lincan/src/open.c

   1 /* open.c
   2  * Linux CAN-bus device driver.
   3  * Written by Arnaud Westenberg email:arnaud@wanadoo.nl
   4  * Rewritten for new CAN queues by Pavel Pisa - OCERA team member
   5  * email:pisa@cmp.felk.cvut.cz
   6  * This software is released under the GPL-License.
   7  * Version lincan-0.2  9 Jul 2003
   8  */
   9
  10 #define __NO_VERSION__
  11 #include <linux/module.h>
  12
  13 #include <linux/autoconf.h>
  14
  15 #include <linux/fs.h>
  16 #include <linux/version.h>
  17 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,4,0))
  18 #include <linux/malloc.h>
  19 #else
  20 #include <linux/slab.h>
  21 #endif
  22
  23 #include "../include/main.h"
  24 #include "../include/open.h"
  25 #include "../include/i82527.h"
  26 #include "../include/setup.h"
  27
  28 int can_open(struct inode *inode, struct file *file)
  29 {
  30         struct msgobj_t *obj;
  31         struct chip_t *chip;
  32         struct canuser_t *canuser;
  33         struct canque_ends_t *qends;
  34
  35         if ( ((obj=objects_p[MINOR_NR]) == NULL) ||
  36                         ((chip=objects_p[MINOR_NR]->hostchip) == NULL) ) {
  37                 CANMSG("There is no hardware support for the device file with minor nr.: %d\n",MINOR_NR);
  38                 return -ENODEV;
  39         }
  40
  41         atomic_inc(&obj->obj_used);
  42         DEBUGMSG("Device %d opened %d times.\n", MINOR_NR, atomic_read(&obj->obj_used));
  43         obj->flags |= OBJ_OPENED;
  44
  45         if (chip->flags & CHIP_CONFIGURED)
  46                 DEBUGMSG("Device is already configured.\n");
  47         else {
  48                 if (chip->chipspecops->chip_config(chip))
  49                         CANMSG("Error configuring chip.\n");
  50                 else
  51                         chip->flags |= CHIP_CONFIGURED;
  52
  53                 if (chip->chipspecops->pre_read_config(chip,obj)<0)
  54                         CANMSG("Error initializing chip for receiving\n");
  55
  56                 /* chip->flags |= OBJ_BUFFERS_ALLOCATED; */
  57
  58         } /* End of chip configuration */
  59
  60         canuser = (struct canuser_t *)kmalloc(sizeof(struct canuser_t), GFP_KERNEL);
  61         if(canuser == NULL) goto no_canuser;
  62         canuser->file = file;
  63         canuser->msgobj = obj;
  64         canuser->magic = CAN_USER_MAGIC;
  65         file->private_data = canuser;
  66
  67         qends = (struct canque_ends_t *)kmalloc(sizeof(struct canque_ends_t), GFP_KERNEL);
  68         if(qends == NULL) goto no_qends;
  69         canqueue_ends_init_kern(qends);
  70         canuser->qends = qends;
  71
  72         list_add(&canuser->peers, &obj->obj_users);
  73
  74         if(canqueue_connect_edge(canque_new_edge_kern(MAX_BUF_LENGTH),
  75                 canuser->qends, obj->qends)<0) goto no_qedge;
  76
  77         if(canqueue_connect_edge(canuser->rx_edge0=canque_new_edge_kern(MAX_BUF_LENGTH),
  78                 obj->qends, canuser->qends)<0) goto no_qedge;
  79
  80 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,50))
  81         MOD_INC_USE_COUNT;
  82 #endif
  83
  84         return 0;
  85
  86     no_qedge:
  87         list_del(&canuser->peers);
  88         canqueue_ends_done_kern(qends, 1);
  89         canuser->qends = NULL;
  90         kfree(qends);
  91         obj->qends = NULL;
  92
  93     no_qends:
  94         kfree(canuser);
  95
  96     no_canuser:
  97         atomic_dec(&obj->obj_used);
  98         return -ENOMEM;
  99 }