can-calc-bit-timing: import bit timing calculation algorithm from v3.18

add missing can_fixup_bittiming()

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

calc-bit-timing/can-calc-bit-timing-v3_18.c

@@ -36,7 +36,6 @@
  * registers of the CAN controller. You can find more information
  * in the header file linux/can/netlink.h.
  */
-
 static int can_update_spt(const struct can_bittiming_const *btc,
 			  int sampl_pt, int tseg, int *tseg1, int *tseg2)
 {
@@ -153,3 +152,43 @@ static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
 
 	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(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;
+}

calc-bit-timing/can-calc-bit-timing.c

@@ -1186,9 +1186,11 @@ static const unsigned int common_data_bitrates[] = {
 
 #define can_update_spt can_update_spt_v3_18
 #define can_calc_bittiming can_calc_bittiming_v3_18
+#define can_fixup_bittiming can_fixup_bittiming_v3_18
 #include "can-calc-bit-timing-v3_18.c"
 #undef can_update_spt
 #undef can_calc_bittiming
+#undef can_fixup_bittiming
 
 #define can_update_sample_point can_update_sample_point_v4_8
 #define can_calc_bittiming can_calc_bittiming_v4_8
@@ -1244,7 +1246,7 @@ static const struct alg alg_list[] = {
 		.name = "v4.8",
 	}, {
 		.calc_bittiming = can_calc_bittiming_v3_18,
-		.fixup_bittiming = can_fixup_bittiming,
+		.fixup_bittiming = can_fixup_bittiming_v3_18,
 		.name = "v3.18",
 	}, {
 		.calc_bittiming = can_calc_bittiming_v2_6_31,