This is a note to let you know that I've just added the patch titled
drivers/rtc/rtc-pl031.c: fix the missing operation on enable
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drivers-rtc-rtc-pl031.c-fix-the-missing-operation-on-enable.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 6ec37f6672820465afae0a1dee6d52b11248f7cd Mon Sep 17 00:00:00 2001
From: Haojian Zhuang <[email protected]>
Date: Mon, 4 Feb 2013 14:28:54 -0800
Subject: drivers/rtc/rtc-pl031.c: fix the missing operation on enable
From: Haojian Zhuang <[email protected]>
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 <[email protected]>
Cc: Srinidhi Kasagar <[email protected]>
Cc: Linus Walleij <[email protected]>
Cc: Alessandro Zummo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <[email protected]>
Cc: Qiang Huang <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
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 */
@@ -312,7 +313,7 @@ static int pl031_probe(struct amba_devic
int ret;
struct pl031_local *ldata;
struct rtc_class_ops *ops = id->data;
- unsigned long time;
+ unsigned long time, data;
ret = amba_request_regions(adev, NULL);
if (ret)
@@ -339,10 +340,11 @@ static int pl031_probe(struct amba_devic
dev_dbg(&adev->dev, "designer ID = 0x%02x\n", ldata->hw_designer);
dev_dbg(&adev->dev, "revision = 0x%01x\n", ldata->hw_revision);
+ data = readl(ldata->base + RTC_CR);
/* Enable the clockwatch on ST Variants */
if (ldata->hw_designer == AMBA_VENDOR_ST)
- 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
Patches currently in stable-queue which might be from [email protected]
are
queue-3.4/drivers-rtc-rtc-pl031.c-fix-the-missing-operation-on-enable.patch
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