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/*
* (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
* Gary Jennejohn, DENX Software Engineering, <gj@denx.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.
*
*/
#include <common.h>
#include <init.h>
#include <clock.h>
#include <mach/hardware.h>
#include <mach/at91_pit.h>
#include <mach/io.h>
#include <io.h>
#include <linux/clk.h>
#include <linux/err.h>
#define PIT_CPIV(x) ((x) & AT91_PIT_CPIV)
#define pit_write(reg, val) __raw_writel(val, pit_base + reg)
#define pit_read(reg) __raw_readl(pit_base + reg)
static __iomem void *pit_base;
uint64_t at91sam9_clocksource_read(void)
{
return pit_read(AT91_PIT_PIIR);
}
static struct clocksource cs = {
.read = at91sam9_clocksource_read,
.mask = CLOCKSOURCE_MASK(32),
.shift = 10,
};
static void at91_pit_stop(void)
{
/* Disable timer and irqs */
pit_write(AT91_PIT_MR, 0);
/* Clear any pending interrupts, wait for PIT to stop counting */
while (PIT_CPIV(pit_read(AT91_PIT_PIVR)) != 0);
}
static void at91sam926x_pit_reset(void)
{
at91_pit_stop();
/* Start PIT but don't enable IRQ */
pit_write(AT91_PIT_MR, 0xfffff | AT91_PIT_PITEN);
}
static int at91_pit_probe(struct device_d *dev)
{
struct clk *clk;
u32 pit_rate;
int ret;
clk = clk_get(dev, NULL);
if (IS_ERR(clk)) {
ret = PTR_ERR(clk);
dev_err(dev, "clock not found: %d\n", ret);
return ret;
}
ret = clk_enable(clk);
if (ret < 0) {
dev_err(dev, "clock failed to enable: %d\n", ret);
clk_put(clk);
return ret;
}
pit_base = dev_request_mem_region_err_null(dev, 0);
if (!pit_base)
return -ENOENT;
pit_rate = clk_get_rate(clk) / 16;
at91sam926x_pit_reset();
cs.mult = clocksource_hz2mult(pit_rate, cs.shift);
return init_clock(&cs);
}
static struct driver_d at91_pit_driver = {
.name = "at91-pit",
.probe = at91_pit_probe,
};
static int at91_pit_init(void)
{
return platform_driver_register(&at91_pit_driver);
}
postcore_initcall(at91_pit_init);
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