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can-calc-bit-timing: import bit timing calculation algorithm from v4.8

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The bit timing algorithm is not identical with the referenced commit.
So re-import from that commit.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Marc Kleine-Budde
2022-08-11 22:25:51 +02:00
parent b777ce2e6d
commit 18eb0ab784
2 changed files with 90 additions and 86 deletions
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calc-bit-timing/can-calc-bit-timing.c
+3 -41
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@@ -1194,55 +1194,17 @@ static const unsigned int common_data_bitrates[] = {
#define can_update_sample_point can_update_sample_point_v4_8
#define can_calc_bittiming can_calc_bittiming_v4_8
#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
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;
}
#undef can_fixup_bittiming
static const struct alg alg_list[] = {
/* 1st will be default */
{
.calc_bittiming = can_calc_bittiming_v4_8,
.fixup_bittiming = can_fixup_bittiming,
.fixup_bittiming = can_fixup_bittiming_v4_8,
.name = "v4.8",
}, {
.calc_bittiming = can_calc_bittiming_v3_18,