rtc: omap: Cut down the shutdown time from 2 seconds to 1 sec

commit 09058eab4b4f77b721572da5291532e751b63931 upstream

Cut down the shutdown time from 2 seconds to 1 sec. In case of roll
over try again.

Signed-off-by: Keerthy <j-keerthy@ti.com>

diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
index 44ff4cc62a61746d775173beb65591ed6107b7bc..320b4a520eb34de9af60969b032636d7ac6dcc7c 100644 (file)
--- a/drivers/rtc/rtc-omap.c
+++ b/drivers/rtc/rtc-omap.c
@@ -421,12 +421,6 @@ static struct omap_rtc *omap_rtc_power_off_rtc;
  * The RTC can be used to control an external PMIC via the pmic_power_en pin,
  * which can be configured to transition to OFF on ALARM2 events.
  *
- * Notes:
- * The two-second alarm offset is the shortest offset possible as the alarm
- * registers must be set before the next timer update and the offset
- * calculation is too heavy for everything to be done within a single access
- * period (~15 us).
- *
  * Called with local interrupts disabled.
  */
 static void omap_rtc_power_off(void)
@@ -434,6 +428,7 @@ static void omap_rtc_power_off(void)
        struct omap_rtc *rtc = omap_rtc_power_off_rtc;
        struct rtc_time tm;
        unsigned long now;
+       int seconds;
        u32 val;
 
        rtc->type->unlock(rtc);
@@ -441,11 +436,13 @@ static void omap_rtc_power_off(void)
        val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
        rtc_writel(rtc, OMAP_RTC_PMIC_REG, val | OMAP_RTC_PMIC_POWER_EN_EN);
 
-       /* set alarm two seconds from now */
+again:
+       /* set alarm one second from now */
        omap_rtc_read_time_raw(rtc, &tm);
+       seconds = tm.tm_sec;
        bcd2tm(&tm);
        rtc_tm_to_time(&tm, &now);
-       rtc_time_to_tm(now + 2, &tm);
+       rtc_time_to_tm(now + 1, &tm);
 
        if (tm2bcd(&tm) < 0) {
                dev_err(&rtc->rtc->dev, "power off failed\n");
@@ -470,14 +467,22 @@ static void omap_rtc_power_off(void)
        val = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
        rtc_writel(rtc, OMAP_RTC_INTERRUPTS_REG,
                        val | OMAP_RTC_INTERRUPTS_IT_ALARM2);
+
+       /* Retry in case roll over happened before alarm was armed. */
+       if (rtc_read(rtc, OMAP_RTC_SECONDS_REG) != seconds) {
+               val = rtc_read(rtc, OMAP_RTC_STATUS_REG);
+               if (!(val & OMAP_RTC_STATUS_ALARM2))
+                       goto again;
+       }
+
        rtc->type->lock(rtc);
 
        /*
-        * Wait for alarm to trigger (within two seconds) and external PMIC to
+        * Wait for alarm to trigger (within one second) and external PMIC to
         * power off the system. Add a 500 ms margin for external latencies
         * (e.g. debounce circuits).
         */
-       mdelay(2500);
+       mdelay(1500);
 }
 
 static const struct rtc_class_ops omap_rtc_ops = {