From 286f9f95fcb165919125ef51bae23ef7a9f24008 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Wed, 27 Oct 2010 15:33:03 -0700 Subject: [PATCH] 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 Acked-by: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-bfin.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) diff --git a/drivers/rtc/rtc-bfin.c b/drivers/rtc/rtc-bfin.c index d4fb82d..3506f33 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; } -- 2.7.4