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Merge pull request #372 from marckleinebudde/calc-bit-timing 

improve can-calc-bittiming
pull/374/head
Marc Kleine-Budde 2022-08-12 15:16:02 +02:00 committed by GitHub
parent cad1cecf1c 7e2010a1c0
commit a44238c9e2
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
10 changed files with 1181 additions and 376 deletions
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1
.gitignore vendored
View File

@ -20,6 +20,7 @@ GNUmakefile.in
/config/m4/ltsugar.m4
/config/m4/ltversion.m4
/config/m4/lt~obsolete.m4
/calc-bit-timing/.dirstamp
/mcp251xfd/.dirstamp
/asc2log

4
CMakeLists.txt
View File

@ -62,6 +62,10 @@ set(PROGRAMS
slcanpty
)
add_executable(can-calc-bit-timing
calc-bit-timing/can-calc-bit-timing.c
)
add_executable(mcp251xfd-dump
mcp251xfd/mcp251xfd-dev-coredump.c
mcp251xfd/mcp251xfd-dump.c

14
GNUmakefile.am
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@ -5,6 +5,8 @@ AM_CPPFLAGS = \
-I$(top_builddir)/include \
$(linux_CFLAGS)
EXTRA_DIST =
# link every app against libcan, it's static so it wouldn't hurt
LDADD = \
libcan.la
@ -39,6 +41,16 @@ libcan_la_SOURCES = \
libj1939_la_SOURCES = \
libj1939.c
can_calc_bit_timing_SOURCES = \
calc-bit-timing/can-calc-bit-timing.c
EXTRA_DIST += \
calc-bit-timing/can-calc-bit-timing-v2_6_31.c \
calc-bit-timing/can-calc-bit-timing-v3_18.c \
calc-bit-timing/can-calc-bit-timing-v4_8.c \
calc-bit-timing/can-calc-bit-timing-v5_16.c \
calc-bit-timing/can-calc-bit-timing-v5_19.c
mcp251xfd_dump_SOURCES = \
mcp251xfd/mcp251xfd-dev-coredump.c \
mcp251xfd/mcp251xfd-dump-userspace.h \
@ -87,7 +99,7 @@ j1939spy_LDADD = libj1939.la
j1939sr_LDADD = libj1939.la
testj1939_LDADD = libj1939.la
EXTRA_DIST = \
EXTRA_DIST += \
.travis.yml \
Android.mk \
README.md \

3
Makefile
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@ -142,5 +142,8 @@ j1939sr: j1939sr.o libj1939.o
testj1939: testj1939.o libj1939.o
canbusload: canbusload.o canframelen.o
can-calc-bit-timing: calc-bit-timing/can-calc-bit-timing.o
$(CC) $(LDFLAGS) $^ $(LDLIBS) -o $@
mcp251xfd-dump: mcp251xfd/mcp251xfd-dev-coredump.o mcp251xfd/mcp251xfd-dump.o mcp251xfd/mcp251xfd-main.o mcp251xfd/mcp251xfd-regmap.o
$(CC) $(LDFLAGS) $^ $(LDLIBS) -o $@

190
calc-bit-timing/can-calc-bit-timing-v2_6_31.c 100644
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@ -0,0 +1,190 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* imported from v2.6.31-rc1~330^2~376
*
* 39549eef3587 can: CAN Network device driver and Netlink interface
*
* cherry-picked for easier integration:
* 61463a30f652 can: make function can_get_bittiming static
* aabdfd6adb80 can: replace the dev_dbg/info/err/... with the new netdev_xxx macros
* 08da7da41ea4 can: provide a separate bittiming_const parameter to bittiming functions
* b25a437206ed can: dev: remove unused variable from can_calc_bittiming() function
*/
/*
* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
* Copyright (C) 2006 Andrey Volkov, Varma Electronics
* Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the version 2 of the GNU General Public License
* as published by the Free Software Foundation
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Bit-timing calculation derived from:
*
* Code based on LinCAN sources and H8S2638 project
* Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
* Copyright 2005 Stanislav Marek
* email: pisa@cmp.felk.cvut.cz
*
* Calculates proper bit-timing parameters for a specified bit-rate
* and sample-point, which can then be used to set the bit-timing
* registers of the CAN controller. You can find more information
* in the header file linux/can/netlink.h.
*/
static int can_update_spt(const struct can_bittiming_const *btc,
int sampl_pt, int tseg, int *tseg1, int *tseg2)
{
*tseg2 = tseg + 1 - (sampl_pt * (tseg + 1)) / 1000;
if (*tseg2 < btc->tseg2_min)
*tseg2 = btc->tseg2_min;
if (*tseg2 > btc->tseg2_max)
*tseg2 = btc->tseg2_max;
*tseg1 = tseg - *tseg2;
if (*tseg1 > btc->tseg1_max) {
*tseg1 = btc->tseg1_max;
*tseg2 = tseg - *tseg1;
}
return 1000 * (tseg + 1 - *tseg2) / (tseg + 1);
}
static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc)
{
struct can_priv *priv = netdev_priv(dev);
long best_error = 1000000000, error = 0;
int best_tseg = 0, best_brp = 0, brp = 0;
int tsegall, tseg = 0, tseg1 = 0, tseg2 = 0;
int spt_error = 1000, spt = 0, sampl_pt;
long rate;
u64 v64;
/* Use CIA recommended sample points */
if (bt->sample_point) {
sampl_pt = bt->sample_point;
} else {
if (bt->bitrate > 800000)
sampl_pt = 750;
else if (bt->bitrate > 500000)
sampl_pt = 800;
else
sampl_pt = 875;
}
/* tseg even = round down, odd = round up */
for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
tsegall = 1 + tseg / 2;
/* Compute all possible tseg choices (tseg=tseg1+tseg2) */
brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
/* chose brp step which is possible in system */
brp = (brp / btc->brp_inc) * btc->brp_inc;
if ((brp < btc->brp_min) || (brp > btc->brp_max))
continue;
rate = priv->clock.freq / (brp * tsegall);
error = bt->bitrate - rate;
/* tseg brp biterror */
if (error < 0)
error = -error;
if (error > best_error)
continue;
best_error = error;
if (error == 0) {
spt = can_update_spt(btc, sampl_pt, tseg / 2,
&tseg1, &tseg2);
error = sampl_pt - spt;
if (error < 0)
error = -error;
if (error > spt_error)
continue;
spt_error = error;
}
best_tseg = tseg / 2;
best_brp = brp;
if (error == 0)
break;
}
if (best_error) {
/* Error in one-tenth of a percent */
error = (best_error * 1000) / bt->bitrate;
if (error > CAN_CALC_MAX_ERROR) {
netdev_err(dev,
"bitrate error %ld.%ld%% too high\n",
error / 10, error % 10);
return -EDOM;
} else {
netdev_warn(dev, "bitrate error %ld.%ld%%\n",
error / 10, error % 10);
}
}
/* real sample point */
bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg,
&tseg1, &tseg2);
v64 = (u64)best_brp * 1000000000UL;
do_div(v64, priv->clock.freq);
bt->tq = (u32)v64;
bt->prop_seg = tseg1 / 2;
bt->phase_seg1 = tseg1 - bt->prop_seg;
bt->phase_seg2 = tseg2;
bt->sjw = 1;
bt->brp = best_brp;
/* real bit-rate */
bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1));
return 0;
}
/*
* Checks the validity of the specified bit-timing parameters prop_seg,
* phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
* prescaler value brp. You can find more information in the header
* file linux/can/netlink.h.
*/
static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc)
{
struct can_priv *priv = netdev_priv(dev);
int tseg1, alltseg;
u64 brp64;
tseg1 = bt->prop_seg + bt->phase_seg1;
if (!bt->sjw)
bt->sjw = 1;
if (bt->sjw > btc->sjw_max ||
tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
return -ERANGE;
brp64 = (u64)priv->clock.freq * (u64)bt->tq;
if (btc->brp_inc > 1)
do_div(brp64, btc->brp_inc);
brp64 += 500000000UL - 1;
do_div(brp64, 1000000000UL); /* the practicable BRP */
if (btc->brp_inc > 1)
brp64 *= btc->brp_inc;
bt->brp = (u32)brp64;
if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
return -EINVAL;
alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
return 0;
}

