Actual driver code for directly mapped SJA1000 into PCI mem region 0.

[lincan.git] / lincan / src / read.c

diff --git a/lincan/src/read.c b/lincan/src/read.c
index c16c76b5a723a1870f7fdf85c77b47b74fbf697f..500c9b30d930e341ed3056474cbf94a9ce5d8dfe 100644 (file)
--- a/lincan/src/read.c
+++ b/lincan/src/read.c
@@ -1,11 +1,36 @@
-/* read.c
- * Linux CAN-bus device driver.
- * Written by Arnaud Westenberg email:arnaud@wanadoo.nl
- * Rewritten for new CAN queues by Pavel Pisa - OCERA team member
- * email:pisa@cmp.felk.cvut.cz
- * This software is released under the GPL-License.
- * Version lincan-0.3  17 Jun 2004
- */
+/**************************************************************************/
+/* File: read.c - read system call support for receiving CAN messages     */
+/*                                                                        */
+/* LinCAN - (Not only) Linux CAN bus driver                               */
+/* Copyright (C) 2002-2009 DCE FEE CTU Prague <http://dce.felk.cvut.cz>   */
+/* Copyright (C) 2002-2009 Pavel Pisa <pisa@cmp.felk.cvut.cz>             */
+/* Funded by OCERA and FRESCOR IST projects                               */
+/* Based on CAN driver code by Arnaud Westenberg <arnaud@wanadoo.nl>      */
+/*                                                                        */
+/* LinCAN is free software; you can redistribute it and/or modify it      */
+/* under terms of the GNU General Public License as published by the      */
+/* Free Software Foundation; either version 2, or (at your option) any    */
+/* later version.  LinCAN is distributed in the hope that it will be      */
+/* useful, but WITHOUT ANY WARRANTY; without even the implied warranty    */
+/* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU    */
+/* General Public License for more details. You should have received a    */
+/* copy of the GNU General Public License along with LinCAN; see file     */
+/* COPYING. If not, write to the Free Software Foundation, 675 Mass Ave,  */
+/* Cambridge, MA 02139, USA.                                              */
+/*                                                                        */
+/* To allow use of LinCAN in the compact embedded systems firmware        */
+/* and RT-executives (RTEMS for example), main authors agree with next    */
+/* special exception:                                                     */
+/*                                                                        */
+/* Including LinCAN header files in a file, instantiating LinCAN generics */
+/* or templates, or linking other files with LinCAN objects to produce    */
+/* an application image/executable, does not by itself cause the          */
+/* resulting application image/executable to be covered by                */
+/* the GNU General Public License.                                        */
+/* This exception does not however invalidate any other reasons           */
+/* why the executable file might be covered by the GNU Public License.    */
+/* Publication of enhanced or derived LinCAN files is required although.  */
+/**************************************************************************/
 
 #include "../include/can.h"
 #include "../include/can_sysdep.h"
@@ -53,20 +78,22 @@ ssize_t can_read(struct file *file, char *buffer, size_t length, loff_t *offset)
                        return -EIO;
                }
        }
-       
-       copy_to_user(buffer, &slot->msg, sizeof(struct canmsg_t));
+
+       ret = copy_to_user(buffer, &slot->msg, sizeof(struct canmsg_t));
        canque_free_outslot(qends, qedge, slot);
        buffer += sizeof(struct canmsg_t);
        bytes_to_copy = length-sizeof(struct canmsg_t);
-       
+       if(ret) return -EFAULT;
+
        while (bytes_to_copy > 0) {
                ret=canque_test_outslot(qends, &qedge, &slot);
                if(ret<0)
                        break;
-               copy_to_user(buffer, &slot->msg, sizeof(struct canmsg_t));
+               ret = copy_to_user(buffer, &slot->msg, sizeof(struct canmsg_t));
                canque_free_outslot(qends, qedge, slot);
                buffer += sizeof(struct canmsg_t);
                bytes_to_copy -= sizeof(struct canmsg_t);
+               if(ret) return -EFAULT;
        }
 
        return length-bytes_to_copy;