[net-next 13/14] ptp: cpts: convert to .adjfine and adjust_by_scaled_ppm

[Jacob Keller <jacob.e.keller@intel.com>]

The cpts 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.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Jiasheng Jiang <jiasheng@iscas.ac.cn>
---

I do not have this hardware, and have only compile tested the change.

 drivers/net/ethernet/ti/cpts.c | 21 ++++++---------------
 1 file changed, 6 insertions(+), 15 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c
index 92ca739fac01..ea3a10576d03 100644
--- a/drivers/net/ethernet/ti/cpts.c
+++ b/drivers/net/ethernet/ti/cpts.c
@@ -213,25 +213,16 @@ static void cpts_update_cur_time(struct cpts *cpts, int match,
 
 /* PTP clock operations */
 
-static int cpts_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
+static int cpts_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
 {
 	struct cpts *cpts = container_of(ptp, struct cpts, info);
-	int neg_adj = 0;
-	u32 diff, mult;
-	u64 adj;
+	u32 mult;
 
-	if (ppb < 0) {
-		neg_adj = 1;
-		ppb = -ppb;
-	}
-	mult = cpts->cc_mult;
-	adj = mult;
-	adj *= ppb;
-	diff = div_u64(adj, 1000000000ULL);
+	mult = (u32)adjust_by_scaled_ppm(cpts->cc_mult, scaled_ppm);
 
 	mutex_lock(&cpts->ptp_clk_mutex);
 
-	cpts->mult_new = neg_adj ? mult - diff : mult + diff;
+	cpts->mult_new = mult;
 
 	cpts_update_cur_time(cpts, CPTS_EV_PUSH, NULL);
 
@@ -435,7 +426,7 @@ static const struct ptp_clock_info cpts_info = {
 	.n_ext_ts	= 0,
 	.n_pins		= 0,
 	.pps		= 0,
-	.adjfreq	= cpts_ptp_adjfreq,
+	.adjfine	= cpts_ptp_adjfine,
 	.adjtime	= cpts_ptp_adjtime,
 	.gettimex64	= cpts_ptp_gettimeex,
 	.settime64	= cpts_ptp_settime,
@@ -794,7 +785,7 @@ struct cpts *cpts_create(struct device *dev, void __iomem *regs,
 
 	cpts_calc_mult_shift(cpts);
 	/* save cc.mult original value as it can be modified
-	 * by cpts_ptp_adjfreq().
+	 * by cpts_ptp_adjfine().
 	 */
 	cpts->cc_mult = cpts->cc.mult;
 
-- 
2.37.1.208.ge72d93e88cb2