[ACPI] S3 resume using RTC

http://bugzilla.kernel.org/show_bug.cgi?id=1320

By: Patrick Mochel, Karol Kozimor, Shaohua Li
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/sleep/proc.c

@@ -83,6 +83,7 @@ static int acpi_system_alarm_seq_show(struct seq_file *seq, void *offset)
 {
 	u32			sec, min, hr;
 	u32			day, mo, yr;
+	unsigned char		rtc_control = 0;
 
 	ACPI_FUNCTION_TRACE("acpi_system_alarm_seq_show");
 
@@ -91,10 +92,12 @@ static int acpi_system_alarm_seq_show(struct seq_file *seq, void *offset)
 	sec = CMOS_READ(RTC_SECONDS_ALARM);
 	min = CMOS_READ(RTC_MINUTES_ALARM);
 	hr = CMOS_READ(RTC_HOURS_ALARM);
+	rtc_control = CMOS_READ(RTC_CONTROL);
 
-#if 0	/* If we ever get an FACP with proper values... */
+	/* If we ever get an FACP with proper values... */
 	if (acpi_gbl_FADT->day_alrm)
-		day = CMOS_READ(acpi_gbl_FADT->day_alrm);
+		/* ACPI spec: only low 6 its should be cared */
+		day = CMOS_READ(acpi_gbl_FADT->day_alrm) & 0x3F;
 	else
 		day =  CMOS_READ(RTC_DAY_OF_MONTH);
 	if (acpi_gbl_FADT->mon_alrm)
@@ -105,24 +108,20 @@ static int acpi_system_alarm_seq_show(struct seq_file *seq, void *offset)
 		yr = CMOS_READ(acpi_gbl_FADT->century) * 100 + CMOS_READ(RTC_YEAR);
 	else
 		yr = CMOS_READ(RTC_YEAR);
-#else
-	day = CMOS_READ(RTC_DAY_OF_MONTH);
-	mo = CMOS_READ(RTC_MONTH);
-	yr = CMOS_READ(RTC_YEAR);
-#endif
 
 	spin_unlock(&rtc_lock);
 
-	BCD_TO_BIN(sec);
-	BCD_TO_BIN(min);
-	BCD_TO_BIN(hr);
-	BCD_TO_BIN(day);
-	BCD_TO_BIN(mo);
-	BCD_TO_BIN(yr);
+	if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
+		BCD_TO_BIN(sec);
+		BCD_TO_BIN(min);
+		BCD_TO_BIN(hr);
+		BCD_TO_BIN(day);
+		BCD_TO_BIN(mo);
+		BCD_TO_BIN(yr);
+	}
 
-#if 0
 	/* we're trusting the FADT (see above)*/
-#else
+	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?
 	 *
@@ -141,8 +140,7 @@ static int acpi_system_alarm_seq_show(struct seq_file *seq, void *offset)
 	 *        s/2000/2100
 	 *
 	 */
-	yr += 2000;
-#endif
+		yr += 2000;
 
 	seq_printf(seq,"%4.4u-", yr);
 	(mo > 12)  ? seq_puts(seq, "**-")  : seq_printf(seq, "%2.2u-", mo);
@@ -316,6 +314,13 @@ acpi_system_write_alarm (
 	}
 
 	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_WRITE(hr, RTC_HOURS_ALARM);
@@ -327,24 +332,21 @@ acpi_system_write_alarm (
 	 * offsets into the CMOS RAM here -- which for some reason are pointing
 	 * to the RTC area of memory.
 	 */
-#if 0
 	if (acpi_gbl_FADT->day_alrm)
 		CMOS_WRITE(day, acpi_gbl_FADT->day_alrm);
 	if (acpi_gbl_FADT->mon_alrm)
 		CMOS_WRITE(mo, acpi_gbl_FADT->mon_alrm);
 	if (acpi_gbl_FADT->century)
 		CMOS_WRITE(yr/100, acpi_gbl_FADT->century);
-#endif
 	/* enable the rtc alarm interrupt */
-	if (!(rtc_control & RTC_AIE)) {
-		rtc_control |= RTC_AIE;
-		CMOS_WRITE(rtc_control,RTC_CONTROL);
-		CMOS_READ(RTC_INTR_FLAGS);
-	}
+	rtc_control |= RTC_AIE;
+	CMOS_WRITE(rtc_control, RTC_CONTROL);
+	CMOS_READ(RTC_INTR_FLAGS);
 
 	spin_unlock_irq(&rtc_lock);
 
-	acpi_set_register(ACPI_BITREG_RT_CLOCK_ENABLE, 1, ACPI_MTX_LOCK);
+	acpi_clear_event(ACPI_EVENT_RTC);
+	acpi_enable_event(ACPI_EVENT_RTC, 0);
 
 	*ppos += count;
 
@@ -449,6 +451,14 @@ static struct file_operations acpi_system_alarm_fops = {
 };
 
 
+static u32 rtc_handler(void * context)
+{
+	acpi_clear_event(ACPI_EVENT_RTC);
+	acpi_disable_event(ACPI_EVENT_RTC, 0);
+
+	return ACPI_INTERRUPT_HANDLED;
+}
+
 static int acpi_sleep_proc_init(void)
 {
 	struct proc_dir_entry	*entry = NULL;
@@ -474,6 +484,7 @@ static int acpi_sleep_proc_init(void)
 	if (entry)
 		entry->proc_fops = &acpi_system_wakeup_device_fops;
 
+	acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, NULL);
 	return 0;
 }