topic Re: CAN RX FIFO Filter in i.MX Processors

CAN RX FIFO Filter

Raana — Thu, 13 Jan 2022 11:41:19 GMT

Dear Team,

I'm using i.mx25 base custom board. I'm using automotive product in the vehicle using this SOC.

When Reverse transmission is engaged, the rear camera of the device should turn ON within 1~2 seconds. But it is turning ON after 50~60 seconds. This delay is happening due to CAN message traffic.

Since the device is accepting and scanning all the CAN RX messages. Instead, I want to accept only the respective messages which we are actually processing. I have set of CAN RX messages and listed below:

/* PGN request */ 0x18EAFFF9, 0x18EAFFFA, 0x18EA4CF9, 0x18EA4CFA, 0x1CE34CF9, /* PITS diagnostic */ 0x0CFF2800, /* RSA */ 0x1CFFFE00, /* SWC */ /* DM 13 handling */ 0x18DF4CF9, 0x18DF4CFA, 0x18DF4CFF, 0x18D54C4D, /* J1939 time/date */ 0x18D04C00, /* CAN dimming */ 0x18EF4C00, /* Audible alarm */ 0x18F00500, /* ETC transmission */ 0x18FEF100, /* Vehicle Speed */ 0x18EEFF4C, /* address claim */ /* VP39 */ 0x0CFF273A, 0x0CFF2717, 0x18FEE617, /* VOLVO time/date */ 0x18FF2600, /* VP38 */ 0x0CFF2F17, /* VP47 */ 0x0CFF2537, /* VP37 */ 0x1CEB4C00, /* TP data transfer */ 0x1CEC4C00 /* TP handling */

I have referred the patch done in i.MX6 which is attached with this post.
I have attached my i.Mx25 patch also. But I'm not seeing any changes and I'm getting below error in ESR and ECR

0327: [AP] ECR::0x7a 0328: [AP] ESR::0x280

and below are the register dump:

0322: [AP] MCR::0x6087003f 0323: [AP] CTRL::0xd37e0c2 0324: [AP] RXGMASK::0x0 0325: [AP] RX14MASK::0x0 0326: [AP] RX15MASK::0x0 0327: [AP] ECR::0x7a 0328: [AP] ESR::0x280 0329: [AP] IMASK2::0xffffffff 0330: [AP] IMASK1::0xffffffff 0331: [AP] IFLAG2::0x0 0332: [AP] IFLAG1::0x0

Please help me to make it work with respect to FIFO/ RX filters. And share me the patches if any related with this done on i.Mx25

Re: CAN RX FIFO Filter

igorpadykov — Thu, 13 Jan 2022 23:06:47 GMT

Hi Raja

unfortunately i.MX25 processors are not supported in NXP BSPs as outdated,

just for test one can try with L2.6.31 where it was supported

https://source.codeaurora.org/external/imx/linux-imx/tree/?h=imx_2.6.31_caf

Best regards
igor

Re: CAN RX FIFO Filter

Raana — Mon, 17 Jan 2022 12:03:18 GMT

Hi igor,

I have downloaded the source code which you shared. Both my code and the one you share is same.
And also there is no filter implementation available in the source code you shared. By default, it is accepting all the messages.

/* Set global mask to receive all messages */ __raw_writel(0, flexcan->io_base + CAN_HW_REG_RXGMASK); __raw_writel(0, flexcan->io_base + CAN_HW_REG_RX14MASK); __raw_writel(0, flexcan->io_base + CAN_HW_REG_RX15MASK); memset(flexcan->hwmb, 0, sizeof(*hwmb) * FLEXCAN_MAX_MB); /* Set individual mask to receive all messages */ memset(flexcan->rx_mask, 0, sizeof(unsigned int) * FLEXCAN_MAX_MB);

I want to add filter implementation into the driver with the set of CAN messages which I posted above.
Please help me to share any of such implementation done in this SOC or Kernel.

Thank you,

Regards,

J.P.RAJA

Re: CAN RX FIFO Filter

Yuri — Tue, 01 Feb 2022 05:59:10 GMT

@Raana
Hello,

according to "i.MX PDK Linux Reference Manual", section "Linux Menu Configuration Options",
it is possible to select

Networking > CAN bus subsystem support > Raw CAN Protocol (raw access with CAN-ID
filtering).

Customer can use CAN-ID filtering code as an example.

Regards,
Yuri.