comedi_fc.h revision 71b5f4f11971dea972832ad63a994c7e5b45db6b 
1/*
2    comedi_fc.h
3
4    This is a place for code driver writers wish to share between
5    two or more drivers. These functions are meant to be used only
6    by drivers, they are NOT part of the kcomedilib API!
7
8    Author:  Frank Mori Hess <fmhess@users.sourceforge.net>
9    Copyright (C) 2002 Frank Mori Hess
10
11    This program is free software; you can redistribute it and/or modify
12    it under the terms of the GNU General Public License as published by
13    the Free Software Foundation; either version 2 of the License, or
14    (at your option) any later version.
15
16    This program is distributed in the hope that it will be useful,
17    but WITHOUT ANY WARRANTY; without even the implied warranty of
18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19    GNU General Public License for more details.
20
21    You should have received a copy of the GNU General Public License
22    along with this program; if not, write to the Free Software
23    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24
25************************************************************************/
26
27#ifndef _COMEDI_FC_H
28#define _COMEDI_FC_H
29
30#include "../comedidev.h"
31
32/* Writes an array of data points to comedi's buffer */
33extern unsigned int cfc_write_array_to_buffer(comedi_subdevice *subd,
34					      void *data,
35					      unsigned int num_bytes);
36
37static inline unsigned int cfc_write_to_buffer(comedi_subdevice *subd,
38					       short data)
39{
40	return cfc_write_array_to_buffer(subd, &data, sizeof(data));
41};
42
43static inline unsigned int cfc_write_long_to_buffer(comedi_subdevice *subd,
44						    unsigned int data)
45{
46	return cfc_write_array_to_buffer(subd, &data, sizeof(data));
47};
48
49extern unsigned int cfc_read_array_from_buffer(comedi_subdevice *subd,
50					       void *data,
51					       unsigned int num_bytes);
52
53extern unsigned int cfc_handle_events(struct comedi_device *dev,
54				      comedi_subdevice *subd);
55
56static inline unsigned int cfc_bytes_per_scan(comedi_subdevice *subd)
57{
58	int num_samples;
59	int bits_per_sample;
60
61	switch (subd->type) {
62	case COMEDI_SUBD_DI:
63	case COMEDI_SUBD_DO:
64	case COMEDI_SUBD_DIO:
65		bits_per_sample = 8 * bytes_per_sample(subd);
66		num_samples = (subd->async->cmd.chanlist_len +
67			       bits_per_sample - 1) / bits_per_sample;
68		break;
69	default:
70		num_samples = subd->async->cmd.chanlist_len;
71		break;
72	}
73	return num_samples * bytes_per_sample(subd);
74}
75
76#endif /* _COMEDI_FC_H */
77