1 /**************************************************************************/
2 /* File: read_rtl.c - RT-Linux variant of read systemcall */
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 /**************************************************************************/
37 #include "../include/can.h"
38 #include "../include/can_sysdep.h"
39 #include "../include/main.h"
41 #include <rtl_posixio.h>
42 #include "../include/can_iortl.h"
44 /* This is the 'Normal' read handler for normal transmission messages */
46 ssize_t can_std_read_rtl(struct canque_ends_t *qends, int nonblock_fl,
47 char *buffer, size_t length)
50 struct canmsg_t *msg_buff = (struct canmsg_t *)buffer;
52 struct canque_edge_t *qedge;
53 struct canque_slot_t *slot;
55 ret=canque_test_outslot(qends, &qedge, &slot);
60 ret=canque_get_outslot_wait_rtl(qends, &qedge, &slot);
63 DEBUGMSG("Rx interrupted\n");
70 *(msg_buff++)=slot->msg;
71 canque_free_outslot(qends, qedge, slot);
72 bytes_to_copy = length-sizeof(struct canmsg_t);
74 while (bytes_to_copy > 0) {
75 ret=canque_test_outslot(qends, &qedge, &slot);
78 *(msg_buff++)=slot->msg;
79 canque_free_outslot(qends, qedge, slot);
80 bytes_to_copy -= sizeof(struct canmsg_t);
83 return length-bytes_to_copy;
87 ssize_t can_read_rtl_posix(struct rtl_file *fptr, char *buffer,
88 size_t length, loff_t *ppos)
90 struct canuser_t *canuser =
91 (struct canuser_t *)can_get_rtl_file_private_data(fptr);
92 struct canque_ends_t *qends;
95 if(!canuser || (canuser->magic != CAN_USER_MAGIC)){
96 CANMSG("can_read_rtl_posix: bad canuser magic\n");
100 if (length < sizeof(struct canmsg_t)) {
101 DEBUGMSG("Trying to read less bytes than a CAN message, \n");
102 DEBUGMSG("this will always return zero.\n");
106 qends = canuser->qends;
108 /*if (((struct canmsg_t *)buffer)->flags & MSG_RTR)
109 ret = can_rtr_read(chip, obj, buffer);
111 ret = can_std_read_rtl(qends, fptr->f_flags & O_NONBLOCK,
117 #endif /*CAN_WITH_RTL*/