cpu/ixp/timer.c

   1 /*
   2  * (C) Copyright 2006
   3  * Stefan Roese, DENX Software Engineering, sr@denx.de.
   4  *
   5  * (C) Copyright 2002
   6  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   7  * Marius Groeger <mgroeger@sysgo.de>
   8  *
   9  * (C) Copyright 2002
  10  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
  11  * Alex Zuepke <azu@sysgo.de>
  12  *
  13  * See file CREDITS for list of people who contributed to this
  14  * project.
  15  *
  16  * This program is free software; you can redistribute it and/or
  17  * modify it under the terms of the GNU General Public License as
  18  * published by the Free Software Foundation; either version 2 of
  19  * the License, or (at your option) any later version.
  20  *
  21  * This program is distributed in the hope that it will be useful,
  22  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  * GNU General Public License for more details.
  25  *
  26  * You should have received a copy of the GNU General Public License
  27  * along with this program; if not, write to the Free Software
  28  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  29  * MA 02111-1307 USA
  30  */
  31
  32 #include <common.h>
  33 #include <asm/arch/ixp425.h>
  34
  35 #ifndef CONFIG_USE_IRQ
  36 ulong get_timer (ulong base)
  37 {
  38        return get_timer_masked () - base;
  39 }
  40
  41 void ixp425_udelay(unsigned long usec)
  42 {
  43         /*
  44          * This function has a max usec, but since it is called from udelay
  45          * we should not have to worry... be happy
  46          */
  47         unsigned long usecs = CONFIG_SYS_HZ/1000000L & ~IXP425_OST_RELOAD_MASK;
  48
  49         *IXP425_OSST = IXP425_OSST_TIMER_1_PEND;
  50         usecs |= IXP425_OST_ONE_SHOT | IXP425_OST_ENABLE;
  51         *IXP425_OSRT1 = usecs;
  52         while (!(*IXP425_OSST & IXP425_OSST_TIMER_1_PEND));
  53 }
  54
  55 void udelay (unsigned long usec)
  56 {
  57         while (usec--) ixp425_udelay(1);
  58 }
  59
  60 static ulong reload_constant = 0xfffffff0;
  61
  62 void reset_timer_masked (void)
  63 {
  64         ulong reload = reload_constant | IXP425_OST_ONE_SHOT | IXP425_OST_ENABLE;
  65
  66         *IXP425_OSST = IXP425_OSST_TIMER_1_PEND;
  67         *IXP425_OSRT1 = reload;
  68 }
  69
  70 ulong get_timer_masked (void)
  71 {
  72         /*
  73          * Note that it is possible for this to wrap!
  74          * In this case we return max.
  75          */
  76         ulong current = *IXP425_OST1;
  77         if (*IXP425_OSST & IXP425_OSST_TIMER_1_PEND)
  78         {
  79                 return reload_constant;
  80         }
  81         return (reload_constant - current);
  82 }
  83 #endif /* #ifndef CONFIG_USE_IRQ */