u-boot/arch/m68k/cpu/mcf547x_8x/slicetimer.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2007, 2012 Freescale Semiconductor, Inc.
 * TsiChung Liew (Tsi-Chung.Liew@freescale.com)
 */

#include <common.h>
#include <init.h>
#include <irq_func.h>
#include <linux/delay.h>

#include <asm/timer.h>
#include <asm/immap.h>
#include <asm/io.h>

DECLARE_GLOBAL_DATA_PTR;

static ulong timestamp;

#if defined(CONFIG_SLTTMR)
#ifndef CONFIG_SYS_UDELAY_BASE
#	error	"uDelay base not defined!"
#endif

#if !defined(CONFIG_SYS_TMR_BASE) || !defined(CONFIG_SYS_INTR_BASE) || !defined(CONFIG_SYS_TMRINTR_NO) || !defined(CONFIG_SYS_TMRINTR_MASK)
#	error	"TMR_BASE, INTR_BASE, TMRINTR_NO or TMRINTR_MASk not defined!"
#endif
extern void dtimer_intr_setup(void);

void __udelay(unsigned long usec)
{
	slt_t *timerp = (slt_t *) (CONFIG_SYS_UDELAY_BASE);
	u32 now, freq;

	/* 1 us period */
	freq = CONFIG_SYS_TIMER_PRESCALER;

	/* Disable */
	out_be32(&timerp->cr, 0);
	out_be32(&timerp->tcnt, usec * freq);
	out_be32(&timerp->cr, SLT_CR_TEN);

	now = in_be32(&timerp->cnt);
	while (now != 0)
		now = in_be32(&timerp->cnt);

	setbits_be32(&timerp->sr, SLT_SR_ST);
	out_be32(&timerp->cr, 0);
}

void dtimer_interrupt(void *not_used)
{
	slt_t *timerp = (slt_t *) (CONFIG_SYS_TMR_BASE);

	/* check for timer interrupt asserted */
	if ((CONFIG_SYS_TMRPND_REG & CONFIG_SYS_TMRINTR_MASK) == CONFIG_SYS_TMRINTR_PEND) {
		setbits_be32(&timerp->sr, SLT_SR_ST);
		timestamp++;
		return;
	}
}

int timer_init(void)
{
	slt_t *timerp = (slt_t *) (CONFIG_SYS_TMR_BASE);

	timestamp = 0;

	/* disable timer */
	out_be32(&timerp->cr, 0);
	out_be32(&timerp->tcnt, 0);
	/* clear status */
	out_be32(&timerp->sr, SLT_SR_BE | SLT_SR_ST);

	/* initialize and enable timer interrupt */
	irq_install_handler(CONFIG_SYS_TMRINTR_NO, dtimer_interrupt, 0);

	/* Interrupt every ms */
	out_be32(&timerp->tcnt, 1000 * CONFIG_SYS_TIMER_PRESCALER);

	dtimer_intr_setup();

	/* set a period of 1us, set timer mode to restart and
	   enable timer and interrupt */
	out_be32(&timerp->cr, SLT_CR_RUN | SLT_CR_IEN | SLT_CR_TEN);
	return 0;
}

ulong get_timer(ulong base)
{
	return (timestamp - base);
}

#endif				/* CONFIG_SLTTMR */