194
calc-bit-timing/can-calc-bit-timing-v3_18.c 100644
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@ -0,0 +1,194 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* imported from v3.18-rc1~52^2~248^2~1
*
*/
/*
* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
* Copyright (C) 2006 Andrey Volkov, Varma Electronics
* Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the version 2 of the GNU General Public License
* as published by the Free Software Foundation
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
/*
* Bit-timing calculation derived from:
*
* Code based on LinCAN sources and H8S2638 project
* Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
* Copyright 2005 Stanislav Marek
* email: pisa@cmp.felk.cvut.cz
*
* Calculates proper bit-timing parameters for a specified bit-rate
* and sample-point, which can then be used to set the bit-timing
* registers of the CAN controller. You can find more information
* in the header file linux/can/netlink.h.
*/
static int can_update_spt(const struct can_bittiming_const *btc,
int sampl_pt, int tseg, int *tseg1, int *tseg2)
{
*tseg2 = tseg + 1 - (sampl_pt * (tseg + 1)) / 1000;
if (*tseg2 < btc->tseg2_min)
*tseg2 = btc->tseg2_min;
if (*tseg2 > btc->tseg2_max)
*tseg2 = btc->tseg2_max;
*tseg1 = tseg - *tseg2;
if (*tseg1 > btc->tseg1_max) {
*tseg1 = btc->tseg1_max;
*tseg2 = tseg - *tseg1;
}
return 1000 * (tseg + 1 - *tseg2) / (tseg + 1);
}
static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc)
{
struct can_priv *priv = netdev_priv(dev);
long best_error = 1000000000, error = 0;
int best_tseg = 0, best_brp = 0, brp = 0;
int tsegall, tseg = 0, tseg1 = 0, tseg2 = 0;
int spt_error = 1000, spt = 0, sampl_pt;
long rate;
u64 v64;
/* Use CIA recommended sample points */
if (bt->sample_point) {
sampl_pt = bt->sample_point;
} else {
if (bt->bitrate > 800000)
sampl_pt = 750;
else if (bt->bitrate > 500000)
sampl_pt = 800;
else
sampl_pt = 875;
}
/* tseg even = round down, odd = round up */
for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
tsegall = 1 + tseg / 2;
/* Compute all possible tseg choices (tseg=tseg1+tseg2) */
brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
/* chose brp step which is possible in system */
brp = (brp / btc->brp_inc) * btc->brp_inc;
if ((brp < btc->brp_min) || (brp > btc->brp_max))
continue;
rate = priv->clock.freq / (brp * tsegall);
error = bt->bitrate - rate;
/* tseg brp biterror */
if (error < 0)
error = -error;
if (error > best_error)
continue;
best_error = error;
if (error == 0) {
spt = can_update_spt(btc, sampl_pt, tseg / 2,
&tseg1, &tseg2);
error = sampl_pt - spt;
if (error < 0)
error = -error;
if (error > spt_error)
continue;
spt_error = error;
}
best_tseg = tseg / 2;
best_brp = brp;
if (error == 0)
break;
}
if (best_error) {
/* Error in one-tenth of a percent */
error = (best_error * 1000) / bt->bitrate;
if (error > CAN_CALC_MAX_ERROR) {
netdev_err(dev,
"bitrate error %ld.%ld%% too high\n",
error / 10, error % 10);
return -EDOM;
} else {
netdev_warn(dev, "bitrate error %ld.%ld%%\n",
error / 10, error % 10);
}
}
/* real sample point */
bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg,
&tseg1, &tseg2);
v64 = (u64)best_brp * 1000000000UL;
do_div(v64, priv->clock.freq);
bt->tq = (u32)v64;
bt->prop_seg = tseg1 / 2;
bt->phase_seg1 = tseg1 - bt->prop_seg;
bt->phase_seg2 = tseg2;
/* check for sjw user settings */
if (!bt->sjw || !btc->sjw_max)
bt->sjw = 1;
else {
/* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
if (bt->sjw > btc->sjw_max)
bt->sjw = btc->sjw_max;
/* bt->sjw must not be higher than tseg2 */
if (tseg2 < bt->sjw)
bt->sjw = tseg2;
}
bt->brp = best_brp;
/* real bit-rate */
bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1));
return 0;
}
/*
* Checks the validity of the specified bit-timing parameters prop_seg,
* phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
* prescaler value brp. You can find more information in the header
* file linux/can/netlink.h.
*/
static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc)
{
struct can_priv *priv = netdev_priv(dev);
int tseg1, alltseg;
u64 brp64;
tseg1 = bt->prop_seg + bt->phase_seg1;
if (!bt->sjw)
bt->sjw = 1;
if (bt->sjw > btc->sjw_max ||
tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
return -ERANGE;
brp64 = (u64)priv->clock.freq * (u64)bt->tq;
if (btc->brp_inc > 1)
do_div(brp64, btc->brp_inc);
brp64 += 500000000UL - 1;
do_div(brp64, 1000000000UL); /* the practicable BRP */
if (btc->brp_inc > 1)
brp64 *= btc->brp_inc;
bt->brp = (u32)brp64;
if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
return -EINVAL;
alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
return 0;
}

