On 21.02.2022 14:43:57, Srinivas Neeli wrote: > > Can you please provide me: > > - the bit timing constants of the IP core for the arbitration and data > > phase > > - the bit rate for the arbitration and data phase > > (especially where the framework calculates not common prescalers) > > - the clock rate of the CAN bus clock > > > > Can you also provide the hand calculated bit timing parameters for the > > above scenarios? > > Baud rate 1/5Mbps > ================ > root@xilinx-vck190-2021_1:~# ip link set can6 type can bitrate 1000000 dbitrate 5000000 fd on > [ 26.837057] xilinx_can ff070000.can can6: bitrate error 0.0% > [ 26.842731] xilinx_can ff070000.can can6: bitrate error 0.0% > can6 txqroot@xilinx-vck190-2021_1:~# ifconfig can6 txqueuelen 1000 > root@xilinx-vck190-2021_1:~# ip link set can6 up > [ 27.340880] IPv6: ADDRCONF(NETDEV_CHANGE): can6: link becomes ready > root@xilinx-vck190-2021_1:~# ip -d -s link show can6 > can6: <NOARP,UP,LOWER_UP,ECHO> mtu 72 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000 > link/can promiscuity 0 minmtu 0 maxmtu 0 > can <FD> state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0 > bitrate 999999 sample-point 0.750 > tq 250 prop-seg 1 phase-seg1 1 phase-seg2 1 sjw 1 > xilinx_can: tseg1 1..256 tseg2 1..128 sjw 1..128 brp 1..256 brp-inc 1 > dbitrate 4999999 dsample-point 0.750 > dtq 50 dprop-seg 1 dphase-seg1 1 dphase-seg2 1 dsjw 1 > xilinx_can: dtseg1 1..32 dtseg2 1..16 dsjw 1..16 dbrp 1..256 dbrp-inc 1 > clock 79999999 > re-started bus-errors arbit-lost error-warn error-pass bus-off > 0 0 0 0 0 0 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535 > RX: bytes packets errors dropped overrun mcast > 0 0 0 0 0 0 > TX: bytes packets errors dropped carrier collsns > 0 0 0 0 0 0 Are you using the mainline xilinx_can driver? The "ip" command says, you're using: > sjw 1..128 brp 1..256 > dsjw 1..16 dbrp 1..256 Looking at the mainline xilinx driver, we have: | /* CAN Bittiming constants as per Xilinx CAN specs */ | static const struct can_bittiming_const xcan_bittiming_const = { | .name = DRIVER_NAME, | .tseg1_min = 1, | .tseg1_max = 16, | .tseg2_min = 1, | .tseg2_max = 8, | .sjw_max = 4, ^ Does not match due to "sjw 1..128". | .brp_min = 1, | .brp_max = 256, | .brp_inc = 1, | }; | | /* AXI CANFD Arbitration Bittiming constants as per AXI CANFD 1.0 spec */ | static const struct can_bittiming_const xcan_bittiming_const_canfd = { | .name = DRIVER_NAME, | .tseg1_min = 1, | .tseg1_max = 64, | .tseg2_min = 1, | .tseg2_max = 16, | .sjw_max = 16, ^^ Does not match due to "sjw 1..128". | .brp_min = 1, | .brp_max = 256, | .brp_inc = 1, | }; | | /* AXI CANFD Data Bittiming constants as per AXI CANFD 1.0 specs */ | static struct can_bittiming_const xcan_data_bittiming_const_canfd = { | .name = DRIVER_NAME, | .tseg1_min = 1, | .tseg1_max = 16, | .tseg2_min = 1, | .tseg2_max = 8, | .sjw_max = 8, ^ Does not match due to "dsjw 1..16" | .brp_min = 1, | .brp_max = 256, | .brp_inc = 1, | }; | | /* AXI CANFD 2.0 Arbitration Bittiming constants as per AXI CANFD 2.0 spec */ | static const struct can_bittiming_const xcan_bittiming_const_canfd2 = { | .name = DRIVER_NAME, | .tseg1_min = 1, | .tseg1_max = 256, | .tseg2_min = 1, | .tseg2_max = 128, | .sjw_max = 128, | .brp_min = 2, ^ Does not match due to "brp 1..256". | .brp_max = 256, | .brp_inc = 1, | }; | | /* AXI CANFD 2.0 Data Bittiming constants as per AXI CANFD 2.0 spec */ | static struct can_bittiming_const xcan_data_bittiming_const_canfd2 = { | .name = DRIVER_NAME, | .tseg1_min = 1, | .tseg1_max = 32, | .tseg2_min = 1, | .tseg2_max = 16, | .sjw_max = 16, | .brp_min = 2, ^ Does not match due to "dbrp 1..256". | .brp_max = 256, | .brp_inc = 1, | }; Can you send patches to update the xilinx CAN driver? I'm continue working on the CAN bittiming code. regards, Marc -- Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung West/Dortmund | Phone: +49-231-2826-924 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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