3 functions for manipulating buffers
5 COMEDILIB - Linux Control and Measurement Device Interface Library
6 Copyright (C) 1997-2001 David A. Schleef <ds@schleef.org>
8 This library is free software; you can redistribute it and/or
9 modify it under the terms of the GNU Lesser General Public
10 License as published by the Free Software Foundation, version 2.1
13 This library is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public
19 License along with this library; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
24 #include "libinternal.h"
27 EXPORT_ALIAS_DEFAULT(_comedi_set_buffer_size,comedi_set_buffer_size,0.7.18);
28 int _comedi_set_buffer_size(comedi_t *it, unsigned int subdev, unsigned int size)
33 memset(&bc, 0, sizeof(bc));
34 bc.subdevice = subdev;
36 ret = comedi_ioctl(it->fd, COMEDI_BUFCONFIG, (unsigned long)&bc);
37 __comedi_errno = errno;
38 if(ret < 0) return ret;
43 EXPORT_ALIAS_DEFAULT(_comedi_set_max_buffer_size,comedi_set_max_buffer_size,0.7.18);
44 int _comedi_set_max_buffer_size(comedi_t *it, unsigned int subdev, unsigned int max_size)
49 memset(&bc, 0, sizeof(bc));
50 bc.subdevice = subdev;
51 bc.maximum_size = max_size;
52 ret = comedi_ioctl(it->fd, COMEDI_BUFCONFIG, (unsigned long)&bc);
53 __comedi_errno = errno;
54 if(ret < 0) return ret;
56 return bc.maximum_size;
59 EXPORT_ALIAS_DEFAULT(_comedi_get_max_buffer_size,comedi_get_max_buffer_size,0.7.18);
60 int _comedi_get_max_buffer_size(comedi_t *it, unsigned int subdevice)
62 return comedi_set_max_buffer_size(it, subdevice, 0);
65 EXPORT_ALIAS_DEFAULT(_comedi_get_buffer_size,comedi_get_buffer_size,0.7.18);
66 int _comedi_get_buffer_size(comedi_t *it, unsigned int subdev)
68 return comedi_set_buffer_size(it, subdev, 0);
71 EXPORT_ALIAS_DEFAULT(_comedi_get_buffer_contents,comedi_get_buffer_contents,0.7.18);
72 int _comedi_get_buffer_contents(comedi_t *it, unsigned int subdev)
74 return comedi_mark_buffer_read(it, subdev, 0);
77 EXPORT_ALIAS_DEFAULT(_comedi_mark_buffer_read,comedi_mark_buffer_read,0.7.18);
78 int _comedi_mark_buffer_read(comedi_t *it, unsigned int subdev, unsigned int bytes)
83 memset(&bi, 0, sizeof(bi));
84 bi.subdevice = subdev;
85 bi.bytes_read = bytes;
86 ret = comedi_ioctl(it->fd, COMEDI_BUFINFO, (unsigned long)&bi);
89 __comedi_errno = errno;
90 if(__comedi_errno == EPIPE)__comedi_errno = EBUF_OVR;
93 return bi.buf_write_count - bi.buf_read_count;
96 EXPORT_ALIAS_DEFAULT(_comedi_mark_buffer_written,comedi_mark_buffer_written,0.8.0);
97 int _comedi_mark_buffer_written(comedi_t *it, unsigned int subdev, unsigned int bytes)
102 memset(&bi, 0, sizeof(bi));
103 bi.subdevice = subdev;
104 bi.bytes_written = bytes;
105 ret = comedi_ioctl(it->fd, COMEDI_BUFINFO, (unsigned long)&bi);
108 __comedi_errno = errno;
109 if(__comedi_errno == EPIPE)__comedi_errno = EBUF_UNDR;
112 return bi.buf_write_count - bi.buf_read_count;
115 EXPORT_ALIAS_DEFAULT(_comedi_get_buffer_offset,comedi_get_buffer_offset,0.7.18);
116 int _comedi_get_buffer_offset(comedi_t *it, unsigned int subdev)
121 memset(&bi, 0, sizeof(bi));
122 bi.subdevice = subdev;
123 ret = comedi_ioctl(it->fd, COMEDI_BUFINFO, (unsigned long)&bi);
124 if(ret < 0) return ret;
125 return bi.buf_read_ptr;
128 EXPORT_ALIAS_DEFAULT(_comedi_get_front_count,comedi_get_front_count,0.7.18);
129 int _comedi_get_front_count(comedi_t *it, unsigned int subdev)
134 memset(&bi, 0, sizeof(bi));
135 bi.subdevice = subdev;
136 ret = comedi_ioctl(it->fd, COMEDI_BUFINFO, (unsigned long)&bi);
137 if(ret < 0) return ret;
138 return bi.buf_write_count;