1 /**************************************************************************/
2 /* File: select.c - systemcall to wait for new messages and free Tx slots */
4 /* LinCAN - (Not only) Linux CAN bus driver */
5 /* Copyright (C) 2002-2009 DCE FEE CTU Prague <http://dce.felk.cvut.cz> */
6 /* Copyright (C) 2002-2009 Pavel Pisa <pisa@cmp.felk.cvut.cz> */
7 /* Funded by OCERA and FRESCOR IST projects */
8 /* Based on CAN driver code by Arnaud Westenberg <arnaud@wanadoo.nl> */
10 /* LinCAN is free software; you can redistribute it and/or modify it */
11 /* under terms of the GNU General Public License as published by the */
12 /* Free Software Foundation; either version 2, or (at your option) any */
13 /* later version. LinCAN is distributed in the hope that it will be */
14 /* useful, but WITHOUT ANY WARRANTY; without even the implied warranty */
15 /* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU */
16 /* General Public License for more details. You should have received a */
17 /* copy of the GNU General Public License along with LinCAN; see file */
18 /* COPYING. If not, write to the Free Software Foundation, 675 Mass Ave, */
19 /* Cambridge, MA 02139, USA. */
21 /* To allow use of LinCAN in the compact embedded systems firmware */
22 /* and RT-executives (RTEMS for example), main authors agree with next */
23 /* special exception: */
25 /* Including LinCAN header files in a file, instantiating LinCAN generics */
26 /* or templates, or linking other files with LinCAN objects to produce */
27 /* an application image/executable, does not by itself cause the */
28 /* resulting application image/executable to be covered by */
29 /* the GNU General Public License. */
30 /* This exception does not however invalidate any other reasons */
31 /* why the executable file might be covered by the GNU Public License. */
32 /* Publication of enhanced or derived LinCAN files is required although. */
33 /**************************************************************************/
35 #include "../include/can.h"
36 #include "../include/can_sysdep.h"
37 #include "../include/main.h"
39 #include <linux/poll.h>
40 #include "../include/select.h"
42 unsigned int can_poll(struct file *file, poll_table *wait)
44 struct canuser_t *canuser = (struct canuser_t*)(file->private_data);
45 struct canque_ends_t *qends;
47 unsigned int mask = 0;
48 struct canque_edge_t *edge;
52 if(!canuser || (canuser->magic != CAN_USER_MAGIC)){
53 CANMSG("can_close: bad canuser magic\n");
57 obj = canuser->msgobj;
58 qends = canuser->qends;
60 if (file->f_mode & FMODE_READ) {
61 poll_wait(file, &qends->endinfo.fileinfo.readq, wait);
62 for(i=CANQUEUE_PRIO_NR;--i>=0;) {
63 if(!list_empty(&qends->active[i]))
64 mask |= POLLIN | POLLRDNORM;
68 if ((file->f_mode & FMODE_WRITE) && !(file->f_flags & O_SYNC)) {
69 poll_wait(file, &qends->endinfo.fileinfo.writeq, wait);
71 canque_for_each_inedge(qends, edge) {
72 if(canque_fifo_test_fl(&edge->fifo,FULL))
77 mask |= POLLOUT | POLLWRNORM;
80 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_SYNC)) {
81 poll_wait(file, &qends->endinfo.fileinfo.emptyq, wait);
83 canque_for_each_inedge(qends, edge) {
84 if(!canque_fifo_test_fl(&edge->fifo,EMPTY))
89 mask |= POLLOUT | POLLWRNORM;