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 * SPDX-License-Identifier:     GPL-2.0+
   9 */
  10
  11#include <common.h>
  12#include <asm/io.h>
  13#include <asm/processor.h>
  14
  15#define CMT_CMCSR_INIT  0x0001  /* PCLK/32 */
  16#define CMT_CMCSR_CALIB 0x0000
  17#define CMT_MAX_COUNTER (0xFFFFFFFF)
  18#define CMT_TIMER_RESET (0xFFFF)
  19
  20static vu_long cmt0_timer;
  21
  22static void cmt_timer_start(unsigned int timer)
  23{
  24        writew(readw(CMSTR) | 0x01, CMSTR);
  25}
  26
  27static void cmt_timer_stop(unsigned int timer)
  28{
  29        writew(readw(CMSTR) & ~0x01, CMSTR);
  30}
  31
  32int timer_init(void)
  33{
  34        cmt0_timer = 0;
  35        /* Divide clock by 32 */
  36        readw(CMCSR_0);
  37        writew(CMT_CMCSR_INIT, CMCSR_0);
  38
  39        /* User Device 0 only */
  40        cmt_timer_stop(0);
  41        writew(CMT_TIMER_RESET, CMCOR_0);
  42        cmt_timer_start(0);
  43
  44        return 0;
  45}
  46
  47unsigned long long get_ticks(void)
  48{
  49        return cmt0_timer;
  50}
  51
  52static vu_long cmcnt = 0;
  53static unsigned long get_usec (void)
  54{
  55        ulong data = readw(CMCNT_0);
  56
  57        if (data >= cmcnt)
  58                cmcnt = data - cmcnt;
  59        else
  60                cmcnt = (CMT_TIMER_RESET - cmcnt) + data;
  61
  62        if ((cmt0_timer + cmcnt) > CMT_MAX_COUNTER)
  63                cmt0_timer = ((cmt0_timer + cmcnt) - CMT_MAX_COUNTER);
  64        else
  65                cmt0_timer += cmcnt;
  66
  67        cmcnt = data;
  68        return cmt0_timer;
  69}
  70
  71/* return msec */
  72ulong get_timer(ulong base)
  73{
  74        return (get_usec() / 1000) - base;
  75}
  76
  77void __udelay(unsigned long usec)
  78{
  79        unsigned long end = get_usec() + usec;
  80
  81        while (get_usec() < end)
  82                continue;
  83}
  84
  85unsigned long get_tbclk(void)
  86{
  87        return CONFIG_SH_CMT_CLK_FREQ;
  88}
  89