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/* ----------------------------------------------------------------------------
* ATMEL Microcontroller Software Support
* ----------------------------------------------------------------------------
* Copyright (c) 2009, Atmel Corporation
*
* 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 disclaimer below.
*
* Atmel's name may not be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
* DISCLAIMED. IN NO EVENT SHALL ATMEL 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.
* ----------------------------------------------------------------------------
*/
/**
* \file
*
* Provides the low-level initialization function that called on chip startup.
*/
/*----------------------------------------------------------------------------
* Headers
*----------------------------------------------------------------------------*/
#include "board.h"
/*----------------------------------------------------------------------------
* Local definitions
*----------------------------------------------------------------------------*/
#define BOARD_OSCOUNT (CKGR_MOR_MOSCXTST(0x8))
#define BOARD_MCKR (PMC_MCKR_PRES_CLK | PMC_MCKR_CSS_PLLA_CLK)
#if (BOARD_MCK == 48000000)
#if (BOARD_MAINOSC == 18432000)
/* Clock settings at 48MHz for 18 MHz crystal */
#define BOARD_PLLAR (CKGR_PLLAR_STUCKTO1 \
| CKGR_PLLAR_MULA(13-1) \
| CKGR_PLLAR_PLLACOUNT(0x1) \
| CKGR_PLLAR_DIVA(5))
#elif (BOARD_MAINOSC == 12000000)
/* QMod has 12 MHz clock, so multply by 8 (96 MHz) and divide by 2 */
#define BOARD_PLLAR (CKGR_PLLAR_STUCKTO1 \
| CKGR_PLLAR_MULA(8-1) \
| CKGR_PLLAR_PLLACOUNT(0x1) \
| CKGR_PLLAR_DIVA(2))
#else
#error "Please define PLLA config for your MAINOSC frequency"
#endif /* MAINOSC */
#elif (BOARD_MCK == 64000000)
#if (BOARD_MAINOSC == 18432000)
/* Clock settings at 64MHz for 18 MHz crystal: 64.512 MHz */
#define BOARD_PLLAR (CKGR_PLLAR_STUCKTO1 \
| CKGR_PLLAR_MULA(7-1) \
| CKGR_PLLAR_PLLACOUNT(0x1) \
| CKGR_PLLAR_DIVA(2))
#elif (BOARD_MAINOSC == 12000000)
/* QMod has 12 MHz clock, so multply by 10 / div by 2: 60 MHz */
#define BOARD_PLLAR (CKGR_PLLAR_STUCKTO1 \
| CKGR_PLLAR_MULA(10-1) \
| CKGR_PLLAR_PLLACOUNT(0x1) \
| CKGR_PLLAR_DIVA(2))
#error "Please define PLLA config for your MAINOSC frequency"
#endif /* MAINOSC */
#else
#error "No PLL settings for current BOARD_MCK."
#endif
#if (BOARD_MAINOSC == 12000000)
#define PLLB_CFG (CKGR_PLLBR_DIVB(2)|CKGR_PLLBR_MULB(8-1)|CKGR_PLLBR_PLLBCOUNT_Msk)
#elif (BOARD_MAINOSC == 18432000)
#define PLLB_CFG (CKGR_PLLBR_DIVB(5)|CKGR_PLLBR_MULB(13-1)|CKGR_PLLBR_PLLBCOUNT_Msk)
#else
#error "Please configure PLLB for your MAINOSC freq"
#endif
/* Define clock timeout */
#define CLOCK_TIMEOUT 0xFFFFFFFF
/**
* \brief Configure 48MHz Clock for USB
*/
static void _ConfigureUsbClock(void)
{
/* Enable PLLB for USB */
PMC->CKGR_PLLBR = PLLB_CFG;
while ((PMC->PMC_SR & PMC_SR_LOCKB) == 0) ;
/* USB Clock uses PLLB */
PMC->PMC_USB = PMC_USB_USBDIV(0) /* /1 (no divider) */
| PMC_USB_USBS; /* PLLB */
}
/*----------------------------------------------------------------------------
* Exported functions
*----------------------------------------------------------------------------*/
/**
* \brief Performs the low-level initialization of the chip.
* This includes EFC and master clock configuration.
* It also enable a low level on the pin NRST triggers a user reset.
