial_req_buf_config[j]);
  			if (ret < 0) {
  				dev_err(&pdev->dev,
  					"unable to set sysClkReq%dRfClkBuf: "
  					"%d
  ", j + 1, ret);
  			}
  		}
  	}
  
  	return 0;
  }
  
  static int ab8500_sysctrl_remove(struct platform_device *pdev)
  {
  	sysctrl_dev = NULL;
  
  	if (pm_power_off == ab8500_power_off)
  		pm_power_off = NULL;
  
  	return 0;
  }
  
  static struct platform_driver ab8500_sysctrl_driver = {
  	.driver = {
  		.name = "ab8500-sysctrl",
  		.owner = THIS_MODULE,
  	},
  	.probe = ab8500_sysctrl_probe,
  	.remove = ab8500_sysctrl_remove,
  };
  
  static int __init ab8500_sysctrl_init(void)
  {
  	return platform_driver_register(&ab8500_sysctrl_driver);
  }
  arch_initcall(ab8500_sysctrl_init);
  
  MODULE_AUTHOR("Mattias Nilsson <mattias.i.nilsson@stericsson.com");
  MODULE_DESCRIPTION("AB8500 system control driver");
  MODULE_LICENSE("GPL v2");