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RIOT/cpu/kw2x/cpu.c

77 lines
2.0 KiB
C

/*
* Copyright (C) 2014 Freie Universität Berlin
* Copyright (C) 2014 PHYTEC Messtechnik GmbH
*
* This file is subject to the terms and conditions of the GNU Lesser General
* Public License v2.1. See the file LICENSE in the top level directory for more
* details.
*/
/**
* @ingroup cpu_kw2x
* @{
*
* @file
* @brief Implementation of the KW2xD CPU initialization
*
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
* @author Johann Fischer <j.fischer@phytec.de>
* @}
*/
#include <stdint.h>
#include "cpu.h"
#include "cpu_conf.h"
#define FLASH_BASE (0x00000000)
static void cpu_clock_init(void);
/**
* @brief Initialize the CPU, set IRQ priorities
*/
void cpu_init(void)
{
/* initialize the Cortex-M core */
cortexm_init();
/* initialize the clock system */
cpu_clock_init();
}
static inline void modem_clock_init(void)
{
SIM->SCGC5 |= (SIM_SCGC5_PORTC_MASK);
SIM->SCGC5 |= (SIM_SCGC5_PORTB_MASK);
/* Use the CLK_OUT of the modem as the clock source. */
/* Modem RST_B is connected to PTB19 and can be used to reset the modem. */
PORTB->PCR[19] = PORT_PCR_MUX(1);
GPIOB->PDDR |= (1 << 19);
GPIOB->PCOR |= (1 << 19);
/* Modem GPIO5 is connected to PTC0 and can be used to select CLK_OUT frequency, */
/* set PTC0 high for CLK_OUT=32.787kHz and low for CLK_OUT=4MHz. */
PORTC->PCR[0] = PORT_PCR_MUX(1);
GPIOC->PDDR |= (1 << 0);
GPIOC->PCOR |= (1 << 0);
/* Modem IRQ_B is connected to PTB3, modem interrupt request to the MCU. */
PORTB->PCR[KW2XDRF_IRQ_PIN] = PORT_PCR_MUX(1);
GPIOB->PDDR &= ~(1 << KW2XDRF_IRQ_PIN);
/* release the reset */
GPIOB->PSOR |= (1 << 19);
/* wait for modem IRQ_B interrupt request */
while (GPIOB->PDIR & (1 << KW2XDRF_IRQ_PIN));
}
/**
* @brief Configure the controllers clock system
*/
static void cpu_clock_init(void)
{
/* setup system prescalers */
SIM->CLKDIV1 = (uint32_t)SIM_CLKDIV1_OUTDIV4(1);
modem_clock_init();
kinetis_mcg_set_mode(KINETIS_MCG_PEE);
}