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<p>Thanks for the comment Joel, I sent an updated patch. I noticed just now I've also missed @brief so I will had that too before pushing..</p>
<p>/Daniel</p>
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<p id="reply-intro">2020-10-16 14:06 skrev Joel Sherrill:</p>
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<div class="v1gmail_attr" dir="ltr">On Fri, Oct 16, 2020, 6:50 AM Daniel Hellstrom <<a href="mailto:daniel@gaisler.com">daniel@gaisler.com</a>> wrote:</div>
<blockquote class="v1gmail_quote" style="margin: 0 0 0 .8ex; border-left: 1px #ccc solid; padding-left: 1ex;">Reimplemented the baud-rate algorithm from scratch to cope with<br /> GRCAN, GRCANFD and OC_CAN devices.<br /> ---<br /> bsps/<a href="http://headers.am" target="_blank" rel="noopener noreferrer">headers.am</a> | 1 +<br /> bsps/include/grlib/canbtrs.h | 80 ++++++++++++++++++++++<br /> bsps/shared/<a href="http://grlib-sources.am" target="_blank" rel="noopener noreferrer">grlib-sources.am</a> | 1 +<br /> bsps/shared/grlib/can/canbtrs.c | 143 ++++++++++++++++++++++++++++++++++++++++<br /> 4 files changed, 225 insertions(+)<br /> create mode 100644 bsps/include/grlib/canbtrs.h<br /> create mode 100644 bsps/shared/grlib/can/canbtrs.c<br /> <br /> diff --git a/bsps/<a href="http://headers.am" target="_blank" rel="noopener noreferrer">headers.am</a> b/bsps/<a href="http://headers.am" target="_blank" rel="noopener noreferrer">headers.am</a><br /> index 5af7e43..2c9b31d 100644<br /> --- a/bsps/<a href="http://headers.am" target="_blank" rel="noopener noreferrer">headers.am</a><br /> +++ b/bsps/<a href="http://headers.am" target="_blank" rel="noopener noreferrer">headers.am</a><br /> @@ -34,6 +34,7 @@ include_grlib_HEADERS += ../../bsps/include/grlib/apbuart_termios.h<br /> include_grlib_HEADERS += ../../bsps/include/grlib/b1553brm.h<br /> include_grlib_HEADERS += ../../bsps/include/grlib/b1553rt.h<br /> include_grlib_HEADERS += ../../bsps/include/grlib/bspcommon.h<br /> +include_grlib_HEADERS += ../../bsps/include/grlib/canbtrs.h<br /> include_grlib_HEADERS += ../../bsps/include/grlib/canmux.h<br /> include_grlib_HEADERS += ../../bsps/include/grlib/cons.h<br /> include_grlib_HEADERS += ../../bsps/include/grlib/debug_defs.h<br /> diff --git a/bsps/include/grlib/canbtrs.h b/bsps/include/grlib/canbtrs.h<br /> new file mode 100644<br /> index 0000000..3b2118b<br /> --- /dev/null<br /> +++ b/bsps/include/grlib/canbtrs.h<br /> @@ -0,0 +1,80 @@<br /> +/* SPDX-License-Identifier: BSD-2-Clause */<br /> +<br /> +/**<br /> + * @file<br /> + * @ingroup can<br /> + * @brief Common CAN baud-rate routines for OCCAN/GRCAN/GRCANFD controllers<br /> + */<br /> +<br /> +/*<br /> + * Copyright (C) 2019, 2020 Cobham Gaisler AB<br /> + *<br /> + * Redistribution and use in source and binary forms, with or without<br /> + * modification, are permitted provided that the following conditions<br /> + * are met:<br /> + * 1. Redistributions of source code must retain the above copyright<br /> + * notice, this list of conditions and the following disclaimer.<br /> + * 2. Redistributions in binary form must reproduce the above copyright<br /> + * notice, this list of conditions and the following disclaimer in the<br /> + * documentation and/or other materials provided with the distribution.<br /> + *<br /> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"<br /> + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE<br /> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE<br /> + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE<br /> + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR<br /> + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF<br /> + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS<br /> + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN<br /> + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)<br /> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE<br /> + * POSSIBILITY OF SUCH DAMAGE.