bf3fe05dfb
This needs some more testing before it's on by default. If the card is otherwise functioning, these messages may be confusing to the user. If the card is not functioning, the driver can be reloaded with debug to check for this condition. Signed-off-by: Shaun Ruffell <sruffell@digium.com> git-svn-id: http://svn.asterisk.org/svn/dahdi/linux/trunk@9205 a0bf4364-ded3-4de4-8d8a-66a801d63aff
114 lines
3.1 KiB
C
114 lines
3.1 KiB
C
/*
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* Written by Oron Peled <oron@actcom.co.il>
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* Copyright (C) 2007, Xorcom
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*
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* All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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*/
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#include <linux/version.h>
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#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
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# warning "This module is tested only with 2.6 kernels"
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#endif
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/parport.h>
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#include "parport_debug.h"
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static struct parport *debug_sync_parport = NULL;
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static int parport_toggles[8]; /* 8 bit flip-flop */
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void flip_parport_bit(unsigned char bitnum)
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{
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static unsigned char last_value;
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spinlock_t lock = SPIN_LOCK_UNLOCKED;
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unsigned long flags;
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unsigned char mask;
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unsigned char value;
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if(!debug_sync_parport) {
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if(printk_ratelimit()) {
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printk(KERN_NOTICE "%s: no debug parallel port\n",
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THIS_MODULE->name);
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}
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return;
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}
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BUG_ON(bitnum > 7);
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mask = 1 << bitnum;
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spin_lock_irqsave(&lock, flags);
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value = last_value & ~mask;
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if(parport_toggles[bitnum] % 2) /* square wave */
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value |= mask;
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last_value = value;
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parport_toggles[bitnum]++;
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spin_unlock_irqrestore(&lock, flags);
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parport_write_data(debug_sync_parport, value);
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}
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EXPORT_SYMBOL(flip_parport_bit);
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static void parport_attach(struct parport *port)
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{
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printk(KERN_INFO "%s: Using %s for debugging\n", THIS_MODULE->name, port->name);
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if(debug_sync_parport) {
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printk(KERN_ERR "%s: Using %s, ignore new attachment %s\n",
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THIS_MODULE->name, debug_sync_parport->name, port->name);
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return;
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}
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parport_get_port(port);
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debug_sync_parport = port;
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}
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static void parport_detach(struct parport *port)
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{
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printk(KERN_INFO "%s: Releasing %s\n", THIS_MODULE->name, port->name);
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if(debug_sync_parport != port) {
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printk(KERN_ERR "%s: Using %s, ignore new detachment %s\n",
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THIS_MODULE->name, debug_sync_parport->name, port->name);
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return;
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}
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parport_put_port(debug_sync_parport);
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debug_sync_parport = NULL;
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}
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static struct parport_driver debug_parport_driver = {
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.name = "parport_debug",
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.attach = parport_attach,
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.detach = parport_detach,
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};
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int __init parallel_dbg_init(void)
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{
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int ret;
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ret = parport_register_driver(&debug_parport_driver);
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return ret;
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}
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void __exit parallel_dbg_cleanup(void)
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{
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parport_unregister_driver(&debug_parport_driver);
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}
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MODULE_DESCRIPTION("Use parallel port to debug drivers");
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MODULE_AUTHOR("Oron Peled <oron@actcom.co.il>");
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MODULE_LICENSE("GPL");
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MODULE_VERSION("$Id:");
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module_init(parallel_dbg_init);
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module_exit(parallel_dbg_cleanup);
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