2 files changed, 49 insertions, 1 deletions

diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 5c1702789be4..d65ced59a18f 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -107,6 +107,7 @@ int is_hpet_enabled(void)
 {
         return is_hpet_capable() && hpet_legacy_int_enabled;
 }
+EXPORT_SYMBOL_GPL(is_hpet_enabled);
 
 /*
  * When the hpet driver (/dev/hpet) is enabled, we need to reserve
@@ -475,6 +476,7 @@ void hpet_disable(void)
  */
 #include <linux/mc146818rtc.h>
 #include <linux/rtc.h>
+#include <asm/rtc.h>
 
 #define DEFAULT_RTC_INT_FREQ    64
 #define DEFAULT_RTC_SHIFT       6
@@ -489,6 +491,38 @@ static unsigned long hpet_default_delta;
 static unsigned long hpet_pie_delta;
 static unsigned long hpet_pie_limit;
 
+static rtc_irq_handler irq_handler;
+
+/*
+ * Registers a IRQ handler.
+ */
+int hpet_register_irq_handler(rtc_irq_handler handler)
+{
+        if (!is_hpet_enabled())
+                return -ENODEV;
+        if (irq_handler)
+                return -EBUSY;
+
+        irq_handler = handler;
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(hpet_register_irq_handler);
+
+/*
+ * Deregisters the IRQ handler registered with hpet_register_irq_handler()
+ * and does cleanup.
+ */
+void hpet_unregister_irq_handler(rtc_irq_handler handler)
+{
+        if (!is_hpet_enabled())
+                return;
+
+        irq_handler = NULL;
+        hpet_rtc_flags = 0;
+}
+EXPORT_SYMBOL_GPL(hpet_unregister_irq_handler);
+
 /*
  * Timer 1 for RTC emulation. We use one shot mode, as periodic mode
  * is not supported by all HPET implementations for timer 1.
@@ -530,6 +564,7 @@ int hpet_rtc_timer_init(void)
 
         return 1;
 }
+EXPORT_SYMBOL_GPL(hpet_rtc_timer_init);
 
 /*
  * The functions below are called from rtc driver.
@@ -544,6 +579,7 @@ int hpet_mask_rtc_irq_bit(unsigned long bit_mask)
         hpet_rtc_flags &= ~bit_mask;
         return 1;
 }
+EXPORT_SYMBOL_GPL(hpet_mask_rtc_irq_bit);
 
 int hpet_set_rtc_irq_bit(unsigned long bit_mask)
 {
@@ -559,6 +595,7 @@ int hpet_set_rtc_irq_bit(unsigned long bit_mask)
 
         return 1;
 }
+EXPORT_SYMBOL_GPL(hpet_set_rtc_irq_bit);
 
 int hpet_set_alarm_time(unsigned char hrs, unsigned char min,
                         unsigned char sec)
@@ -572,6 +609,7 @@ int hpet_set_alarm_time(unsigned char hrs, unsigned char min,
 
         return 1;
 }
+EXPORT_SYMBOL_GPL(hpet_set_alarm_time);
 
 int hpet_set_periodic_freq(unsigned long freq)
 {
@@ -590,11 +628,13 @@ int hpet_set_periodic_freq(unsigned long freq)
         }
         return 1;
 }
+EXPORT_SYMBOL_GPL(hpet_set_periodic_freq);
 
 int hpet_rtc_dropped_irq(void)
 {
         return is_hpet_enabled();
 }
+EXPORT_SYMBOL_GPL(hpet_rtc_dropped_irq);
 
 static void hpet_rtc_timer_reinit(void)
 {
@@ -638,9 +678,10 @@ irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
         unsigned long rtc_int_flag = 0;
 
         hpet_rtc_timer_reinit();
+        memset(&curr_time, 0, sizeof(struct rtc_time));
 
         if (hpet_rtc_flags & (RTC_UIE | RTC_AIE))
-                rtc_get_rtc_time(&curr_time);
+                get_rtc_time(&curr_time);
 
         if (hpet_rtc_flags & RTC_UIE &&
             curr_time.tm_sec != hpet_prev_update_sec) {
@@ -662,8 +703,12 @@ irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
 
         if (rtc_int_flag) {
                 rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8));
+                if (irq_handler)
+                        irq_handler(rtc_int_flag, dev_id);
+
                 rtc_interrupt(rtc_int_flag, dev_id);
         }
         return IRQ_HANDLED;
 }
+EXPORT_SYMBOL_GPL(hpet_rtc_interrupt);
 #endif
diff --git a/include/asm-x86/hpet.h b/include/asm-x86/hpet.h
index 624f600f7161..6a9b4ac59bf7 100644
--- a/include/asm-x86/hpet.h
+++ b/include/asm-x86/hpet.h
@@ -69,6 +69,7 @@ extern void force_hpet_resume(void);
 
 #include <linux/interrupt.h>
 
+typedef irqreturn_t (*rtc_irq_handler)(int interrupt, void *cookie);
 extern int hpet_mask_rtc_irq_bit(unsigned long bit_mask);
 extern int hpet_set_rtc_irq_bit(unsigned long bit_mask);
 extern int hpet_set_alarm_time(unsigned char hrs, unsigned char min,
@@ -77,6 +78,8 @@ extern int hpet_set_periodic_freq(unsigned long freq);
 extern int hpet_rtc_dropped_irq(void);
 extern int hpet_rtc_timer_init(void);
 extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id);
+extern int hpet_register_irq_handler(rtc_irq_handler handler);
+extern void hpet_unregister_irq_handler(rtc_irq_handler handler);
 
 #endif /* CONFIG_HPET_EMULATE_RTC */