cpu/ixp/timer.c

   1 /* vi: set ts=8 sw=8 noet: */
   2 /*
   3  * (C) Copyright 2002
   4  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   5  * Marius Groeger <mgroeger@sysgo.de>
   6  *
   7  * (C) Copyright 2002
   8  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   9  * Alex Zuepke <azu@sysgo.de>
  10  *
  11  * See file CREDITS for list of people who contributed to this
  12  * project.
  13  *
  14  * This program is free software; you can redistribute it and/or
  15  * modify it under the terms of the GNU General Public License as
  16  * published by the Free Software Foundation; either version 2 of
  17  * the License, or (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, write to the Free Software
  26  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  27  * MA 02111-1307 USA
  28  */
  29
  30 #include <common.h>
  31 #include <asm/arch/ixp425.h>
  32
  33 ulong get_timer (ulong base)
  34 {
  35        return get_timer_masked () - base;
  36 }
  37
  38 void ixp425_udelay(unsigned long usec)
  39 {
  40         /*
  41          * This function has a max usec, but since it is called from udelay
  42          * we should not have to worry... be happy
  43          */
  44         unsigned long usecs = CFG_HZ/1000000L & ~IXP425_OST_RELOAD_MASK;
  45
  46         *IXP425_OSST = IXP425_OSST_TIMER_1_PEND;
  47         usecs |= IXP425_OST_ONE_SHOT | IXP425_OST_ENABLE;
  48         *IXP425_OSRT1 = usecs;
  49         while (!(*IXP425_OSST & IXP425_OSST_TIMER_1_PEND));
  50 }
  51
  52 void udelay (unsigned long usec)
  53 {
  54         while (usec--) ixp425_udelay(1);
  55 }
  56
  57 static ulong reload_constant = 0xfffffff0;
  58
  59 void reset_timer_masked (void)
  60 {
  61         ulong reload = reload_constant | IXP425_OST_ONE_SHOT | IXP425_OST_ENABLE;
  62
  63         *IXP425_OSST = IXP425_OSST_TIMER_1_PEND;
  64         *IXP425_OSRT1 = reload;
  65 }
  66
  67 ulong get_timer_masked (void)
  68 {
  69         /*
  70          * Note that it is possible for this to wrap!
  71          * In this case we return max.
  72          */
  73         ulong current = *IXP425_OST1;
  74         if (*IXP425_OSST & IXP425_OSST_TIMER_1_PEND)
  75         {
  76                 return reload_constant;
  77         }
  78         return (reload_constant - current);
  79 }