Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [ 17/34] drivers/rtc/rtc-pl031.c: fix the missing operation on enable | Date | Thu, 7 Feb 2013 16:57:13 -0800 |
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3.7-stable review patch. If anyone has any objections, please let me know.
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From: Haojian Zhuang <haojian.zhuang@linaro.org>
commit e7e034e18a0ab6bafb2425c3242cac311164f4d6 upstream.
The RTC control register should be enabled in the process of initializing.
Without this patch, I failed to enable RTC in Hisilicon Hi3620 SoC. The register mapping section in RTC is always read as zero. So I doubt that ST guys may already enable this register in bootloader. So they won't meet this issue.
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org> Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com> Cc: Linus Walleij <linus.walleij@linaro.org> 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/rtc/rtc-pl031.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
--- a/drivers/rtc/rtc-pl031.c +++ b/drivers/rtc/rtc-pl031.c @@ -44,6 +44,7 @@ #define RTC_YMR 0x34 /* Year match register */ #define RTC_YLR 0x38 /* Year data load register */ +#define RTC_CR_EN (1 << 0) /* counter enable bit */ #define RTC_CR_CWEN (1 << 26) /* Clockwatch enable bit */ #define RTC_TCR_EN (1 << 1) /* Periodic timer enable bit */ @@ -320,7 +321,7 @@ static int pl031_probe(struct amba_devic struct pl031_local *ldata; struct pl031_vendor_data *vendor = id->data; struct rtc_class_ops *ops = &vendor->ops; - unsigned long time; + unsigned long time, data; ret = amba_request_regions(adev, NULL); if (ret) @@ -345,10 +346,11 @@ static int pl031_probe(struct amba_devic dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev)); dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev)); + data = readl(ldata->base + RTC_CR); /* Enable the clockwatch on ST Variants */ if (vendor->clockwatch) - writel(readl(ldata->base + RTC_CR) | RTC_CR_CWEN, - ldata->base + RTC_CR); + data |= RTC_CR_CWEN; + writel(data | RTC_CR_EN, ldata->base + RTC_CR); /* * On ST PL031 variants, the RTC reset value does not provide correct
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