[PATCH v3 0/4] iplink_can: cleaning, fixes and adding TDC support.

[PATCH v3 0/4] iplink_can: cleaning, fixes and adding TDC support.

[Vincent Mailhol]

The main purpose is to add commandline support for Transmitter Delay
Compensation (TDC) in iproute. Other issues found during the
development of this feature also get addressed.

This patch series contains four patches which respectively:
  1. Correct the bittiming ranges in the print_usage function.
  2. factorize the many print_*(PRINT_JSON, ...) and fprintf
  occurrences in a single print_*(PRINT_ANY, ...) call and fix the
  signedness while doing that.
  3. report the value of the bitrate prescalers (brp and dbrp).
  4. adds command line support for the TDC in iproute and goes together
  with below series in the kernel:
  https://lore.kernel.org/r/20210603151550.140727-3-mailhol.vincent@wanadoo.fr


** Changelog **

From RFC v1 to RFC v2:
  * Add an additional patch to the series to fix the issues reported
    by Stephen Hemminger
    Ref: https://lore.kernel.org/linux-can/20210506112007.1666738-1-mailhol.vincent@wanadoo.fr/T/#t

From RFC v2 to v3:
  * Dropped the RFC tag. Now that the kernel patch reach the testing
    branch, I am finaly ready.
  * Regression fix: configuring a link with only nominal bittiming
    returned -EOPNOTSUPP
  * Added two more patches to the series:
      - iplink_can: fix configuration ranges in print_usage()
      - iplink_can: print brp and dbrp bittiming variables
  * Other small fixes on formatting.

Vincent Mailhol (4):
  iplink_can: fix configuration ranges in print_usage()
  iplink_can: use PRINT_ANY to factorize code and fix signedness
  iplink_can: print brp and dbrp bittiming variables
  iplink_can: add new CAN FD bittiming parameters: Transmitter Delay
    Compensation (TDC)

 include/uapi/linux/can/netlink.h |  25 +-
 ip/iplink_can.c                  | 430 ++++++++++++++++---------------
 2 files changed, 247 insertions(+), 208 deletions(-)

-- 
2.31.1

[PATCH v3 1/4] iplink_can: fix configuration ranges in print_usage()

[Vincent Mailhol]

The configuration ranges in print_usage() are taken from "Table 8 -
Time segments' minimum configuration ranges" in section 11.3.1.2
"Configuration of the bit time parameters" of ISO 11898-1.

The standard clearly specifies that "implementations may allow time
segments that exceed the minimum required configuration ranges
specified in Table 8".

Because no maximum ranges are given, all given ranges { a..b } are
simply replaced with { NUMBER }.

The actual ranges are specific to earch device and should be confirmed
doing:

$ ip --details link show can0
1: can0: <NOARP,ECHO> mtu 16 qdisc noop state DOWN mode DEFAULT group default qlen 10
    link/can  promiscuity 0 minmtu 0 maxmtu 0
    can state STOPPED restart-ms 0
	  ES582.1/ES584.1: tseg1 2..256 tseg2 2..128 sjw 1..128 brp 1..512 brp-inc 1
	  ES582.1/ES584.1: dtseg1 2..32 dtseg2 1..16 dsjw 1..8 dbrp 1..32 dbrp-inc 1
	  clock 80000000 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
---
 ip/iplink_can.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/ip/iplink_can.c b/ip/iplink_can.c
index 6a26f3ff..2736f3ab 100644
--- a/ip/iplink_can.c
+++ b/ip/iplink_can.c
@@ -44,13 +44,13 @@ static void print_usage(FILE *f)
 		"\n"
 		"\t[ termination { 0..65535 } ]\n"
 		"\n"
-		"\tWhere: BITRATE	:= { 1..1000000 }\n"
+		"\tWhere: BITRATE	:= { NUMBER }\n"
 		"\t	  SAMPLE-POINT	:= { 0.000..0.999 }\n"
 		"\t	  TQ		:= { NUMBER }\n"
-		"\t	  PROP-SEG	:= { 1..8 }\n"
-		"\t	  PHASE-SEG1	:= { 1..8 }\n"
-		"\t	  PHASE-SEG2	:= { 1..8 }\n"
-		"\t	  SJW		:= { 1..4 }\n"
+		"\t	  PROP-SEG	:= { NUMBER }\n"
+		"\t	  PHASE-SEG1	:= { NUMBER }\n"
+		"\t	  PHASE-SEG2	:= { NUMBER }\n"
+		"\t	  SJW		:= { NUMBER }\n"
 		"\t	  RESTART-MS	:= { 0 | NUMBER }\n"
 		);
 }
-- 
2.31.1

[PATCH v3 2/4] iplink_can: use PRINT_ANY to factorize code and fix signedness

[Vincent Mailhol]

Current implementation heavily relies on some "if (is_json_context())"
switches to decide the context and then does some print_*(PRINT_JSON,
...) when in json context and some fprintf(...) else.

Furthermore, current implementation uses either print_int() or the
conversion specifier %d to print unsigned integers.

