drivers/rtc/rtc-pl031.c: restore ST variant functionality

Commit e7e034e ("drivers/rtc/rtc-pl031.c: fix the missing operation on enable") accidentally broke the ST variants of PL031. The bit that is being poked as "clockwatch" enable bit for the ST variants does the work of bit 0 on this variant. Bit 0 is used for a clock divider on the ST variants, and setting it to 1 will affect timekeeping in a very bad way. Signed-off-by: Linus Walleij <[email protected]> Acked-by: Haojian Zhuang <[email protected]> Cc: Mian Yousaf KAUKAB <[email protected]> Cc: Srinidhi Kasagar <[email protected]> Cc: Alessandro Zummo <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
jimmycarry · Feb 12, 2013 · 3399cfb · 3399cfb
1 parent 211b0cd
commit 3399cfb
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
@@ -350,7 +350,9 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
 	/* Enable the clockwatch on ST Variants */
 	if (vendor->clockwatch)
 		data |= RTC_CR_CWEN;
-	writel(data | RTC_CR_EN, ldata->base + RTC_CR);
+	else
+		data |= RTC_CR_EN;
+	writel(data, ldata->base + RTC_CR);
 
 	/*
 	 * On ST PL031 variants, the RTC reset value does not provide correct