From 581a6bd59b095ec06affc9847c940f9c3435d4fe Mon Sep 17 00:00:00 2001
From: Richard Cochran <richardcochran@gmail.com>
Date: Fri, 31 May 2019 07:25:45 -0700
Subject: [PATCH] Accept external PHC devices from the command line.

A single, external PTP Hardware Clock device may be wired to one or more
MAC devices, providing the MACs with an input clock.  This patch adds
support for such a hardware architecture by letting the command line PHC
override the one discovered via the ethtool ioctl.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
---
 clock.c | 11 ++++++-----
 port.c  |  8 +++++++-
 port.h  |  4 +++-
 3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/clock.c b/clock.c
index 146576a..b210649 100644
--- a/clock.c
+++ b/clock.c
@@ -771,8 +771,8 @@ struct currentDS *clock_current_dataset(struct clock *c)
 	return &c->cur;
 }
 
-static int clock_add_port(struct clock *c, int phc_index,
-			  enum timestamp_type timestamping,
+static int clock_add_port(struct clock *c, const char *phc_device,
+			  int phc_index, enum timestamp_type timestamping,
 			  struct interface *iface)
 {
 	struct port *p, *piter, *lastp = NULL;
@@ -780,7 +780,8 @@ static int clock_add_port(struct clock *c, int phc_index,
 	if (clock_resize_pollfd(c, c->nports + 1)) {
 		return -1;
 	}
-	p = port_open(phc_index, timestamping, ++c->last_port_number, iface, c);
+	p = port_open(phc_device, phc_index, timestamping,
+		      ++c->last_port_number, iface, c);
 	if (!p) {
 		/* No need to shrink pollfd */
 		return -1;
@@ -1136,7 +1137,7 @@ struct clock *clock_create(enum clock_type type, struct config *config,
 	}
 
 	/* Create the UDS interface. */
-	c->uds_port = port_open(phc_index, timestamping, 0, udsif, c);
+	c->uds_port = port_open(phc_device, phc_index, timestamping, 0, udsif, c);
 	if (!c->uds_port) {
 		pr_err("failed to open the UDS port");
 		return NULL;
@@ -1145,7 +1146,7 @@ struct clock *clock_create(enum clock_type type, struct config *config,
 
 	/* Create the ports. */
 	STAILQ_FOREACH(iface, &config->interfaces, list) {
-		if (clock_add_port(c, phc_index, timestamping, iface)) {
+		if (clock_add_port(c, phc_device, phc_index, timestamping, iface)) {
 			pr_err("failed to open port %s", iface->name);
 			return NULL;
 		}
diff --git a/port.c b/port.c
index 58fbe66..f26f1db 100644
--- a/port.c
+++ b/port.c
@@ -2934,7 +2934,8 @@ err:
 	msg_put(msg);
 }
 
-struct port *port_open(int phc_index,
+struct port *port_open(const char *phc_device,
+		       int phc_index,
 		       enum timestamp_type timestamping,
 		       int number,
 		       struct interface *interface,
@@ -2998,6 +2999,11 @@ struct port *port_open(int phc_index,
 		if (p->jbod) {
 			pr_warning("port %d: just a bunch of devices", number);
 			p->phc_index = interface->ts_info.phc_index;
+		} else if (phc_device) {
+			pr_warning("port %d: taking %s from the command line, "
+				   "not the attached ptp%d", number, phc_device,
+				   interface->ts_info.phc_index);
+			p->phc_index = phc_index;
 		} else {
 			pr_err("port %d: PHC device mismatch", number);
 			pr_err("port %d: /dev/ptp%d requested, ptp%d attached",
diff --git a/port.h b/port.h
index aa3b1ec..a45a7a4 100644
--- a/port.h
+++ b/port.h
@@ -192,6 +192,7 @@ void port_notify_event(struct port *p, enum notification event);
 
 /**
  * Open a network port.
+ * @param phc_device    The name of PHC device as found on the command line.
  * @param phc_index     The PHC device index for the network device.
  * @param timestamping  The timestamping mode for this port.
  * @param number	An arbitrary number assigned to this port.
@@ -199,7 +200,8 @@ void port_notify_event(struct port *p, enum notification event);
  * @param clock         A pointer to the system PTP clock.
  * @return A pointer to an open port on success, or NULL otherwise.
  */
-struct port *port_open(int phc_index,
+struct port *port_open(const char *phc_device,
+		       int phc_index,
 		       enum timestamp_type timestamping,
 		       int number,
 		       struct interface *interface,