NAME

       comedi_get_clock_source - get master clock for a subdevice

SYNOPSIS

       #include <comedilib.h>

       int comedi_get_clock_source(comedi_t * device, unsigned int subdevice,
                                   unsigned int channel, unsigned int * clock,
                                   unsigned int * period_ns);

STATUS

       alpha

DESCRIPTION

       This function queries the master clock for a subdevice, as set by comedi_set_clock_source.
       The currently configured master clock will be written to *clock. The possible values and
       their corresponding clocks are driver-dependant. The period of the clock in nanoseconds
       (or zero if it is unknown) will be written to *period_ns. If the subdevice does not
       support configuring its master clocks on a per-channel basis, then the channel parameter
       will be ignored.

       It is safe to pass NULL pointers as the clock or period_ns parameters. This function is
       only useable on subdevices that provide support for the INSN_CONFIG_GET_CLOCK_SRC
       configuration instruction.

RETURN VALUE

       0 on success, -1 on error.

AUTHORS

       David Schleef <ds@schleef.org>
           Author.

       Frank Mori Hess <fmhess@users.sourceforge.net>
           Author.

       Herman Bruyninckx <Herman.Bruyninckx@mech.kuleuven.ac.be>
           Author.

       Bernd Porr <tech@linux-usb-daq.co.uk>
           Author.

       Ian Abbott <abbotti@mev.co.uk>
           Author.

       Éric Piel <piel@delmic.com>
           Author.

COPYRIGHT

       Copyright © 1998-2003 David Schleef
       Copyright © 2001-2003, 2005, 2008 Frank Mori Hess
       Copyright © 2002-2003 Herman Bruyninckx
       Copyright © 2012 Bernd Porr
       Copyright © 2012 Ian Abbott
       Copyright © 2012, 2015 Éric Piel

       This document is part of Comedilib. In the context of this document, the term "source
       code" as defined by the license is interpreted as the XML source.

       This library is free software; you can redistribute it and/or modify it under the terms of
       the GNU Lesser General Public License as published by the Free Software Foundation,
       version 2.1 of the License.

       This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
       without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
       See the GNU Lesser General Public License for more details.

       You should have received a copy of the GNU Lesser General Public License along with this
       library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
       Boston, MA 02111-1307 USA.