1 files changed, 15 insertions, 1 deletions

diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
index 734e40804732..03bce134414c 100644
--- a/drivers/rtc/rtc-omap.c
+++ b/drivers/rtc/rtc-omap.c
@@ -96,6 +96,9 @@
 #define OMAP_RTC_INTERRUPTS_IT_ALARM    BIT(3)
 #define OMAP_RTC_INTERRUPTS_IT_TIMER    BIT(2)
 
+/* OMAP_RTC_OSC_REG bit fields: */
+#define OMAP_RTC_OSC_32KCLK_EN          BIT(6)
+
 /* OMAP_RTC_IRQWAKEEN bit fields: */
 #define OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN BIT(1)
 
@@ -111,6 +114,12 @@
  */
 #define OMAP_RTC_HAS_IRQWAKEEN          BIT(1)
 
+/*
+ * Some RTC IP revisions (like those in AM335x and DRA7x) need
+ * the 32KHz clock to be explicitly enabled.
+ */
+#define OMAP_RTC_HAS_32KCLK_EN          BIT(2)
+
 static void __iomem     *rtc_base;
 
 #define rtc_read(addr)          readb(rtc_base + (addr))
@@ -319,7 +328,8 @@ static struct platform_device_id omap_rtc_devtype[] = {
         },
         [OMAP_RTC_DATA_AM3352_IDX] = {
                 .name   = "am3352-rtc",
-                .driver_data = OMAP_RTC_HAS_KICKER | OMAP_RTC_HAS_IRQWAKEEN,
+                .driver_data = OMAP_RTC_HAS_KICKER | OMAP_RTC_HAS_IRQWAKEEN |
+                               OMAP_RTC_HAS_32KCLK_EN,
         },
         [OMAP_RTC_DATA_DA830_IDX] = {
                 .name   = "da830-rtc",
@@ -398,6 +408,10 @@ static int __init omap_rtc_probe(struct platform_device *pdev)
          */
         rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
 
+        /* enable RTC functional clock */
+        if (id_entry->driver_data & OMAP_RTC_HAS_32KCLK_EN)
+                rtc_writel(OMAP_RTC_OSC_32KCLK_EN, OMAP_RTC_OSC_REG);
+
         /* clear old status */
         reg = rtc_read(OMAP_RTC_STATUS_REG);
         if (reg & (u8) OMAP_RTC_STATUS_POWER_UP) {