rtc: s3c: fix disabled clocks for alarm

The clock enable/disable codes for alarm have been removed from
commit 24e1455493da ("drivers/rtc/rtc-s3c.c: delete duplicate clock
control") and the clocks are disabled even if alarm is set, so alarm
interrupt can't happen.

The s3c_rtc_setaie function can be called several times with 'enabled'
argument having same value, so it needs to check whether clocks are
enabled or not.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Cc: <stable@vger.kernel.org> # v4.1
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

1 files changed, 18 insertions, 6 deletions

diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c
index a0f832362199..2e709e239dbc 100644
--- a/drivers/rtc/rtc-s3c.c
+++ b/drivers/rtc/rtc-s3c.c
@@ -39,6 +39,7 @@ struct s3c_rtc {
         void __iomem *base;
         struct clk *rtc_clk;
         struct clk *rtc_src_clk;
+        bool clk_disabled;
 
         struct s3c_rtc_data *data;
 
@@ -71,9 +72,12 @@ static void s3c_rtc_enable_clk(struct s3c_rtc *info)
         unsigned long irq_flags;
 
         spin_lock_irqsave(&info->alarm_clk_lock, irq_flags);
-        clk_enable(info->rtc_clk);
-        if (info->data->needs_src_clk)
-                clk_enable(info->rtc_src_clk);
+        if (info->clk_disabled) {
+                clk_enable(info->rtc_clk);
+                if (info->data->needs_src_clk)
+                        clk_enable(info->rtc_src_clk);
+                info->clk_disabled = false;
+        }
         spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags);
 }
 
@@ -82,9 +86,12 @@ static void s3c_rtc_disable_clk(struct s3c_rtc *info)
         unsigned long irq_flags;
 
         spin_lock_irqsave(&info->alarm_clk_lock, irq_flags);
-        if (info->data->needs_src_clk)
-                clk_disable(info->rtc_src_clk);
-        clk_disable(info->rtc_clk);
+        if (!info->clk_disabled) {
+                if (info->data->needs_src_clk)
+                        clk_disable(info->rtc_src_clk);
+                clk_disable(info->rtc_clk);
+                info->clk_disabled = true;
+        }
         spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags);
 }
 
@@ -128,6 +135,11 @@ static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
 
         s3c_rtc_disable_clk(info);
 
+        if (enabled)
+                s3c_rtc_enable_clk(info);
+        else
+                s3c_rtc_disable_clk(info);
+
         return 0;
 }