223
calc-bit-timing/can-calc-bit-timing-v4_8.c 100644
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@ -0,0 +1,223 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* imported from v4.8-rc1~140^2~304^2~11
*
*/
/*
* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
* Copyright (C) 2006 Andrey Volkov, Varma Electronics
* Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the version 2 of the GNU General Public License
* as published by the Free Software Foundation
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
/*
* Bit-timing calculation derived from:
*
* Code based on LinCAN sources and H8S2638 project
* Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
* Copyright 2005 Stanislav Marek
* email: pisa@cmp.felk.cvut.cz
*
* Calculates proper bit-timing parameters for a specified bit-rate
* and sample-point, which can then be used to set the bit-timing
* registers of the CAN controller. You can find more information
* in the header file linux/can/netlink.h.
*/
static int can_update_sample_point(const struct can_bittiming_const *btc,
unsigned int sample_point_nominal, unsigned int tseg,
unsigned int *tseg1_ptr, unsigned int *tseg2_ptr,
unsigned int *sample_point_error_ptr)
{
unsigned int sample_point_error, best_sample_point_error = UINT_MAX;
unsigned int sample_point, best_sample_point = 0;
unsigned int tseg1, tseg2;
int i;
for (i = 0; i <= 1; i++) {
tseg2 = tseg + CAN_CALC_SYNC_SEG - (sample_point_nominal * (tseg + CAN_CALC_SYNC_SEG)) / 1000 - i;
tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max);
tseg1 = tseg - tseg2;
if (tseg1 > btc->tseg1_max) {
tseg1 = btc->tseg1_max;
tseg2 = tseg - tseg1;
}
sample_point = 1000 * (tseg + CAN_CALC_SYNC_SEG - tseg2) / (tseg + CAN_CALC_SYNC_SEG);
sample_point_error = abs(sample_point_nominal - sample_point);
if ((sample_point <= sample_point_nominal) && (sample_point_error < best_sample_point_error)) {
best_sample_point = sample_point;
best_sample_point_error = sample_point_error;
*tseg1_ptr = tseg1;
*tseg2_ptr = tseg2;
}
}
if (sample_point_error_ptr)
*sample_point_error_ptr = best_sample_point_error;
return best_sample_point;
}
static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc)
{
struct can_priv *priv = netdev_priv(dev);
unsigned int bitrate; /* current bitrate */
unsigned int bitrate_error; /* difference between current and nominal value */
unsigned int best_bitrate_error = UINT_MAX;
unsigned int sample_point_error; /* difference between current and nominal value */
unsigned int best_sample_point_error = UINT_MAX;
unsigned int sample_point_nominal; /* nominal 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;
u64 v64;
/* Use CiA recommended sample points */
if (bt->sample_point) {
sample_point_nominal = bt->sample_point;
} else {
if (bt->bitrate > 800000)
sample_point_nominal = 750;
else if (bt->bitrate > 500000)
sample_point_nominal = 800;
else
sample_point_nominal = 875;
}
/* tseg even = round down, odd = round up */
for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
tsegall = CAN_CALC_SYNC_SEG + tseg / 2;
/* Compute all possible tseg choices (tseg=tseg1+tseg2) */
brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
/* choose brp step which is possible in system */
brp = (brp / btc->brp_inc) * btc->brp_inc;
if ((brp < btc->brp_min) || (brp > btc->brp_max))
continue;
bitrate = priv->clock.freq / (brp * tsegall);
bitrate_error = abs(bt->bitrate - bitrate);
/* tseg brp biterror */
if (bitrate_error > best_bitrate_error)
continue;
/* reset sample point error if we have a better bitrate */
if (bitrate_error < best_bitrate_error)
best_sample_point_error = UINT_MAX;
can_update_sample_point(btc, sample_point_nominal, tseg / 2, &tseg1, &tseg2, &sample_point_error);
if (sample_point_error > best_sample_point_error)
continue;
best_sample_point_error = sample_point_error;
best_bitrate_error = bitrate_error;
best_tseg = tseg / 2;
best_brp = brp;
if (bitrate_error == 0 && sample_point_error == 0)
break;
}
if (best_bitrate_error) {
/* Error in one-tenth of a percent */
v64 = (u64)best_bitrate_error * 1000;
do_div(v64, bt->bitrate);
bitrate_error = (u32)v64;
if (bitrate_error > CAN_CALC_MAX_ERROR) {
netdev_err(dev,
"bitrate error %d.%d%% too high\n",
bitrate_error / 10, bitrate_error % 10);
return -EDOM;
}
netdev_warn(dev, "bitrate error %d.%d%%\n",
bitrate_error / 10, bitrate_error % 10);
}
/* real sample point */
bt->sample_point = can_update_sample_point(btc, sample_point_nominal, best_tseg,
&tseg1, &tseg2, NULL);
v64 = (u64)best_brp * 1000 * 1000 * 1000;
do_div(v64, priv->clock.freq);
bt->tq = (u32)v64;
bt->prop_seg = tseg1 / 2;
bt->phase_seg1 = tseg1 - bt->prop_seg;
bt->phase_seg2 = tseg2;
/* check for sjw user settings */
if (!bt->sjw || !btc->sjw_max) {
bt->sjw = 1;
} else {
/* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
if (bt->sjw > btc->sjw_max)
bt->sjw = btc->sjw_max;
/* bt->sjw must not be higher than tseg2 */
if (tseg2 < bt->sjw)
bt->sjw = tseg2;
}
bt->brp = best_brp;
/* real bitrate */
bt->bitrate = priv->clock.freq / (bt->brp * (CAN_CALC_SYNC_SEG + tseg1 + tseg2));
return 0;
}
/*
* Checks the validity of the specified bit-timing parameters prop_seg,
* phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
* prescaler value brp. You can find more information in the header
* file linux/can/netlink.h.
*/
static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc)
{
struct can_priv *priv = netdev_priv(dev);
int tseg1, alltseg;
u64 brp64;
tseg1 = bt->prop_seg + bt->phase_seg1;
if (!bt->sjw)
bt->sjw = 1;
if (bt->sjw > btc->sjw_max ||
tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
return -ERANGE;
brp64 = (u64)priv->clock.freq * (u64)bt->tq;
if (btc->brp_inc > 1)
do_div(brp64, btc->brp_inc);
brp64 += 500000000UL - 1;
do_div(brp64, 1000000000UL); /* the practicable BRP */
if (btc->brp_inc > 1)
brp64 *= btc->brp_inc;
bt->brp = (u32)brp64;
if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
return -EINVAL;
alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
return 0;
}

