ptp: ravb: convert to .adjfine and adjust_by_scaled_ppm

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

Convert this driver to .adjfine and use the adjust_by_scaled_ppm helper
function to calculate the new addend.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Cc: Sergey Shtylyov <s.shtylyov@omp.ru>
Cc: Biju Das <biju.das.jz@bp.renesas.com>
Cc: Phil Edworthy <phil.edworthy@renesas.com>
Cc: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Cc: linux-renesas-soc@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/renesas/ravb_ptp.c

@@ -88,24 +88,17 @@ static int ravb_ptp_update_compare(struct ravb_private *priv, u32 ns)
 }
 
 /* PTP clock operations */
-static int ravb_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
+static int ravb_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
 {
 	struct ravb_private *priv = container_of(ptp, struct ravb_private,
 						 ptp.info);
 	struct net_device *ndev = priv->ndev;
 	unsigned long flags;
-	u32 diff, addend;
-	bool neg_adj = false;
+	u32 addend;
 	u32 gccr;
 
-	if (ppb < 0) {
-		neg_adj = true;
-		ppb = -ppb;
-	}
-	addend = priv->ptp.default_addend;
-	diff = div_u64((u64)addend * ppb, NSEC_PER_SEC);
-
-	addend = neg_adj ? addend - diff : addend + diff;
+	addend = (u32)adjust_by_scaled_ppm(priv->ptp.default_addend,
+					   scaled_ppm);
 
 	spin_lock_irqsave(&priv->lock, flags);
 
@@ -295,7 +288,7 @@ static const struct ptp_clock_info ravb_ptp_info = {
 	.max_adj	= 50000000,
 	.n_ext_ts	= N_EXT_TS,
 	.n_per_out	= N_PER_OUT,
-	.adjfreq	= ravb_ptp_adjfreq,
+	.adjfine	= ravb_ptp_adjfine,
 	.adjtime	= ravb_ptp_adjtime,
 	.gettime64	= ravb_ptp_gettime64,
 	.settime64	= ravb_ptp_settime64,