Bring dpll monitor in line with the rest of iproute2 by allowing each
received notification to be prefixed with a wall-clock timestamp.

  -t / --timestamp  emit a separate "Timestamp:" line before each event,
                    using the default text form of print_timestamp()
                    (matches ip / bridge / tc -t monitor)
  --tshort          emit a compact ISO 8601 prefix
                    "[YYYY-MM-DDTHH:MM:SS.uuuuuu]" inline instead
                    (matches ip -ts monitor)

When combined with -j, the timestamp shows up as a "timestamp" /
"timestamp_short" field on each notification object, the same way
ip -j -t mptcp monitor integrates the helper.

The flag is parsed globally but only consulted from the monitor
callback, so passing -t to non-monitor commands is a no-op.

--tshort has no short alias, so its long_options entry uses an
identifier above the ASCII range (OPT_TSHORT = 256) following the
iproute2 convention used in misc/ss.c, instead of consuming an
ASCII letter that could later collide with a real short option.

Signed-off-by: Petr Oros <poros@redhat.com>
---
 bash-completion/dpll |  8 ++++++--
 dpll/dpll.c          | 21 +++++++++++++++++++--
 man/man8/dpll.8      | 23 ++++++++++++++++++++++-
 3 files changed, 47 insertions(+), 5 deletions(-)

diff --git a/bash-completion/dpll b/bash-completion/dpll
index 7ddcf529d429db..f615d69147d140 100644
--- a/bash-completion/dpll
+++ b/bash-completion/dpll
@@ -299,7 +299,7 @@ _dpll_monitor()
 _dpll()
 {
     local cur prev words cword
-    local opt='--Version --json --pretty'
+    local opt='--Version --json --pretty --timestamp --tshort'
     local objects="device pin monitor"
 
     _init_completion || return
@@ -326,7 +326,11 @@ _dpll()
                 return 0
                 ;;
             -j|--json)
-                COMPREPLY=( $( compgen -W "--pretty $objects" -- "$cur" ) )
+                COMPREPLY=( $( compgen -W "--pretty --timestamp --tshort $objects" -- "$cur" ) )
+                return 0
+                ;;
+            -t|--timestamp|--tshort)
+                COMPREPLY=( $( compgen -W "monitor" -- "$cur" ) )
                 return 0
                 ;;
             *)
diff --git a/dpll/dpll.c b/dpll/dpll.c
index 81caa510078830..a3cda2c2903f71 100644
--- a/dpll/dpll.c
+++ b/dpll/dpll.c
@@ -29,7 +29,10 @@
 
 #define pr_err(args...) fprintf(stderr, ##args)
 
+#define OPT_TSHORT 256
+
 int json;
+int timestamp;
 
 struct dpll {
 	struct mnlu_gen_socket nlg;
@@ -535,7 +538,8 @@ static void help(void)
 {
 	pr_err("Usage: dpll [ OPTIONS ] OBJECT { COMMAND | help }\n"
 	       "where  OBJECT := { device | pin | monitor }\n"
-	       "       OPTIONS := { -V | --Version | -j | --json | -p | --pretty }\n");
+	       "       OPTIONS := { -V | --Version | -j | --json | -p | --pretty |\n"
+	       "                    -t | --timestamp | --tshort }\n");
 }
 
 static int cmd_device(struct dpll *dpll);
@@ -599,9 +603,11 @@ int main(int argc, char **argv)
 		{ "Version", no_argument, NULL, 'V' },
 		{ "json", no_argument, NULL, 'j' },
 		{ "pretty", no_argument, NULL, 'p' },
+		{ "timestamp", no_argument, NULL, 't' },
+		{ "tshort", no_argument, NULL, OPT_TSHORT },
 		{ NULL, 0, NULL, 0 }
 	};
-	const char *opt_short = "Vjp";
+	const char *opt_short = "Vjpt";
 	struct dpll *dpll;
 	int err, opt, ret;
 
@@ -624,6 +630,13 @@ int main(int argc, char **argv)
 		case 'p':
 			pretty = true;
 			break;
+		case 't':
+			timestamp = 1;
+			break;
+		case OPT_TSHORT:
+			timestamp = 1;
+			timestamp_short = 1;
+			break;
 		default:
 			pr_err("Unknown option.\n");
 			help();
@@ -2305,6 +2318,8 @@ static int cmd_monitor_cb(const struct nlmsghdr *nlh, void *data)
 
 		new_json_obj_plain(json);
 		open_json_object(NULL);
+		if (timestamp)
+			print_timestamp(stdout);
 		print_string(PRINT_JSON, "name", NULL, json_name);
 		open_json_object("msg");
 		print_string(PRINT_FP, NULL, "[%s] ", cmd_name);
@@ -2334,6 +2349,8 @@ static int cmd_monitor_cb(const struct nlmsghdr *nlh, void *data)
 
 		new_json_obj_plain(json);
 		open_json_object(NULL);
+		if (timestamp)
+			print_timestamp(stdout);
 		print_string(PRINT_JSON, "name", NULL, json_name);
 		open_json_object("msg");
 		print_string(PRINT_FP, NULL, "[%s] ", cmd_name);
diff --git a/man/man8/dpll.8 b/man/man8/dpll.8
index 6b52970972f41a..43daa0cac2d5d2 100644
--- a/man/man8/dpll.8
+++ b/man/man8/dpll.8
@@ -29,7 +29,9 @@ dpll \- Digital Phase Locked Loop (DPLL) subsystem management
 .IR OPTIONS " := { "
 \fB\-V\fR | \fB\-\-Version\fR |
 \fB\-j\fR | \fB\-\-json\fR |
-\fB\-p\fR | \fB\-\-pretty\fR }
+\fB\-p\fR | \fB\-\-pretty\fR |
+\fB\-t\fR | \fB\-\-timestamp\fR |
+\fB\-\-tshort\fR }
 
 .SH DESCRIPTION
 The
@@ -58,6 +60,25 @@ Output results in JavaScript Object Notation (JSON).
 When combined with \-j, generates a pretty JSON output with indentation
 and newlines for better human readability.
 
+.TP
+.BR "\-t" , " \-\-timestamp"
+When used with the
+.B monitor
+object, print a
+.B Timestamp:
+line before each received notification, in the same format used by
+.BR "ip monitor" .
+
+.TP
+.B "\-\-tshort"
+Like
+.BR \-t ,
+but emits a more compact, ISO 8601 inline prefix
+.RB \(lq [ YYYY-MM-DD T HH:MM:SS . uuuuuu ] \(rq
+in front of each notification instead of a separate
+.B Timestamp:
+line.
+
 .SH DEVICE COMMANDS
 
 .SS dpll device show [ id ID ] [ module-name NAME ] [ clock-id ID ] [ type TYPE ] [ mode MODE ] [ lock-status STATUS ]
-- 
2.53.0