ptp: lan743x: use diff_by_scaled_ppm in .adjfine implementation

Update the lan743x driver to use the recently added diff_by_scaled_ppm
helper function. This reduces the amount of code required in lan743x_ptp.c
driver file.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Cc: Bryan Whitehead <bryan.whitehead@microchip.com>
Cc: UNGLinuxDriver@microchip.com
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/microchip/lan743x_ptp.c b/drivers/net/ethernet/microchip/lan743x_ptp.c
index 28930f3..39e1066 100644 (file)
--- a/drivers/net/ethernet/microchip/lan743x_ptp.c
+++ b/drivers/net/ethernet/microchip/lan743x_ptp.c
@@ -339,25 +339,18 @@ static int lan743x_ptpci_adjfine(struct ptp_clock_info *ptpci, long scaled_ppm)
        struct lan743x_adapter *adapter =
                container_of(ptp, struct lan743x_adapter, ptp);
        u32 lan743x_rate_adj = 0;
-       bool positive = true;
-       u64 u64_delta = 0;
+       u64 u64_delta;
 
        if ((scaled_ppm < (-LAN743X_PTP_MAX_FINE_ADJ_IN_SCALED_PPM)) ||
            scaled_ppm > LAN743X_PTP_MAX_FINE_ADJ_IN_SCALED_PPM) {
                return -EINVAL;
        }
-       if (scaled_ppm > 0) {
-               u64_delta = (u64)scaled_ppm;
-               positive = true;
-       } else {
-               u64_delta = (u64)(-scaled_ppm);
-               positive = false;
-       }
-       u64_delta = (u64_delta << 19);
-       lan743x_rate_adj = div_u64(u64_delta, 1000000);
 
-       if (positive)
-               lan743x_rate_adj |= PTP_CLOCK_RATE_ADJ_DIR_;
+       /* diff_by_scaled_ppm returns true if the difference is negative */
+       if (diff_by_scaled_ppm(1ULL << 35, scaled_ppm, &u64_delta))
+               lan743x_rate_adj = (u32)u64_delta;
+       else
+               lan743x_rate_adj = (u32)u64_delta | PTP_CLOCK_RATE_ADJ_DIR_;
 
        lan743x_csr_write(adapter, PTP_CLOCK_RATE_ADJ,
                          lan743x_rate_adj);