#include <linux/proc_fs.h>
  #include <linux/seq_file.h>

  #include <linux/export.h>

  #include <linux/suspend.h>
  #include <linux/bcd.h>
  #include <asm/uaccess.h>
  
  #include <acpi/acpi_bus.h>
  #include <acpi/acpi_drivers.h>
  
  #ifdef CONFIG_X86
  #include <linux/mc146818rtc.h>
  #endif
  
  #include "sleep.h"

  #define _COMPONENT		ACPI_SYSTEM_COMPONENT

  
  /*
   * this file provides support for:

   * /proc/acpi/alarm
   * /proc/acpi/wakeup
   */

  ACPI_MODULE_NAME("sleep")

  #if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || !defined(CONFIG_X86)

  /* use /sys/class/rtc/rtcX/wakealarm instead; it's not ACPI-specific */
  #else
  #define	HAVE_ACPI_LEGACY_ALARM
  #endif
  
  #ifdef	HAVE_ACPI_LEGACY_ALARM

  static u32 cmos_bcd_read(int offset, int rtc_control);

  static int acpi_system_alarm_seq_show(struct seq_file *seq, void *offset)
  {

  	u32 sec, min, hr;

  	u32 day, mo, yr, cent = 0;

  	u32 today = 0;

  	unsigned char rtc_control = 0;
  	unsigned long flags;

  	spin_lock_irqsave(&rtc_lock, flags);

  	rtc_control = CMOS_READ(RTC_CONTROL);

  	sec = cmos_bcd_read(RTC_SECONDS_ALARM, rtc_control);
  	min = cmos_bcd_read(RTC_MINUTES_ALARM, rtc_control);
  	hr = cmos_bcd_read(RTC_HOURS_ALARM, rtc_control);

  
  	/* If we ever get an FACP with proper values... */

  	if (acpi_gbl_FADT.day_alarm) {

  		/* ACPI spec: only low 6 its should be cared */

  		day = CMOS_READ(acpi_gbl_FADT.day_alarm) & 0x3F;

  		if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
  			day = bcd2bin(day);
  	} else
  		day = cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);

  	if (acpi_gbl_FADT.month_alarm)

  		mo = cmos_bcd_read(acpi_gbl_FADT.month_alarm, rtc_control);
  	else {
  		mo = cmos_bcd_read(RTC_MONTH, rtc_control);
  		today = cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
  	}

  	if (acpi_gbl_FADT.century)

  		cent = cmos_bcd_read(acpi_gbl_FADT.century, rtc_control);

  	yr = cmos_bcd_read(RTC_YEAR, rtc_control);

  
  	spin_unlock_irqrestore(&rtc_lock, flags);

  	/* we're trusting the FADT (see above) */

  	if (!acpi_gbl_FADT.century)

  		/* If we're not trusting the FADT, we should at least make it
  		 * right for _this_ century... ehm, what is _this_ century?
  		 *
  		 * TBD:
  		 *  ASAP: find piece of code in the kernel, e.g. star tracker driver,
  		 *        which we can trust to determine the century correctly. Atom
  		 *        watch driver would be nice, too...
  		 *
  		 *  if that has not happened, change for first release in 2050:
  		 *        if (yr<50)
  		 *                yr += 2100;
  		 *        else
  		 *                yr += 2000;   // current line of code
  		 *
  		 *  if that has not happened either, please do on 2099/12/31:23:59:59
  		 *        s/2000/2100
  		 *
  		 */

  		yr += 2000;

  	else
  		yr += cent * 100;

  	/*
  	 * Show correct dates for alarms up to a month into the future.
  	 * This solves issues for nearly all situations with the common
  	 * 30-day alarm clocks in PC hardware.
  	 */
  	if (day < today) {
  		if (mo < 12) {
  			mo += 1;
  		} else {
  			mo = 1;
  			yr += 1;
  		}
  	}

  	seq_printf(seq, "%4.4u-", yr);
  	(mo > 12) ? seq_puts(seq, "**-") : seq_printf(seq, "%2.2u-", mo);
  	(day > 31) ? seq_puts(seq, "** ") : seq_printf(seq, "%2.2u ", day);
  	(hr > 23) ? seq_puts(seq, "**:") : seq_printf(seq, "%2.2u:", hr);
  	(min > 59) ? seq_puts(seq, "**:") : seq_printf(seq, "%2.2u:", min);

  	(sec > 59) ? seq_puts(seq, "**
  ") : seq_printf(seq, "%2.2u
  ", sec);
  
  	return 0;
  }
  
  static int acpi_system_alarm_open_fs(struct inode *inode, struct file *file)
  {
  	return single_open(file, acpi_system_alarm_seq_show, PDE(inode)->data);
  }

  static int get_date_field(char **p, u32 * value)

  {

  	char *next = NULL;
  	char *string_end = NULL;
  	int result = -EINVAL;

  
  	/*
  	 * Try to find delimeter, only to insert null.  The end of the
  	 * string won't have one, but is still valid.
  	 */

  	if (*p == NULL)
  		return result;

  	next = strpbrk(*p, "- :");
  	if (next)
  		*next++ = '\0';
  
