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Commit e7e034e1 authored by Haojian Zhuang's avatar Haojian Zhuang Committed by Linus Torvalds
Browse files

drivers/rtc/rtc-pl031.c: fix the missing operation on enable 



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: default avatarHaojian 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>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 72fca4a4

drivers/rtc/rtc-pl031.c

+5 −3
Original line number Diff line number Diff line
@@ -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_device *adev, const struct amba_id *id) 
	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_device *adev, const struct amba_id *id) 
	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