LXR uboot/arch/sh/lib/time

   1/*
   2 * Copyright (C) 2007,2008 Nobobuhiro Iwamatsu <iwamatsu@nigauri.org>
   3 * Copyright (C) 2008 Renesas Solutions Corp.
   4 *
   5 * (C) Copyright 2003
   6 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   7 *
   8 * See file CREDITS for list of people who contributed to this
   9 * project.
  10 *
  11 * This program is free software; you can redistribute it and/or
  12 * modify it under the terms of the GNU General Public License as
  13 * published by the Free Software Foundation; either version 2 of
  14 * the License, or (at your option) any later version.
  15 *
  16 * This program is distributed in the hope that it will be useful,
  17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 * GNU General Public License for more details.
  20 *
  21 * You should have received a copy of the GNU General Public License
  22 * along with this program; if not, write to the Free Software
  23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  24 * MA 02111-1307 USA
  25 */
  26
  27#include <common.h>
  28#include <asm/io.h>
  29#include <asm/processor.h>
  30
  31#define CMT_CMCSR_INIT  0x0001  /* PCLK/32 */
  32#define CMT_CMCSR_CALIB 0x0000
  33#define CMT_MAX_COUNTER (0xFFFFFFFF)
  34#define CMT_TIMER_RESET (0xFFFF)
  35
  36static vu_long cmt0_timer;
  37
  38static void cmt_timer_start(unsigned int timer)
  39{
  40        writew(readw(CMSTR) | 0x01, CMSTR);
  41}
  42
  43static void cmt_timer_stop(unsigned int timer)
  44{
  45        writew(readw(CMSTR) & ~0x01, CMSTR);
  46}
  47
  48int timer_init(void)
  49{
  50        cmt0_timer = 0;
  51        /* Divide clock by 32 */
  52        readw(CMCSR_0);
  53        writew(CMT_CMCSR_INIT, CMCSR_0);
  54
  55        /* User Device 0 only */
  56        cmt_timer_stop(0);
  57        writew(CMT_TIMER_RESET, CMCOR_0);
  58        cmt_timer_start(0);
  59
  60        return 0;
  61}
  62
  63unsigned long long get_ticks(void)
  64{
  65        return cmt0_timer;
  66}
  67
  68static vu_long cmcnt = 0;
  69static unsigned long get_usec (void)
  70{
  71        ulong data = readw(CMCNT_0);
  72
  73        if (data >= cmcnt)
  74                cmcnt = data - cmcnt;
  75        else
  76                cmcnt = (CMT_TIMER_RESET - cmcnt) + data;
  77
  78        if ((cmt0_timer + cmcnt) > CMT_MAX_COUNTER)
  79                cmt0_timer = ((cmt0_timer + cmcnt) - CMT_MAX_COUNTER);
  80        else
  81                cmt0_timer += cmcnt;
  82
  83        cmcnt = data;
  84        return cmt0_timer;
  85}
  86
  87/* return msec */
  88ulong get_timer(ulong base)
  89{
  90        return (get_usec() / 1000) - base;
  91}
  92
  93void __udelay(unsigned long usec)
  94{
  95        unsigned long end = get_usec() + usec;
  96
  97        while (get_usec() < end)
  98                continue;
  99}
 100
 101unsigned long get_tbclk(void)
 102{
 103        return CONFIG_SYS_HZ;
 104}
 105