216
calc-bit-timing/can-calc-bit-timing-v5_16.c 100644
View File

@ -0,0 +1,216 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* imported from v5.16-rc1~159^2~104^2~13
*
*/
/* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
* Copyright (C) 2006 Andrey Volkov, Varma Electronics
* Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
*/
/* Bit-timing calculation derived from:
*
* Code based on LinCAN sources and H8S2638 project
* Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
* Copyright 2005 Stanislav Marek
* email: pisa@cmp.felk.cvut.cz
*
* Calculates proper bit-timing parameters for a specified bit-rate
* and sample-point, which can then be used to set the bit-timing
* registers of the CAN controller. You can find more information
* in the header file linux/can/netlink.h.
*/
static int
can_update_sample_point(const struct can_bittiming_const *btc,
unsigned int sample_point_nominal, unsigned int tseg,
unsigned int *tseg1_ptr, unsigned int *tseg2_ptr,
unsigned int *sample_point_error_ptr)
{
unsigned int sample_point_error, best_sample_point_error = UINT_MAX;
unsigned int sample_point, best_sample_point = 0;
unsigned int tseg1, tseg2;
int i;
for (i = 0; i <= 1; i++) {
tseg2 = tseg + CAN_SYNC_SEG -
(sample_point_nominal * (tseg + CAN_SYNC_SEG)) /
1000 - i;
tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max);
tseg1 = tseg - tseg2;
if (tseg1 > btc->tseg1_max) {
tseg1 = btc->tseg1_max;
tseg2 = tseg - tseg1;
}
sample_point = 1000 * (tseg + CAN_SYNC_SEG - tseg2) /
(tseg + CAN_SYNC_SEG);
sample_point_error = abs(sample_point_nominal - sample_point);
if (sample_point <= sample_point_nominal &&
sample_point_error < best_sample_point_error) {
best_sample_point = sample_point;
best_sample_point_error = sample_point_error;
*tseg1_ptr = tseg1;
*tseg2_ptr = tseg2;
}
}
if (sample_point_error_ptr)
*sample_point_error_ptr = best_sample_point_error;
return best_sample_point;
}
int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc)
{
struct can_priv *priv = netdev_priv(dev);
unsigned int bitrate; /* current bitrate */
unsigned int bitrate_error; /* difference between current and nominal value */
unsigned int best_bitrate_error = UINT_MAX;
unsigned int sample_point_error; /* difference between current and nominal value */
unsigned int best_sample_point_error = UINT_MAX;
unsigned int sample_point_nominal; /* nominal 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;
u64 v64;
/* Use CiA recommended sample points */
if (bt->sample_point) {
sample_point_nominal = bt->sample_point;
} else {
if (bt->bitrate > 800 * CAN_KBPS)
sample_point_nominal = 750;
else if (bt->bitrate > 500 * CAN_KBPS)
sample_point_nominal = 800;
else
sample_point_nominal = 875;
}
/* tseg even = round down, odd = round up */
for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
tsegall = CAN_SYNC_SEG + tseg / 2;
/* Compute all possible tseg choices (tseg=tseg1+tseg2) */
brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
/* choose brp step which is possible in system */
brp = (brp / btc->brp_inc) * btc->brp_inc;
if (brp < btc->brp_min || brp > btc->brp_max)
continue;
bitrate = priv->clock.freq / (brp * tsegall);
bitrate_error = abs(bt->bitrate - bitrate);
/* tseg brp biterror */
if (bitrate_error > best_bitrate_error)
continue;
/* reset sample point error if we have a better bitrate */
if (bitrate_error < best_bitrate_error)
best_sample_point_error = UINT_MAX;
can_update_sample_point(btc, sample_point_nominal, tseg / 2,
&tseg1, &tseg2, &sample_point_error);
if (sample_point_error > best_sample_point_error)
continue;
best_sample_point_error = sample_point_error;
best_bitrate_error = bitrate_error;
best_tseg = tseg / 2;
best_brp = brp;
if (bitrate_error == 0 && sample_point_error == 0)
break;
}
if (best_bitrate_error) {
/* Error in one-tenth of a percent */
v64 = (u64)best_bitrate_error * 1000;
do_div(v64, bt->bitrate);
bitrate_error = (u32)v64;
if (bitrate_error > CAN_CALC_MAX_ERROR) {
netdev_err(dev,
"bitrate error %d.%d%% too high\n",
bitrate_error / 10, bitrate_error % 10);
return -EDOM;
}
netdev_warn(dev, "bitrate error %d.%d%%\n",
bitrate_error / 10, bitrate_error % 10);
}
/* real sample point */
bt->sample_point = can_update_sample_point(btc, sample_point_nominal,
best_tseg, &tseg1, &tseg2,
NULL);
v64 = (u64)best_brp * 1000 * 1000 * 1000;
do_div(v64, priv->clock.freq);
bt->tq = (u32)v64;
bt->prop_seg = tseg1 / 2;
bt->phase_seg1 = tseg1 - bt->prop_seg;
bt->phase_seg2 = tseg2;
/* check for sjw user settings */
if (!bt->sjw || !btc->sjw_max) {
bt->sjw = 1;
} else {
/* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
if (bt->sjw > btc->sjw_max)
bt->sjw = btc->sjw_max;
/* bt->sjw must not be higher than tseg2 */
if (tseg2 < bt->sjw)
bt->sjw = tseg2;
}
bt->brp = best_brp;
/* real bitrate */
bt->bitrate = priv->clock.freq /
(bt->brp * (CAN_SYNC_SEG + tseg1 + tseg2));
return 0;
}
/* Checks the validity of the specified bit-timing parameters prop_seg,
* phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
* prescaler value brp. You can find more information in the header
* file linux/can/netlink.h.
*/
static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc)
{
struct can_priv *priv = netdev_priv(dev);
unsigned int tseg1, alltseg;
u64 brp64;
tseg1 = bt->prop_seg + bt->phase_seg1;
if (!bt->sjw)
bt->sjw = 1;
if (bt->sjw > btc->sjw_max ||
tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
return -ERANGE;
brp64 = (u64)priv->clock.freq * (u64)bt->tq;
if (btc->brp_inc > 1)
do_div(brp64, btc->brp_inc);
brp64 += 500000000UL - 1;
do_div(brp64, 1000000000UL); /* the practicable BRP */
if (btc->brp_inc > 1)
brp64 *= btc->brp_inc;
bt->brp = (u32)brp64;
if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
return -EINVAL;
alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
return 0;
}

