1 /*
2 * arch/arm/mach-netx/pfifo.c
3 *
4 * Copyright (c) 2005 Sascha Hauer <s.hauer@pengutronix.de>, 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
pfifo_request(unsigned int pfifo_mask)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);
49 writel(val, NETX_PFIFO_RESET);
50
51 out:
52 mutex_unlock(&pfifo_lock);
53 return err;
54 }
55
pfifo_free(unsigned int pfifo_mask)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);
67 EXPORT_SYMBOL(pfifo_request);
68 EXPORT_SYMBOL(pfifo_free);
69