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authorRajkumar Kasirajan <rajkumar.kasirajan@stericsson.com>2012-05-17 17:03:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-17 18:00:51 -0700
commitc0a5f4a05af588a0f9951f8d24e2564b09501918 (patch)
treef96b6f0e201978ad9d2cb03a59a83940304fbe3b
parent1be5f0b7575e090fd100a98b303860879b5800de (diff)
drivers/rtc/rtc-pl031.c: configure correct wday for 2000-01-01
The reset date of the ST Micro version of PL031 is 2000-01-01. The correct weekday for 2000-01-01 is saturday, but pl031 is initialized to sunday. This may lead to alarm malfunction, so configure the correct wday if RTC_DR indicates reset. Signed-off-by: Rajkumar Kasirajan <rajkumar.kasirajan@stericsson.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Cc: Mattias Wallin <mattias.wallin@stericsson.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/rtc/rtc-pl031.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
index 684ef4bbfce4..f027c063fb20 100644
--- a/drivers/rtc/rtc-pl031.c
+++ b/drivers/rtc/rtc-pl031.c
@@ -312,6 +312,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
int ret;
struct pl031_local *ldata;
struct rtc_class_ops *ops = id->data;
+ unsigned long time;
ret = amba_request_regions(adev, NULL);
if (ret)
@@ -343,6 +344,23 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
writel(readl(ldata->base + RTC_CR) | RTC_CR_CWEN,
ldata->base + RTC_CR);
+ /*
+ * On ST PL031 variants, the RTC reset value does not provide correct
+ * weekday for 2000-01-01. Correct the erroneous sunday to saturday.
+ */
+ if (ldata->hw_designer == AMBA_VENDOR_ST) {
+ if (readl(ldata->base + RTC_YDR) == 0x2000) {
+ time = readl(ldata->base + RTC_DR);
+ if ((time &
+ (RTC_MON_MASK | RTC_MDAY_MASK | RTC_WDAY_MASK))
+ == 0x02120000) {
+ time = time | (0x7 << RTC_WDAY_SHIFT);
+ writel(0x2000, ldata->base + RTC_YLR);
+ writel(time, ldata->base + RTC_LR);
+ }
+ }
+ }
+
ldata->rtc = rtc_device_register("pl031", &adev->dev, ops,
THIS_MODULE);
if (IS_ERR(ldata->rtc)) {