LXR uboot/arch/arm/cpu/pxa/timer.c

   1/*
   2 * (C) Copyright 2002
   3 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   4 * Marius Groeger <mgroeger@sysgo.de>
   5 *
   6 * (C) Copyright 2002
   7 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   8 * Alex Zuepke <azu@sysgo.de>
   9 *
  10 * See file CREDITS for list of people who contributed to this
  11 * project.
  12 *
  13 * This program is free software; you can redistribute it and/or
  14 * modify it under the terms of the GNU General Public License as
  15 * published by the Free Software Foundation; either version 2 of
  16 * the License, or (at your option) any later version.
  17 *
  18 * This program is distributed in the hope that it will be useful,
  19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 * GNU General Public License for more details.
  22 *
  23 * You should have received a copy of the GNU General Public License
  24 * along with this program; if not, write to the Free Software
  25 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  26 * MA 02111-1307 USA
  27 */
  28
  29#include <asm/arch/pxa-regs.h>
  30#include <asm/io.h>
  31#include <common.h>
  32#include <div64.h>
  33
  34#ifdef CONFIG_USE_IRQ
  35#error: interrupts not implemented yet
  36#endif
  37
  38#if defined(CONFIG_PXA27X) || defined(CONFIG_CPU_MONAHANS)
  39#define TIMER_FREQ_HZ 3250000
  40#elif defined(CONFIG_PXA250)
  41#define TIMER_FREQ_HZ 3686400
  42#else
  43#error "Timer frequency unknown - please config PXA CPU type"
  44#endif
  45
  46static inline unsigned long long tick_to_time(unsigned long long tick)
  47{
  48        tick *= CONFIG_SYS_HZ;
  49        do_div(tick, TIMER_FREQ_HZ);
  50        return tick;
  51}
  52
  53static inline unsigned long long us_to_tick(unsigned long long us)
  54{
  55        us = us * TIMER_FREQ_HZ + 999999;
  56        do_div(us, 1000000);
  57        return us;
  58}
  59
  60int timer_init (void)
  61{
  62        reset_timer();
  63
  64        return 0;
  65}
  66
  67void reset_timer (void)
  68{
  69        reset_timer_masked ();
  70}
  71
  72ulong get_timer (ulong base)
  73{
  74        return get_timer_masked () - base;
  75}
  76
  77void set_timer (ulong t)
  78{
  79        /* nop */
  80}
  81
  82void __udelay (unsigned long usec)
  83{
  84        udelay_masked (usec);
  85}
  86
  87
  88void reset_timer_masked (void)
  89{
  90        writel(0, OSCR);
  91}
  92
  93ulong get_timer_masked (void)
  94{
  95        return tick_to_time(get_ticks());
  96}
  97
  98void udelay_masked (unsigned long usec)
  99{
 100        unsigned long long tmp;
 101        ulong tmo;
 102
 103        tmo = us_to_tick(usec);
 104        tmp = get_ticks() + tmo;        /* get current timestamp */
 105
 106        while (get_ticks() < tmp)       /* loop till event */
 107                 /*NOP*/;
 108
 109}
 110
 111/*
 112 * This function is derived from PowerPC code (read timebase as long long).
 113 * On ARM it just returns the timer value.
 114 */
 115unsigned long long get_ticks(void)
 116{
 117        return readl(OSCR);
 118}
 119
 120/*
 121 * This function is derived from PowerPC code (timebase clock frequency).
 122 * On ARM it returns the number of timer ticks per second.
 123 */
 124ulong get_tbclk (void)
 125{
 126        ulong tbclk;
 127        tbclk = TIMER_FREQ_HZ;
 128        return tbclk;
 129}
 130