Commit 5981804b authored Jan 27, 2016 by Javier Martinez Canillas Committed by Alexandre Belloni Feb 04, 2016

rtc: max77686: Use usleep_range() instead of msleep()

Documentation/timers/timers-howto.txt suggest to use usleep_range()
instead of msleep() for small msec (1ms - 20ms) since msleep() will
often sleep for 20ms for any value in that range.

This is fine in this case since 16ms is the _minimum_ delay required
by max77686 for an RTC update but by using usleep_range() instead of
msleep(), the driver can support other RTC IP blocks with a shorter
minimum delay (i.e: in the range of usecs instead of msecs).

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

parent 862f9453

drivers/rtc/rtc-max77686.c

+3 −2

Original line number	Original line	Diff line number	Diff line
	@@ -41,7 +41,7 @@
	#define ALARM_ENABLE_SHIFT 7		#define ALARM_ENABLE_SHIFT 7
	#define ALARM_ENABLE_MASK (1 << ALARM_ENABLE_SHIFT)		#define ALARM_ENABLE_MASK (1 << ALARM_ENABLE_SHIFT)

	#define MAX77686_RTC_UPDATE_DELAY 16		#define MAX77686_RTC_UPDATE_DELAY 16000

	enum {		enum {
	RTC_SEC = 0,		RTC_SEC = 0,
	@@ -130,7 +130,8 @@ static int max77686_rtc_update(struct max77686_rtc_info *info,
	__func__, ret, data);		__func__, ret, data);
	else {		else {
	/* Minimum 16ms delay required before RTC update. */		/* Minimum 16ms delay required before RTC update. */
	msleep(MAX77686_RTC_UPDATE_DELAY);		usleep_range(MAX77686_RTC_UPDATE_DELAY,
			MAX77686_RTC_UPDATE_DELAY * 2);
	}		}

	return ret;		return ret;