1 /**************************************************************************/
2 /* File: ioctl_remote.c - remote CAN messages support IOCTL 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 /**************************************************************************/
35 #include "../include/can.h"
36 #include "../include/can_sysdep.h"
37 #include "../include/main.h"
38 #include "../include/read.h"
39 #include "../include/ioctl.h"
41 /* This is the 'RTR' read handler for remote transmission request messages */
42 int can_ioctl_remote_read(struct canuser_t *canuser, struct canmsg_t *rtr_msg,
43 unsigned long rtr_id, int options)
45 can_spin_irqflags_t flags;
46 struct rtr_id *rtr_current, *new_rtr_entry;
48 struct canchip_t *chip;
49 /*struct canque_ends_t *qends;*/
51 DEBUGMSG("Remote transmission request\n");
53 /*qends = canuser->qends;*/
55 /* Initialize hardware pointers */
56 obj = canuser->msgobj;
58 CANMSG("Could not assign buffer structure\n");
62 if ( (chip = obj->hostchip) == NULL) {
63 CANMSG("Device is not correctly configured,\n");
64 CANMSG("please reload the driver.\n");
68 can_spin_lock_irqsave(&hardware_p->rtr_lock, flags);
69 if (hardware_p->rtr_queue == NULL) { //No remote messages pending
70 new_rtr_entry=(struct rtr_id *)kmalloc(sizeof(struct rtr_id),GFP_ATOMIC);
71 if (new_rtr_entry == NULL) {
72 can_spin_unlock_irqrestore(&hardware_p->rtr_lock,
76 hardware_p->rtr_queue=new_rtr_entry;
79 rtr_current=hardware_p->rtr_queue;
80 while (rtr_current->next != NULL)
81 rtr_current=rtr_current->next;
82 new_rtr_entry=(struct rtr_id *)kmalloc(sizeof(struct rtr_id),GFP_ATOMIC);
83 rtr_current->next=new_rtr_entry;
85 init_waitqueue_head(&new_rtr_entry->rtr_wq);
86 new_rtr_entry->id = rtr_id;
87 new_rtr_entry->rtr_message = rtr_msg;
88 new_rtr_entry->next=NULL;
90 can_spin_unlock_irqrestore(&hardware_p->rtr_lock, flags);
92 /* Send remote transmission request */
93 chip->chipspecops->remote_request(chip,obj);
95 interruptible_sleep_on(&new_rtr_entry->rtr_wq);
97 can_spin_lock_irqsave(&hardware_p->rtr_lock, flags);
98 if (hardware_p->rtr_queue == new_rtr_entry) {
99 if (new_rtr_entry->next != NULL)
100 hardware_p->rtr_queue=new_rtr_entry->next;
102 hardware_p->rtr_queue=NULL;
105 rtr_current=hardware_p->rtr_queue;
106 while (rtr_current->next != new_rtr_entry)
107 rtr_current=rtr_current->next;
108 if (new_rtr_entry->next != NULL)
109 rtr_current->next=new_rtr_entry->next;
111 rtr_current->next=NULL;
113 can_spin_unlock_irqrestore(&hardware_p->rtr_lock, flags);
114 kfree(new_rtr_entry);