LXR uboot/arch/arm/mach-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 * SPDX-License-Identifier:     GPL-2.0+
  22 */
  23
  24#include <common.h>
  25#include <asm/io.h>
  26#include <asm/arch/timer_defs.h>
  27#include <div64.h>
  28
  29DECLARE_GLOBAL_DATA_PTR;
  30
  31static struct davinci_timer * const timer =
  32        (struct davinci_timer *)CONFIG_SYS_TIMERBASE;
  33
  34#define TIMER_LOAD_VAL  0xffffffff
  35
  36#define TIM_CLK_DIV     16
  37
  38int timer_init(void)
  39{
  40        /* We are using timer34 in unchained 32-bit mode, full speed */
  41        writel(0x0, &timer->tcr);
  42        writel(0x0, &timer->tgcr);
  43        writel(0x06 | ((TIM_CLK_DIV - 1) << 8), &timer->tgcr);
  44        writel(0x0, &timer->tim34);
  45        writel(TIMER_LOAD_VAL, &timer->prd34);
  46        writel(2 << 22, &timer->tcr);
  47        gd->arch.timer_rate_hz = CONFIG_SYS_HZ_CLOCK / TIM_CLK_DIV;
  48        gd->arch.timer_reset_value = 0;
  49
  50        return(0);
  51}
  52
  53/*
  54 * Get the current 64 bit timer tick count
  55 */
  56unsigned long long get_ticks(void)
  57{
  58        unsigned long now = readl(&timer->tim34);
  59
  60        /* increment tbu if tbl has rolled over */
  61        if (now < gd->arch.tbl)
  62                gd->arch.tbu++;
  63        gd->arch.tbl = now;
  64
  65        return (((unsigned long long)gd->arch.tbu) << 32) | gd->arch.tbl;
  66}
  67
  68ulong get_timer(ulong base)
  69{
  70        unsigned long long timer_diff;
  71
  72        timer_diff = get_ticks() - gd->arch.timer_reset_value;
  73
  74        return lldiv(timer_diff,
  75                     (gd->arch.timer_rate_hz / CONFIG_SYS_HZ)) - base;
  76}
  77
  78void __udelay(unsigned long usec)
  79{
  80        unsigned long long endtime;
  81
  82        endtime = lldiv((unsigned long long)usec * gd->arch.timer_rate_hz,
  83                        1000000UL);
  84        endtime += get_ticks();
  85
  86        while (get_ticks() < endtime)
  87                ;
  88}
  89
  90/*
  91 * This function is derived from PowerPC code (timebase clock frequency).
  92 * On ARM it returns the number of timer ticks per second.
  93 */
  94ulong get_tbclk(void)
  95{
  96        return gd->arch.timer_rate_hz;
  97}
  98
  99#ifdef CONFIG_HW_WATCHDOG
 100static struct davinci_timer * const wdttimer =
 101        (struct davinci_timer *)CONFIG_SYS_WDTTIMERBASE;
 102
 103/*
 104 * See prufw2.pdf for using Timer as a WDT
 105 */
 106void davinci_hw_watchdog_enable(void)
 107{
 108        writel(0x0, &wdttimer->tcr);
 109        writel(0x0, &wdttimer->tgcr);
 110        /* TIMMODE = 2h */
 111        writel(0x08 | 0x03 | ((TIM_CLK_DIV - 1) << 8), &wdttimer->tgcr);
 112        writel(CONFIG_SYS_WDT_PERIOD_LOW, &wdttimer->prd12);
 113        writel(CONFIG_SYS_WDT_PERIOD_HIGH, &wdttimer->prd34);
 114        writel(2 << 22, &wdttimer->tcr);
 115        writel(0x0, &wdttimer->tim12);
 116        writel(0x0, &wdttimer->tim34);
 117        /* set WDEN bit, WDKEY 0xa5c6 */
 118        writel(0xa5c64000, &wdttimer->wdtcr);
 119        /* clear counter register */
 120        writel(0xda7e4000, &wdttimer->wdtcr);
 121}
 122
 123void davinci_hw_watchdog_reset(void)
 124{
 125        writel(0xa5c64000, &wdttimer->wdtcr);
 126        writel(0xda7e4000, &wdttimer->wdtcr);
 127}
 128#endif
 129