1 /*
2 comedi/drivers/comedi_fc.c
3
4 This is a place for code driver writers wish to share between
5 two or more drivers. fc is short
6 for frank-common.
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 #include "../comedidev.h"
28
29 #include "comedi_fc.h"
30
increment_scan_progress(struct comedi_subdevice * subd,unsigned int num_bytes)31 static void increment_scan_progress(struct comedi_subdevice *subd,
32 unsigned int num_bytes)
33 {
34 struct comedi_async *async = subd->async;
35 unsigned int scan_length = cfc_bytes_per_scan(subd);
36
37 async->scan_progress += num_bytes;
38 if (async->scan_progress >= scan_length) {
39 async->scan_progress %= scan_length;
40 async->events |= COMEDI_CB_EOS;
41 }
42 }
43
44 /* Writes an array of data points to comedi's buffer */
cfc_write_array_to_buffer(struct comedi_subdevice * subd,void * data,unsigned int num_bytes)45 unsigned int cfc_write_array_to_buffer(struct comedi_subdevice *subd,
46 void *data, unsigned int num_bytes)
47 {
48 struct comedi_async *async = subd->async;
49 unsigned int retval;
50
51 if (num_bytes == 0)
52 return 0;
53
54 retval = comedi_buf_write_alloc(async, num_bytes);
55 if (retval != num_bytes) {
56 printk(KERN_WARNING "comedi: buffer overrun\n");
57 async->events |= COMEDI_CB_OVERFLOW;
58 return 0;
59 }
60
61 comedi_buf_memcpy_to(async, 0, data, num_bytes);
62 comedi_buf_write_free(async, num_bytes);
63 increment_scan_progress(subd, num_bytes);
64 async->events |= COMEDI_CB_BLOCK;
65
66 return num_bytes;
67 }
68 EXPORT_SYMBOL(cfc_write_array_to_buffer);
69
cfc_read_array_from_buffer(struct comedi_subdevice * subd,void * data,unsigned int num_bytes)70 unsigned int cfc_read_array_from_buffer(struct comedi_subdevice *subd,
71 void *data, unsigned int num_bytes)
72 {
73 struct comedi_async *async = subd->async;
74
75 if (num_bytes == 0)
76 return 0;
77
78 num_bytes = comedi_buf_read_alloc(async, num_bytes);
79 comedi_buf_memcpy_from(async, 0, data, num_bytes);
80 comedi_buf_read_free(async, num_bytes);
81 increment_scan_progress(subd, num_bytes);
82 async->events |= COMEDI_CB_BLOCK;
83
84 return num_bytes;
85 }
86 EXPORT_SYMBOL(cfc_read_array_from_buffer);
87
cfc_handle_events(struct comedi_device * dev,struct comedi_subdevice * subd)88 unsigned int cfc_handle_events(struct comedi_device *dev,
89 struct comedi_subdevice *subd)
90 {
91 unsigned int events = subd->async->events;
92
93 if (events == 0)
94 return events;
95
96 if (events & (COMEDI_CB_EOA | COMEDI_CB_ERROR | COMEDI_CB_OVERFLOW))
97 subd->cancel(dev, subd);
98
99 comedi_event(dev, subd);
100
101 return events;
102 }
103 EXPORT_SYMBOL(cfc_handle_events);
104
105 MODULE_AUTHOR("Frank Mori Hess <fmhess@users.sourceforge.net>");
106 MODULE_DESCRIPTION("Shared functions for Comedi low-level drivers");
107 MODULE_LICENSE("GPL");
108
comedi_fc_init_module(void)109 static int __init comedi_fc_init_module(void)
110 {
111 return 0;
112 }
113
comedi_fc_cleanup_module(void)114 static void __exit comedi_fc_cleanup_module(void)
115 {
116 }
117
118 module_init(comedi_fc_init_module);
119 module_exit(comedi_fc_cleanup_module);
120