u-boot/cpu/arm926ejs/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>
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <asm/io.h>
struct davinci_timer {
u_int32_t pid12;
u_int32_t emumgt;
u_int32_t na1;
u_int32_t na2;
u_int32_t tim12;
u_int32_t tim34;
u_int32_t prd12;
u_int32_t prd34;
u_int32_t tcr;
u_int32_t tgcr;
u_int32_t wdtcr;
};
static struct davinci_timer * const timer =
(struct davinci_timer *)CONFIG_SYS_TIMERBASE;
#define TIMER_LOAD_VAL (CONFIG_SYS_HZ_CLOCK / CONFIG_SYS_HZ)
#define TIM_CLK_DIV 16
static ulong timestamp;
static ulong lastinc;
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);
lastinc = 0;
timestamp = 0;
writel(2 << 22, &timer->tcr);
return(0);
}
void reset_timer(void)
{
writel(0x0, &timer->tcr);
writel(0x0, &timer->tim34);
lastinc = 0;
timestamp = 0;
writel(2 << 22, &timer->tcr);
}
static ulong get_timer_raw(void)
{
ulong now = readl(&timer->tim34);
if (now >= lastinc) {
/* normal mode */
timestamp += now - lastinc;
} else {
/* overflow ... */
timestamp += now + TIMER_LOAD_VAL - lastinc;
}
lastinc = now;
return timestamp;
}
ulong get_timer(ulong base)
{
return((get_timer_raw() / (TIMER_LOAD_VAL / TIM_CLK_DIV)) - base);
}
void set_timer(ulong t)
{
timestamp = t;
}
void __udelay(unsigned long usec)
{
ulong tmo;
ulong endtime;
signed long diff;
tmo = CONFIG_SYS_HZ_CLOCK / 1000;
tmo *= usec;
tmo /= (1000 * TIM_CLK_DIV);
endtime = get_timer_raw() + tmo;
do {
ulong now = get_timer_raw();
diff = endtime - now;
} while (diff >= 0);
}
/*
* This function is derived from PowerPC code (read timebase as long long).
* On ARM it just returns the timer value.
*/
unsigned long long get_ticks(void)
{
return(get_timer(0));
}
/*
* 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 CONFIG_SYS_HZ;
}