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/*
* Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <assert.h>
#include <delay_timer.h>
#include <platform_def.h>
/***********************************************************
* The delay timer implementation
***********************************************************/
static const timer_ops_t *ops;
/***********************************************************
* Delay for the given number of microseconds. The driver must
* be initialized before calling this function.
***********************************************************/
void udelay(uint32_t usec)
{
assert(ops != NULL &&
(ops->clk_mult != 0) &&
(ops->clk_div != 0) &&
(ops->get_timer_value != NULL));
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 != NULL &&
(ops_ptr->clk_mult != 0) &&
(ops_ptr->clk_div != 0) &&
(ops_ptr->get_timer_value != NULL));
ops = ops_ptr;
}
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