init function

The init function initializes the master interface. The prototype for this function is:

void *init( void *hdl,
            char *options );

The arguments are:

The handle of the high-level code.
A pointer to the command-line arguments for the low-level module.

The function must return either a handle, which is the pointer to the SPIDEV of the low-level module, or NULL if an error occurred.