RFC: Introduce Zephyr driver for Local Interconnect Network (LIN)

[thenguyenyf]

Problem Description

Currently, Zephyr doesn't support any Local Interconnect Network (LIN) software stack. We are trying to add a LIN communication stack following the OSI model, referring to LIN Specification Pack Rev2.1 (published by LIN CiA). The first step is to add the LIN physical layer and part of the data link layer as a Zephyr device driver.

Proposed Change (Summary)

Introduce the LIN driver subsystem, under include/zephyr/drivers/lin.h and drivers/lin

Proposed Change (Detailed)

See #95975.
Introduce the following APIs

__subsystem struct lin_driver_api {
	lin_start_t start;
	lin_stop_t stop;
	lin_configure_t configure;
	lin_get_config_t get_config;
	lin_set_rx_filter_t set_rx_filter;
	lin_send_t send;
	lin_receive_t receive;
	lin_response_t response;
	lin_read_t read;
	lin_wakeup_send_t wakeup_send;
	lin_enter_sleep_t enter_sleep;
	lin_set_callback_t set_callback;
};

Dependencies

No response

Concerns and Unresolved Questions

No response

Alternatives Considered

No response

[manuargue]

hi @thenguyenyf , @henrikbrixandersen are you planning to discuss this in the arch WG? I'd be interested in participating. Thanks

[adamsanta]

Hello @thenguyenyf , @henrikbrixandersen ,
I am planning to program a LIN master for the NXP S32K3X4EVB-T172 board (using Zephyr of course).
I am new to Zephyr but I'd be happy to help you going on with this PR.
If I understand well, you're planning to add a lin_renesas_ra_sci_b.c file, based on lin_skeleton.c, to implement Renesas SCI specific LIN code, right ? Should I do the same for my NXP board ?
Thanks !

[thenguyenyf]

Hello @adamsanta . Nice to see you!

If I understand well, you're planning to add a lin_renesas_ra_sci_b.c file, based on lin_skeleton.c, to implement Renesas SCI specific LIN code, right ?

Yes. There are some works in background for lin_renesas_ra_sci_b.c since last time I pushed to #95975. lin_renesas_ra_sci_b.c will be sent out soon, and lin_skeleton.c also has some modifications with a small change in interface design.

So, if you don't mind, please wait until next weekend at the latest after I put out some updates for #95975 before starting your development.

[thenguyenyf]

Hello @adamsanta . Support for SCI B LIN driver have been put out by #95975.
Additionally, the test suite for the LIN driver has been updated to extend the scope of functional verification.

You can refer to https://github.com/zephyrproject-rtos/zephyr/blob/6fa5e24098554d8a20ff3e9ceab98cce8726ef89/drivers/lin/renesas/ra/lin_renesas_ra_sci_b.c to start porting your driver.

[adamsanta]

Hello @thenguyenyf ,
Thanks for the update :)
In the mean time, I have set up a Zephyr LIN driver by starting from this repo https://github.com/dragonlock2/zephyrboards by @dragonlock2 (blog post: https://matthewtran.dev/2022/12/zephyr-lin-driver/).
If i find some time, I will create a PR on his repo to support S32K3X4EVB-T172 (LIN transceiver is TJA1022T). Then, I may port the support to your driver version.