<br /> + */<br /> +<br /> +#ifndef __GRLIB_CANBTRS_H__<br /> +#define __GRLIB_CANBTRS_H__<br /> +<br /> +#ifdef __cplusplus<br /> +extern "C" {<br /> +#endif<br /> +<br /> +/* CAN Baud-rate parameters, range of valid parameter values */<br /> +struct grlib_canbtrs_ranges {<br /> + unsigned int max_scaler;<br /> + char has_bpr;<br /> + unsigned char divfactor;<br /> + unsigned char min_tseg1;<br /> + unsigned char max_tseg1;<br /> + unsigned char min_tseg2;<br /> + unsigned char max_tseg2;<br /> +};<br /> +<br /> +struct grlib_canbtrs_timing {<br /> + unsigned char scaler;<br /> + unsigned char ps1;<br /> + unsigned char ps2;<br /> + unsigned char rsj;<br /> + unsigned char bpr;<br /> +};<br /> +<br /> +/* Calculate CAN baud-rate generation parameters from requested baud-rate<br /> + *<br /> + * \param baud The CAN baud rate requested<br /> + * \param core_hz Input clock [Hz] to CAN core<br /> + * \param sampl_pt CAN sample point in %, 80 means 80%<br /> + * \param br CAN Baud-rate parameters limitations<br /> + * \param timing result is placed here<br /> + */</blockquote>
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<div dir="auto">I thought we used @ notation for Doxygen not leading backslash in front of commands.</div>
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<blockquote class="v1gmail_quote" style="margin: 0 0 0 .8ex; border-left: 1px #ccc solid; padding-left: 1ex;">+int grlib_canbtrs_calc_timing(<br /> + unsigned int baud,<br /> + unsigned int core_hz,<br /> + unsigned int sampl_pt,<br /> + struct grlib_canbtrs_ranges *br,<br /> + struct grlib_canbtrs_timing *timing<br /> + );<br /> +<br /> +#ifdef __cplusplus<br /> +}<br /> +#endif<br /> +<br /> +#endif<br /> diff --git a/bsps/shared/<a href="http://grlib-sources.am" target="_blank" rel="noopener noreferrer">grlib-sources.am</a> b/bsps/shared/<a href="http://grlib-sources.am" target="_blank" rel="noopener noreferrer">grlib-sources.am</a><br /> index 512a48c..f2ad1bf 100644<br /> --- a/bsps/shared/<a href="http://grlib-sources.am" target="_blank" rel="noopener noreferrer">grlib-sources.am</a><br /> +++ b/bsps/shared/<a href="http://grlib-sources.am" target="_blank" rel="noopener noreferrer">grlib-sources.am</a><br /> @@ -20,6 +20,7 @@ librtemsbsp_a_SOURCES += ../../../../../../bsps/shared/grlib/ascs/grascs.c<br /> librtemsbsp_a_SOURCES += ../../../../../../bsps/shared/grlib/btimer/gptimer.c<br /> librtemsbsp_a_SOURCES += ../../../../../../bsps/shared/grlib/btimer/tlib.c<br /> librtemsbsp_a_SOURCES += ../../../../../../bsps/shared/grlib/btimer/tlib_ckinit.c<br /> +librtemsbsp_a_SOURCES += ../../../../../../bsps/shared/grlib/can/canbtrs.c<br /> librtemsbsp_a_SOURCES += ../../../../../../bsps/shared/grlib/can/canmux.c<br /> librtemsbsp_a_SOURCES += ../../../../../../bsps/shared/grlib/can/grcan.c<br /> librtemsbsp_a_SOURCES += ../../../../../../bsps/shared/grlib/can/occan.c<br /> diff --git a/bsps/shared/grlib/can/canbtrs.c b/bsps/shared/grlib/can/canbtrs.c<br /> new file mode 100644<br /> index 0000000..d28efbc<br /> --- /dev/null<br /> +++ b/bsps/shared/grlib/can/canbtrs.c<br /> @@ -0,0 +1,143 @@<br /> +/* SPDX-License-Identifier: BSD-2-Clause */<br /> +<br /> +/**<br /> + * @file<br /> + *<br /> + * @ingroup can<br /> + *<br /> + * @brief Common CAN baud-rate routines for OCCAN/GRCAN/GRCANFD controllers<br /> + *<br /> + * Implements common routines for calculating CAN baud-rate parameters from<br /> + * a user provided baud-rate speed.<br /> + */<br /> +<br /> +/*<br /> + * Copyright (C) 2019, 2020 Cobham Gailer AB<br /> + *<br /> + * Redistribution and use in source and binary forms, with or without<br /> + * modification, are permitted provided that the following conditions<br /> + * are met:<br /> + * 1. Redistributions of source code must retain the above copyright<br /> + * notice, this list of conditions and the following disclaimer.<br /> + * 2. Redistributions in binary form must reproduce the above copyright<br /> + * notice, this list of conditions and the following disclaimer in the<br /> + * documentation and/or other materials provided with the distribution.