static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt)
{
struct can_priv *priv = netdev_priv(dev);
int err;
if (priv->bittiming_const) {
if (!bt->tq)
err = can_calc_bittiming(dev, bt);
else
err = can_fixup_bittiming(dev, bt);
if (err)
return err;
}
return 0;
}
static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt)
{
struct can_priv *priv = netdev_priv(dev);
int err;
/* Check if the CAN device has bit-timing parameters */
if (priv->bittiming_const) {
/* Non-expert mode? Check if the bitrate has been pre-defined */
if (!bt->tq)
/* Determine bit-timing parameters */
err = can_calc_bittiming(dev, bt);
else
/* Check bit-timing params and calculate proper brp */
err = can_fixup_bittiming(dev, bt);
if (err)
return err;
}
return 0;
}
static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc)
{
int err;
/* Check if the CAN device has bit-timing parameters */
if (!btc)
return -EOPNOTSUPP;
/*
* 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)
err = can_calc_bittiming(dev, bt, btc);
else if (bt->tq && !bt->bitrate)
err = can_fixup_bittiming(dev, bt, btc);
else
err = -EINVAL;
return err;
}
static void print_bit_timing(const struct can_bittiming_const *btc,
__u32 bitrate, __u32 sample_point, __u32 ref_clk,
int quiet)
{
struct net_device dev = {
.priv.bittiming_const = btc,
.priv.clock.freq = ref_clk,
};
struct can_bittiming bt = {
.bitrate = bitrate,
.sample_point = sample_point,
};
long rate_error, spt_error;
if (!quiet) {
printf("Bit timing parameters for %s with %.6f MHz ref clock\n"
"nominal real Bitrt nom real SampP\n"
"Bitrate TQ[ns] PrS PhS1 PhS2 SJW BRP Bitrate Error SampP SampP Error ",
btc->name,
ref_clk / 1000000.0);
btc->printf_btr(&bt, 1);
printf("\n");
}
if (can_calc_bittiming(&dev, &bt)) {
printf("%7d ***bitrate not possible***\n", bitrate);
return;
}
/* get nominal sample point */
if (!sample_point)
sample_point = get_cia_sample_point(bitrate);
rate_error = abs((__s32)(bitrate - bt.bitrate));
spt_error = abs((__s32)(sample_point - bt.sample_point));
printf("%7d "
"%6d %3d %4d %4d "
"%3d %3d "
"%7d %4.1f%% "
"%4.1f%% %4.1f%% %4.1f%% ",
bitrate,
bt.tq, bt.prop_seg, bt.phase_seg1, bt.phase_seg2,
bt.sjw, bt.brp,
bt.bitrate,
100.0 * rate_error / bitrate,
sample_point / 10.0,
bt.sample_point / 10.0,
100.0 * spt_error / sample_point);
btc->printf_btr(&bt, 0);
printf("\n");
}
static void do_list(void)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(can_calc_consts); i++)
printf("%s\n", can_calc_consts[i].name);
}
