/**
 * \file
 *
 * \brief ARM functions for busy-wait delay loops
 *
 * Copyright (c) 2014-2018 Microchip Technology Inc. and its subsidiaries.
 *
 * \asf_license_start
 *
 * \page License
 *
 * Subject to your compliance with these terms, you may use Microchip
 * software and any derivatives exclusively with Microchip products.
 * It is your responsibility to comply with third party license terms applicable
 * to your use of third party software (including open source software) that
 * may accompany Microchip software.
 *
 * THIS SOFTWARE IS SUPPLIED BY MICROCHIP "AS IS". NO WARRANTIES,
 * WHETHER EXPRESS, IMPLIED OR STATUTORY, APPLY TO THIS SOFTWARE,
 * INCLUDING ANY IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY,
 * AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT WILL MICROCHIP BE
 * LIABLE FOR ANY INDIRECT, SPECIAL, PUNITIVE, INCIDENTAL OR CONSEQUENTIAL
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 * ALLOWED BY LAW, MICROCHIP'S TOTAL LIABILITY ON ALL CLAIMS IN ANY WAY
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/*
 * Support and FAQ: visit <a href="https://www.microchip.com/support/">Microchip Support</a>
 */

#include "delay.h"

/**
 * Value used to calculate ms delay. Default to be used with a 8MHz clock;
 */
static uint32_t cycles_per_ms = 8000000UL / 1000;
static uint32_t cycles_per_us = 8000000UL / 1000000;

/**
 * \brief Initialize the delay driver.
 *
 * This must be called during start up to initialize the delay routine with
 * the current used main clock. It must run any time the main CPU clock is changed.
 */
void delay_init(void)
{
	cycles_per_ms = system_gclk_gen_get_hz(0);
	cycles_per_ms /= 1000;
	cycles_per_us = cycles_per_ms / 1000;

	SysTick->CTRL = SysTick_CTRL_CLKSOURCE_Msk | SysTick_CTRL_ENABLE_Msk;
}

/**
 * \brief Delay loop to delay at least n number of microseconds
 *
 * \param n  Number of microseconds to wait
 */
void delay_cycles_us(
		uint32_t n)
{
	while (n--) {
		/* Devide up to blocks of 10u */
		delay_cycles(cycles_per_us);
	}
}

/**
 * \brief Delay loop to delay at least n number of milliseconds
 *
 * \param n  Number of milliseconds to wait
 */
void delay_cycles_ms(
		uint32_t n)
{
	while (n--) {
		/* Devide up to blocks of 1ms */
		delay_cycles(cycles_per_ms);
	}
}