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 <init.h>
  12#include <time.h>
  13#include <asm/io.h>
  14#include <asm/processor.h>
  15#include <linux/delay.h>
  16
  17#define CMT_CMCSR_INIT  0x0001  /* PCLK/32 */
  18#define CMT_CMCSR_CALIB 0x0000
  19#define CMT_MAX_COUNTER (0xFFFFFFFF)
  20#define CMT_TIMER_RESET (0xFFFF)
  21
  22static vu_long cmt0_timer;
  23
  24static void cmt_timer_start(unsigned int timer)
  25{
  26        writew(readw(CMSTR) | 0x01, CMSTR);
  27}
  28
  29static void cmt_timer_stop(unsigned int timer)
  30{
  31        writew(readw(CMSTR) & ~0x01, CMSTR);
  32}
  33
  34int timer_init(void)
  35{
  36        cmt0_timer = 0;
  37        /* Divide clock by 32 */
  38        readw(CMCSR_0);
  39        writew(CMT_CMCSR_INIT, CMCSR_0);
  40
  41        /* User Device 0 only */
  42        cmt_timer_stop(0);
  43        writew(CMT_TIMER_RESET, CMCOR_0);
  44        cmt_timer_start(0);
  45
  46        return 0;
  47}
  48
  49unsigned long long get_ticks(void)
  50{
  51        return cmt0_timer;
  52}
  53
  54static vu_long cmcnt = 0;
  55static unsigned long get_usec (void)
  56{
  57        ulong data = readw(CMCNT_0);
  58
  59        if (data >= cmcnt)
  60                cmcnt = data - cmcnt;
  61        else
  62                cmcnt = (CMT_TIMER_RESET - cmcnt) + data;
  63
  64        if ((cmt0_timer + cmcnt) > CMT_MAX_COUNTER)
  65                cmt0_timer = ((cmt0_timer + cmcnt) - CMT_MAX_COUNTER);
  66        else
  67                cmt0_timer += cmcnt;
  68
  69        cmcnt = data;
  70        return cmt0_timer;
  71}
  72
  73/* return msec */
  74ulong get_timer(ulong base)
  75{
  76        return (get_usec() / 1000) - base;
  77}
  78
  79void __udelay(unsigned long usec)
  80{
  81        unsigned long end = get_usec() + usec;
  82
  83        while (get_usec() < end)
  84                continue;
  85}
  86
  87unsigned long get_tbclk(void)
  88{
  89        return CONFIG_SH_CMT_CLK_FREQ;
  90}
  91