/* ---------------------------------------------------------------------------- * ATMEL Microcontroller Software Support * ---------------------------------------------------------------------------- * Copyright (c) 2009, Atmel Corporation * Copyright (c) 2018, sysmocom -s.f.m.c. GmbH, Author: Kevin Redon * * 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) /** configure PLL to generate main clock based on main oscillator frequency */ #if (BOARD_MAINOSC == 12000000) && (BOARD_MCK == 48000000) #define BOARD_PLLAR (CKGR_PLLAR_STUCKTO1 \ | CKGR_PLLAR_MULA(8-1) \ | CKGR_PLLAR_PLLACOUNT(0x1) \ | CKGR_PLLAR_DIVA(2)) #elif (BOARD_MAINOSC == 12000000) && (BOARD_MCK == 58000000) #define BOARD_PLLAR (CKGR_PLLAR_STUCKTO1 \ | CKGR_PLLAR_MULA(29-1) \ | CKGR_PLLAR_PLLACOUNT(0x1) \ | CKGR_PLLAR_DIVA(6)) #elif (BOARD_MAINOSC == 12000000) && (BOARD_MCK == 60000000) #define BOARD_PLLAR (CKGR_PLLAR_STUCKTO1 \ | CKGR_PLLAR_MULA(10-1) \ | CKGR_PLLAR_PLLACOUNT(0x1) \ | CKGR_PLLAR_DIVA(2)) #elif (BOARD_MAINOSC == 18432000) && (BOARD_MCK == 47923200) #define BOARD_PLLAR (CKGR_PLLAR_STUCKTO1 \ | CKGR_PLLAR_MULA(13-1) \ | CKGR_PLLAR_PLLACOUNT(0x1) \ | CKGR_PLLAR_DIVA(5)) #elif (BOARD_MAINOSC == 18432000) && (BOARD_MCK == 58982400) #define BOARD_PLLAR (CKGR_PLLAR_STUCKTO1 \ | CKGR_PLLAR_MULA(16-1) \ | CKGR_PLLAR_PLLACOUNT(0x1) \ | CKGR_PLLAR_DIVA(5)) #elif (BOARD_MAINOSC == 18432000) && (BOARD_MCK == 64512000) #define BOARD_PLLAR (CKGR_PLLAR_STUCKTO1 \ | CKGR_PLLAR_MULA(7-1) \ | CKGR_PLLAR_PLLACOUNT(0x1) \ | CKGR_PLLAR_DIVA(2)) #else #error "Please define PLLA config for your BOARD_MCK/MAINOSC frequency" #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; /* disable ERASE pin to prevent accidental flash erase */ MATRIX->CCFG_SYSIO |= CCFG_SYSIO_SYSIO12; /* 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 BOARD_MAINOSC_BYPASS /* 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 /* Board has external clock, not a crystal oscillator */ 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); } void abort() { NVIC_SystemReset(); while(1) {}; }