ptp: mlx5: convert to .adjfine and adjust_by_scaled_ppm

The mlx5 implementation of .adjfreq is implemented in terms of a
straight forward "base * ppb / 1 billion" calculation.

Convert this to the .adjfine interface and use adjust_by_scaled_ppm for the
calculation  of the new mult value.

Note that the mlx5_ptp_adjfreq_real_time function expects input in terms of
ppb, so use the scaled_ppm_to_ppb to convert before passing to this
function.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Shirly Ohnona <shirlyo@nvidia.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Cc: Gal Pressman <gal@nvidia.com>
Cc: Saeed Mahameed <saeedm@nvidia.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Aya Levin <ayal@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c

@@ -339,35 +339,25 @@ static int mlx5_ptp_adjfreq_real_time(struct mlx5_core_dev *mdev, s32 freq)
 	return mlx5_set_mtutc(mdev, in, sizeof(in));
 }
 
-static int mlx5_ptp_adjfreq(struct ptp_clock_info *ptp, s32 delta)
+static int mlx5_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
 {
 	struct mlx5_clock *clock = container_of(ptp, struct mlx5_clock, ptp_info);
 	struct mlx5_timer *timer = &clock->timer;
 	struct mlx5_core_dev *mdev;
 	unsigned long flags;
-	int neg_adj = 0;
-	u32 diff;
-	u64 adj;
+	u32 mult;
 	int err;
 
 	mdev = container_of(clock, struct mlx5_core_dev, clock);
-	err = mlx5_ptp_adjfreq_real_time(mdev, delta);
+	err = mlx5_ptp_adjfreq_real_time(mdev, scaled_ppm_to_ppb(scaled_ppm));
 	if (err)
 		return err;
 
-	if (delta < 0) {
-		neg_adj = 1;
-		delta = -delta;
-	}
-
-	adj = timer->nominal_c_mult;
-	adj *= delta;
-	diff = div_u64(adj, 1000000000ULL);
+	mult = (u32)adjust_by_scaled_ppm(timer->nominal_c_mult, scaled_ppm);
 
 	write_seqlock_irqsave(&clock->lock, flags);
 	timecounter_read(&timer->tc);
-	timer->cycles.mult = neg_adj ? timer->nominal_c_mult - diff :
-				       timer->nominal_c_mult + diff;
+	timer->cycles.mult = mult;
 	mlx5_update_clock_info_page(mdev);
 	write_sequnlock_irqrestore(&clock->lock, flags);
 
@@ -697,7 +687,7 @@ static const struct ptp_clock_info mlx5_ptp_clock_info = {
 	.n_per_out	= 0,
 	.n_pins		= 0,
 	.pps		= 0,
-	.adjfreq	= mlx5_ptp_adjfreq,
+	.adjfine	= mlx5_ptp_adjfine,
 	.adjtime	= mlx5_ptp_adjtime,
 	.gettimex64	= mlx5_ptp_gettimex,
 	.settime64	= mlx5_ptp_settime,