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ptp: idt82p33: optimize _idt82p33_adjfine 

Use div_s64 so that the neg_adj is not needed.

Signed-off-by: Min Li <min.li.xe@renesas.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Link: https://lore.kernel.org/r/1604634729-24960-3-git-send-email-min.li.xe@renesas.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Min Li 2020-11-05 22:52:09 -05:00 committed by Jakub Kicinski
parent e4c6eb6834
commit 6c196f36f5
1 changed files with 1 additions and 9 deletions
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10
drivers/ptp/ptp_idt82p33.c
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@ -320,7 +320,6 @@ static int _idt82p33_adjfine(struct idt82p33_channel *channel, long scaled_ppm)
{
struct idt82p33 *idt82p33 = channel->idt82p33;
unsigned char buf[5] = {0};
int neg_adj = 0;
int err, i;
s64 fcw;
@ -340,16 +339,9 @@ static int _idt82p33_adjfine(struct idt82p33_channel *channel, long scaled_ppm)
* FCW = -------------
* 168 * 2^4
*/
if (scaled_ppm < 0) {
neg_adj = 1;
scaled_ppm = -scaled_ppm;
}
fcw = scaled_ppm * 244140625ULL;
fcw = div_u64(fcw, 2688);
if (neg_adj)
fcw = -fcw;
fcw = div_s64(fcw, 2688);
for (i = 0; i < 5; i++) {
buf[i] = fcw & 0xff;