diff options
| author | Haojian Zhuang <haojian.zhuang@linaro.org> | 2013-02-04 14:28:54 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-06-07 16:02:13 -0700 |
| commit | d188fc097b4c8fb907ff871651e4109196ea5c9d (patch) | |
| tree | ef1de544b7b2cee2782775d423dd6b5ea48da860 /drivers/rtc | |
| parent | 309fabafdb5cf7112d1a89922ab6acbe7ea7c790 (diff) | |
drivers/rtc/rtc-pl031.c: fix the missing operation on enable
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>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Qiang Huang <h.huangqiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-pl031.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c index f027c063fb2..33060939f8f 100644 --- 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_device *adev, const struct amba_id *id) 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_device *adev, const struct amba_id *id) 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 |