This patch factorizes each pairs of print_*(PRINT_JSON, ...) and
fprintf into a signle print_*(PRINT_ANY, ...) call. While doing this
replacement, it uses proper unsigned function print_uint() as well as
the conversion specifier %u when the parameter is an unsigned integer.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
---
 ip/iplink_can.c | 341 ++++++++++++++++++++----------------------------
 1 file changed, 141 insertions(+), 200 deletions(-)

diff --git a/ip/iplink_can.c b/ip/iplink_can.c
index 2736f3ab..ec4e122f 100644
--- a/ip/iplink_can.c
+++ b/ip/iplink_can.c
@@ -266,14 +266,34 @@ static const char *can_state_names[CAN_STATE_MAX] = {
 	[CAN_STATE_SLEEPING] = "SLEEPING"
 };
 
-static void can_print_json_timing_min_max(const char *attr, int min, int max)
+static void can_print_nl_indent(void)
+{
+	print_nl();
+	print_string(PRINT_FP, NULL, "%s", "\t ");
+}
+
+static void can_print_timing_min_max(const char *attr, int min, int max)
 {
 	open_json_object(attr);
-	print_int(PRINT_JSON, "min", NULL, min);
-	print_int(PRINT_JSON, "max", NULL, max);
+	print_uint(PRINT_ANY, "min", " %u", min);
+	print_uint(PRINT_ANY, "max", "..%u", max);
 	close_json_object();
 }
 
+/* Print nominal bittiming */
+static void can_print_nom_timing_min_max(const char *attr, int min, int max)
+{
+	print_string(PRINT_FP, NULL, " %s", attr);
+	can_print_timing_min_max(attr, min, max);
+}
+
+/* Print data bittiming: use a "d" prefix when printing to the file pointer */
+static void can_print_data_timing_min_max(const char *attr, int min, int max)
+{
+	print_string(PRINT_FP, NULL, " d%s", attr);
+	can_print_timing_min_max(attr, min, max);
+}
+
 static void can_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 {
 	if (!tb)
@@ -297,56 +317,38 @@ static void can_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 		struct can_berr_counter *bc =
 			RTA_DATA(tb[IFLA_CAN_BERR_COUNTER]);
 
-		if (is_json_context()) {
-			open_json_object("berr_counter");
-			print_int(PRINT_JSON, "tx", NULL, bc->txerr);
-			print_int(PRINT_JSON, "rx", NULL, bc->rxerr);
-			close_json_object();
-		} else {
-			fprintf(f, "(berr-counter tx %d rx %d) ",
-				bc->txerr, bc->rxerr);
-		}
+		open_json_object("berr_counter");
+		print_uint(PRINT_ANY, "tx", "(berr-counter tx %u", bc->txerr);
+		print_uint(PRINT_ANY, "rx", " rx %u) ", bc->rxerr);
+		close_json_object();
 	}
 
 	if (tb[IFLA_CAN_RESTART_MS]) {
 		__u32 *restart_ms = RTA_DATA(tb[IFLA_CAN_RESTART_MS]);
 
-		print_int(PRINT_ANY,
-			  "restart_ms",
-			  "restart-ms %d ",
-			  *restart_ms);
+		print_uint(PRINT_ANY, "restart_ms", "restart-ms %u ",
+			   *restart_ms);
 	}
 
 	/* bittiming is irrelevant if fixed bitrate is defined */
 	if (tb[IFLA_CAN_BITTIMING] && !tb[IFLA_CAN_BITRATE_CONST]) {
 		struct can_bittiming *bt = RTA_DATA(tb[IFLA_CAN_BITTIMING]);
-
-		if (is_json_context()) {
-			json_writer_t *jw;
-
-			open_json_object("bittiming");
-			print_int(PRINT_ANY, "bitrate", NULL, bt->bitrate);
-			jw = get_json_writer();
-			jsonw_name(jw, "sample_point");
-			jsonw_printf(jw, "%.3f",
-				     (float) bt->sample_point / 1000);
-			print_int(PRINT_ANY, "tq", NULL, bt->tq);
-			print_int(PRINT_ANY, "prop_seg", NULL, bt->prop_seg);
-			print_int(PRINT_ANY, "phase_seg1",
-				  NULL, bt->phase_seg1);
-			print_int(PRINT_ANY, "phase_seg2",
-				  NULL, bt->phase_seg2);
-			print_int(PRINT_ANY, "sjw", NULL, bt->sjw);
-			close_json_object();
-		} else {
-			fprintf(f, "\n	  bitrate %d sample-point %.3f ",
-				bt->bitrate, (float) bt->sample_point / 1000.);
-			fprintf(f,
-				"\n	  tq %d prop-seg %d phase-seg1 %d phase-seg2 %d sjw %d",
-				bt->tq, bt->prop_seg,
-				bt->phase_seg1, bt->phase_seg2,
-				bt->sjw);
-		}
+		char sp[6];
+
+		open_json_object("bittiming");
+		can_print_nl_indent();
+		print_uint(PRINT_ANY, "bitrate", " bitrate %u", bt->bitrate);
+		snprintf(sp, sizeof(sp), "%.3f", bt->sample_point / 1000.);
+		print_string(PRINT_ANY, "sample_point", " sample-point %s", sp);
+		can_print_nl_indent();
+		print_uint(PRINT_ANY, "tq", " tq %u", bt->tq);
+		print_uint(PRINT_ANY, "prop_seg", " prop-seg %u", bt->prop_seg);
+		print_uint(PRINT_ANY, "phase_seg1", " phase-seg1 %u",
+			   bt->phase_seg1);
+		print_uint(PRINT_ANY, "phase_seg2", "phase-seg2 %u ",
+			   bt->phase_seg2);
+		print_uint(PRINT_ANY, "sjw", " sjw %u", bt->sjw);
+		close_json_object();
 	}
 
