ptp: remember the adjusted frequency

This patch adds a field to the representation of a PTP hardware clock in
order to remember the frequency adjustment value dialed by the user.

Adding this field will let us answer queries in the manner of adjtimex
in a follow on patch.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 2 insertions, 0 deletions

diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index 966875dcda56..67e628ee0365 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -147,6 +147,7 @@ static int ptp_clock_adjtime(struct posix_clock *pc, struct timex *tx)
         } else if (tx->modes & ADJ_FREQUENCY) {
 
                 err = ops->adjfreq(ops, scaled_ppm_to_ppb(tx->freq));
+                ptp->dialed_frequency = tx->freq;
         }
 
         return err;
diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index 4d5b5082c3b1..69d32070cc65 100644
--- a/drivers/ptp/ptp_private.h
+++ b/drivers/ptp/ptp_private.h
@@ -45,6 +45,7 @@ struct ptp_clock {
         dev_t devid;
         int index; /* index into clocks.map */
         struct pps_device *pps_source;
+        long dialed_frequency; /* remembers the frequency adjustment */
         struct timestamp_event_queue tsevq; /* simple fifo for time stamps */
         struct mutex tsevq_mux; /* one process at a time reading the fifo */
         wait_queue_head_t tsev_wq;