mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-05 02:51:00 +00:00
38b343dd05
Add timer driver. Signed-off-by: Michal Simek <monstr@monstr.eu> CC: Joe Hershberger <joe.hershberger@gmail.com> CC: Marek Vasut <marex@denx.de> Acked-by: Marek Vasut <marex@denx.de>
150 lines
3.9 KiB
C
150 lines
3.9 KiB
C
/*
|
|
* Copyright (C) 2012 Michal Simek <monstr@monstr.eu>
|
|
* Copyright (C) 2011-2012 Xilinx, Inc. All rights reserved.
|
|
*
|
|
* (C) Copyright 2008
|
|
* Guennadi Liakhovetki, DENX Software Engineering, <lg@denx.de>
|
|
*
|
|
* (C) Copyright 2004
|
|
* Philippe Robin, ARM Ltd. <philippe.robin@arm.com>
|
|
*
|
|
* (C) Copyright 2002-2004
|
|
* Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
|
|
*
|
|
* (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>
|
|
*
|
|
* 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 <div64.h>
|
|
#include <asm/io.h>
|
|
|
|
DECLARE_GLOBAL_DATA_PTR;
|
|
|
|
struct scu_timer {
|
|
u32 load; /* Timer Load Register */
|
|
u32 counter; /* Timer Counter Register */
|
|
u32 control; /* Timer Control Register */
|
|
};
|
|
|
|
static struct scu_timer *timer_base =
|
|
(struct scu_timer *) CONFIG_SCUTIMER_BASEADDR;
|
|
|
|
#define SCUTIMER_CONTROL_PRESCALER_MASK 0x0000FF00 /* Prescaler */
|
|
#define SCUTIMER_CONTROL_PRESCALER_SHIFT 8
|
|
#define SCUTIMER_CONTROL_AUTO_RELOAD_MASK 0x00000002 /* Auto-reload */
|
|
#define SCUTIMER_CONTROL_ENABLE_MASK 0x00000001 /* Timer enable */
|
|
|
|
#define TIMER_LOAD_VAL 0xFFFFFFFF
|
|
#define TIMER_PRESCALE 255
|
|
#define TIMER_TICK_HZ (CONFIG_CPU_FREQ_HZ / 2 / TIMER_PRESCALE)
|
|
|
|
int timer_init(void)
|
|
{
|
|
const u32 emask = SCUTIMER_CONTROL_AUTO_RELOAD_MASK |
|
|
(TIMER_PRESCALE << SCUTIMER_CONTROL_PRESCALER_SHIFT) |
|
|
SCUTIMER_CONTROL_ENABLE_MASK;
|
|
|
|
/* Load the timer counter register */
|
|
writel(0xFFFFFFFF, &timer_base->counter);
|
|
|
|
/*
|
|
* Start the A9Timer device
|
|
* Enable Auto reload mode, Clear prescaler control bits
|
|
* Set prescaler value, Enable the decrementer
|
|
*/
|
|
clrsetbits_le32(&timer_base->control, SCUTIMER_CONTROL_PRESCALER_MASK,
|
|
emask);
|
|
|
|
/* Reset time */
|
|
gd->lastinc = readl(&timer_base->counter) /
|
|
(TIMER_TICK_HZ / CONFIG_SYS_HZ);
|
|
gd->tbl = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* This function is derived from PowerPC code (read timebase as long long).
|
|
* On ARM it just returns the timer value.
|
|
*/
|
|
ulong get_timer_masked(void)
|
|
{
|
|
ulong now;
|
|
|
|
now = readl(&timer_base->counter) / (TIMER_TICK_HZ / CONFIG_SYS_HZ);
|
|
|
|
if (gd->lastinc >= now) {
|
|
/* Normal mode */
|
|
gd->tbl += gd->lastinc - now;
|
|
} else {
|
|
/* We have an overflow ... */
|
|
gd->tbl += gd->lastinc + TIMER_LOAD_VAL - now;
|
|
}
|
|
gd->lastinc = now;
|
|
|
|
return gd->tbl;
|
|
}
|
|
|
|
void __udelay(unsigned long usec)
|
|
{
|
|
unsigned long long tmp;
|
|
ulong tmo;
|
|
|
|
tmo = usec / (1000000 / CONFIG_SYS_HZ);
|
|
tmp = get_ticks() + tmo; /* Get current timestamp */
|
|
|
|
while (get_ticks() < tmp) { /* Loop till event */
|
|
/* NOP */;
|
|
}
|
|
}
|
|
|
|
/* Timer without interrupts */
|
|
ulong get_timer(ulong base)
|
|
{
|
|
return get_timer_masked() - base;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|