drivers/rtc/rtc-ab8500.c: use UIE emulation

RTC: Fix to correct improper implementation of clock update irq
(RTC_UIE) and enable UIE Emulation.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Ramesh Chandrasekaran <ramesh.chandrasekaran@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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>

2 files changed, 15 insertions, 1 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 08cbdb900a18..668da5922d9e 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -694,6 +694,7 @@ config RTC_DRV_AB3100
 config RTC_DRV_AB8500
         tristate "ST-Ericsson AB8500 RTC"
         depends on AB8500_CORE
+        select RTC_INTF_DEV_UIE_EMUL
         help
           Select this to enable the ST-Ericsson AB8500 power management IC RTC
           support. This chip contains a battery- and capacitor-backed RTC.
diff --git a/drivers/rtc/rtc-ab8500.c b/drivers/rtc/rtc-ab8500.c
index 370889d0489b..1a57e03e169d 100644
--- a/drivers/rtc/rtc-ab8500.c
+++ b/drivers/rtc/rtc-ab8500.c
@@ -225,7 +225,8 @@ static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 {
         int retval, i;
         unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
-        unsigned long mins, secs = 0;
+        unsigned long mins, secs = 0, cursec = 0;
+        struct rtc_time curtm;
 
         if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
                 dev_dbg(dev, "year should be equal to or greater than %d\n",
@@ -237,6 +238,18 @@ static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
         rtc_tm_to_time(&alarm->time, &secs);
 
         /*
+         * Check whether alarm is set less than 1min.
+         * Since our RTC doesn't support alarm resolution less than 1min,
+         * return -EINVAL, so UIE EMUL can take it up, incase of UIE_ON
+         */
+        ab8500_rtc_read_time(dev, &curtm); /* Read current time */
+        rtc_tm_to_time(&curtm, &cursec);
+        if ((secs - cursec) < 59) {
+                dev_dbg(dev, "Alarm less than 1 minute not supported\r\n");
+                return -EINVAL;
+        }
+
+        /*
          * Convert it to the number of seconds since 01-01-2000 00:00:00, since
          * we only have a small counter in the RTC.
          */