216
calc-bit-timing/can-calc-bit-timing-v5_19.c 100644
View File

@ -0,0 +1,216 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* imported from v5.19-rc1~159^2~286^2~15
*
*/
/* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
* Copyright (C) 2006 Andrey Volkov, Varma Electronics
* Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
*/
/* Bit-timing calculation derived from:
*
* Code based on LinCAN sources and H8S2638 project
* Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
* Copyright 2005 Stanislav Marek
* email: pisa@cmp.felk.cvut.cz
*
* Calculates proper bit-timing parameters for a specified bit-rate
* and sample-point, which can then be used to set the bit-timing
* registers of the CAN controller. You can find more information
* in the header file linux/can/netlink.h.
*/
static int
can_update_sample_point(const struct can_bittiming_const *btc,
const unsigned int sample_point_nominal, const unsigned int tseg,
unsigned int *tseg1_ptr, unsigned int *tseg2_ptr,
unsigned int *sample_point_error_ptr)
{
unsigned int sample_point_error, best_sample_point_error = UINT_MAX;
unsigned int sample_point, best_sample_point = 0;
unsigned int tseg1, tseg2;
int i;
for (i = 0; i <= 1; i++) {
tseg2 = tseg + CAN_SYNC_SEG -
(sample_point_nominal * (tseg + CAN_SYNC_SEG)) /
1000 - i;
tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max);
tseg1 = tseg - tseg2;
if (tseg1 > btc->tseg1_max) {
tseg1 = btc->tseg1_max;
tseg2 = tseg - tseg1;
}
sample_point = 1000 * (tseg + CAN_SYNC_SEG - tseg2) /
(tseg + CAN_SYNC_SEG);
sample_point_error = abs(sample_point_nominal - sample_point);
if (sample_point <= sample_point_nominal &&
sample_point_error < best_sample_point_error) {
best_sample_point = sample_point;
best_sample_point_error = sample_point_error;
*tseg1_ptr = tseg1;
*tseg2_ptr = tseg2;
}
}
if (sample_point_error_ptr)
*sample_point_error_ptr = best_sample_point_error;
return best_sample_point;
}
int can_calc_bittiming(const struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc)
{
struct can_priv *priv = netdev_priv(dev);
unsigned int bitrate; /* current bitrate */
unsigned int bitrate_error; /* difference between current and nominal value */
unsigned int best_bitrate_error = UINT_MAX;
unsigned int sample_point_error; /* difference between current and nominal value */
unsigned int best_sample_point_error = UINT_MAX;
unsigned int sample_point_nominal; /* nominal 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;
u64 v64;
/* Use CiA recommended sample points */
if (bt->sample_point) {
sample_point_nominal = bt->sample_point;
} else {
if (bt->bitrate > 800 * KILO /* BPS */)
sample_point_nominal = 750;
else if (bt->bitrate > 500 * KILO /* BPS */)
sample_point_nominal = 800;
else
sample_point_nominal = 875;
}
/* tseg even = round down, odd = round up */
for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
tsegall = CAN_SYNC_SEG + tseg / 2;
/* Compute all possible tseg choices (tseg=tseg1+tseg2) */
brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
/* choose brp step which is possible in system */
brp = (brp / btc->brp_inc) * btc->brp_inc;
if (brp < btc->brp_min || brp > btc->brp_max)
continue;
bitrate = priv->clock.freq / (brp * tsegall);
bitrate_error = abs(bt->bitrate - bitrate);
/* tseg brp biterror */
if (bitrate_error > best_bitrate_error)
continue;
/* reset sample point error if we have a better bitrate */
if (bitrate_error < best_bitrate_error)
best_sample_point_error = UINT_MAX;
can_update_sample_point(btc, sample_point_nominal, tseg / 2,
&tseg1, &tseg2, &sample_point_error);
if (sample_point_error >= best_sample_point_error)
continue;
best_sample_point_error = sample_point_error;
best_bitrate_error = bitrate_error;
best_tseg = tseg / 2;
best_brp = brp;
if (bitrate_error == 0 && sample_point_error == 0)
break;
}
if (best_bitrate_error) {
/* Error in one-tenth of a percent */
v64 = (u64)best_bitrate_error * 1000;
do_div(v64, bt->bitrate);
bitrate_error = (u32)v64;
if (bitrate_error > CAN_CALC_MAX_ERROR) {
netdev_err(dev,
"bitrate error %d.%d%% too high\n",
bitrate_error / 10, bitrate_error % 10);
return -EDOM;
}
netdev_warn(dev, "bitrate error %d.%d%%\n",
bitrate_error / 10, bitrate_error % 10);
}
/* real sample point */
bt->sample_point = can_update_sample_point(btc, sample_point_nominal,
best_tseg, &tseg1, &tseg2,
NULL);
v64 = (u64)best_brp * 1000 * 1000 * 1000;
do_div(v64, priv->clock.freq);
bt->tq = (u32)v64;
bt->prop_seg = tseg1 / 2;
bt->phase_seg1 = tseg1 - bt->prop_seg;
bt->phase_seg2 = tseg2;
/* check for sjw user settings */
if (!bt->sjw || !btc->sjw_max) {
bt->sjw = 1;
} else {
/* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
if (bt->sjw > btc->sjw_max)
bt->sjw = btc->sjw_max;
/* bt->sjw must not be higher than tseg2 */
if (tseg2 < bt->sjw)
bt->sjw = tseg2;
}
bt->brp = best_brp;
/* real bitrate */
bt->bitrate = priv->clock.freq /
(bt->brp * (CAN_SYNC_SEG + tseg1 + tseg2));
return 0;
}
/* Checks the validity of the specified bit-timing parameters prop_seg,
* phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
* prescaler value brp. You can find more information in the header
* file linux/can/netlink.h.
*/
static int can_fixup_bittiming(const struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc)
{
const struct can_priv *priv = netdev_priv(dev);
unsigned int tseg1, alltseg;
u64 brp64;
tseg1 = bt->prop_seg + bt->phase_seg1;
if (!bt->sjw)
bt->sjw = 1;
if (bt->sjw > btc->sjw_max ||
tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
return -ERANGE;
brp64 = (u64)priv->clock.freq * (u64)bt->tq;
if (btc->brp_inc > 1)
do_div(brp64, btc->brp_inc);
brp64 += 500000000UL - 1;
do_div(brp64, 1000000000UL); /* the practicable BRP */
if (btc->brp_inc > 1)
brp64 *= btc->brp_inc;
bt->brp = (u32)brp64;
if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
return -EINVAL;
alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
return 0;
}

