staging: comedi: pcl818: tidy up pcl818_check()

Browse source

This function probes a number of the boards registers during the
(*attach) to verify that it is actually a PCL-818 compatible board.
For aesthetics, move the function closer to the (*attach).

Refactor the function to return an errno if fails. Change the errno
from -EIO to -ENODEV and remove the unnecessary comedi_error() noise.

Make sure the CONTROL register is reset to a known state after the
check. The 0x18 value actually defines an invalid interrupt selection
and sets an undefined bit.

Add a couple comments to clarify the magic values.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

H Hartley Sweeten 2014-02-17 14:27:57 -07:00 • committed by Greg Kroah-Hartman

parent 18c7a6df49

commit 243e7146c8

1 changed files with 27 additions and 23 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

50

drivers/staging/comedi/drivers/pcl818.c

View file