drivers/rtc/rtc-s3c.c: fix incorrect way of save/restore of S3C2410_TICNT for TYPE_S3C64XX

On exynos5250, exynos5420 and exynos5260 it was observed that, after 1
cycle of S2R, the rtc-tick occurs at a very fast rate as compared to the
rtc-tick occuring before S2R.

This patch fixes the above issue by correcting the wrong way of
save/restore of S3C2410_TICNT for TYPE_S3C64XX.

Signed-off-by: Vikas Sajjan <vikas.sajjan@samsung.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 12 insertions, 5 deletions

diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c
index 7afd373b9595..c4cde9c08f1f 100644
--- a/drivers/rtc/rtc-s3c.c
+++ b/drivers/rtc/rtc-s3c.c
@@ -580,10 +580,12 @@ static int s3c_rtc_suspend(struct device *dev)
 
         clk_enable(rtc_clk);
         /* save TICNT for anyone using periodic interrupts */
-        ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
         if (s3c_rtc_cpu_type == TYPE_S3C64XX) {
                 ticnt_en_save = readw(s3c_rtc_base + S3C2410_RTCCON);
                 ticnt_en_save &= S3C64XX_RTCCON_TICEN;
+                ticnt_save = readl(s3c_rtc_base + S3C2410_TICNT);
+        } else {
+                ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
         }
         s3c_rtc_enable(pdev, 0);
 
@@ -605,10 +607,15 @@ static int s3c_rtc_resume(struct device *dev)
 
         clk_enable(rtc_clk);
         s3c_rtc_enable(pdev, 1);
-        writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
-        if (s3c_rtc_cpu_type == TYPE_S3C64XX && ticnt_en_save) {
-                tmp = readw(s3c_rtc_base + S3C2410_RTCCON);
-                writew(tmp | ticnt_en_save, s3c_rtc_base + S3C2410_RTCCON);
+        if (s3c_rtc_cpu_type == TYPE_S3C64XX) {
+                writel(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
+                if (ticnt_en_save) {
+                        tmp = readw(s3c_rtc_base + S3C2410_RTCCON);
+                        writew(tmp | ticnt_en_save,
+                                        s3c_rtc_base + S3C2410_RTCCON);
+                }
+        } else {
+                writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
         }
 
         if (device_may_wakeup(dev) && wake_en) {