LXR uboot/lib_sh/time.c

   1/*
   2 * (C) Copyright 2009
   3 * Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
   4 *
   5 * (C) Copyright 2007-2008
   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/clk.h>
  34#include <asm/io.h>
  35
  36#define TMU_MAX_COUNTER (~0UL)
  37
  38static ulong timer_freq;
  39
  40static inline unsigned long long tick_to_time(unsigned long long tick)
  41{
  42        tick *= CONFIG_SYS_HZ;
  43        do_div(tick, timer_freq);
  44
  45        return tick;
  46}
  47
  48static inline unsigned long long usec_to_tick(unsigned long long usec)
  49{
  50        usec *= timer_freq;
  51        do_div(usec, 1000000);
  52
  53        return usec;
  54}
  55
  56static void tmu_timer_start (unsigned int timer)
  57{
  58        if (timer > 2)
  59                return;
  60        writeb(readb(TSTR) | (1 << timer), TSTR);
  61}
  62
  63static void tmu_timer_stop (unsigned int timer)
  64{
  65        if (timer > 2)
  66                return;
  67        writeb(readb(TSTR) & ~(1 << timer), TSTR);
  68}
  69
  70int timer_init (void)
  71{
  72        /* Divide clock by CONFIG_SYS_TMU_CLK_DIV */
  73        u16 bit = 0;
  74
  75        switch (CONFIG_SYS_TMU_CLK_DIV) {
  76        case 1024:
  77                bit = 4;
  78                break;
  79        case 256:
  80                bit = 3;
  81                break;
  82        case 64:
  83                bit = 2;
  84                break;
  85        case 16:
  86                bit = 1;
  87                break;
  88        case 4:
  89        default:
  90                break;
  91        }
  92        writew(readw(TCR0) | bit, TCR0);
  93
  94        /* Calc clock rate */
  95        timer_freq = get_tmu0_clk_rate() >> ((bit + 1) * 2);
  96
  97        tmu_timer_stop(0);
  98        tmu_timer_start(0);
  99
 100        return 0;
 101}
 102
 103unsigned long long get_ticks (void)
 104{
 105        return 0 - readl(TCNT0);
 106}
 107
 108void udelay (unsigned long usec)
 109{
 110        unsigned long long tmp;
 111        ulong tmo;
 112
 113        tmo = usec_to_tick(usec);
 114        tmp = get_ticks() + tmo;        /* get current timestamp */
 115
 116        while (get_ticks() < tmp)       /* loop till event */
 117                 /*NOP*/;
 118}
 119
 120unsigned long get_timer (unsigned long base)
 121{
 122        /* return msec */
 123        return tick_to_time(get_ticks()) - base;
 124}
 125
 126void set_timer (unsigned long t)
 127{
 128        writel((0 - t), TCNT0);
 129}
 130
 131void reset_timer (void)
 132{
 133        tmu_timer_stop(0);
 134        set_timer (0);
 135        tmu_timer_start(0);
 136}
 137
 138unsigned long get_tbclk (void)
 139{
 140        return timer_freq;
 141}
 142