452
can-calc-bit-timing.c → calc-bit-timing/can-calc-bit-timing.c
View File

@ -140,15 +140,25 @@ struct calc_bittiming_const {
const void (*printf_data_btr)(struct can_bittiming *bt, bool hdr);
};
struct can_calc_bittiming {
int (*alg)(struct net_device *dev, struct can_bittiming *bt,
struct alg {
union {
int (*calc_bittiming)(struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc);
int (*calc_bittiming_const)(const struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc);
};
union {
int (*fixup_bittiming)(struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc);
int (*fixup_bittiming_const)(const struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc);
};
const char *name;
};
struct calc_data {
const struct can_bittiming_const *bittiming_const;
const struct can_calc_bittiming *calc_bittiming;
const struct alg *alg;
const void (*printf_btr)(struct can_bittiming *bt, bool hdr);
const char *name;
@ -163,6 +173,7 @@ struct calc_data {
const struct can_bittiming *opt_bt;
bool quiet;
bool fd_mode;
};
static inline void *netdev_priv(const struct net_device *dev)
@ -445,6 +456,7 @@ static const struct calc_bittiming_const can_calc_consts[] = {
.ref_clk = {
/* The mcp251x uses half of the external OSC clock as the base clock */
{ .clk = 8000000 / 2, .name = "8 MHz OSC" },
{ .clk = 12000000 / 2, .name = "12 MHz OSC" },
{ .clk = 16000000 / 2, .name = "16 MHz OSC" },
{ .clk = 20000000 / 2, .name = "20 MHz OSC" },
},
@ -976,9 +988,12 @@ static const struct calc_bittiming_const can_calc_consts[] = {
{ .clk = 20000000, .name = "CIA recommendation" },
{ .clk = 40000000, .name = "CIA recommendation" },
{ .clk = 24000000, .name = "stm32mp1 - ck_hse" },
{ .clk = 24573875, .name = "stm32mp1 - pll3_1" },
{ .clk = 74250000, .name = "stm32mp1 - pll4_r" },
{ .clk = 24573875, .name = "stm32mp1 - pll3_q" },
{ .clk = 29700000, .name = "stm32mp1 - pll4_q" },
{ .clk = 48000000, .name = "stm32mp1 lxatac (new)" },
{ .clk = 60000000, .name = "stm32mp1 ecu02.5- pll4_r" },
{ .clk = 62500000, .name = "stm32mp1 lxatac (old) - pll4_r" },
{ .clk = 74250000, .name = "stm32mp1 - pll4_r" },
},
.printf_btr = printf_btr_mcan,
}, {
@ -1133,6 +1148,8 @@ static const struct calc_bittiming_const can_calc_consts[] = {
.ref_clk = {
{ .clk = 20000000, .name = "CIA recommendation" },
{ .clk = 40000000, .name = "CIA recommendation" },
{ .clk = 79999999, .name = "Versal ACAP" },
{ .clk = 80000000, .name = "Versal ACAP" },
},
},
};
@ -1140,11 +1157,14 @@ static const struct calc_bittiming_const can_calc_consts[] = {
static const unsigned int common_bitrates[] = {
1000000,
800000,
666666,
500000,
250000,
125000,
100000,
83333,
50000,
33333,
20000,
10000,
0
@ -1163,356 +1183,75 @@ static const unsigned int common_data_bitrates[] = {
#define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
#define CAN_CALC_SYNC_SEG 1
#define CAN_SYNC_SEG 1
#define CAN_KBPS 1000
#define KILO 1000UL
/*
* Bit-timing calculation derived from:
*
* Code based on LinCAN sources and H8S2638 project
* Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
* Copyright 2005 Stanislav Marek
* email: pisa@cmp.felk.cvut.cz
*
* Calculates proper bit-timing parameters for a specified bit-rate
* and sample-point, which can then be used to set the bit-timing
* registers of the CAN controller. You can find more information
* in the header file linux/can/netlink.h.
*/
/*
* imported from v3.18-rc1~52^2~248^2~1
*
* b25a437206ed can: dev: remove unused variable from can_calc_bittiming() function
*/
#undef can_calc_bittiming
#define can_update_spt can_update_spt_v2_6_31
#define can_calc_bittiming can_calc_bittiming_v2_6_31
#define can_fixup_bittiming can_fixup_bittiming_v2_6_31
#include "can-calc-bit-timing-v2_6_31.c"
#undef can_update_spt
#define can_calc_bittiming can_calc_bittiming_v3_18
#undef can_calc_bittiming
#undef can_fixup_bittiming
#define can_update_spt can_update_spt_v3_18
static int can_update_spt(const struct can_bittiming_const *btc,
int sampl_pt, int tseg, int *tseg1, int *tseg2)
{
*tseg2 = tseg + 1 - (sampl_pt * (tseg + 1)) / 1000;
if (*tseg2 < btc->tseg2_min)
*tseg2 = btc->tseg2_min;
if (*tseg2 > btc->tseg2_max)
*tseg2 = btc->tseg2_max;
*tseg1 = tseg - *tseg2;
if (*tseg1 > btc->tseg1_max) {
*tseg1 = btc->tseg1_max;
*tseg2 = tseg - *tseg1;
}
return 1000 * (tseg + 1 - *tseg2) / (tseg + 1);
}
static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc)
{
struct can_priv *priv = netdev_priv(dev);
long best_error = 1000000000, error = 0;
int best_tseg = 0, best_brp = 0, brp = 0;
int tsegall, tseg = 0, tseg1 = 0, tseg2 = 0;
int spt_error = 1000, spt = 0, sampl_pt;
long rate;
u64 v64;
/* Use CIA recommended sample points */
if (bt->sample_point) {
sampl_pt = bt->sample_point;
} else {
if (bt->bitrate > 800000)
sampl_pt = 750;
else if (bt->bitrate > 500000)
sampl_pt = 800;
else
sampl_pt = 875;
}
/* tseg even = round down, odd = round up */
for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
tsegall = 1 + tseg / 2;
/* Compute all possible tseg choices (tseg=tseg1+tseg2) */
brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
/* chose brp step which is possible in system */
brp = (brp / btc->brp_inc) * btc->brp_inc;
if ((brp < btc->brp_min) || (brp > btc->brp_max))
continue;
rate = priv->clock.freq / (brp * tsegall);
error = bt->bitrate - rate;
/* tseg brp biterror */
if (error < 0)
error = -error;
if (error > best_error)
continue;
best_error = error;
if (error == 0) {
spt = can_update_spt(btc, sampl_pt, tseg / 2,
&tseg1, &tseg2);
error = sampl_pt - spt;
if (error < 0)
error = -error;