  	*value = simple_strtoul(*p, &string_end, 10);
  
  	/* Signal success if we got a good digit */
  	if (string_end != *p)
  		result = 0;
  
  	if (next)
  		*p = next;

  	else
  		*p = NULL;

  
  	return result;
  }

  /* Read a possibly BCD register, always return binary */
  static u32 cmos_bcd_read(int offset, int rtc_control)
  {
  	u32 val = CMOS_READ(offset);
  	if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)

  		val = bcd2bin(val);

  	return val;
  }
  
  /* Write binary value into possibly BCD register */
  static void cmos_bcd_write(u32 val, int offset, int rtc_control)
  {
  	if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)

  		val = bin2bcd(val);

  	CMOS_WRITE(val, offset);
  }

  static ssize_t

  acpi_system_write_alarm(struct file *file,
  			const char __user * buffer, size_t count, loff_t * ppos)

  {

  	int result = 0;
  	char alarm_string[30] = { '\0' };
  	char *p = alarm_string;
  	u32 sec, min, hr, day, mo, yr;
  	int adjust = 0;
  	unsigned char rtc_control = 0;

  	if (count > sizeof(alarm_string) - 1)

  		return -EINVAL;

  	if (copy_from_user(alarm_string, buffer, count))

  		return -EFAULT;

  
  	alarm_string[count] = '\0';
  
  	/* check for time adjustment */
  	if (alarm_string[0] == '+') {
  		p++;
  		adjust = 1;
  	}
  
  	if ((result = get_date_field(&p, &yr)))
  		goto end;
  	if ((result = get_date_field(&p, &mo)))
  		goto end;
  	if ((result = get_date_field(&p, &day)))
  		goto end;
  	if ((result = get_date_field(&p, &hr)))
  		goto end;
  	if ((result = get_date_field(&p, &min)))
  		goto end;
  	if ((result = get_date_field(&p, &sec)))
  		goto end;

  	spin_lock_irq(&rtc_lock);
  
  	rtc_control = CMOS_READ(RTC_CONTROL);

  
  	if (adjust) {

  		yr += cmos_bcd_read(RTC_YEAR, rtc_control);
  		mo += cmos_bcd_read(RTC_MONTH, rtc_control);
  		day += cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
  		hr += cmos_bcd_read(RTC_HOURS, rtc_control);
  		min += cmos_bcd_read(RTC_MINUTES, rtc_control);
  		sec += cmos_bcd_read(RTC_SECONDS, rtc_control);

  	}
  
  	spin_unlock_irq(&rtc_lock);

  	if (sec > 59) {

  		min += sec/60;
  		sec = sec%60;

  	}
  	if (min > 59) {

  		hr += min/60;
  		min = min%60;

  	}
  	if (hr > 23) {

  		day += hr/24;
  		hr = hr%24;

  	}
  	if (day > 31) {

  		mo += day/32;
  		day = day%32;

  	}
  	if (mo > 12) {

  		yr += mo/13;
  		mo = mo%13;

  	}

  
  	spin_lock_irq(&rtc_lock);
  	/*
  	 * Disable alarm interrupt before setting alarm timer or else
  	 * when ACPI_EVENT_RTC is enabled, a spurious ACPI interrupt occurs
  	 */
  	rtc_control &= ~RTC_AIE;
  	CMOS_WRITE(rtc_control, RTC_CONTROL);
  	CMOS_READ(RTC_INTR_FLAGS);
  
  	/* write the fields the rtc knows about */

  	cmos_bcd_write(hr, RTC_HOURS_ALARM, rtc_control);
  	cmos_bcd_write(min, RTC_MINUTES_ALARM, rtc_control);
  	cmos_bcd_write(sec, RTC_SECONDS_ALARM, rtc_control);

  
  	/*
  	 * If the system supports an enhanced alarm it will have non-zero
  	 * offsets into the CMOS RAM here -- which for some reason are pointing
  	 * to the RTC area of memory.
  	 */

  	if (acpi_gbl_FADT.day_alarm)

  		cmos_bcd_write(day, acpi_gbl_FADT.day_alarm, rtc_control);

  	if (acpi_gbl_FADT.month_alarm)

  		cmos_bcd_write(mo, acpi_gbl_FADT.month_alarm, rtc_control);

  	if (acpi_gbl_FADT.century) {
  		if (adjust)
  			yr += cmos_bcd_read(acpi_gbl_FADT.century, rtc_control) * 100;

  		cmos_bcd_write(yr / 100, acpi_gbl_FADT.century, rtc_control);

  	}

  	/* enable the rtc alarm interrupt */
  	rtc_control |= RTC_AIE;
  	CMOS_WRITE(rtc_control, RTC_CONTROL);
  	CMOS_READ(RTC_INTR_FLAGS);
  
  	spin_unlock_irq(&rtc_lock);
  
  	acpi_clear_event(ACPI_EVENT_RTC);
  	acpi_enable_event(ACPI_EVENT_RTC, 0);
  
  	*ppos += count;
  
  	result = 0;

        end:

  	return result ? result : count;

