LXR uboot/arch/sh/lib/time

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Copyright (C) 2007,2008 Nobobuhiro Iwamatsu <iwamatsu@nigauri.org>
   4 * Copyright (C) 2008 Renesas Solutions Corp.
   5 *
   6 * (C) Copyright 2003
   7 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   8 */
   9
  10#include <common.h>
  11#include <asm/io.h>
  12#include <asm/processor.h>
  13
  14#define CMT_CMCSR_INIT  0x0001  /* PCLK/32 */
  15#define CMT_CMCSR_CALIB 0x0000
  16#define CMT_MAX_COUNTER (0xFFFFFFFF)
  17#define CMT_TIMER_RESET (0xFFFF)
  18
  19static vu_long cmt0_timer;
  20
  21static void cmt_timer_start(unsigned int timer)
  22{
  23        writew(readw(CMSTR) | 0x01, CMSTR);
  24}
  25
  26static void cmt_timer_stop(unsigned int timer)
  27{
  28        writew(readw(CMSTR) & ~0x01, CMSTR);
  29}
  30
  31int timer_init(void)
  32{
  33        cmt0_timer = 0;
  34        /* Divide clock by 32 */
  35        readw(CMCSR_0);
  36        writew(CMT_CMCSR_INIT, CMCSR_0);
  37
  38        /* User Device 0 only */
  39        cmt_timer_stop(0);
  40        writew(CMT_TIMER_RESET, CMCOR_0);
  41        cmt_timer_start(0);
  42
  43        return 0;
  44}
  45
  46unsigned long long get_ticks(void)
  47{
  48        return cmt0_timer;
  49}
  50
  51static vu_long cmcnt = 0;
  52static unsigned long get_usec (void)
  53{
  54        ulong data = readw(CMCNT_0);
  55
  56        if (data >= cmcnt)
  57                cmcnt = data - cmcnt;
  58        else
  59                cmcnt = (CMT_TIMER_RESET - cmcnt) + data;
  60
  61        if ((cmt0_timer + cmcnt) > CMT_MAX_COUNTER)
  62                cmt0_timer = ((cmt0_timer + cmcnt) - CMT_MAX_COUNTER);
  63        else
  64                cmt0_timer += cmcnt;
  65
  66        cmcnt = data;
  67        return cmt0_timer;
  68}
  69
  70/* return msec */
  71ulong get_timer(ulong base)
  72{
  73        return (get_usec() / 1000) - base;
  74}
  75
  76void __udelay(unsigned long usec)
  77{
  78        unsigned long end = get_usec() + usec;
  79
  80        while (get_usec() < end)
  81                continue;
  82}
  83
  84unsigned long get_tbclk(void)
  85{
  86        return CONFIG_SH_CMT_CLK_FREQ;
  87}
  88