Commit 1d147cb7 authored by Vincent Mailhol's avatar Vincent Mailhol Committed by Marc Kleine-Budde
Browse files

can: calc_bittiming: replace misleading "nominal" by "reference" 



The functions can_update_sample_point() and can_calc_bittiming() are
generic and meant to be used for both the nominal and the data bittiming
calculation.

However, those functions use misleading terminologies such as "bitrate
nominal" or "sample point nominal". Replace all places where the word
"nominal" appears with "reference" in order to better distinguish it from
the calculated values.

Signed-off-by: default avatarVincent Mailhol <mailhol@kernel.org>
Signed-off-by: default avatarOliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20251126-canxl-v8-12-e7e3eb74f889@pengutronix.de


Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 46552323

drivers/net/can/dev/calc_bittiming.c

+13 −13
Original line number Diff line number Diff line
@@ -24,7 +24,7 @@ 
 */

static int

can_update_sample_point(const struct can_bittiming_const *btc,

			const unsigned int sample_point_nominal, const unsigned int tseg,

			const unsigned int sample_point_reference, const unsigned int tseg,

			unsigned int *tseg1_ptr, unsigned int *tseg2_ptr,

			unsigned int *sample_point_error_ptr)

{
@@ -35,7 +35,7 @@ can_update_sample_point(const struct can_bittiming_const *btc, 


	for (i = 0; i <= 1; i++) {

		tseg2 = tseg + CAN_SYNC_SEG -

			(sample_point_nominal * (tseg + CAN_SYNC_SEG)) /

			(sample_point_reference * (tseg + CAN_SYNC_SEG)) /

			1000 - i;

		tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max);

		tseg1 = tseg - tseg2;
@@ -46,9 +46,9 @@ can_update_sample_point(const struct can_bittiming_const *btc, 


		sample_point = 1000 * (tseg + CAN_SYNC_SEG - tseg2) /

			(tseg + CAN_SYNC_SEG);

		sample_point_error = abs(sample_point_nominal - sample_point);

		sample_point_error = abs(sample_point_reference - sample_point);



		if (sample_point <= sample_point_nominal &&

		if (sample_point <= sample_point_reference &&

		    sample_point_error < best_sample_point_error) {

			best_sample_point = sample_point;

			best_sample_point_error = sample_point_error;
@@ -68,11 +68,11 @@ int can_calc_bittiming(const struct net_device *dev, struct can_bittiming *bt, 
{

	struct can_priv *priv = netdev_priv(dev);

	unsigned int bitrate;			/* current bitrate */

	unsigned int bitrate_error;		/* difference between current and nominal value */

	unsigned int bitrate_error;		/* diff between calculated and reference value */

	unsigned int best_bitrate_error = UINT_MAX;

	unsigned int sample_point_error;	/* difference between current and nominal value */

	unsigned int sample_point_error;	/* diff between calculated and reference value */

	unsigned int best_sample_point_error = UINT_MAX;

	unsigned int sample_point_nominal;	/* nominal sample point */

	unsigned int sample_point_reference;	/* reference sample point */

	unsigned int best_tseg = 0;		/* current best value for tseg */

	unsigned int best_brp = 0;		/* current best value for brp */

	unsigned int brp, tsegall, tseg, tseg1 = 0, tseg2 = 0;
@@ -81,14 +81,14 @@ int can_calc_bittiming(const struct net_device *dev, struct can_bittiming *bt, 


	/* Use CiA recommended sample points */

	if (bt->sample_point) {

		sample_point_nominal = bt->sample_point;

		sample_point_reference = bt->sample_point;

	} else {

		if (bt->bitrate > 800 * KILO /* BPS */)

			sample_point_nominal = 750;

			sample_point_reference = 750;

		else if (bt->bitrate > 500 * KILO /* BPS */)

			sample_point_nominal = 800;

			sample_point_reference = 800;

		else

			sample_point_nominal = 875;

			sample_point_reference = 875;

	}



	/* tseg even = round down, odd = round up */
@@ -115,7 +115,7 @@ int can_calc_bittiming(const struct net_device *dev, struct can_bittiming *bt, 
		if (bitrate_error < best_bitrate_error)

			best_sample_point_error = UINT_MAX;



		can_update_sample_point(btc, sample_point_nominal, tseg / 2,

		can_update_sample_point(btc, sample_point_reference, tseg / 2,

					&tseg1, &tseg2, &sample_point_error);

		if (sample_point_error >= best_sample_point_error)

			continue;
@@ -146,7 +146,7 @@ int can_calc_bittiming(const struct net_device *dev, struct can_bittiming *bt, 
	}



	/* real sample point */

	bt->sample_point = can_update_sample_point(btc, sample_point_nominal,

	bt->sample_point = can_update_sample_point(btc, sample_point_reference,

						   best_tseg, &tseg1, &tseg2,

						   NULL);