<br /> + *<br /> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"<br /> + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE<br /> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE<br /> + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE<br /> + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR<br /> + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF<br /> + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS<br /> + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN<br /> + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)<br /> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE<br /> + * POSSIBILITY OF SUCH DAMAGE.<br /> + */<br /> +<br /> +#include <grlib/canbtrs.h><br /> +<br /> +/*#define GRLIB_CANBTRS_DEBUG*/<br /> +<br /> +/* Calculate CAN baud-rate generation parameters from requested baud-rate */<br /> +int grlib_canbtrs_calc_timing(<br /> + unsigned int baud,<br /> + unsigned int core_hz,<br /> + unsigned int sampl_pt,<br /> + struct grlib_canbtrs_ranges *br,<br /> + struct grlib_canbtrs_timing *timing<br /> + )<br /> +{<br /> + int best_error = 2000000000, best_tseg=0, best_scaler=0;<br /> + int tseg=0, tseg1=0, tseg2=0, sc, error;<br /> +<br /> + /* Default to 80% sample point */<br /> + if ((sampl_pt < 50) || (sampl_pt > 99))<br /> + sampl_pt = 80;<br /> +<br /> + /* step though all TSEG1+TSEG2 values possible */<br /> + for (tseg = (br->min_tseg1 + br->min_tseg2);<br /> + tseg <= (br->max_tseg1 + br->max_tseg2);<br /> + tseg++) {<br /> + /* calculate scaler */<br /> + sc = core_hz / ((br->divfactor + tseg) * baud);<br /> + if (sc <= 0 || sc > br->max_scaler)<br /> + continue;<br /> + if (br->has_bpr &&<br /> + (((sc > 256 * 1) && (sc <= 256 * 2) && (sc & 0x1)) ||<br /> + ((sc > 256 * 2) && (sc <= 256 * 4) && (sc & 0x3)) ||<br /> + ((sc > 256 * 4) && (sc <= 256 * 8) && (sc & 0x7))))<br /> + continue;<br /> +<br /> + error = baud - core_hz / (sc * (br->divfactor + tseg));<br /> +#ifdef GRLIB_CANBTRS_DEBUG<br /> + printf(" baud=%d, tseg=%d, sc=%d, error=%d\n",<br /> + baud, tseg, sc, error);<br /> +#endif<br /> + if (error < 0)<br /> + error = -error;<br /> +<br /> + /* tseg is increasing, so we accept higher tseg with the same<br /> + * baudrate to get better sampling point.<br /> + */<br /> + if (error <= best_error) {<br /> + best_error = error;<br /> + best_tseg = tseg;<br /> + best_scaler = sc;<br /> +#ifdef GRLIB_CANBTRS_DEBUG<br /> + printf(" ! best baud=%d\n",<br /> + core_hz/(sc * (br->divfactor + tseg)));<br /> +#endif<br /> + }<br /> + }<br /> +<br /> + /* return an error if 5% off baud-rate */<br /> + if (best_error && (baud / best_error <= 5)) {<br /> + return -2;<br /> + } else if (!timing) {<br /> + return 0; /* nothing to store result in, but a valid bitrate can be calculated */<br /> + }<br /> +<br /> + tseg2 = (best_tseg + br->divfactor) -<br /> + ((sampl_pt * (best_tseg + br->divfactor)) / 100);<br /> + if (tseg2 < br->min_tseg2) {<br /> + tseg2 = br->min_tseg2;<br /> + } else if (tseg2 > br->max_tseg2) {<br /> + tseg2 = br->max_tseg2;<br /> + }<br /> +<br /> + tseg1 = best_tseg - tseg2;<br /> + if (tseg1 > br->max_tseg1) {<br /> + tseg1 = br->max_tseg1;<br /> + tseg2 = best_tseg - tseg1;<br /> + } else if (tseg1 < br->min_tseg1) {<br /> + tseg1 = br->min_tseg1;<br /> + tseg2 = best_tseg - tseg1;<br /> + }<br /> +<br /> + /* Get scaler and BPR from pseudo SCALER clock */<br /> + if (best_scaler <= 256) {<br /> + timing->scaler = best_scaler - 1;<br /> + timing->bpr = 0;<br /> + } else if (best_scaler <= 256 * 2) {<br /> + timing->scaler = ((best_scaler + 1) >> 1) - 1;<br /> + timing->bpr = 1;<br /> + } else if (best_scaler <= 256 * 4) {<br /> + timing->scaler = ((best_scaler + 1) >> 2) - 1;<br /> + timing->bpr = 2;<br /> + } else {<br /> + timing->scaler = ((best_scaler + 1) >> 3) - 1;<br /> + timing->bpr = 3;<br /> + }<br /> +<br /> + timing->ps1 = tseg1;<br /> + timing->ps2 = tseg2;<br /> + timing->rsj = 1;<br /> +<br /> +#ifdef GRLIB_CANBTRS_DEBUG<br /> + printf(" ! result: sc=%d,bpr=%d,ps1=%d,ps2=%d\n", timing->scaler, timing->bpr, timing->ps1, timing->ps2);<br /> +#endif<br /> +<br /> + return 0;<br /> +}<br /> -- <br /> 2.7.4<br /> <br /> _______________________________________________<br /> devel mailing list<br /> <a href="mailto:devel@rtems.org">devel@rtems.org</a><br /> <a href="http://lists.rtems.org/mailman/listinfo/devel" target="_blank" rel="noopener noreferrer">http://lists.rtems.org/mailman/listinfo/devel</a></blockquote>
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