ptp: xgbe: convert to .adjfine and adjust_by_scaled_ppm

The xgbe implementation of .adjfreq is implemented in terms of a
straight forward "base * ppb / 1 billion" calculation.

Convert this driver to .adjfine and use adjust_by_scaled_ppm to calculate
the new addend value.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/amd/xgbe/xgbe-ptp.c

@@ -134,27 +134,15 @@ static u64 xgbe_cc_read(const struct cyclecounter *cc)
 	return nsec;
 }
 
-static int xgbe_adjfreq(struct ptp_clock_info *info, s32 delta)
+static int xgbe_adjfine(struct ptp_clock_info *info, long scaled_ppm)
 {
 	struct xgbe_prv_data *pdata = container_of(info,
 						   struct xgbe_prv_data,
 						   ptp_clock_info);
 	unsigned long flags;
-	u64 adjust;
-	u32 addend, diff;
-	unsigned int neg_adjust = 0;
+	u64 addend;
 
-	if (delta < 0) {
-		neg_adjust = 1;
-		delta = -delta;
-	}
-
-	adjust = pdata->tstamp_addend;
-	adjust *= delta;
-	diff = div_u64(adjust, 1000000000UL);
-
-	addend = (neg_adjust) ? pdata->tstamp_addend - diff :
-				pdata->tstamp_addend + diff;
+	addend = adjust_by_scaled_ppm(pdata->tstamp_addend, scaled_ppm);
 
 	spin_lock_irqsave(&pdata->tstamp_lock, flags);
 
@@ -235,7 +223,7 @@ void xgbe_ptp_register(struct xgbe_prv_data *pdata)
 		 netdev_name(pdata->netdev));
 	info->owner = THIS_MODULE;
 	info->max_adj = pdata->ptpclk_rate;
-	info->adjfreq = xgbe_adjfreq;
+	info->adjfine = xgbe_adjfine;
 	info->adjtime = xgbe_adjtime;
 	info->gettime64 = xgbe_gettime;
 	info->settime64 = xgbe_settime;