 	/* bittiming const is irrelevant if fixed bitrate is defined */
@@ -354,28 +356,18 @@ static void can_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 		struct can_bittiming_const *btc =
 			RTA_DATA(tb[IFLA_CAN_BITTIMING_CONST]);
 
-		if (is_json_context()) {
-			open_json_object("bittiming_const");
-			print_string(PRINT_JSON, "name", NULL, btc->name);
-			can_print_json_timing_min_max("tseg1",
-						      btc->tseg1_min,
-						      btc->tseg1_max);
-			can_print_json_timing_min_max("tseg2",
-						      btc->tseg2_min,
-						      btc->tseg2_max);
-			can_print_json_timing_min_max("sjw", 1, btc->sjw_max);
-			can_print_json_timing_min_max("brp",
-						      btc->brp_min,
-						      btc->brp_max);
-			print_int(PRINT_JSON, "brp_inc", NULL, btc->brp_inc);
-			close_json_object();
-		} else {
-			fprintf(f, "\n	  %s: tseg1 %d..%d tseg2 %d..%d "
-				"sjw 1..%d brp %d..%d brp-inc %d",
-				btc->name, btc->tseg1_min, btc->tseg1_max,
-				btc->tseg2_min, btc->tseg2_max, btc->sjw_max,
-				btc->brp_min, btc->brp_max, btc->brp_inc);
-		}
+		open_json_object("bittiming_const");
+		can_print_nl_indent();
+		print_string(PRINT_ANY, "name", " %s:", btc->name);
+		can_print_nom_timing_min_max("tseg1",
+					     btc->tseg1_min, btc->tseg1_max);
+		can_print_nom_timing_min_max("tseg2",
+					     btc->tseg2_min, btc->tseg2_max);
+		can_print_nom_timing_min_max("sjw", 1, btc->sjw_max);
+		can_print_nom_timing_min_max("brp",
+					     btc->brp_min, btc->brp_max);
+		print_uint(PRINT_ANY, "brp_inc", " brp_inc %u", btc->brp_inc);
+		close_json_object();
 	}
 
 	if (tb[IFLA_CAN_BITRATE_CONST]) {
@@ -391,64 +383,47 @@ static void can_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 			bitrate = bt->bitrate;
 		}
 
-		if (is_json_context()) {
-			print_uint(PRINT_JSON,
-				   "bittiming_bitrate",
-				   NULL, bitrate);
-			open_json_array(PRINT_JSON, "bitrate_const");
-			for (i = 0; i < bitrate_cnt; ++i)
-				print_uint(PRINT_JSON, NULL, NULL,
-					   bitrate_const[i]);
-			close_json_array(PRINT_JSON, NULL);
-		} else {
-			fprintf(f, "\n	  bitrate %u", bitrate);
-			fprintf(f, "\n	     [");
-
-			for (i = 0; i < bitrate_cnt - 1; ++i) {
-				/* This will keep lines below 80 signs */
-				if (!(i % 6) && i)
-					fprintf(f, "\n	      ");
-
-				fprintf(f, "%8u, ", bitrate_const[i]);
+		can_print_nl_indent();
+		print_uint(PRINT_ANY, "bittiming_bitrate", " bitrate %u",
+			   bitrate);
+		can_print_nl_indent();
+		open_json_array(PRINT_ANY, is_json_context() ?
+				"bitrate_const" : "    [");
+		for (i = 0; i < bitrate_cnt; ++i) {
+			/* This will keep lines below 80 signs */
+			if (!(i % 6) && i) {
+				can_print_nl_indent();
+				print_string(PRINT_FP, NULL, "%s", "     ");
 			}
-
-			if (!(i % 6) && i)
-				fprintf(f, "\n	      ");
-			fprintf(f, "%8u ]", bitrate_const[i]);
+			print_uint(PRINT_ANY, NULL,
+				   i < bitrate_cnt - 1 ? "%8u, " : "%8u",
+				   bitrate_const[i]);
 		}
+		close_json_array(PRINT_JSON, " ]");
 	}
 
