@@ -149,18 +149,14 @@ enum ptp_packet_state {
/* Maximum parts-per-billion adjustment that is acceptable */
#define MAX_PPB 1000000
-/* Number of bits required to hold the above */
-#define MAX_PPB_BITS 20
-
-/* Number of extra bits allowed when calculating fractional ns.
- * EXTRA_BITS + MC_CMD_PTP_IN_ADJUST_BITS + MAX_PPB_BITS should
- * be less than 63.
- */
-#define PPB_EXTRA_BITS 2
-
/* Precalculate scale word to avoid long long division at runtime */
-#define PPB_SCALE_WORD ((1LL << (PPB_EXTRA_BITS + MC_CMD_PTP_IN_ADJUST_BITS +\
- MAX_PPB_BITS)) / 1000000000LL)
+/* This is equivalent to 2^66 / 10^9. */
+#define PPB_SCALE_WORD ((1LL << (57)) / 1953125LL)
+
+/* How much to shift down after scaling to convert to FP40 */
+#define PPB_SHIFT_FP40 26
+/* ... and FP44. */
+#define PPB_SHIFT_FP44 22
#define PTP_SYNC_ATTEMPTS 4
@@ -261,6 +257,8 @@ struct efx_ptp_timeset {
* @evt_code: Last event code
* @start: Address at which MC indicates ready for synchronisation
* @host_time_pps: Host time at last PPS
+ * @adjfreq_ppb_shift: Shift required to convert scaled parts-per-billion
+ * frequency adjustment into a fixed point fractional nanosecond format.
* @current_adjfreq: Current ppb adjustment.
* @phc_clock: Pointer to registered phc device (if primary function)
* @phc_clock_info: Registration structure for phc device
@@ -310,6 +308,7 @@ struct efx_ptp_data {
unsigned int sync_event_minor_shift;
} nic_time;
unsigned int min_synchronisation_ns;
+ unsigned int capabilities;
struct {
s32 ptp_tx;
s32 ptp_rx;
@@ -323,6 +322,7 @@ struct efx_ptp_data {
int evt_code;
struct efx_buffer start;
struct pps_event_time host_time_pps;
+ unsigned int adjfreq_ppb_shift;
s64 current_adjfreq;
struct ptp_clock *phc_clock;
struct ptp_clock_info phc_clock_info;
@@ -676,6 +676,22 @@ static int efx_ptp_get_attributes(struct efx_nic *efx)
else
ptp->min_synchronisation_ns = DEFAULT_MIN_SYNCHRONISATION_NS;
+ if (rc == 0 &&
+ out_len >= MC_CMD_PTP_OUT_GET_ATTRIBUTES_LEN)
+ ptp->capabilities = MCDI_DWORD(outbuf,
+ PTP_OUT_GET_ATTRIBUTES_CAPABILITIES);
+ else
+ ptp->capabilities = 0;
+
+ /* Set up the shift for conversion between frequency
+ * adjustments in parts-per-billion and the fixed-point
+ * fractional ns format that the adapter uses.
+ */
+ if (ptp->capabilities & (1 << MC_CMD_PTP_OUT_GET_ATTRIBUTES_FP44_FREQ_ADJ_LBN))
+ ptp->adjfreq_ppb_shift = PPB_SHIFT_FP44;
+ else
+ ptp->adjfreq_ppb_shift = PPB_SHIFT_FP40;
+
return 0;
}
@@ -2027,9 +2043,10 @@ static int efx_phc_adjfreq(struct ptp_clock_info *ptp, s32 delta)
else if (delta < -MAX_PPB)
delta = -MAX_PPB;
- /* Convert ppb to fixed point ns. */
- adjustment_ns = (((s64)delta * PPB_SCALE_WORD) >>
- (PPB_EXTRA_BITS + MAX_PPB_BITS));
+ /* Convert ppb to fixed point ns taking care to round correctly. */
+ adjustment_ns = ((s64)delta * PPB_SCALE_WORD +
+ (1 << (ptp_data->adjfreq_ppb_shift - 1))) >>
+ ptp_data->adjfreq_ppb_shift;
MCDI_SET_DWORD(inadj, PTP_IN_OP, MC_CMD_PTP_OP_ADJUST);
MCDI_SET_DWORD(inadj, PTP_IN_PERIPH_ID, 0);