u-boot/arch/sh/lib/time_sh2.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2007,2008 Nobobuhiro Iwamatsu <iwamatsu@nigauri.org>
* Copyright (C) 2008 Renesas Solutions Corp.
*
* (C) Copyright 2003
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*/
#include <common.h>
#include <init.h>
#include <time.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <linux/delay.h>
#define CMT_CMCSR_INIT 0x0001 /* PCLK/32 */
#define CMT_CMCSR_CALIB 0x0000
#define CMT_MAX_COUNTER (0xFFFFFFFF)
#define CMT_TIMER_RESET (0xFFFF)
static vu_long cmt0_timer;
static void cmt_timer_start(unsigned int timer)
{
writew(readw(CMSTR) | 0x01, CMSTR);
}
static void cmt_timer_stop(unsigned int timer)
{
writew(readw(CMSTR) & ~0x01, CMSTR);
}
int timer_init(void)
{
cmt0_timer = 0;
/* Divide clock by 32 */
readw(CMCSR_0);
writew(CMT_CMCSR_INIT, CMCSR_0);
/* User Device 0 only */
cmt_timer_stop(0);
2011-07-15 02:18:12 +00:00
writew(CMT_TIMER_RESET, CMCOR_0);
cmt_timer_start(0);
return 0;
}
unsigned long long get_ticks(void)
{
return cmt0_timer;
}
static vu_long cmcnt = 0;
static unsigned long get_usec (void)
{
ulong data = readw(CMCNT_0);
if (data >= cmcnt)
cmcnt = data - cmcnt;
else
cmcnt = (CMT_TIMER_RESET - cmcnt) + data;
if ((cmt0_timer + cmcnt) > CMT_MAX_COUNTER)
cmt0_timer = ((cmt0_timer + cmcnt) - CMT_MAX_COUNTER);
else
cmt0_timer += cmcnt;
cmcnt = data;
return cmt0_timer;
}
/* return msec */
ulong get_timer(ulong base)
{
return (get_usec() / 1000) - base;
}
void __udelay(unsigned long usec)
{
unsigned long end = get_usec() + usec;
while (get_usec() < end)
continue;
}
unsigned long get_tbclk(void)
{
return CONFIG_SH_CMT_CLK_FREQ;
}