iplink_can: print_usage: describe the CAN bittiming units

While the meaning of "bps" or "ns" may be relatively easy to understand,
some of the CAN specific units such as "mtq" (minimum time quanta) may be
harder to understand.

Add a new paragraph to the help menu which describes all the different
units used for the CAN bittiming parameters.

Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

diff --git a/ip/iplink_can.c b/ip/iplink_can.c
index ee27659c5509646735fb8d13dd9093ac89c93881..d5abc43a2d0969de80f8f69a2d1ccdcbaaa0ba9d 100644 (file)
--- a/ip/iplink_can.c
+++ b/ip/iplink_can.c
@@ -60,6 +60,13 @@ static void print_usage(FILE *f)
                "\t     TDCO            := { NUMBER in mtq }\n"
                "\t     TDCF            := { NUMBER in mtq }\n"
                "\t     RESTART-MS      := { 0 | NUMBER in ms }\n"
+               "\n"
+               "\tUnits:\n"
+               "\t     bps     := bit per second\n"
+               "\t     ms      := millisecond\n"
+               "\t     mtq     := minimum time quanta\n"
+               "\t     ns      := nanosecond\n"
+               "\t     tq      := time quanta\n"
                );
 }