LXR uboot/arch/arm/cpu/arm926ejs/davinci/timer.c

   1/*
   2 * (C) Copyright 2003
   3 * Texas Instruments <www.ti.com>
   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 * (C) Copyright 2002-2004
  14 * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
  15 *
  16 * (C) Copyright 2004
  17 * Philippe Robin, ARM Ltd. <philippe.robin@arm.com>
  18 *
  19 * Copyright (C) 2007 Sergey Kubushyn <ksi@koi8.net>
  20 *
  21 * See file CREDITS for list of people who contributed to this
  22 * project.
  23 *
  24 * This program is free software; you can redistribute it and/or
  25 * modify it under the terms of the GNU General Public License as
  26 * published by the Free Software Foundation; either version 2 of
  27 * the License, or (at your option) any later version.
  28 *
  29 * This program is distributed in the hope that it will be useful,
  30 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  31 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  32 * GNU General Public License for more details.
  33 *
  34 * You should have received a copy of the GNU General Public License
  35 * along with this program; if not, write to the Free Software
  36 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  37 * MA 02111-1307 USA
  38 */
  39
  40#include <common.h>
  41#include <asm/io.h>
  42
  43DECLARE_GLOBAL_DATA_PTR;
  44
  45struct davinci_timer {
  46        u_int32_t       pid12;
  47        u_int32_t       emumgt;
  48        u_int32_t       na1;
  49        u_int32_t       na2;
  50        u_int32_t       tim12;
  51        u_int32_t       tim34;
  52        u_int32_t       prd12;
  53        u_int32_t       prd34;
  54        u_int32_t       tcr;
  55        u_int32_t       tgcr;
  56        u_int32_t       wdtcr;
  57};
  58
  59static struct davinci_timer * const timer =
  60        (struct davinci_timer *)CONFIG_SYS_TIMERBASE;
  61
  62#define TIMER_LOAD_VAL  0xffffffff
  63
  64#define TIM_CLK_DIV     16
  65
  66int timer_init(void)
  67{
  68        /* We are using timer34 in unchained 32-bit mode, full speed */
  69        writel(0x0, &timer->tcr);
  70        writel(0x0, &timer->tgcr);
  71        writel(0x06 | ((TIM_CLK_DIV - 1) << 8), &timer->tgcr);
  72        writel(0x0, &timer->tim34);
  73        writel(TIMER_LOAD_VAL, &timer->prd34);
  74        writel(2 << 22, &timer->tcr);
  75        gd->timer_rate_hz = CONFIG_SYS_HZ_CLOCK / TIM_CLK_DIV;
  76        gd->timer_reset_value = 0;
  77
  78        return(0);
  79}
  80
  81void reset_timer(void)
  82{
  83        gd->timer_reset_value = get_ticks();
  84}
  85
  86/*
  87 * Get the current 64 bit timer tick count
  88 */
  89unsigned long long get_ticks(void)
  90{
  91        unsigned long now = readl(&timer->tim34);
  92
  93        /* increment tbu if tbl has rolled over */
  94        if (now < gd->tbl)
  95                gd->tbu++;
  96        gd->tbl = now;
  97
  98        return (((unsigned long long)gd->tbu) << 32) | gd->tbl;
  99}
 100
 101ulong get_timer(ulong base)
 102{
 103        unsigned long long timer_diff;
 104
 105        timer_diff = get_ticks() - gd->timer_reset_value;
 106
 107        return (timer_diff / (gd->timer_rate_hz / CONFIG_SYS_HZ)) - base;
 108}
 109
 110void __udelay(unsigned long usec)
 111{
 112        unsigned long long endtime;
 113
 114        endtime = ((unsigned long long)usec * gd->timer_rate_hz) / 1000000UL;
 115        endtime += get_ticks();
 116
 117        while (get_ticks() < endtime)
 118                ;
 119}
 120
 121/*
 122 * This function is derived from PowerPC code (timebase clock frequency).
 123 * On ARM it returns the number of timer ticks per second.
 124 */
 125ulong get_tbclk(void)
 126{
 127        return CONFIG_SYS_HZ;
 128}
 129