The can-mcp2515 is a driver for the Microchip MCP2515 CAN Controller. It's available with full source code, which makes it a good example of the libcan driver.
You can find the source code at: https://gitlab.com/qnx/projects/drivers/can-mcp2515. The code is organized into the following directories:
- lib
Contains code that interacts with the MCP2515 hardware using io-spi. Since this directory is hardware-specific, it's beyond the scope of this document.
- driver
Contains code that uses the code in the lib directory to integrate with the libcan library.
This directory is organized into several source and header files:
command_line.h, command_line.c
- Functions to parse the command line.
debug.h, debug.c
- Functions to generate debug information in the logging sinks.
drv_state.h, drv_state.c
- State information required by the driver to function.
- Functions to initialize and clean up the state information.
rpi4.h, rpi4.c
- RPI4 platform support.
- Functions used to interact with GPIOs and associated IRQs.
version.h, version.c
- Functions related to the version of the driver.
main.c
- Entry point into the driver program; initializes the driver state and calls the execute() function from core.c.
core.h, core.c
- Main logic of the driver (execute()), called from main().
- Contains required callback functions, which include libcan_transmit_cb(), libcan_devctl_cb(), and libcan_event_handler_cb().
- Hardware-specific initialization functions.
- Contains libcan and CAN device configuration (configure_libcan(), configure_mcp2515()), initialization (go(), connect()), and cleanup (destroy_libcan(), disconnect()) functions.
- Contains utility functions.
