ARM: 5787/1: U300 COH 901 331 fixes

This will fix some small issues with the COH 901 331 RTC driver:
- Interrupt is disabled after alarm so that we don't fire
  multiple interrupts.
- We return 0 from the coh901331_alarm_irq_enable() ridding
  a compile warning.
- We alter the name in the U300 device registry to match that
  of the driver so they sucessfully resolve.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

2 files changed, 12 insertions, 1 deletions

diff --git a/arch/arm/mach-u300/core.c b/arch/arm/mach-u300/core.c
index be60d6deee8b..653e25be3dd8 100644
--- a/arch/arm/mach-u300/core.c
+++ b/arch/arm/mach-u300/core.c
@@ -408,7 +408,7 @@ static struct platform_device keypad_device = {
 };
 
 static struct platform_device rtc_device = {
-        .name = "rtc0",
+        .name = "rtc-coh901331",
         .id = -1,
         .num_resources = ARRAY_SIZE(rtc_resources),
         .resource = rtc_resources,
diff --git a/drivers/rtc/rtc-coh901331.c b/drivers/rtc/rtc-coh901331.c
index 7fe1fa26c52c..03ea530981d1 100644
--- a/drivers/rtc/rtc-coh901331.c
+++ b/drivers/rtc/rtc-coh901331.c
@@ -58,7 +58,16 @@ static irqreturn_t coh901331_interrupt(int irq, void *data)
         clk_enable(rtap->clk);
         /* Ack IRQ */
         writel(1, rtap->virtbase + COH901331_IRQ_EVENT);
+        /*
+         * Disable the interrupt. This is necessary because
+         * the RTC lives on a lower-clocked line and will
+         * not release the IRQ line until after a few (slower)
+         * clock cycles. The interrupt will be re-enabled when
+         * a new alarm is set anyway.
+         */
+        writel(0, rtap->virtbase + COH901331_IRQ_MASK);
         clk_disable(rtap->clk);
+
         /* Set alarm flag */
         rtc_update_irq(rtap->rtc, 1, RTC_AF);
 
@@ -128,6 +137,8 @@ static int coh901331_alarm_irq_enable(struct device *dev, unsigned int enabled)
         else
                 writel(0, rtap->virtbase + COH901331_IRQ_MASK);
         clk_disable(rtap->clk);
+
+        return 0;
 }
 
 static struct rtc_class_ops coh901331_ops = {