drivers/rtc/rtc-twl.c: optimize IRQ bit access
As the TWL RTC driver has a cached copy of enabled RTC interrupt bits in
variable rtc_irq_bits, that can be checked before really setting or
masking any of the interrupt bits.
Signed-off-by: Venu Byravarasu <vbyravarasu@nvidia.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/rtc-twl.c b/drivers/rtc/rtc-twl.c
index d43b4f6..18dff52 100644
--- a/drivers/rtc/rtc-twl.c
+++ b/drivers/rtc/rtc-twl.c
@@ -176,6 +176,10 @@
unsigned char val;
int ret;
+ /* if the bit is set, return from here */
+ if (rtc_irq_bits & bit)
+ return 0;
+
val = rtc_irq_bits | bit;
val &= ~BIT_RTC_INTERRUPTS_REG_EVERY_M;
ret = twl_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG);
@@ -193,6 +197,10 @@
unsigned char val;
int ret;
+ /* if the bit is clear, return from here */
+ if (!(rtc_irq_bits & bit))
+ return 0;
+
val = rtc_irq_bits & ~bit;
ret = twl_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG);
if (ret == 0)