[ 32/55] drivers/rtc/rtc-pl031.c: configure correct wday for 2000-01-01
From: Greg KH <gregkh@linuxfoundation.org>
Date: 2012-05-27 00:59:42
Also in:
lkml
3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Rajkumar Kasirajan <redacted> commit c0a5f4a05af588a0f9951f8d24e2564b09501918 upstream. 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 <redacted> Signed-off-by: Linus Walleij <redacted> Cc: Mattias Wallin <redacted> Cc: Alessandro Zummo <redacted> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/rtc/rtc-pl031.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
--- a/drivers/rtc/rtc-pl031.c
+++ b/drivers/rtc/rtc-pl031.c@@ -312,6 +312,7 @@ static int pl031_probe(struct amba_devic 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_devic 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)) {