blackfin RTC driver: drop PIE/stopwatch code since the hardware can only do a max...

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Cc: David Brownell <david-b@pacbell.net>
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-bfin.c b/drivers/rtc/rtc-bfin.c
index ceebce7e0a0feb97dd143ab77268ea115fc98dd2..a1af4c27939b446b0de1f43d8d61c7a51b610d21 100644 (file)
--- 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 <linux/bcd.h>
 #include <linux/completion.h>
 #include <linux/delay.h>
@@ -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);