*/
extern WEAK void LowLevelInit( void )
{
uint32_t timeout = 0;
/* Configure the Supply Monitor to reset the CPU in case VDDIO is
* lower than 3.0V. As we run the board on 3.3V, any lower voltage
* might be some kind of leakage that creeps in some way, but is not
* the "official" power supply */
SUPC->SUPC_SMMR = SUPC_SMMR_SMTH_3_0V | SUPC_SMMR_SMSMPL_CSM |
SUPC_SMMR_SMRSTEN_ENABLE;
/* enable both LED and green LED */
PIOA->PIO_PER |= PIO_LED_RED | PIO_LED_GREEN;
PIOA->PIO_OER |= PIO_LED_RED | PIO_LED_GREEN;
PIOA->PIO_CODR |= PIO_LED_RED | PIO_LED_GREEN;
/* Set 3 FWS for Embedded Flash Access */
EFC->EEFC_FMR = EEFC_FMR_FWS(3);
/* Select external slow clock */
/* if ((SUPC->SUPC_SR & SUPC_SR_OSCSEL) != SUPC_SR_OSCSEL_CRYST)
{
SUPC->SUPC_CR = (uint32_t)(SUPC_CR_XTALSEL_CRYSTAL_SEL | SUPC_CR_KEY(0xA5));
timeout = 0;
while (!(SUPC->SUPC_SR & SUPC_SR_OSCSEL_CRYST) );
}
*/
#ifndef qmod
/* Initialize main oscillator */
if ( !(PMC->CKGR_MOR & CKGR_MOR_MOSCSEL) )
{
PMC->CKGR_MOR = CKGR_MOR_KEY(0x37) | BOARD_OSCOUNT | CKGR_MOR_MOSCRCEN | CKGR_MOR_MOSCXTEN;
timeout = 0;
while (!(PMC->PMC_SR & PMC_SR_MOSCXTS) && (timeout++ < CLOCK_TIMEOUT));
}
/* Switch to 3-20MHz Xtal oscillator */
PIOB->PIO_PDR = (1 << 8) | (1 << 9);
PIOB->PIO_PUDR = (1 << 8) | (1 << 9);
PIOB->PIO_PPDDR = (1 << 8) | (1 << 9);
PMC->CKGR_MOR = CKGR_MOR_KEY(0x37) | BOARD_OSCOUNT | CKGR_MOR_MOSCRCEN | CKGR_MOR_MOSCXTEN | CKGR_MOR_MOSCSEL;
/* wait for Main XTAL oscillator stabilization */
timeout = 0;
while (!(PMC->PMC_SR & PMC_SR_MOSCSELS) && (timeout++ < CLOCK_TIMEOUT));
#else
/* QMOD has external 12MHz clock source */
PIOB->PIO_PDR = (1 << 9);
PIOB->PIO_PUDR = (1 << 9);
PIOB->PIO_PPDDR = (1 << 9);
PMC->CKGR_MOR = CKGR_MOR_KEY(0x37) | CKGR_MOR_MOSCRCEN | CKGR_MOR_MOSCXTBY| CKGR_MOR_MOSCSEL;
#endif
/* disable the red LED after main clock initialization */
PIOA->PIO_SODR = PIO_LED_RED;
/* "switch" to main clock as master clock source (should already be the case */
PMC->PMC_MCKR = (PMC->PMC_MCKR & ~(uint32_t)PMC_MCKR_CSS_Msk) | PMC_MCKR_CSS_MAIN_CLK;
/* wait for master clock to be ready */
for ( timeout = 0; !(PMC->PMC_SR & PMC_SR_MCKRDY) && (timeout++ < CLOCK_TIMEOUT) ; );
/* Initialize PLLA */
PMC->CKGR_PLLAR = BOARD_PLLAR;
/* Wait for PLLA to lock */
timeout = 0;
while (!(PMC->PMC_SR & PMC_SR_LOCKA) && (timeout++ < CLOCK_TIMEOUT));
/* Switch to main clock (again ?!?) */
PMC->PMC_MCKR = (BOARD_MCKR & ~PMC_MCKR_CSS_Msk) | PMC_MCKR_CSS_MAIN_CLK;
/* wait for master clock to be ready */
for ( timeout = 0; !(PMC->PMC_SR & PMC_SR_MCKRDY) && (timeout++ < CLOCK_TIMEOUT) ; );
/* switch to PLLA as master clock source */
PMC->PMC_MCKR = BOARD_MCKR ;
/* wait for master clock to be ready */
for ( timeout = 0; !(PMC->PMC_SR & PMC_SR_MCKRDY) && (timeout++ < CLOCK_TIMEOUT) ; );
/* Configure SysTick for 1ms */
SysTick_Config(BOARD_MCK/1000);
_ConfigureUsbClock();
}
/* SysTick based delay function */
volatile uint32_t jiffies;
/* Interrupt handler for SysTick interrupt */
void SysTick_Handler(void)
{
jiffies++;
}
void mdelay(unsigned int msecs)
{
uint32_t jiffies_start = jiffies;
do {
} while ((jiffies - jiffies_start) < msecs);
}
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