u-boot/arch/arm/mach-davinci/timer.c

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/*
* (C) Copyright 2003
* Texas Instruments <www.ti.com>
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Alex Zuepke <azu@sysgo.de>
*
* (C) Copyright 2002-2004
* Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
*
* (C) Copyright 2004
* Philippe Robin, ARM Ltd. <philippe.robin@arm.com>
*
* Copyright (C) 2007 Sergey Kubushyn <ksi@koi8.net>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/io.h>
#include <asm/arch/timer_defs.h>
#include <div64.h>
DECLARE_GLOBAL_DATA_PTR;
static struct davinci_timer * const timer =
(struct davinci_timer *)CONFIG_SYS_TIMERBASE;
#define TIMER_LOAD_VAL 0xffffffff
#define TIM_CLK_DIV 16
int timer_init(void)
{
/* We are using timer34 in unchained 32-bit mode, full speed */
writel(0x0, &timer->tcr);
writel(0x0, &timer->tgcr);
writel(0x06 | ((TIM_CLK_DIV - 1) << 8), &timer->tgcr);
writel(0x0, &timer->tim34);
writel(TIMER_LOAD_VAL, &timer->prd34);
writel(2 << 22, &timer->tcr);
gd->arch.timer_rate_hz = CONFIG_SYS_HZ_CLOCK / TIM_CLK_DIV;
gd->arch.timer_reset_value = 0;
return(0);
}
/*
* Get the current 64 bit timer tick count
*/
unsigned long long get_ticks(void)
{
unsigned long now = readl(&timer->tim34);
/* increment tbu if tbl has rolled over */
if (now < gd->arch.tbl)
gd->arch.tbu++;
gd->arch.tbl = now;
return (((unsigned long long)gd->arch.tbu) << 32) | gd->arch.tbl;
}
ulong get_timer(ulong base)
{
unsigned long long timer_diff;
timer_diff = get_ticks() - gd->arch.timer_reset_value;
return lldiv(timer_diff,
(gd->arch.timer_rate_hz / CONFIG_SYS_HZ)) - base;
}
void __udelay(unsigned long usec)
{
unsigned long long endtime;
endtime = lldiv((unsigned long long)usec * gd->arch.timer_rate_hz,
1000000UL);
endtime += get_ticks();
while (get_ticks() < endtime)
;
}
/*
* This function is derived from PowerPC code (timebase clock frequency).
* On ARM it returns the number of timer ticks per second.
*/
ulong get_tbclk(void)
{
return gd->arch.timer_rate_hz;
}
#ifdef CONFIG_HW_WATCHDOG
static struct davinci_timer * const wdttimer =
(struct davinci_timer *)CONFIG_SYS_WDTTIMERBASE;
/*
* See prufw2.pdf for using Timer as a WDT
*/
void davinci_hw_watchdog_enable(void)
{
writel(0x0, &wdttimer->tcr);
writel(0x0, &wdttimer->tgcr);
/* TIMMODE = 2h */
writel(0x08 | 0x03 | ((TIM_CLK_DIV - 1) << 8), &wdttimer->tgcr);
writel(CONFIG_SYS_WDT_PERIOD_LOW, &wdttimer->prd12);
writel(CONFIG_SYS_WDT_PERIOD_HIGH, &wdttimer->prd34);
writel(2 << 22, &wdttimer->tcr);
writel(0x0, &wdttimer->tim12);
writel(0x0, &wdttimer->tim34);
/* set WDEN bit, WDKEY 0xa5c6 */
writel(0xa5c64000, &wdttimer->wdtcr);
/* clear counter register */
writel(0xda7e4000, &wdttimer->wdtcr);
}
void davinci_hw_watchdog_reset(void)
{
writel(0xa5c64000, &wdttimer->wdtcr);
writel(0xda7e4000, &wdttimer->wdtcr);
}
#endif