[RFC,1/4] ethdev: add frequency adjustment API

diff --git a/lib/ethdev/ethdev_driver.h b/lib/ethdev/ethdev_driver.h
index 2c9d615..b1451d2 100644
--- a/lib/ethdev/ethdev_driver.h
+++ b/lib/ethdev/ethdev_driver.h
@@ -633,6 +633,9 @@  typedef int (*eth_timesync_read_tx_timestamp_t)(struct rte_eth_dev *dev,
 /** @internal Function used to adjust the device clock. */
 typedef int (*eth_timesync_adjust_time)(struct rte_eth_dev *dev, int64_t);
 
+/** @internal Function used to adjust the clock frequency. */
+typedef int (*eth_timesync_adjust_freq)(struct rte_eth_dev *dev, int64_t);
+
 /** @internal Function used to get time from the device clock. */
 typedef int (*eth_timesync_read_time)(struct rte_eth_dev *dev,
 				      struct timespec *timestamp);
@@ -1344,6 +1347,8 @@  struct eth_dev_ops {
 	eth_timesync_read_tx_timestamp_t timesync_read_tx_timestamp;
 	/** Adjust the device clock */
 	eth_timesync_adjust_time   timesync_adjust_time;
+	/** Adjust the clock frequency */
+	eth_timesync_adjust_freq   timesync_adjust_freq;
 	/** Get the device clock time */
 	eth_timesync_read_time     timesync_read_time;
 	/** Set the device clock time */
diff --git a/lib/ethdev/ethdev_trace.h b/lib/ethdev/ethdev_trace.h
index 3dc7d02..d92554b 100644
--- a/lib/ethdev/ethdev_trace.h
+++ b/lib/ethdev/ethdev_trace.h
@@ -2196,6 +2196,15 @@  RTE_TRACE_POINT_FP(
 	rte_trace_point_emit_int(ret);
 )
 
+/* Called in loop in examples/ptpclient */
+RTE_TRACE_POINT_FP(
+	rte_eth_trace_timesync_adjust_freq,
+	RTE_TRACE_POINT_ARGS(uint16_t port_id, int64_t ppm, int ret),
+	rte_trace_point_emit_u16(port_id);
+	rte_trace_point_emit_i64(ppm);
+	rte_trace_point_emit_int(ret);
+)
+
 /* Called in loop in app/test-flow-perf */
 RTE_TRACE_POINT_FP(
 	rte_flow_trace_create,
diff --git a/lib/ethdev/ethdev_trace_points.c b/lib/ethdev/ethdev_trace_points.c
index 61010ca..c01b5d3 100644
--- a/lib/ethdev/ethdev_trace_points.c
+++ b/lib/ethdev/ethdev_trace_points.c
@@ -406,6 +406,9 @@  RTE_TRACE_POINT_REGISTER(rte_eth_trace_timesync_read_tx_timestamp,
 RTE_TRACE_POINT_REGISTER(rte_eth_trace_timesync_adjust_time,
 	lib.ethdev.timesync_adjust_time)
 
+RTE_TRACE_POINT_REGISTER(rte_eth_trace_timesync_adjust_freq,
+	lib.ethdev.timesync_adjust_freq)
+
 RTE_TRACE_POINT_REGISTER(rte_eth_trace_timesync_read_time,
 	lib.ethdev.timesync_read_time)
 
diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
index 4d03255..f5934bb 100644
--- a/lib/ethdev/rte_ethdev.c
+++ b/lib/ethdev/rte_ethdev.c
@@ -6017,6 +6017,24 @@  rte_eth_timesync_adjust_time(uint16_t port_id, int64_t delta)
 }
 
 int
+rte_eth_timesync_adjust_freq(uint16_t port_id, int64_t ppm)
+{
+	struct rte_eth_dev *dev;
+	int ret;
+
+	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
+	dev = &rte_eth_devices[port_id];
+
+	if (*dev->dev_ops->timesync_adjust_freq == NULL)
+		return -ENOTSUP;
+	ret = eth_err(port_id, (*dev->dev_ops->timesync_adjust_freq)(dev, ppm));
+
+	rte_eth_trace_timesync_adjust_freq(port_id, ppm, ret);
+
+	return ret;
+}
+
+int
 rte_eth_timesync_read_time(uint16_t port_id, struct timespec *timestamp)
 {
 	struct rte_eth_dev *dev;
diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
index 99fe9e2..9737461 100644
--- a/lib/ethdev/rte_ethdev.h
+++ b/lib/ethdev/rte_ethdev.h
@@ -5102,6 +5102,25 @@  int rte_eth_timesync_read_tx_timestamp(uint16_t port_id,
 int rte_eth_timesync_adjust_time(uint16_t port_id, int64_t delta);
 
 /**
+ * Adjust the clock increment rate on an Ethernet device.
+ *
+ * This is usually used in conjunction with other Ethdev timesync functions to
+ * synchronize the device time using the IEEE1588/802.1AS protocol.
+ *
+ * @param port_id
+ *  The port identifier of the Ethernet device.
+ * @param ppm
+ *  Parts per million with 16-bit fractional field
+ *
+ * @return
+ *   - 0: Success.
+ *   - -ENODEV: The port ID is invalid.
+ *   - -EIO: if device is removed.
+ *   - -ENOTSUP: The function is not supported by the Ethernet driver.
+ */
+int rte_eth_timesync_adjust_freq(uint16_t port_id, int64_t ppm);
+
+/**
  * Read the time from the timesync clock on an Ethernet device.
  *
  * This is usually used in conjunction with other Ethdev timesync functions to