sdi_findspec finds a matching device specification routine.
Target drivers might need special handling of certain devices.
An example is a disk which requires a power-up command
on the first open.
This routine looks for a match of an inquiry
string of a device against those kept in the
dev_spec structure defined in
the Space.c file of the target driver.
Arguments
edtp
Pointer to an EDT structure for the desired device
dev_spec
Array of pointers to device specific functions
relative to each of the target driver entry points
Return values
Pointer to a dev_spec entry or NULL
if no match is found.
Usage
During a target driver init routine,
the sdi_findspec is called
to get the dev_spec structure (if defined)
of the various function
pointers of the device specific routines.
The device specific routines
which can be defined are first_open,
last_close, intr, and the command helper.
Only the needed functions should be defined.
Included in the dev_spec
structure is the inquiry string of the
device which has the need for
the special functions.
It is also possible to define standard supported
commands for the device and those which
should use the command helper routine.