comedi: c6xdigio: Add sanity checks for I/O base address

The "c6xdigio" driver uses an admin-supplied configuration option
(`it->options[0]`) to configure the I/O port base address of a supported
C6x_DIGIO DSP device connected to a PC printer parallel port (driving
the port's I/O registers directly).  Currently, the driver allows any
I/O base address to be specified as long as the I/O region can be
reserved, and it converts the specified `int` option value holding the
base address to `unsigned long`.

It doesn't make sense to allow base addresses that are not aligned to
4-byte boundaries (for SPP printer ports, although printer ports with
EPP/ECP support actually need to be aligned on 8-byte boundaries), so
add a check for 4-byte alignment.

Convert the option value that specifies the base address from `int` to
`unsigned int` instead of `unsigned long` so it ends up the same on
32-bit and 64-bit systems.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://patch.msgid.link/20260130170416.49994-10-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

0 files changed, 0 insertions, 0 deletions