ACPI / proc: Remove alarm proc file

Alarm proc file provides the info and control of RTC-CMOS alarm and
RTC CMOS driver provides wakealarm sysfs attribute for the same
purpose. The alarm file isn't compiled into kernel when RTC CMOS
driver is selected. The driver is default to be selected for x86
platform. So alarm file is default not to include. This patch is
to remove it to prepare remove /proc/acpi directory.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/proc.c

@@ -8,289 +8,17 @@
 #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, "**\n") : seq_printf(seq, "%2.2u\n", 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_DATA(inode));
-}
-
-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)
 {
@@ -417,41 +145,8 @@ static const struct file_operations acpi_system_wakeup_device_fops = {
 	.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);