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/*
* Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of ARM nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <assert.h>
#include <delay_timer.h>
#include <platform_def.h>
/***********************************************************
* The delay timer implementation
***********************************************************/
static const timer_ops_t *ops;
/***********************************************************
* Get a timer value in microseconds. The driver must
* be initialized before calling this function.
***********************************************************/
uint32_t timer_value_get(void)
{
assert(ops != 0 &&
(ops->clk_mult != 0) &&
(ops->clk_div != 0) &&
(ops->get_timer_value != 0));
return (~ops->get_timer_value() * ops->clk_mult) / ops->clk_div;
}
/***********************************************************
* Get a timer value in miliseconds. The driver must
* be initialized before calling this function.
***********************************************************/
uint32_t timer_value_ms_get(void)
{
return timer_value_get() / 1000;
}
/***********************************************************
* Delay for the given number of microseconds. The driver must
* be initialized before calling this function.
***********************************************************/
void udelay(uint32_t usec)
{
assert(ops != 0 &&
(ops->clk_mult != 0) &&
(ops->clk_div != 0) &&
(ops->get_timer_value != 0));
uint32_t start, delta, total_delta;
assert(usec < UINT32_MAX / ops->clk_div);
start = ops->get_timer_value();
total_delta = (usec * ops->clk_div) / ops->clk_mult;
do {
/*
* If the timer value wraps around, the subtraction will
* overflow and it will still give the correct result.
*/
delta = start - ops->get_timer_value(); /* Decreasing counter */
} while (delta < total_delta);
}
/***********************************************************
* Delay for the given number of milliseconds. The driver must
* be initialized before calling this function.
***********************************************************/
void mdelay(uint32_t msec)
{
udelay(msec*1000);
}
/***********************************************************
* Initialize the timer. The fields in the provided timer
* ops pointer must be valid.
***********************************************************/
void timer_init(const timer_ops_t *ops_ptr)
{
assert(ops_ptr != 0 &&
(ops_ptr->clk_mult != 0) &&
(ops_ptr->clk_div != 0) &&
(ops_ptr->get_timer_value != 0));
ops = ops_ptr;
}
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