arch/arm/mach-netx/pfifo.c

   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
  24 #include <asm/io.h>
  25 #include <asm/hardware.h>
  26 #include <asm/arch/netx-regs.h>
  27 #include <asm/arch/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);
  49         writel(val, 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);
  67 EXPORT_SYMBOL(pfifo_request);
  68 EXPORT_SYMBOL(pfifo_free);