LXR uboot/arch/sh/lib/time.c

   1/*
   2 * (C) Copyright 2009
   3 * Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
   4 *
   5 * (C) Copyright 2007-2012
   6 * Nobobuhiro Iwamatsu <iwamatsu@nigauri.org>
   7 *
   8 * (C) Copyright 2003
   9 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  10 *
  11 * See file CREDITS for list of people who contributed to this
  12 * project.
  13 *
  14 * This program is free software; you can redistribute it and/or
  15 * modify it under the terms of the GNU General Public License as
  16 * published by the Free Software Foundation; either version 2 of
  17 * the License, or (at your option) any later version.
  18 *
  19 * This program is distributed in the hope that it will be useful,
  20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 * GNU General Public License for more details.
  23 *
  24 * You should have received a copy of the GNU General Public License
  25 * along with this program; if not, write to the Free Software
  26 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  27 * MA 02111-1307 USA
  28 */
  29
  30#include <common.h>
  31#include <div64.h>
  32#include <asm/processor.h>
  33#include <asm/io.h>
  34#include <sh_tmu.h>
  35
  36static struct tmu_regs *tmu = (struct tmu_regs *)TMU_BASE;
  37
  38static u16 bit;
  39static unsigned long last_tcnt;
  40static unsigned long long overflow_ticks;
  41
  42unsigned long get_tbclk(void)
  43{
  44        return get_tmu0_clk_rate() >> ((bit + 1) * 2);
  45}
  46
  47static inline unsigned long long tick_to_time(unsigned long long tick)
  48{
  49        tick *= CONFIG_SYS_HZ;
  50        do_div(tick, get_tbclk());
  51
  52        return tick;
  53}
  54
  55static inline unsigned long long usec_to_tick(unsigned long long usec)
  56{
  57        usec *= get_tbclk();
  58        do_div(usec, 1000000);
  59
  60        return usec;
  61}
  62
  63static void tmu_timer_start(unsigned int timer)
  64{
  65        if (timer > 2)
  66                return;
  67        writeb(readb(&tmu->tstr) | (1 << timer), &tmu->tstr);
  68}
  69
  70static void tmu_timer_stop(unsigned int timer)
  71{
  72        if (timer > 2)
  73                return;
  74        writeb(readb(&tmu->tstr) & ~(1 << timer), &tmu->tstr);
  75}
  76
  77int timer_init(void)
  78{
  79        bit = (ffs(CONFIG_SYS_TMU_CLK_DIV) >> 1) - 1;
  80        writew(readw(&tmu->tcr0) | bit, &tmu->tcr0);
  81
  82        tmu_timer_stop(0);
  83        tmu_timer_start(0);
  84
  85        last_tcnt = 0;
  86        overflow_ticks = 0;
  87
  88        return 0;
  89}
  90
  91unsigned long long get_ticks(void)
  92{
  93        unsigned long tcnt = 0 - readl(&tmu->tcnt0);
  94
  95        if (last_tcnt > tcnt) /* overflow */
  96                overflow_ticks++;
  97        last_tcnt = tcnt;
  98
  99        return (overflow_ticks << 32) | tcnt;
 100}
 101
 102void __udelay(unsigned long usec)
 103{
 104        unsigned long long tmp;
 105        ulong tmo;
 106
 107        tmo = usec_to_tick(usec);
 108        tmp = get_ticks() + tmo;        /* get current timestamp */
 109
 110        while (get_ticks() < tmp)       /* loop till event */
 111                 /*NOP*/;
 112}
 113
 114unsigned long get_timer(unsigned long base)
 115{
 116        /* return msec */
 117        return tick_to_time(get_ticks()) - base;
 118}
 119
 120void set_timer(unsigned long t)
 121{
 122        writel((0 - t), &tmu->tcnt0);
 123}
 124
 125void reset_timer(void)
 126{
 127        tmu_timer_stop(0);
 128        set_timer(0);
 129        tmu_timer_start(0);
 130}
 131