 	/* data bittiming is irrelevant if fixed bitrate is defined */
 	if (tb[IFLA_CAN_DATA_BITTIMING] && !tb[IFLA_CAN_DATA_BITRATE_CONST]) {
 		struct can_bittiming *dbt =
 			RTA_DATA(tb[IFLA_CAN_DATA_BITTIMING]);
-
-		if (is_json_context()) {
-			json_writer_t *jw;
-
-			open_json_object("data_bittiming");
-			print_int(PRINT_JSON, "bitrate", NULL, dbt->bitrate);
-			jw = get_json_writer();
-			jsonw_name(jw, "sample_point");
-			jsonw_printf(jw, "%.3f",
-				     (float) dbt->sample_point / 1000.);
-			print_int(PRINT_JSON, "tq", NULL, dbt->tq);
-			print_int(PRINT_JSON, "prop_seg", NULL, dbt->prop_seg);
-			print_int(PRINT_JSON, "phase_seg1",
-				  NULL, dbt->phase_seg1);
-			print_int(PRINT_JSON, "phase_seg2",
-				  NULL, dbt->phase_seg2);
-			print_int(PRINT_JSON, "sjw", NULL, dbt->sjw);
-			close_json_object();
-		} else {
-			fprintf(f, "\n	  dbitrate %d dsample-point %.3f ",
-				dbt->bitrate,
-				(float) dbt->sample_point / 1000.);
-			fprintf(f, "\n	  dtq %d dprop-seg %d dphase-seg1 %d "
-				"dphase-seg2 %d dsjw %d",
-				dbt->tq, dbt->prop_seg, dbt->phase_seg1,
-				dbt->phase_seg2, dbt->sjw);
-		}
+		char dsp[6];
+
+		open_json_object("data_bittiming");
+		can_print_nl_indent();
+		print_uint(PRINT_ANY, "bitrate", " dbitrate %u", dbt->bitrate);
+		snprintf(dsp, sizeof(dsp), "%.3f", dbt->sample_point / 1000.);
+		print_string(PRINT_ANY, "sample_point", " dsample-point %s",
+			     dsp);
+		can_print_nl_indent();
+		print_uint(PRINT_ANY, "tq", " dtq %u", dbt->tq);
+		print_uint(PRINT_ANY, "prop_seg", " dprop-seg %u",
+			   dbt->prop_seg);
+		print_uint(PRINT_ANY, "phase_seg1", " dphase-seg1 %u",
+			   dbt->phase_seg1);
+		print_uint(PRINT_ANY, "phase_seg2", " dphase-seg2 %u",
+			   dbt->phase_seg2);
+		print_uint(PRINT_ANY, "sjw", " dsjw %u", dbt->sjw);
+		close_json_object();
 	}
 
 	/* data bittiming const is irrelevant if fixed bitrate is defined */
@@ -457,29 +432,18 @@ static void can_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 		struct can_bittiming_const *dbtc =
 			RTA_DATA(tb[IFLA_CAN_DATA_BITTIMING_CONST]);
 
-		if (is_json_context()) {
-			open_json_object("data_bittiming_const");
-			print_string(PRINT_JSON, "name", NULL, dbtc->name);
-			can_print_json_timing_min_max("tseg1",
-						      dbtc->tseg1_min,
-						      dbtc->tseg1_max);
-			can_print_json_timing_min_max("tseg2",
-						      dbtc->tseg2_min,
-						      dbtc->tseg2_max);
-			can_print_json_timing_min_max("sjw", 1, dbtc->sjw_max);
-			can_print_json_timing_min_max("brp",
-						      dbtc->brp_min,
-						      dbtc->brp_max);
-
-			print_int(PRINT_JSON, "brp_inc", NULL, dbtc->brp_inc);
-			close_json_object();
-		} else {
-			fprintf(f, "\n	  %s: dtseg1 %d..%d dtseg2 %d..%d "
-				"dsjw 1..%d dbrp %d..%d dbrp-inc %d",
-				dbtc->name, dbtc->tseg1_min, dbtc->tseg1_max,
-				dbtc->tseg2_min, dbtc->tseg2_max, dbtc->sjw_max,
-				dbtc->brp_min, dbtc->brp_max, dbtc->brp_inc);
-		}
+		open_json_object("data_bittiming_const");
+		can_print_nl_indent();
+		print_string(PRINT_ANY, "name", " %s:", dbtc->name);
+		can_print_data_timing_min_max("tseg1",
+					      dbtc->tseg1_min, dbtc->tseg1_max);
+		can_print_data_timing_min_max("tseg2",
+					      dbtc->tseg2_min, dbtc->tseg2_max);
+		can_print_data_timing_min_max("sjw", 1, dbtc->sjw_max);
+		can_print_data_timing_min_max("brp",
+					      dbtc->brp_min, dbtc->brp_max);
+		print_uint(PRINT_ANY, "brp_inc", " brp_inc %u", dbtc->brp_inc);
+		close_json_object();
 	}
 
 	if (tb[IFLA_CAN_DATA_BITRATE_CONST]) {
@@ -497,30 +461,23 @@ static void can_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 			dbitrate = dbt->bitrate;
 		}
 
-		if (is_json_context()) {
-			print_uint(PRINT_JSON, "data_bittiming_bitrate",
-				   NULL, dbitrate);
-			open_json_array(PRINT_JSON, "data_bitrate_const");
-			for (i = 0; i < dbitrate_cnt; ++i)
-				print_uint(PRINT_JSON, NULL, NULL,
-					   dbitrate_const[i]);
-			close_json_array(PRINT_JSON, NULL);
-		} else {
-			fprintf(f, "\n	  dbitrate %u", dbitrate);
-			fprintf(f, "\n	     [");
-
-			for (i = 0; i < dbitrate_cnt - 1; ++i) {
-				/* This will keep lines below 80 signs */
-				if (!(i % 6) && i)
-					fprintf(f, "\n	      ");
-
-				fprintf(f, "%8u, ", dbitrate_const[i]);
+		can_print_nl_indent();
+		print_uint(PRINT_ANY, "data_bittiming_bitrate", " dbitrate %u",
+			   dbitrate);
+		can_print_nl_indent();
+		open_json_array(PRINT_ANY, is_json_context() ?
+				"data_bitrate_const" : "    [");
+		for (i = 0; i < dbitrate_cnt; ++i) {
+			/* This will keep lines below 80 signs */
+			if (!(i % 6) && i) {
+				can_print_nl_indent();
+				print_string(PRINT_FP, NULL, "%s", "     ");
 			}
-
-			if (!(i % 6) && i)
-				fprintf(f, "\n	      ");
-			fprintf(f, "%8u ]", dbitrate_const[i]);
+			print_uint(PRINT_ANY, NULL,
+				   i < dbitrate_cnt - 1 ? "%8u, " : "%8u",
+				   dbitrate_const[i]);
 		}
+		close_json_array(PRINT_JSON, " ]");
 	}
 
