T: git git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next.git
F: Documentation/devicetree/bindings/net/can/
F: drivers/net/can/
+F: include/linux/can/bittiming.h
F: include/linux/can/dev.h
F: include/linux/can/led.h
F: include/linux/can/platform/
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_CAN_DEV) += can-dev.o
+can-dev-y += bittiming.o
can-dev-y += dev.o
can-dev-y += rx-offload.o
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
+ * Copyright (C) 2006 Andrey Volkov, Varma Electronics
+ * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
+ */
+
+#include <linux/can/dev.h>
+
+#ifdef CONFIG_CAN_CALC_BITTIMING
+#define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
+
+/* 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 > 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_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;
+}
+#endif /* CONFIG_CAN_CALC_BITTIMING */
+
+/* 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;
+}
+
+/* Checks the validity of predefined bitrate settings */
+static int
+can_validate_bitrate(struct net_device *dev, struct can_bittiming *bt,
+ const u32 *bitrate_const,
+ const unsigned int bitrate_const_cnt)
+{
+ struct can_priv *priv = netdev_priv(dev);
+ unsigned int i;
+
+ for (i = 0; i < bitrate_const_cnt; i++) {
+ if (bt->bitrate == bitrate_const[i])
+ break;
+ }
+
+ if (i >= priv->bitrate_const_cnt)
+ return -EINVAL;
+
+ return 0;
+}
+
+int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
+ const struct can_bittiming_const *btc,
+ const u32 *bitrate_const,
+ const unsigned int bitrate_const_cnt)
+{
+ int err;
+
+ /* Depending on the given can_bittiming parameter structure the CAN
+ * timing parameters are calculated based on the provided bitrate OR
+ * alternatively the CAN timing parameters (tq, prop_seg, etc.) are
+ * provided directly which are then checked and fixed up.
+ */
+ if (!bt->tq && bt->bitrate && btc)
+ err = can_calc_bittiming(dev, bt, btc);
+ else if (bt->tq && !bt->bitrate && btc)
+ err = can_fixup_bittiming(dev, bt, btc);
+ else if (!bt->tq && bt->bitrate && bitrate_const)
+ err = can_validate_bitrate(dev, bt, bitrate_const,
+ bitrate_const_cnt);
+ else
+ err = -EINVAL;
+
+ return err;
+}
}
EXPORT_SYMBOL_GPL(can_fd_len2dlc);
-#ifdef CONFIG_CAN_CALC_BITTIMING
-#define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
-
-/* 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;
-}
-
-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_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;
-}
-#else /* !CONFIG_CAN_CALC_BITTIMING */
-static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
- const struct can_bittiming_const *btc)
-{
- netdev_err(dev, "bit-timing calculation not available\n");
- return -EINVAL;
-}
-#endif /* CONFIG_CAN_CALC_BITTIMING */
-
-/* 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;
-}
-
-/* Checks the validity of predefined bitrate settings */
-static int
-can_validate_bitrate(struct net_device *dev, struct can_bittiming *bt,
- const u32 *bitrate_const,
- const unsigned int bitrate_const_cnt)
-{
- struct can_priv *priv = netdev_priv(dev);
- unsigned int i;
-
- for (i = 0; i < bitrate_const_cnt; i++) {
- if (bt->bitrate == bitrate_const[i])
- break;
- }
-
- if (i >= priv->bitrate_const_cnt)
- return -EINVAL;
-
- return 0;
-}
-
-static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
- const struct can_bittiming_const *btc,
- const u32 *bitrate_const,
- const unsigned int bitrate_const_cnt)
-{
- int err;
-
- /* Depending on the given can_bittiming parameter structure the CAN
- * timing parameters are calculated based on the provided bitrate OR
- * alternatively the CAN timing parameters (tq, prop_seg, etc.) are
- * provided directly which are then checked and fixed up.
- */
- if (!bt->tq && bt->bitrate && btc)
- err = can_calc_bittiming(dev, bt, btc);
- else if (bt->tq && !bt->bitrate && btc)
- err = can_fixup_bittiming(dev, bt, btc);
- else if (!bt->tq && bt->bitrate && bitrate_const)
- err = can_validate_bitrate(dev, bt, bitrate_const,
- bitrate_const_cnt);
- else
- err = -EINVAL;
-
- return err;
-}
-
static void can_update_state_error_stats(struct net_device *dev,
enum can_state new_state)
{
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2020 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de>
+ */
+
+#ifndef _CAN_BITTIMING_H
+#define _CAN_BITTIMING_H
+
+#include <linux/netdevice.h>
+#include <linux/can/netlink.h>
+
+#define CAN_SYNC_SEG 1
+
+#ifdef CONFIG_CAN_CALC_BITTIMING
+int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
+ const struct can_bittiming_const *btc);
+#else /* !CONFIG_CAN_CALC_BITTIMING */
+static inline int
+can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
+ const struct can_bittiming_const *btc)
+{
+ netdev_err(dev, "bit-timing calculation not available\n");
+ return -EINVAL;
+}
+#endif /* CONFIG_CAN_CALC_BITTIMING */
+
+int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
+ const struct can_bittiming_const *btc,
+ const u32 *bitrate_const,
+ const unsigned int bitrate_const_cnt);
+
+/*
+ * can_bit_time() - Duration of one bit
+ *
+ * Please refer to ISO 11898-1:2015, section 11.3.1.1 "Bit time" for
+ * additional information.
+ *
+ * Return: the number of time quanta in one bit.
+ */
+static inline unsigned int can_bit_time(const struct can_bittiming *bt)
+{
+ return CAN_SYNC_SEG + bt->prop_seg + bt->phase_seg1 + bt->phase_seg2;
+}
+
+#endif /* !_CAN_BITTIMING_H */
#define _CAN_DEV_H
#include <linux/can.h>
+#include <linux/can/bittiming.h>
#include <linux/can/error.h>
#include <linux/can/led.h>
#include <linux/can/netlink.h>
#endif
};
-#define CAN_SYNC_SEG 1
-
-/*
- * can_bit_time() - Duration of one bit
- *
- * Please refer to ISO 11898-1:2015, section 11.3.1.1 "Bit time" for
- * additional information.
- *
- * Return: the number of time quanta in one bit.
- */
-static inline unsigned int can_bit_time(const struct can_bittiming *bt)
-{
- return CAN_SYNC_SEG + bt->prop_seg + bt->phase_seg1 + bt->phase_seg2;
-}
-
/*
* can_cc_dlc2len(value) - convert a given data length code (dlc) of a
* Classical CAN frame into a valid data length of max. 8 bytes.
projects / kernel.git / commitdiff