if (error > spt_error)
continue;
spt_error = error;
}
best_tseg = tseg / 2;
best_brp = brp;
if (error == 0)
break;
}
if (best_error) {
/* Error in one-tenth of a percent */
error = (best_error * 1000) / bt->bitrate;
if (error > CAN_CALC_MAX_ERROR) {
netdev_err(dev,
"bitrate error %ld.%ld%% too high\n",
error / 10, error % 10);
return -EDOM;
} else {
netdev_warn(dev, "bitrate error %ld.%ld%%\n",
error / 10, error % 10);
}
}
/* real sample point */
bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg,
&tseg1, &tseg2);
v64 = (u64)best_brp * 1000000000UL;
do_div(v64, priv->clock.freq);
bt->tq = (u32)v64;
bt->prop_seg = tseg1 / 2;
bt->phase_seg1 = tseg1 - bt->prop_seg;
bt->phase_seg2 = tseg2;
/* check for sjw user settings */
if (!bt->sjw || !btc->sjw_max)
bt->sjw = 1;
else {
/* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
if (bt->sjw > btc->sjw_max)
bt->sjw = btc->sjw_max;
/* bt->sjw must not be higher than tseg2 */
if (tseg2 < bt->sjw)
bt->sjw = tseg2;
}
bt->brp = best_brp;
/* real bit-rate */
bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1));
return 0;
}
/*
* imported from v4.8-rc1~140^2~304^2~11
*
* 7da29f97d6c8 can: dev: can-calc-bit-timing(): better sample point calculation
*/
#define can_calc_bittiming can_calc_bittiming_v3_18
#define can_fixup_bittiming can_fixup_bittiming_v3_18
#include "can-calc-bit-timing-v3_18.c"
#undef can_update_spt
#undef can_calc_bittiming
#define can_update_spt can_update_spt_v4_8
#undef can_fixup_bittiming
#define can_update_sample_point can_update_sample_point_v4_8
#define can_calc_bittiming can_calc_bittiming_v4_8
static int can_update_spt(const struct can_bittiming_const *btc,
unsigned int spt_nominal, unsigned int tseg,
unsigned int *tseg1_ptr, unsigned int *tseg2_ptr,
unsigned int *spt_error_ptr)
{
unsigned int spt_error, best_spt_error = UINT_MAX;
unsigned int spt, best_spt = 0;
unsigned int tseg1, tseg2;
int i;
for (i = 0; i <= 1; i++) {
tseg2 = tseg + CAN_CALC_SYNC_SEG - (spt_nominal * (tseg + CAN_CALC_SYNC_SEG)) / 1000 - i;
tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max);
tseg1 = tseg - tseg2;
if (tseg1 > btc->tseg1_max) {
tseg1 = btc->tseg1_max;
tseg2 = tseg - tseg1;
}
spt = 1000 * (tseg + CAN_CALC_SYNC_SEG - tseg2) / (tseg + CAN_CALC_SYNC_SEG);
spt_error = abs(spt_nominal - spt);
if ((spt <= spt_nominal) && (spt_error < best_spt_error)) {
best_spt = spt;
best_spt_error = spt_error;
*tseg1_ptr = tseg1;
*tseg2_ptr = tseg2;
}
}
if (spt_error_ptr)
*spt_error_ptr = best_spt_error;
return best_spt;
}
static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc)
{
struct can_priv *priv = netdev_priv(dev);
unsigned int rate; /* current bitrate */
unsigned int rate_error; /* difference between current and nominal value */
unsigned int best_rate_error = UINT_MAX;
unsigned int spt_error; /* difference between current and nominal value */
unsigned int best_spt_error = UINT_MAX;
unsigned int spt_nominal; /* nominal 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;
u64 v64;
/* Use CiA recommended sample points */
if (bt->sample_point) {
spt_nominal = bt->sample_point;
} else {
if (bt->bitrate > 800000)
spt_nominal = 750;
else if (bt->bitrate > 500000)
spt_nominal = 800;
else
spt_nominal = 875;
}
/* tseg even = round down, odd = round up */
for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
tsegall = CAN_CALC_SYNC_SEG + tseg / 2;
/* Compute all possible tseg choices (tseg=tseg1+tseg2) */
brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
/* choose brp step which is possible in system */
brp = (brp / btc->brp_inc) * btc->brp_inc;
if ((brp < btc->brp_min) || (brp > btc->brp_max))
continue;
rate = priv->clock.freq / (brp * tsegall);
rate_error = abs(bt->bitrate - rate);
/* tseg brp biterror */
if (rate_error > best_rate_error)
continue;
/* reset sample point error if we have a better bitrate */
if (rate_error < best_rate_error)
best_spt_error = UINT_MAX;
can_update_spt(btc, spt_nominal, tseg / 2, &tseg1, &tseg2, &spt_error);
if (spt_error > best_spt_error)
continue;
best_spt_error = spt_error;
best_rate_error = rate_error;
best_tseg = tseg / 2;
best_brp = brp;
if (rate_error == 0 && spt_error == 0)
break;
}
if (best_rate_error) {
/* Error in one-tenth of a percent */
rate_error = (best_rate_error * 1000) / bt->bitrate;
if (rate_error > CAN_CALC_MAX_ERROR) {
netdev_err(dev,
"bitrate error %ld.%ld%% too high\n",
rate_error / 10, rate_error % 10);
return -EDOM;
}
netdev_warn(dev, "bitrate error %ld.%ld%%\n",
rate_error / 10, rate_error % 10);
}
/* real sample point */
bt->sample_point = can_update_spt(btc, spt_nominal, best_tseg,
&tseg1, &tseg2, NULL);
v64 = (u64)best_brp * 1000 * 1000 * 1000;
do_div(v64, priv->clock.freq);
bt->tq = (u32)v64;
bt->prop_seg = tseg1 / 2;
bt->phase_seg1 = tseg1 - bt->prop_seg;
bt->phase_seg2 = tseg2;
/* check for sjw user settings */
if (!bt->sjw || !btc->sjw_max) {
bt->sjw = 1;
} else {
/* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
if (bt->sjw > btc->sjw_max)
bt->sjw = btc->sjw_max;
/* bt->sjw must not be higher than tseg2 */
if (tseg2 < bt->sjw)
bt->sjw = tseg2;
}
bt->brp = best_brp;
/* real bit-rate */
bt->bitrate = priv->clock.freq / (bt->brp * (CAN_CALC_SYNC_SEG + tseg1 + tseg2));
return 0;
}
#define can_fixup_bittiming can_fixup_bittiming_v4_8
#include "can-calc-bit-timing-v4_8.c"
#undef can_update_sample_point
#undef can_calc_bittiming
#undef can_update_spt
#undef can_fixup_bittiming
static const struct can_calc_bittiming calc_bittiming_list[] = {
#define can_update_sample_point can_update_sample_point_v5_16
