rtc-bfin: shrink/optimize interrupt handler a bit

By unifying the RTC_ISTAT clearing steps, we shrink the interrupt handler
and avoid multiple writes to the hardware registers.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 16 insertions, 11 deletions

diff --git a/drivers/rtc/rtc-bfin.c b/drivers/rtc/rtc-bfin.c
index d4fb82d85e9b..3506f330e97e 100644
--- a/drivers/rtc/rtc-bfin.c
+++ b/drivers/rtc/rtc-bfin.c
@@ -183,29 +183,33 @@ static irqreturn_t bfin_rtc_interrupt(int irq, void *dev_id)
         struct bfin_rtc *rtc = dev_get_drvdata(dev);
         unsigned long events = 0;
         bool write_complete = false;
-        u16 rtc_istat, rtc_ictl;
+        u16 rtc_istat, rtc_istat_clear, rtc_ictl, bits;
 
         dev_dbg_stamp(dev);
 
         rtc_istat = bfin_read_RTC_ISTAT();
         rtc_ictl = bfin_read_RTC_ICTL();
+        rtc_istat_clear = 0;
 
-        if (rtc_istat & RTC_ISTAT_WRITE_COMPLETE) {
-                bfin_write_RTC_ISTAT(RTC_ISTAT_WRITE_COMPLETE);
+        bits = RTC_ISTAT_WRITE_COMPLETE;
+        if (rtc_istat & bits) {
+                rtc_istat_clear |= bits;
                 write_complete = true;
                 complete(&bfin_write_complete);
         }
 
-        if (rtc_ictl & (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY)) {
-                if (rtc_istat & (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY)) {
-                        bfin_write_RTC_ISTAT(RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY);
+        bits = (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY);
+        if (rtc_ictl & bits) {
+                if (rtc_istat & bits) {
+                        rtc_istat_clear |= bits;
                         events |= RTC_AF | RTC_IRQF;
                 }
         }
 
-        if (rtc_ictl & RTC_ISTAT_SEC) {
-                if (rtc_istat & RTC_ISTAT_SEC) {
-                        bfin_write_RTC_ISTAT(RTC_ISTAT_SEC);
+        bits = RTC_ISTAT_SEC;
+        if (rtc_ictl & bits) {
+                if (rtc_istat & bits) {
+                        rtc_istat_clear |= bits;
                         events |= RTC_UF | RTC_IRQF;
                 }
         }
@@ -213,9 +217,10 @@ static irqreturn_t bfin_rtc_interrupt(int irq, void *dev_id)
         if (events)
                 rtc_update_irq(rtc->rtc_dev, 1, events);
 
-        if (write_complete || events)
+        if (write_complete || events) {
+                bfin_write_RTC_ISTAT(rtc_istat_clear);
                 return IRQ_HANDLED;
-        else
+        } else
                 return IRQ_NONE;
 }