 	if (tb[IFLA_CAN_TERMINATION_CONST] && tb[IFLA_CAN_TERMINATION]) {
@@ -530,29 +487,21 @@ static void can_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 			sizeof(*trm_const);
 		int i;
 
-		if (is_json_context()) {
-			print_hu(PRINT_JSON, "termination", NULL, *trm);
-			open_json_array(PRINT_JSON, "termination_const");
-			for (i = 0; i < trm_cnt; ++i)
-				print_hu(PRINT_JSON, NULL, NULL, trm_const[i]);
-			close_json_array(PRINT_JSON, NULL);
-		} else {
-			fprintf(f, "\n	  termination %hu [ ", *trm);
-
-			for (i = 0; i < trm_cnt - 1; ++i)
-				fprintf(f, "%hu, ", trm_const[i]);
-
-			fprintf(f, "%hu ]", trm_const[i]);
-		}
+		can_print_nl_indent();
+		print_hu(PRINT_ANY, "termination", " termination %hu [ ", *trm);
+		open_json_array(PRINT_JSON, "termination_const");
+		for (i = 0; i < trm_cnt; ++i)
+			print_hu(PRINT_ANY, NULL,
+				 i < trm_cnt - 1 ? "%hu, " : "%hu",
+				 trm_const[i]);
+		close_json_array(PRINT_JSON, " ]");
 	}
 
 	if (tb[IFLA_CAN_CLOCK]) {
 		struct can_clock *clock = RTA_DATA(tb[IFLA_CAN_CLOCK]);
 
-		print_int(PRINT_ANY,
-			  "clock",
-			  "\n	  clock %d ",
-			  clock->freq);
+		can_print_nl_indent();
+		print_uint(PRINT_ANY, "clock", " clock %u ", clock->freq);
 	}
 
 }
@@ -565,31 +514,23 @@ static void can_print_xstats(struct link_util *lu,
 	if (xstats && RTA_PAYLOAD(xstats) == sizeof(*stats)) {
 		stats = RTA_DATA(xstats);
 
-		if (is_json_context()) {
-			print_int(PRINT_JSON, "restarts",
-				  NULL, stats->restarts);
-			print_int(PRINT_JSON, "bus_error",
-				  NULL, stats->bus_error);
-			print_int(PRINT_JSON, "arbitration_lost",
-				  NULL, stats->arbitration_lost);
-			print_int(PRINT_JSON, "error_warning",
-				  NULL, stats->error_warning);
-			print_int(PRINT_JSON, "error_passive",
-				  NULL, stats->error_passive);
-			print_int(PRINT_JSON, "bus_off", NULL, stats->bus_off);
-		} else {
-			fprintf(f, "\n	  re-started bus-errors arbit-lost "
-				"error-warn error-pass bus-off");
-			fprintf(f, "\n	  %-10d %-10d %-10d %-10d %-10d %-10d",
-				stats->restarts, stats->bus_error,
-				stats->arbitration_lost, stats->error_warning,
-				stats->error_passive, stats->bus_off);
-		}
+		can_print_nl_indent();
+		print_string(PRINT_FP, NULL, "%s",
+			     " re-started bus-errors arbit-lost error-warn error-pass bus-off");
+		can_print_nl_indent();
+		print_uint(PRINT_ANY, "restarts", " %-10u", stats->restarts);
+		print_uint(PRINT_ANY, "bus_error", " %-10u", stats->bus_error);
+		print_uint(PRINT_ANY, "arbitration_lost", " %-10u",
+			   stats->arbitration_lost);
+		print_uint(PRINT_ANY, "error_warning", " %-10u",
+			   stats->error_warning);
+		print_uint(PRINT_ANY, "error_passive", " %-10u",
+			   stats->error_passive);
+		print_uint(PRINT_ANY, "bus_off", " %-10u", stats->bus_off);
 	}
 }
 
-static void can_print_help(struct link_util *lu, int argc, char **argv,
-			   FILE *f)
+static void can_print_help(struct link_util *lu, int argc, char **argv, FILE *f)
 {
 	print_usage(f);
 }
-- 
2.31.1

[PATCH v3 3/4] iplink_can: print brp and dbrp bittiming variables

[Vincent Mailhol]

Report the value of the bit-rate prescaler (brp) for both the nominal
and the data bittiming.

Currently, only the constant brp values (brp_{min,max,inc}) are being
reported. Also, brp is the only member of struct can_bittiming not
being reported.

