u-boot-brain/arch/arm/cpu/arm926ejs/davinci/timer.c
Nick Thompson e465cf2377 davinci: Rewrite timer.c to use tbl/tbu emulation variables in gd
This change allows the davinci timer functions to be used before
relocation since it avoids using static variables prior to BSS being
made available.

The code is based on that used in the at91 timers, modified to use
a davinci specific hardware timer. It also maintains reset_timer()
to allow deprecated timer usage to continue to work (for example,
in nand_base.c)

Signed-off-by: Nick Thompson <nick.thompson@ge.com>
Tested-by: Ben Gardiner <bengardiner@nanometrics.ca>
Tested-by: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Tested-by: Sandeep Paulraj <s-paulraj@ti.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
2010-12-11 10:46:46 -05:00

129 lines
3.0 KiB
C

/*
* (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>
DECLARE_GLOBAL_DATA_PTR;
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 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->timer_rate_hz = CONFIG_SYS_HZ_CLOCK / TIM_CLK_DIV;
gd->timer_reset_value = 0;
return(0);
}
void reset_timer(void)
{
gd->timer_reset_value = get_ticks();
}
/*
* 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->tbl)
gd->tbu++;
gd->tbl = now;
return (((unsigned long long)gd->tbu) << 32) | gd->tbl;
}
ulong get_timer(ulong base)
{
unsigned long long timer_diff;
timer_diff = get_ticks() - gd->timer_reset_value;
return (timer_diff / (gd->timer_rate_hz / CONFIG_SYS_HZ)) - base;
}
void __udelay(unsigned long usec)
{
unsigned long long endtime;
endtime = ((unsigned long long)usec * gd->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 CONFIG_SYS_HZ;
}