From 26cb8bb21b11245a53f79d9fa766537752f77d88 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Tue, 5 Aug 2008 13:01:21 -0700 Subject: [PATCH] blackfin RTC driver: drop PIE/stopwatch code since the hardware can only do a max of 1HZ and this same functionality is provided by UIE Signed-off-by: Mike Frysinger Signed-off-by: Bryan Wu Cc: David Brownell Cc: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-bfin.c | 46 +++++++++++++----------------------------- 1 file changed, 14 insertions(+), 32 deletions(-) diff --git a/drivers/rtc/rtc-bfin.c b/drivers/rtc/rtc-bfin.c index ceebce7e0a..a1af4c2793 100644 --- a/drivers/rtc/rtc-bfin.c +++ b/drivers/rtc/rtc-bfin.c @@ -32,6 +32,15 @@ * writes to clear status registers complete immediately. */ +/* It may seem odd that there is no SWCNT code in here (which would be exposed + * via the periodic interrupt event, or PIE). Since the Blackfin RTC peripheral + * runs in units of seconds (N/HZ) but the Linux framework runs in units of HZ + * (2^N HZ), there is no point in keeping code that only provides 1 HZ PIEs. + * The same exact behavior can be accomplished by using the update interrupt + * event (UIE). Maybe down the line the RTC peripheral will suck less in which + * case we can re-introduce PIE support. + */ + #include #include #include @@ -151,7 +160,6 @@ static void bfin_rtc_reset(struct device *dev, u16 rtc_ictl) bfin_rtc_sync_pending(dev); bfin_write_RTC_PREN(0x1); bfin_write_RTC_ICTL(rtc_ictl); - bfin_write_RTC_SWCNT(0); bfin_write_RTC_ALARM(0); bfin_write_RTC_ISTAT(0xFFFF); rtc->rtc_wrote_regs = 0; @@ -194,14 +202,6 @@ static irqreturn_t bfin_rtc_interrupt(int irq, void *dev_id) } } - if (rtc_ictl & RTC_ISTAT_STOPWATCH) { - if (rtc_istat & RTC_ISTAT_STOPWATCH) { - bfin_write_RTC_ISTAT(RTC_ISTAT_STOPWATCH); - events |= RTC_PF | RTC_IRQF; - bfin_write_RTC_SWCNT(rtc->rtc_dev->irq_freq); - } - } - if (rtc_ictl & RTC_ISTAT_SEC) { if (rtc_istat & RTC_ISTAT_SEC) { bfin_write_RTC_ISTAT(RTC_ISTAT_SEC); @@ -361,33 +361,14 @@ static int bfin_rtc_proc(struct device *dev, struct seq_file *seq) seq_printf(seq, "alarm_IRQ\t: %s\n" "wkalarm_IRQ\t: %s\n" - "seconds_IRQ\t: %s\n" - "periodic_IRQ\t: %s\n", + "seconds_IRQ\t: %s\n", yesno(ictl & RTC_ISTAT_ALARM), yesno(ictl & RTC_ISTAT_ALARM_DAY), - yesno(ictl & RTC_ISTAT_SEC), - yesno(ictl & RTC_ISTAT_STOPWATCH)); + yesno(ictl & RTC_ISTAT_SEC)); return 0; #undef yesno } -static int bfin_irq_set_state(struct device *dev, int enabled) -{ - struct bfin_rtc *rtc = dev_get_drvdata(dev); - - dev_dbg_stamp(dev); - - bfin_rtc_sync_pending(dev); - - if (enabled) { - bfin_rtc_int_set(RTC_ISTAT_STOPWATCH); - bfin_write_RTC_SWCNT(rtc->rtc_dev->irq_freq); - } else - bfin_rtc_int_clear(~RTC_ISTAT_STOPWATCH); - - return 0; -} - static struct rtc_class_ops bfin_rtc_ops = { .open = bfin_rtc_open, .release = bfin_rtc_release, @@ -397,7 +378,6 @@ static struct rtc_class_ops bfin_rtc_ops = { .read_alarm = bfin_rtc_read_alarm, .set_alarm = bfin_rtc_set_alarm, .proc = bfin_rtc_proc, - .irq_set_state = bfin_irq_set_state, }; static int __devinit bfin_rtc_probe(struct platform_device *pdev) @@ -416,7 +396,9 @@ static int __devinit bfin_rtc_probe(struct platform_device *pdev) ret = PTR_ERR(rtc->rtc_dev); goto err; } - rtc->rtc_dev->irq_freq = 1; + + /* see comment at top of file about stopwatch/PIE */ + bfin_write_RTC_SWCNT(0); platform_set_drvdata(pdev, rtc); -- 2.39.5