Although brp is not used as an input for bittiming calculation, it
makes sense to output it.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
---
 ip/iplink_can.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/ip/iplink_can.c b/ip/iplink_can.c
index ec4e122f..311c097d 100644
--- a/ip/iplink_can.c
+++ b/ip/iplink_can.c
@@ -348,6 +348,7 @@ static void can_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 		print_uint(PRINT_ANY, "phase_seg2", "phase-seg2 %u ",
 			   bt->phase_seg2);
 		print_uint(PRINT_ANY, "sjw", " sjw %u", bt->sjw);
+		print_uint(PRINT_ANY, "brp", " brp %u", bt->brp);
 		close_json_object();
 	}
 
@@ -423,6 +424,7 @@ static void can_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 		print_uint(PRINT_ANY, "phase_seg2", " dphase-seg2 %u",
 			   dbt->phase_seg2);
 		print_uint(PRINT_ANY, "sjw", " dsjw %u", dbt->sjw);
+		print_uint(PRINT_ANY, "brp", " dbrp %u", dbt->brp);
 		close_json_object();
 	}
 
-- 
2.31.1

[PATCH v3 4/4] iplink_can: add new CAN FD bittiming parameters: Transmitter Delay Compensation (TDC)

[Vincent Mailhol]

At high bit rates, the propagation delay from the TX pin to the RX pin
of the transceiver causes measurement errors: the sample point on the
RX pin might occur on the previous bit.

This issue is addressed in ISO 11898-1 section 11.3.3 "Transmitter
delay compensation" (TDC).

This patch brings command line support to six TDC parameters which
were recently added to the kernel's CAN netlink interface in order to
implement TDC:
  - IFLA_CAN_TDC_TDCV_MAX: Transmitter Delay Compensation Value
    maximum value
  - IFLA_CAN_TDC_TDCO_MAX: Transmitter Delay Compensation Offset
    maximum value
  - IFLA_CAN_TDC_TDCF_MAX: Transmitter Delay Compensation Filter
    window maximum value
  - IFLA_CAN_TDC_TDCV: Transmitter Delay Compensation Value
  - IFLA_CAN_TDC_TDCO: Transmitter Delay Compensation Offset
  - IFLA_CAN_TDC_TDCF: Transmitter Delay Compensation Filter window

All those new parameters are nested together into the attribute
IFLA_CAN_TDC.

Zero has a special meaning for both tdcv and tdco:
  * tdcv: zero means that tdcv is automatically calculated by the
    transmitter.
  * tdco: zero means that tdc is disabled and that all parameters
    (tdcv, tdco and tdcf) should be ignored. In that case, tdc
    variables are not reported.
Please refer to the documentation of struct can_tdc for more details.

For reference, here are a few samples of how the output looks like:

$ ip link set can0 type can bitrate 1000000 dbitrate 8000000 fd on tdcv 0 tdco 7 tdcf 8

$ ip --details link show can0
1: can0: <NOARP,ECHO> mtu 72 qdisc noop state DOWN mode DEFAULT group default qlen 10
    link/can  promiscuity 0 minmtu 0 maxmtu 0
    can <FD> state STOPPED (berr-counter tx 0 rx 0) restart-ms 0
	  bitrate 1000000 sample-point 0.750
	  tq 12 prop-seg 29 phase-seg1 30phase-seg2 20  sjw 1 brp 1
	  ES582.1/ES584.1: tseg1 2..256 tseg2 2..128 sjw 1..128 brp 1..512 brp_inc 1
	  dbitrate 8000000 dsample-point 0.700
	  dtq 12 dprop-seg 3 dphase-seg1 3 dphase-seg2 3 dsjw 1 dbrp 1
	  tdcv 0 tdco 7 tdcf 8
	  ES582.1/ES584.1: dtseg1 2..32 dtseg2 1..16 dsjw 1..8 dbrp 1..32 brp_inc 1
	  tdcv_max 0 tdco_max 127 tdcf_max 127
	  clock 80000000 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535

$ ip --details --json --pretty link show can0
[ {
        "ifindex": 1,
        "ifname": "can0",
        "flags": [ "NOARP","ECHO" ],
        "mtu": 72,
        "qdisc": "noop",
        "operstate": "DOWN",
        "linkmode": "DEFAULT",
        "group": "default",
        "txqlen": 10,
        "link_type": "can",
        "promiscuity": 0,
        "min_mtu": 0,
        "max_mtu": 0,
        "linkinfo": {
            "info_kind": "can",
            "info_data": {
                "ctrlmode": [ "FD" ],
                "state": "STOPPED",
                "berr_counter": {
                    "tx": 0,
                    "rx": 0
                },
                "restart_ms": 0,
                "bittiming": {
                    "bitrate": 1000000,
                    "sample_point": "0.750",
                    "tq": 12,
                    "prop_seg": 29,
                    "phase_seg1": 30,
                    "phase_seg2": 20,
                    "sjw": 1,
                    "brp": 1
                },
                "bittiming_const": {
                    "name": "ES582.1/ES584.1",
                    "tseg1": {
                        "min": 2,
                        "max": 256
                    },
                    "tseg2": {
                        "min": 2,
                        "max": 128
                    },
                    "sjw": {
                        "min": 1,
                        "max": 128
                    },
                    "brp": {
                        "min": 1,
                        "max": 512
                    },
                    "brp_inc": 1
                },
                "data_bittiming": {
                    "bitrate": 8000000,
                    "sample_point": "0.700",
                    "tq": 12,
                    "prop_seg": 3,
                    "phase_seg1": 3,
                    "phase_seg2": 3,
                    "sjw": 1,
                    "brp": 1,
                    "tdc": {
                        "tdcv": 0,
                        "tdco": 7,
                        "tdcf": 8
                    }
                },
                "data_bittiming_const": {
                    "name": "ES582.1/ES584.1",
                    "tseg1": {
                        "min": 2,
                        "max": 32
                    },
                    "tseg2": {
                        "min": 1,
                        "max": 16
                    },
                    "sjw": {
                        "min": 1,
                        "max": 8
                    },
                    "brp": {
                        "min": 1,
                        "max": 32
                    },
                    "brp_inc": 1,
                    "tdc": {
                        "tdcv_max": 0,
                        "tdco_max": 127,
                        "tdcf_max": 127
                    }
                },
                "clock": 80000000
            }
        },
        "num_tx_queues": 1,
        "num_rx_queues": 1,
        "gso_max_size": 65536,
        "gso_max_segs": 65535
    } ]

