lincan/src/open_rtl.c

   1 /**************************************************************************/
   2 /* File: open_rtl.c - RT-Linux open systemcall variant                    */
   3 /*                                                                        */
   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>      */
   9 /*                                                                        */
  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.                                              */
  20 /*                                                                        */
  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:                                                     */
  24 /*                                                                        */
  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 /**************************************************************************/
  34
  35 #ifdef CAN_WITH_RTL
  36
  37 #include "../include/can.h"
  38 #include "../include/can_sysdep.h"
  39 #include "../include/main.h"
  40
  41 #include <rtl_malloc.h>
  42 #include <rtl_posixio.h>
  43 #include "../include/can_iortl.h"
  44
  45 #define __NO_VERSION__
  46 #include <linux/module.h>
  47
  48
  49 static inline
  50 int can_open_rtl_common(struct canuser_t *canuser, int open_flags)
  51 {
  52         struct msgobj_t *obj=canuser->msgobj;
  53         struct canchip_t *chip;
  54         struct canque_ends_t *qends;
  55         struct canque_edge_t *edge;
  56         can_spin_irqflags_t iflags;
  57
  58         if(!obj) return -ENODEV;
  59
  60         can_msgobj_set_fl(obj,OPENED);
  61
  62         chip=obj->hostchip;
  63         if (chip) {
  64                 if (!(chip->flags & CHIP_CONFIGURED)) {
  65                         if (chip->chipspecops->chip_config(chip))
  66                                 CANMSG("Error configuring chip.\n");
  67                         else
  68                                 chip->flags |= CHIP_CONFIGURED;
  69
  70                         if (chip->chipspecops->pre_read_config(chip,obj)<0)
  71                                 CANMSG("Error initializing chip for receiving\n");
  72
  73                 }
  74         } /* End of chip configuration */
  75
  76
  77         qends = (struct canque_ends_t *)rt_malloc(sizeof(struct canque_ends_t));
  78         if(qends == NULL) goto no_qends;
  79         canqueue_ends_init_rtl(qends);
  80         /* mark memory as allocated from RTL memory pool */
  81         qends->ends_flags|=CAN_ENDSF_MEM_RTL;
  82         canuser->qends = qends;
  83
  84         can_spin_lock_irqsave(&canuser_manipulation_lock, iflags);
  85         list_add(&canuser->peers, &obj->obj_users);
  86         can_spin_unlock_irqrestore(&canuser_manipulation_lock, iflags);
  87
  88         if(canqueue_connect_edge(edge=canque_new_edge_rtl(MAX_BUF_LENGTH),
  89                 canuser->qends, obj->qends)<0) goto no_tx_qedge;
  90
  91         if(canqueue_connect_edge(canuser->rx_edge0=canque_new_edge_rtl(MAX_BUF_LENGTH),
  92                 obj->qends, canuser->qends)<0) goto no_rx_qedge;
  93         /*FIXME: more generic model should be used there*/
  94         canque_edge_decref(canuser->rx_edge0);
  95         canque_edge_decref(edge);
  96
  97 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,50))
  98         MOD_INC_USE_COUNT;      /*is this enough for RT-Linux context ?*/
  99 #endif
 100
 101         return 0;
 102
 103     no_rx_qedge:
 104         canque_notify_bothends(edge, CANQUEUE_NOTIFY_DEAD_WANTED);
 105         canque_edge_decref(edge);
 106     no_tx_qedge:
 107         list_del(&canuser->peers);
 108         canuser->qends = NULL;
 109         canqueue_ends_dispose_kern(qends, 1);
 110
 111     no_qends:
 112
 113         return -ENOMEM;
 114 }
 115
 116
 117 int can_open_rtl_posix(struct rtl_file *fptr)
 118 {
 119         int ret;
 120         struct msgobj_t *obj;
 121         struct canchip_t *chip;
 122         struct canuser_t *canuser;
 123         int minor_nr = RTL_MINOR_FROM_FILEPTR(fptr);
 124
 125         if(minor_nr>=MAX_TOT_MSGOBJS)
 126                 return -ENODEV;
 127
 128         if ( ((obj=objects_p[minor_nr]) == NULL) ||
 129                         ((chip=objects_p[minor_nr]->hostchip) == NULL) ) {
 130                 CANMSG("There is no hardware support for the device file with minor nr.: %d\n",minor_nr);
 131                 return -ENODEV;
 132         }
 133
 134         atomic_inc(&obj->obj_used);
 135         DEBUGMSG("Device %d opened %d times.\n", minor_nr, atomic_read(&obj->obj_used));
 136
 137         canuser = (struct canuser_t *)rt_malloc(sizeof(struct canuser_t));
 138         if(canuser == NULL){
 139                 ret=-ENOMEM;
 140                 goto no_canuser;
 141         }
 142         canuser->flags=CANUSER_RTL_CLIENT | CANUSER_RTL_MEM;
 143         canuser->userinfo.rtlinfo.file = fptr;
 144         canuser->msgobj = obj;
 145         canuser->magic = CAN_USER_MAGIC;
 146
 147         /*next line would solve many problems, but RT-Linux lacks this fundamental field */
 148         /*fptr->private_data = canuser;*/
 149         /*to test code I am adding this terible hack*/
 150         can_set_rtl_file_private_data(fptr,canuser);
 151
 152         ret=can_open_rtl_common(canuser, fptr->f_flags);
 153         if(ret>=0) return ret;
 154
 155         rt_free(canuser);
 156
 157     no_canuser:
 158         atomic_dec(&obj->obj_used);
 159
 160         return ret;
 161 }
 162
 163 #endif /*CAN_WITH_RTL*/