  }

  #endif				/* HAVE_ACPI_LEGACY_ALARM */

  static int
  acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset)
  {

  	struct list_head *node, *next;

  	seq_printf(seq, "Device\tS-state\t  Status   Sysfs node
  ");

  	mutex_lock(&acpi_device_lock);

  	list_for_each_safe(node, next, &acpi_wakeup_device_list) {

  		struct acpi_device *dev =
  		    container_of(node, struct acpi_device, wakeup_list);

  		struct device *ldev;

  
  		if (!dev->wakeup.flags.valid)
  			continue;

  
  		ldev = acpi_get_physical_device(dev->handle);
  		seq_printf(seq, "%s\t  S%d\t%c%-8s  ",

  			   dev->pnp.bus_id,
  			   (u32) dev->wakeup.sleep_state,

  			   dev->wakeup.flags.run_wake ? '*' : ' ',

  			   (device_may_wakeup(&dev->dev)
  			     || (ldev && device_may_wakeup(ldev))) ?
  			       "enabled" : "disabled");

  		if (ldev)
  			seq_printf(seq, "%s:%s",

  				   ldev->bus ? ldev->bus->name : "no-bus",

  				   dev_name(ldev));

  		seq_printf(seq, "
  ");
  		put_device(ldev);

  	}

  	mutex_unlock(&acpi_device_lock);

  	return 0;
  }

  static void physical_device_enable_wakeup(struct acpi_device *adev)
  {
  	struct device *dev = acpi_get_physical_device(adev->handle);

  	if (dev && device_can_wakeup(dev)) {
  		bool enable = !device_may_wakeup(dev);
  		device_set_wakeup_enable(dev, enable);
  	}

  }

  static ssize_t

  acpi_system_write_wakeup_device(struct file *file,
  				const char __user * buffer,
  				size_t count, loff_t * ppos)

  {

  	struct list_head *node, *next;
  	char strbuf[5];
  	char str[5] = "";

  	unsigned int len = count;

  	if (len > 4)
  		len = 4;

  	if (len < 0)
  		return -EFAULT;

  
  	if (copy_from_user(strbuf, buffer, len))
  		return -EFAULT;
  	strbuf[len] = '\0';
  	sscanf(strbuf, "%s", str);

  	mutex_lock(&acpi_device_lock);

  	list_for_each_safe(node, next, &acpi_wakeup_device_list) {

  		struct acpi_device *dev =
  		    container_of(node, struct acpi_device, wakeup_list);

  		if (!dev->wakeup.flags.valid)
  			continue;
  
  		if (!strncmp(dev->pnp.bus_id, str, 4)) {

  			if (device_can_wakeup(&dev->dev)) {
  				bool enable = !device_may_wakeup(&dev->dev);
  				device_set_wakeup_enable(&dev->dev, enable);
  			} else {
  				physical_device_enable_wakeup(dev);
  			}

  			break;
  		}
  	}

  	mutex_unlock(&acpi_device_lock);

  	return count;
  }
  
  static int
  acpi_system_wakeup_device_open_fs(struct inode *inode, struct file *file)
  {

  	return single_open(file, acpi_system_wakeup_device_seq_show,
  			   PDE(inode)->data);

  }

  static const struct file_operations acpi_system_wakeup_device_fops = {

  	.owner = THIS_MODULE,

  	.open = acpi_system_wakeup_device_open_fs,
  	.read = seq_read,
  	.write = acpi_system_write_wakeup_device,
  	.llseek = seq_lseek,
  	.release = single_release,

  };

  #ifdef	HAVE_ACPI_LEGACY_ALARM

  static const struct file_operations acpi_system_alarm_fops = {

  	.owner = THIS_MODULE,

  	.open = acpi_system_alarm_open_fs,
  	.read = seq_read,
  	.write = acpi_system_write_alarm,
  	.llseek = seq_lseek,
  	.release = single_release,

  };

  static u32 rtc_handler(void *context)

  {
  	acpi_clear_event(ACPI_EVENT_RTC);
  	acpi_disable_event(ACPI_EVENT_RTC, 0);
  
  	return ACPI_INTERRUPT_HANDLED;
  }

  #endif				/* HAVE_ACPI_LEGACY_ALARM */

  int __init acpi_sleep_proc_init(void)

  {

  #ifdef	HAVE_ACPI_LEGACY_ALARM

  	/* 'alarm' [R/W] */

  	proc_create("alarm", S_IFREG | S_IRUGO | S_IWUSR,
  		    acpi_root_dir, &acpi_system_alarm_fops);

  	acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, NULL);

  	/*
  	 * Disable the RTC event after installing RTC handler.
  	 * Only when RTC alarm is set will it be enabled.
  	 */
  	acpi_clear_event(ACPI_EVENT_RTC);
  	acpi_disable_event(ACPI_EVENT_RTC, 0);

  #endif				/* HAVE_ACPI_LEGACY_ALARM */

  	/* 'wakeup device' [R/W] */

  	proc_create("wakeup", S_IFREG | S_IRUGO | S_IWUSR,
  		    acpi_root_dir, &acpi_system_wakeup_device_fops);

  	return 0;
  }