#include <linux/can/dev.h>
+void can_sjw_set_default(struct can_bittiming *bt)
+{
+ if (bt->sjw)
+ return;
+
+ /* If user space provides no sjw, use 1 as default */
+ bt->sjw = 1;
+}
+
+int can_sjw_check(const struct net_device *dev, const struct can_bittiming *bt,
+ const struct can_bittiming_const *btc, struct netlink_ext_ack *extack)
+{
+ if (bt->sjw > btc->sjw_max)
+ return -ERANGE;
+
+ 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_bittiming_const *btc,
+ struct netlink_ext_ack *extack)
{
+ const unsigned int tseg1 = bt->prop_seg + bt->phase_seg1;
const struct can_priv *priv = netdev_priv(dev);
- unsigned int tseg1, alltseg;
u64 brp64;
+ int err;
- 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 (tseg1 < btc->tseg1_min) {
+ NL_SET_ERR_MSG_FMT(extack, "prop-seg + phase-seg1: %u less than tseg1-min: %u",
+ tseg1, btc->tseg1_min);
+ return -EINVAL;
+ }
+ if (tseg1 > btc->tseg1_max) {
+ NL_SET_ERR_MSG_FMT(extack, "prop-seg + phase-seg1: %u greater than tseg1-max: %u",
+ tseg1, btc->tseg1_max);
+ return -EINVAL;
+ }
+ if (bt->phase_seg2 < btc->tseg2_min) {
+ NL_SET_ERR_MSG_FMT(extack, "phase-seg2: %u less than tseg2-min: %u",
+ bt->phase_seg2, btc->tseg2_min);
+ return -EINVAL;
+ }
+ if (bt->phase_seg2 > btc->tseg2_max) {
+ NL_SET_ERR_MSG_FMT(extack, "phase-seg2: %u greater than tseg2-max: %u",
+ bt->phase_seg2, btc->tseg2_max);
+ return -EINVAL;
+ }
+
+ can_sjw_set_default(bt);
+
+ err = can_sjw_check(dev, bt, btc, extack);
+ if (err)
+ return err;
brp64 = (u64)priv->clock.freq * (u64)bt->tq;
if (btc->brp_inc > 1)
brp64 *= btc->brp_inc;
bt->brp = (u32)brp64;
- if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
+ if (bt->brp < btc->brp_min) {
+ NL_SET_ERR_MSG_FMT(extack, "resulting brp: %u less than brp-min: %u",
+ bt->brp, btc->brp_min);
return -EINVAL;
+ }
+ if (bt->brp > btc->brp_max) {
+ NL_SET_ERR_MSG_FMT(extack, "resulting brp: %u greater than brp-max: %u",
+ 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;
+ bt->bitrate = priv->clock.freq / (bt->brp * can_bit_time(bt));
+ bt->sample_point = ((CAN_SYNC_SEG + tseg1) * 1000) / can_bit_time(bt);
+ bt->tq = DIV_U64_ROUND_CLOSEST(mul_u32_u32(bt->brp, NSEC_PER_SEC),
+ priv->clock.freq);
return 0;
}
static int
can_validate_bitrate(const struct net_device *dev, const struct can_bittiming *bt,
const u32 *bitrate_const,
- const unsigned int bitrate_const_cnt)
+ const unsigned int bitrate_const_cnt,
+ struct netlink_ext_ack *extack)
{
unsigned int i;
int can_get_bittiming(const struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc,
const u32 *bitrate_const,
- const unsigned int bitrate_const_cnt)
+ const unsigned int bitrate_const_cnt,
+ struct netlink_ext_ack *extack)
{
- 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;
+ return can_calc_bittiming(dev, bt, btc, extack);
+ if (bt->tq && !bt->bitrate && btc)
+ return can_fixup_bittiming(dev, bt, btc, extack);
+ if (!bt->tq && bt->bitrate && bitrate_const)
+ return can_validate_bitrate(dev, bt, bitrate_const,
+ bitrate_const_cnt, extack);
+
+ return -EINVAL;
}