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#include <asm/arch/timer_defs.h>
  43#include <div64.h>
  44
  45DECLARE_GLOBAL_DATA_PTR;
  46
  47static struct davinci_timer * const timer =
  48        (struct davinci_timer *)CONFIG_SYS_TIMERBASE;
  49
  50#define TIMER_LOAD_VAL  0xffffffff
  51
  52#define TIM_CLK_DIV     16
  53
  54int timer_init(void)
  55{
  56        /* We are using timer34 in unchained 32-bit mode, full speed */
  57        writel(0x0, &timer->tcr);
  58        writel(0x0, &timer->tgcr);
  59        writel(0x06 | ((TIM_CLK_DIV - 1) << 8), &timer->tgcr);
  60        writel(0x0, &timer->tim34);
  61        writel(TIMER_LOAD_VAL, &timer->prd34);
  62        writel(2 << 22, &timer->tcr);
  63        gd->timer_rate_hz = CONFIG_SYS_HZ_CLOCK / TIM_CLK_DIV;
  64        gd->timer_reset_value = 0;
  65
  66        return(0);
  67}
  68
  69/*
  70 * Get the current 64 bit timer tick count
  71 */
  72unsigned long long get_ticks(void)
  73{
  74        unsigned long now = readl(&timer->tim34);
  75
  76        /* increment tbu if tbl has rolled over */
  77        if (now < gd->tbl)
  78                gd->tbu++;
  79        gd->tbl = now;
  80
  81        return (((unsigned long long)gd->tbu) << 32) | gd->tbl;
  82}
  83
  84ulong get_timer(ulong base)
  85{
  86        unsigned long long timer_diff;
  87
  88        timer_diff = get_ticks() - gd->timer_reset_value;
  89
  90        return lldiv(timer_diff, (gd->timer_rate_hz / CONFIG_SYS_HZ)) - base;
  91}
  92
  93void __udelay(unsigned long usec)
  94{
  95        unsigned long long endtime;
  96
  97        endtime = lldiv((unsigned long long)usec * gd->timer_rate_hz,
  98                        1000000UL);
  99        endtime += get_ticks();
 100
 101        while (get_ticks() < endtime)
 102                ;
 103}
 104
 105/*
 106 * This function is derived from PowerPC code (timebase clock frequency).
 107 * On ARM it returns the number of timer ticks per second.
 108 */
 109ulong get_tbclk(void)
 110{
 111        return gd->timer_rate_hz;
 112}
 113
 114#ifdef CONFIG_HW_WATCHDOG
 115static struct davinci_timer * const wdttimer =
 116        (struct davinci_timer *)CONFIG_SYS_WDTTIMERBASE;
 117
 118/*
 119 * See prufw2.pdf for using Timer as a WDT
 120 */
 121void davinci_hw_watchdog_enable(void)
 122{
 123        writel(0x0, &wdttimer->tcr);
 124        writel(0x0, &wdttimer->tgcr);
 125        /* TIMMODE = 2h */
 126        writel(0x08 | 0x03 | ((TIM_CLK_DIV - 1) << 8), &wdttimer->tgcr);
 127        writel(CONFIG_SYS_WDT_PERIOD_LOW, &wdttimer->prd12);
 128        writel(CONFIG_SYS_WDT_PERIOD_HIGH, &wdttimer->prd34);
 129        writel(2 << 22, &wdttimer->tcr);
 130        writel(0x0, &wdttimer->tim12);
 131        writel(0x0, &wdttimer->tim34);
 132        /* set WDEN bit, WDKEY 0xa5c6 */
 133        writel(0xa5c64000, &wdttimer->wdtcr);
 134        /* clear counter register */
 135        writel(0xda7e4000, &wdttimer->wdtcr);
 136}
 137
 138void davinci_hw_watchdog_reset(void)
 139{
 140        writel(0xa5c64000, &wdttimer->wdtcr);
 141        writel(0xda7e4000, &wdttimer->wdtcr);
 142}
 143#endif
 144