/******************************************************************************
 * The MIT License
 *
 * Copyright (c) 2010 Perry Hung.
 * Copyright (c) 2011 LeafLabs, LLC.
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy,
 * modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *****************************************************************************/

/**
 * @file libmaple/include/libmaple/delay.h
 * @brief Delay implementation
 */

#ifndef _LIBMAPLE_DELAY_H_
#define _LIBMAPLE_DELAY_H_

#ifdef __cplusplus
extern "C" {
#endif

#include <libmaple/libmaple_types.h>
#include <libmaple/stm32.h>

/**
 * @brief Delay the given number of microseconds.
 *
 * @param us Number of microseconds to delay.
 */
static inline void delay_us(uint32 us) {
    us *= STM32_DELAY_US_MULT;

    /* fudge for function call overhead  */
    us--;
    asm volatile("   mov r0, %[us]          \n\t"
                 "1: subs r0, #1            \n\t"
                 "   bhi 1b                 \n\t"
                 :
                 : [us] "r" (us)
                 : "r0");
}

#ifdef __cplusplus
}
#endif

#endif