Linux Kernel  3.7.1
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pfifo.c
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1 /*
2  * arch/arm/mach-netx/pfifo.c
3  *
4  * Copyright (c) 2005 Sascha Hauer <[email protected]>, Pengutronix
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2
8  * as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  */
19 
20 #include <linux/init.h>
21 #include <linux/module.h>
22 #include <linux/mutex.h>
23 #include <linux/io.h>
24 
25 #include <mach/hardware.h>
26 #include <mach/netx-regs.h>
27 #include <mach/pfifo.h>
28 
29 static DEFINE_MUTEX(pfifo_lock);
30 
31 static unsigned int pfifo_used = 0;
32 
33 int pfifo_request(unsigned int pfifo_mask)
34 {
35  int err = 0;
36  unsigned int val;
37 
38  mutex_lock(&pfifo_lock);
39 
40  if (pfifo_mask & pfifo_used) {
41  err = -EBUSY;
42  goto out;
43  }
44 
45  pfifo_used |= pfifo_mask;
46 
47  val = readl(NETX_PFIFO_RESET);
48  writel(val | pfifo_mask, NETX_PFIFO_RESET);
50 
51 out:
52  mutex_unlock(&pfifo_lock);
53  return err;
54 }
55 
56 void pfifo_free(unsigned int pfifo_mask)
57 {
58  mutex_lock(&pfifo_lock);
59  pfifo_used &= ~pfifo_mask;
60  mutex_unlock(&pfifo_lock);
61 }
62 
63 EXPORT_SYMBOL(pfifo_push);
64 EXPORT_SYMBOL(pfifo_pop);
65 EXPORT_SYMBOL(pfifo_fill_level);
66 EXPORT_SYMBOL(pfifo_empty);