Re: [PATCH v2 2/2] can: netlink: add interface for CAN-FD Transmitter Delay Compensation (TDC)

On 04.06.2021 00:15:50, Vincent Mailhol wrote:

Add the netlink interface for TDC parameters of struct can_tdc_const
and can_tdc.

Contrary to the can_bittiming(_const) structures for which there is
just a single IFLA_CAN(_DATA)_BITTMING(_CONST) entry per structure,
here, we create a nested entry IFLA_CAN_TDC. Within this nested entry,
additional IFLA_CAN_TDC_TDC* entries are added for each of the TDC
parameters of the newly introduced struct can_tdc_const and struct
can_tdc.

For struct can_tdc_const, these are:
        IFLA_CAN_TDC_TDCV_MAX
        IFLA_CAN_TDC_TDCO_MAX
        IFLA_CAN_TDC_TDCF_MAX

For struct can_tdc, these are:
        IFLA_CAN_TDC_TDCV
        IFLA_CAN_TDC_TDCO
        IFLA_CAN_TDC_TDCF

I just noticed in the mcp2518fd data sheet:

| bit 14-8 TDCO[6:0]: Transmitter Delay Compensation Offset bits;
| Secondary Sample Point (SSP) Two’s complement; offset can be positive,
| zero, or negative.
| 
| 011 1111 = 63 x TSYSCLK
| ...
| 000 0000 = 0 x TSYSCLK
| ...
| 111 1111 = –64 x TSYSCLK

Have you takes this into account?

regards,
Marc

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