LXR uboot/cpu/arm920t/at91rm9200/timer.c

   1/*
   2 * (C) Copyright 2002
   3 * Lineo, Inc. <www.lineo.com>
   4 * Bernhard Kuhn <bkuhn@lineo.com>
   5 *
   6 * (C) Copyright 2002
   7 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   8 * Marius Groeger <mgroeger@sysgo.de>
   9 *
  10 * (C) Copyright 2002
  11 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
  12 * Alex Zuepke <azu@sysgo.de>
  13 *
  14 * See file CREDITS for list of people who contributed to this
  15 * project.
  16 *
  17 * This program is free software; you can redistribute it and/or
  18 * modify it under the terms of the GNU General Public License as
  19 * published by the Free Software Foundation; either version 2 of
  20 * the License, or (at your option) any later version.
  21 *
  22 * This program is distributed in the hope that it will be useful,
  23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25 * GNU General Public License for more details.
  26 *
  27 * You should have received a copy of the GNU General Public License
  28 * along with this program; if not, write to the Free Software
  29 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  30 * MA 02111-1307 USA
  31 */
  32
  33#include <common.h>
  34/*#include <asm/io.h>*/
  35#include <asm/arch/hardware.h>
  36/*#include <asm/proc/ptrace.h>*/
  37
  38/* the number of clocks per CONFIG_SYS_HZ */
  39#define TIMER_LOAD_VAL (CONFIG_SYS_HZ_CLOCK/CONFIG_SYS_HZ)
  40
  41/* macro to read the 16 bit timer */
  42#define READ_TIMER (tmr->TC_CV & 0x0000ffff)
  43AT91PS_TC tmr;
  44
  45static ulong timestamp;
  46static ulong lastinc;
  47
  48int timer_init (void)
  49{
  50        tmr = AT91C_BASE_TC0;
  51
  52        /* enables TC1.0 clock */
  53        *AT91C_PMC_PCER = 1 << AT91C_ID_TC0;  /* enable clock */
  54
  55        *AT91C_TCB0_BCR = 0;
  56        *AT91C_TCB0_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_NONE | AT91C_TCB_TC2XC2S_NONE;
  57        tmr->TC_CCR = AT91C_TC_CLKDIS;
  58#define AT91C_TC_CMR_CPCTRG (1 << 14)
  59        /* set to MCLK/2 and restart the timer when the vlaue in TC_RC is reached */
  60        tmr->TC_CMR = AT91C_TC_TIMER_DIV1_CLOCK | AT91C_TC_CMR_CPCTRG;
  61
  62        tmr->TC_IDR = ~0ul;
  63        tmr->TC_RC = TIMER_LOAD_VAL;
  64        lastinc = 0;
  65        tmr->TC_CCR = AT91C_TC_SWTRG | AT91C_TC_CLKEN;
  66        timestamp = 0;
  67
  68        return (0);
  69}
  70
  71/*
  72 * timer without interrupts
  73 */
  74
  75void reset_timer (void)
  76{
  77        reset_timer_masked ();
  78}
  79
  80ulong get_timer (ulong base)
  81{
  82        return get_timer_masked () - base;
  83}
  84
  85void set_timer (ulong t)
  86{
  87        timestamp = t;
  88}
  89
  90void udelay (unsigned long usec)
  91{
  92        udelay_masked(usec);
  93}
  94
  95void reset_timer_masked (void)
  96{
  97        /* reset time */
  98        lastinc = READ_TIMER;
  99        timestamp = 0;
 100}
 101
 102ulong get_timer_raw (void)
 103{
 104        ulong now = READ_TIMER;
 105
 106        if (now >= lastinc) {
 107                /* normal mode */
 108                timestamp += now - lastinc;
 109        } else {
 110                /* we have an overflow ... */
 111                timestamp += now + TIMER_LOAD_VAL - lastinc;
 112        }
 113        lastinc = now;
 114
 115        return timestamp;
 116}
 117
 118ulong get_timer_masked (void)
 119{
 120        return get_timer_raw()/TIMER_LOAD_VAL;
 121}
 122
 123void udelay_masked (unsigned long usec)
 124{
 125        ulong tmo;
 126        ulong endtime;
 127        signed long diff;
 128
 129        tmo = CONFIG_SYS_HZ_CLOCK / 1000;
 130        tmo *= usec;
 131        tmo /= 1000;
 132
 133        endtime = get_timer_raw () + tmo;
 134
 135        do {
 136                ulong now = get_timer_raw ();
 137                diff = endtime - now;
 138        } while (diff >= 0);
 139}
 140
 141/*
 142 * This function is derived from PowerPC code (read timebase as long long).
 143 * On ARM it just returns the timer value.
 144 */
 145unsigned long long get_ticks(void)
 146{
 147        return get_timer(0);
 148}
 149
 150/*
 151 * This function is derived from PowerPC code (timebase clock frequency).
 152 * On ARM it returns the number of timer ticks per second.
 153 */
 154ulong get_tbclk (void)
 155{
 156        ulong tbclk;
 157
 158        tbclk = CONFIG_SYS_HZ;
 159        return tbclk;
 160}
 161