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/*
* (C) Copyright 2010 Juergen Beisert - Pengutronix
*
* 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 <init.h>
#include <clock.h>
#include <notifier.h>
#include <mach/imx-regs.h>
#include <mach/clock.h>
#include <asm/io.h>
#define TIMROTCTRL 0x00
#define TIMCTRL1 0x40
#define TIMCTRL1_SET 0x44
#define TIMCTRL1_CLR 0x48
#define TIMCTRL1_TOG 0x4c
# define TIMCTRL_RELOAD (1 << 6)
# define TIMCTRL_UPDATE (1 << 7)
# define TIMCTRL_PRESCALE(x) ((x & 0x3) << 4)
# define TIMCTRL_SELECT(x) (x & 0xf)
#define TIMCOUNT1 0x50
static const unsigned long timer_base = IMX_TIM1_BASE;
#define CLOCK_TICK_RATE (32000)
static uint64_t imx23_clocksource_read(void)
{
/* only the upper bits are the valid */
return ~(readl(timer_base + TIMCOUNT1) >> 16);
}
static struct clocksource cs = {
.read = imx23_clocksource_read,
.mask = CLOCKSOURCE_MASK(16),
.shift = 10,
};
static int imx23_clocksource_clock_change(struct notifier_block *nb, unsigned long event, void *data)
{
cs.mult = clocksource_hz2mult(CLOCK_TICK_RATE/*imx_get_xclk()*/, cs.shift);
return 0;
}
static struct notifier_block imx23_clock_notifier = {
.notifier_call = imx23_clocksource_clock_change,
};
static int clocksource_init(void)
{
/* enable the whole timer block */
writel(0x3e000000, timer_base + TIMROTCTRL);
/* setup general purpose timer 1 */
writel(0x00000000, timer_base + TIMCTRL1);
writel(TIMCTRL_UPDATE, timer_base + TIMCTRL1);
writel(0x0000ffff, timer_base + TIMCOUNT1);
writel(TIMCTRL_UPDATE | TIMCTRL_RELOAD | TIMCTRL_PRESCALE(0) | TIMCTRL_SELECT(8), timer_base + TIMCTRL1);
cs.mult = clocksource_hz2mult(CLOCK_TICK_RATE/*imx_get_xclk()*/, cs.shift);
init_clock(&cs);
clock_register_client(&imx23_clock_notifier);
return 0;
}
core_initcall(clocksource_init);