#define can_calc_bittiming can_calc_bittiming_v5_16
#define can_fixup_bittiming can_fixup_bittiming_v5_16
#include "can-calc-bit-timing-v5_16.c"
#undef can_update_sample_point
#undef can_calc_bittiming
#undef can_fixup_bittiming
#define can_update_sample_point can_update_sample_point_v5_19
#define can_calc_bittiming can_calc_bittiming_v5_19
#define can_fixup_bittiming can_fixup_bittiming_v5_19
#include "can-calc-bit-timing-v5_19.c"
#undef can_update_sample_point
#undef can_calc_bittiming
#undef can_fixup_bittiming
static const struct alg alg_list[] = {
/* 1st will be default */
{
.alg = can_calc_bittiming_v4_8,
.calc_bittiming_const = can_calc_bittiming_v5_19,
.fixup_bittiming_const = can_fixup_bittiming_v5_19,
.name = "v5.19",
}, {
.calc_bittiming = can_calc_bittiming_v5_16,
.fixup_bittiming = can_fixup_bittiming_v5_16,
.name = "v5.16",
}, {
.calc_bittiming = can_calc_bittiming_v4_8,
.fixup_bittiming = can_fixup_bittiming_v4_8,
.name = "v4.8",
}, {
.alg = can_calc_bittiming_v3_18,
.calc_bittiming = can_calc_bittiming_v3_18,
.fixup_bittiming = can_fixup_bittiming_v3_18,
.name = "v3.18",
}, {
.calc_bittiming = can_calc_bittiming_v2_6_31,
.fixup_bittiming = can_fixup_bittiming_v2_6_31,
.name = "v2.6.31",
},
};
static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc)
{
struct can_priv *priv = netdev_priv(dev);
unsigned int tseg1, alltseg;
u64 brp64, v64;
tseg1 = bt->prop_seg + bt->phase_seg1;
if (!bt->sjw)
bt->sjw = 1;
if (bt->sjw > btc->sjw_max ||
tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
return -ERANGE;
if (!bt->brp) {
brp64 = (u64)priv->clock.freq * (u64)bt->tq;
if (btc->brp_inc > 1)
do_div(brp64, btc->brp_inc);
brp64 += 500000000UL - 1;
do_div(brp64, 1000000000UL); /* the practicable BRP */
if (btc->brp_inc > 1)
brp64 *= btc->brp_inc;
bt->brp = brp64;
}
v64 = bt->brp * 1000 * 1000 * 1000;
do_div(v64, priv->clock.freq);
bt->tq = v64;
if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
return -EINVAL;
alltseg = CAN_CALC_SYNC_SEG + bt->prop_seg + bt->phase_seg1 + bt->phase_seg2;
bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
bt->sample_point = ((CAN_CALC_SYNC_SEG + tseg1) * 1000) / alltseg;
return 0;
}
static __u32 get_cia_sample_point(__u32 bitrate)
{
__u32 sampl_pt;
@ -1527,14 +1266,15 @@ static __u32 get_cia_sample_point(__u32 bitrate)
return sampl_pt;
}
static void print_bittiming_one(const struct can_calc_bittiming *calc_bittiming,
static void print_bittiming_one(const struct alg *alg,
const struct can_bittiming_const *bittiming_const,
const struct can_bittiming *ref_bt,
const struct calc_ref_clk *ref_clk,
unsigned int bitrate_nominal,
unsigned int sample_point_nominal,
void (*printf_btr)(struct can_bittiming *bt, bool hdr),
bool quiet)
bool quiet,
bool fd_mode)
{
struct net_device dev = {
.priv.clock.freq = ref_clk->clk,
@ -1546,15 +1286,16 @@ static void print_bittiming_one(const struct can_calc_bittiming *calc_bittiming,
unsigned int bitrate_error, sample_point_error;
if (!quiet) {
printf("Bit timing parameters for %s with %.6f MHz ref clock %s%s%susing algo '%s'\n"
printf("%sBit timing parameters for %s with %.6f MHz ref clock %s%s%susing algo '%s'\n"
" nominal real Bitrt nom real SampP\n"
" Bitrate TQ[ns] PrS PhS1 PhS2 SJW BRP Bitrate Error SampP SampP Error ",
fd_mode ? "Data " : "",
bittiming_const->name,
ref_clk->clk / 1000000.0,
ref_clk->name ? "(" : "",
ref_clk->name ? ref_clk->name : "",
ref_clk->name ? ") " : "",
calc_bittiming->name);
alg->name);
printf_btr(&bt, true);
printf("\n");
@ -1563,12 +1304,12 @@ static void print_bittiming_one(const struct can_calc_bittiming *calc_bittiming,
if (ref_bt) {
bt = *ref_bt;
if (can_fixup_bittiming(&dev, &bt, bittiming_const)) {
if (alg->fixup_bittiming(&dev, &bt, bittiming_const)) {
printf("%8d ***parameters exceed controller's range***\n", bitrate_nominal);
return;
}
} else {
if (calc_bittiming->alg(&dev, &bt, bittiming_const)) {
if (alg->calc_bittiming(&dev, &bt, bittiming_const)) {
printf("%8d ***bitrate not possible***\n", bitrate_nominal);
return;
}
@ -1633,14 +1374,15 @@ static void print_bittiming(const struct calc_data *data)
else
sample_point = get_cia_sample_point(*bitrates);
print_bittiming_one(data->calc_bittiming,
print_bittiming_one(data->alg,
data->bittiming_const,
data->opt_bt,
ref_clks,
*bitrates,
sample_point,
printf_btr,
quiet);
quiet,
data->fd_mode);
bitrates++;
quiet = true;
}
@ -1654,8 +1396,8 @@ static void do_list_calc_bittiming_list(void)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(calc_bittiming_list); i++)
printf(" %s\n", calc_bittiming_list[i].name);
for (i = 0; i < ARRAY_SIZE(alg_list); i++)
printf(" %s\n", alg_list[i].name);
}
static void do_list(void)
@ -1697,6 +1439,8 @@ static void do_calc(struct calc_data *data)
else
data->bitrates = common_bitrates;
data->fd_mode = false;
print_bittiming(data);
}
@ -1720,6 +1464,8 @@ static void do_calc(struct calc_data *data)
else
data->bitrates = common_data_bitrates;
data->fd_mode = true;
print_bittiming(data);
}
}
@ -1748,7 +1494,7 @@ int main(int argc, char *argv[])
};
struct calc_data data[] = {
{
.calc_bittiming = calc_bittiming_list,
.alg = alg_list,
}
};
const char *opt_alg_name = NULL;
@ -1873,9 +1619,9 @@ int main(int argc, char *argv[])
bool alg_found = false;
unsigned int i;
for (i = 0; i < ARRAY_SIZE(calc_bittiming_list); i++) {
if (!strcmp(opt_alg_name, calc_bittiming_list[i].name)) {
data->calc_bittiming = &calc_bittiming_list[i];
for (i = 0; i < ARRAY_SIZE(alg_list); i++) {
if (!strcmp(opt_alg_name, alg_list[i].name)) {
data->alg = &alg_list[i];
alg_found = true;
}
}