From: Javier Martinez Canillas Date: Mon, 13 Oct 2014 22:53:03 +0000 (-0700) Subject: rtc: max77686: Use ffs() to calculate tm_wday X-Git-Tag: firefly_0821_release~176^2~3041^2~76 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=a20cd88e20e59ce11ebca84fac769654193c51e0;p=firefly-linux-kernel-4.4.55.git rtc: max77686: Use ffs() to calculate tm_wday max77686_rtc_calculate_wday() is used to calculate the day of the week to be filled in struct rtc_time but that function only calculates the number of bits shifted. So the ffs() function can be used to find the first bit set instead of a special function. [akpm@linux-foundation.org: add comment clarifying ffs() use] Signed-off-by: Javier Martinez Canillas Cc: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/rtc/rtc-max77686.c b/drivers/rtc/rtc-max77686.c index b177ba199a3d..cf73e969c8cc 100644 --- a/drivers/rtc/rtc-max77686.c +++ b/drivers/rtc/rtc-max77686.c @@ -70,16 +70,6 @@ enum MAX77686_RTC_OP { MAX77686_RTC_READ, }; -static inline int max77686_rtc_calculate_wday(u8 shifted) -{ - int counter = -1; - while (shifted) { - shifted >>= 1; - counter++; - } - return counter; -} - static void max77686_rtc_data_to_tm(u8 *data, struct rtc_time *tm, int rtc_24hr_mode) { @@ -93,7 +83,8 @@ static void max77686_rtc_data_to_tm(u8 *data, struct rtc_time *tm, tm->tm_hour += 12; } - tm->tm_wday = max77686_rtc_calculate_wday(data[RTC_WEEKDAY] & 0x7f); + /* Only a single bit is set in data[], so fls() would be equivalent */ + tm->tm_wday = ffs(data[RTC_WEEKDAY] & 0x7f) - 1; tm->tm_mday = data[RTC_DATE] & 0x1f; tm->tm_mon = (data[RTC_MONTH] & 0x0f) - 1; tm->tm_year = (data[RTC_YEAR] & 0x7f) + 100;