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
---
 include/uapi/linux/can/netlink.h | 25 +++++++++--
 ip/iplink_can.c                  | 77 ++++++++++++++++++++++++++++++++
 2 files changed, 99 insertions(+), 3 deletions(-)

diff --git a/include/uapi/linux/can/netlink.h b/include/uapi/linux/can/netlink.h
index 00c763df..d5cc2761 100644
--- a/include/uapi/linux/can/netlink.h
+++ b/include/uapi/linux/can/netlink.h
@@ -134,12 +134,31 @@ enum {
 	IFLA_CAN_BITRATE_CONST,
 	IFLA_CAN_DATA_BITRATE_CONST,
 	IFLA_CAN_BITRATE_MAX,
-	__IFLA_CAN_MAX
-};
+	IFLA_CAN_TDC,
 
-#define IFLA_CAN_MAX	(__IFLA_CAN_MAX - 1)
+	/* add new constants above here */
+	__IFLA_CAN_MAX,
+	IFLA_CAN_MAX = __IFLA_CAN_MAX - 1
+};
 
 /* u16 termination range: 1..65535 Ohms */
 #define CAN_TERMINATION_DISABLED 0
 
+/*
+ * CAN FD Transmitter Delay Compensation (TDC)
+ */
+enum {
+	IFLA_CAN_TDC_UNSPEC,
+	IFLA_CAN_TDC_TDCV_MAX,	/* u32 */
+	IFLA_CAN_TDC_TDCO_MAX,	/* u32 */
+	IFLA_CAN_TDC_TDCF_MAX,	/* u32 */
+	IFLA_CAN_TDC_TDCV,	/* u32 */
+	IFLA_CAN_TDC_TDCO,	/* u32 */
+	IFLA_CAN_TDC_TDCF,	/* u32 */
+
+	/* add new constants above here */
+	__IFLA_CAN_TDC,
+	IFLA_CAN_TDC_MAX = __IFLA_CAN_TDC - 1
+};
+
 #endif /* !_UAPI_CAN_NETLINK_H */
diff --git a/ip/iplink_can.c b/ip/iplink_can.c
index 311c097d..ea049999 100644
--- a/ip/iplink_can.c
+++ b/ip/iplink_can.c
@@ -28,6 +28,7 @@ static void print_usage(FILE *f)
 		"\n"
 		"\t[ dbitrate BITRATE [ dsample-point SAMPLE-POINT] ] |\n"
 		"\t[ dtq TQ dprop-seg PROP_SEG dphase-seg1 PHASE-SEG1\n \t  dphase-seg2 PHASE-SEG2 [ dsjw SJW ] ]\n"
+		"\t[ tdcv TDCV tdco TDCO tdcf TDCF ]\n"
 		"\n"
 		"\t[ loopback { on | off } ]\n"
 		"\t[ listen-only { on | off } ]\n"
@@ -51,6 +52,9 @@ static void print_usage(FILE *f)
 		"\t	  PHASE-SEG1	:= { NUMBER }\n"
 		"\t	  PHASE-SEG2	:= { NUMBER }\n"
 		"\t	  SJW		:= { NUMBER }\n"
+		"\t	  TDCV		:= { 0 | NUMBER }\n"
+		"\t	  TDCO		:= { 0 | NUMBER }\n"
+		"\t	  TDCF		:= { NUMBER }\n"
 		"\t	  RESTART-MS	:= { 0 | NUMBER }\n"
 		);
 }
@@ -116,6 +120,8 @@ static int can_parse_opt(struct link_util *lu, int argc, char **argv,
 {
 	struct can_bittiming bt = {}, dbt = {};
 	struct can_ctrlmode cm = {0, 0};
+	struct rtattr *tdc;
+	__u32 tdcv = -1, tdco = -1, tdcf = -1;
 
