Linux Device Drivers Development

Driver initialization and registration

For devices sitting on a bus, whether it is a physical one or the pseudo platform bus, most of the time, everything is done in the probe function. The init and exit functions are just used to register/unregister the driver with the bus core:

static int __init foo_init(void) 
{ 
    [...] /*My init code */ 
   return spi_register_driver(&foo_driver); 
} 
module_init(foo_init); 
 
static void __exit foo_cleanup(void) 
{ 
    [...] /* My clean up code */ 
   spi_unregister_driver(&foo_driver); 
} 
module_exit(foo_cleanup); 

If you do not do anything else but register/unregister the driver, the kernel offers a macro:

module_spi_driver(foo_driver); 

This will internally call spi_register_driver and spi_unregister_driver. It is exactly ...