drivers/rtc/rtc-s3c.c: fix no occurrence of alarm interrupt
Donggeun Kim [Wed, 14 Sep 2011 23:22:19 +0000 (16:22 -0700)]
The driver does not generate an alarm interrupt even though a time for
an alarm is set.

This results from disabling rtc_clk after setting the alarm time.

To generate an alarm interrupt the driver should maintain its enabled
state for rtc_clk the until alarm interrupt occurs.  This patch permits
generation of an alarm interrupt.

[akpm@linux-foundation.org: make s3c_rtc_alarm_clk_lock local to s3c_rtc_alarm_clk_enable()]
Signed-off-by: Donggeun Kim <dg77.kim@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-s3c.c

index 4e7c04e..7639ab9 100644 (file)
@@ -51,6 +51,27 @@ static enum s3c_cpu_type s3c_rtc_cpu_type;
 
 static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
 
+static void s3c_rtc_alarm_clk_enable(bool enable)
+{
+       static DEFINE_SPINLOCK(s3c_rtc_alarm_clk_lock);
+       static bool alarm_clk_enabled;
+       unsigned long irq_flags;
+
+       spin_lock_irqsave(&s3c_rtc_alarm_clk_lock, irq_flags);
+       if (enable) {
+               if (!alarm_clk_enabled) {
+                       clk_enable(rtc_clk);
+                       alarm_clk_enabled = true;
+               }
+       } else {
+               if (alarm_clk_enabled) {
+                       clk_disable(rtc_clk);
+                       alarm_clk_enabled = false;
+               }
+       }
+       spin_unlock_irqrestore(&s3c_rtc_alarm_clk_lock, irq_flags);
+}
+
 /* IRQ Handlers */
 
 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
@@ -64,6 +85,9 @@ static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
                writeb(S3C2410_INTP_ALM, s3c_rtc_base + S3C2410_INTP);
 
        clk_disable(rtc_clk);
+
+       s3c_rtc_alarm_clk_enable(false);
+
        return IRQ_HANDLED;
 }
 
@@ -97,6 +121,8 @@ static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
        writeb(tmp, s3c_rtc_base + S3C2410_RTCALM);
        clk_disable(rtc_clk);
 
+       s3c_rtc_alarm_clk_enable(enabled);
+
        return 0;
 }