 	while (argc > 0) {
 		if (matches(*argv, "bitrate") == 0) {
@@ -181,6 +187,18 @@ static int can_parse_opt(struct link_util *lu, int argc, char **argv,
 			NEXT_ARG();
 			if (get_u32(&dbt.sjw, *argv, 0))
 				invarg("invalid \"dsjw\" value\n", *argv);
+		} else if (matches(*argv, "tdcv") == 0) {
+			NEXT_ARG();
+			if (get_u32(&tdcv, *argv, 0))
+				invarg("invalid \"tdcv\" value\n", *argv);
+		} else if (matches(*argv, "tdco") == 0) {
+			NEXT_ARG();
+			if (get_u32(&tdco, *argv, 0))
+				invarg("invalid \"tdco\" value\n", *argv);
+		} else if (matches(*argv, "tdcf") == 0) {
+			NEXT_ARG();
+			if (get_u32(&tdcf, *argv, 0))
+				invarg("invalid \"tdcf\" value\n", *argv);
 		} else if (matches(*argv, "loopback") == 0) {
 			NEXT_ARG();
 			set_ctrlmode("loopback", *argv, &cm,
@@ -254,6 +272,17 @@ static int can_parse_opt(struct link_util *lu, int argc, char **argv,
 	if (cm.mask)
 		addattr_l(n, 1024, IFLA_CAN_CTRLMODE, &cm, sizeof(cm));
 
+	if (tdcv != -1 || tdco != -1 || tdcf != -1) {
+		tdc = addattr_nest(n, 1024, IFLA_CAN_TDC | NLA_F_NESTED);
+		if (tdcv != -1)
+			addattr32(n, 1024, IFLA_CAN_TDC_TDCV, tdcv);
+		if (tdco != -1)
+			addattr32(n, 1024, IFLA_CAN_TDC_TDCO, tdco);
+		if (tdcf != -1)
+			addattr32(n, 1024, IFLA_CAN_TDC_TDCF, tdcf);
+		addattr_nest_end(n, tdc);
+	}
+
 	return 0;
 }
 
@@ -294,6 +323,46 @@ static void can_print_data_timing_min_max(const char *attr, int min, int max)
 	can_print_timing_min_max(attr, min, max);
 }
 
+static void can_print_tdc_opt(FILE *f, struct rtattr *tdc_attr)
+{
+	struct rtattr *tb[IFLA_CAN_TDC_MAX + 1];
+
+	parse_rtattr_nested(tb, IFLA_CAN_TDC_MAX, tdc_attr);
+	if (tb[IFLA_CAN_TDC_TDCV] && tb[IFLA_CAN_TDC_TDCO] &&
+	    tb[IFLA_CAN_TDC_TDCF]) {
+		__u32 *tdcv = RTA_DATA(tb[IFLA_CAN_TDC_TDCV]);
+		__u32 *tdco = RTA_DATA(tb[IFLA_CAN_TDC_TDCO]);
+		__u32 *tdcf = RTA_DATA(tb[IFLA_CAN_TDC_TDCF]);
+
+		open_json_object("tdc");
+		can_print_nl_indent();
+		print_uint(PRINT_ANY, "tdcv", " tdcv %u", *tdcv);
+		print_uint(PRINT_ANY, "tdco", " tdco %u", *tdco);
+		print_uint(PRINT_ANY, "tdcf", " tdcf %u", *tdcf);
+		close_json_object();
+	}
+}
+
+static void can_print_tdc_const_opt(FILE *f, struct rtattr *tdc_attr)
+{
+	struct rtattr *tb[IFLA_CAN_TDC_MAX + 1];
+
+	parse_rtattr_nested(tb, IFLA_CAN_TDC_MAX, tdc_attr);
+	if (tb[IFLA_CAN_TDC_TDCV_MAX] && tb[IFLA_CAN_TDC_TDCO_MAX] &&
+	    tb[IFLA_CAN_TDC_TDCF_MAX]) {
+		__u32 *tdcv_max = RTA_DATA(tb[IFLA_CAN_TDC_TDCV_MAX]);
+		__u32 *tdco_max = RTA_DATA(tb[IFLA_CAN_TDC_TDCO_MAX]);
+		__u32 *tdcf_max = RTA_DATA(tb[IFLA_CAN_TDC_TDCF_MAX]);
+
+		open_json_object("tdc");
+		can_print_nl_indent();
+		print_uint(PRINT_ANY, "tdcv_max", " tdcv_max %u", *tdcv_max);
+		print_uint(PRINT_ANY, "tdco_max", " tdco_max %u", *tdco_max);
+		print_uint(PRINT_ANY, "tdcf_max", " tdcf_max %u", *tdcf_max);
+		close_json_object();
+	}
+}
+
 static void can_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 {
 	if (!tb)
@@ -425,6 +494,10 @@ static void can_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 			   dbt->phase_seg2);
 		print_uint(PRINT_ANY, "sjw", " dsjw %u", dbt->sjw);
 		print_uint(PRINT_ANY, "brp", " dbrp %u", dbt->brp);
+
+		if (tb[IFLA_CAN_TDC])
+			can_print_tdc_opt(f, tb[IFLA_CAN_TDC]);
+
 		close_json_object();
 	}
 
@@ -445,6 +518,10 @@ static void can_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 		can_print_data_timing_min_max("brp",
 					      dbtc->brp_min, dbtc->brp_max);
 		print_uint(PRINT_ANY, "brp_inc", " brp_inc %u", dbtc->brp_inc);
+
+		if (tb[IFLA_CAN_TDC])
+			can_print_tdc_const_opt(f, tb[IFLA_CAN_TDC]);
+
 		close_json_object();
 	}
 
-- 
2.31.1