ChibiOS/demos/ARM7-AT91SAM7X-GCC/board.c

87 lines
2.5 KiB
C

/*
ChibiOS/RT - Copyright (C) 2006-2007 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/RT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <ch.h>
#include "at91lib/AT91SAM7X256.h"
extern void FiqHandler(void);
__attribute__((interrupt("IRQ")))
static void SpuriousHandler(void) {
AT91C_BASE_AIC->AIC_EOICR = (AT91_REG)AT91C_BASE_AIC;
}
void hwinit(void) {
int i;
AT91PS_PMC pmcp = AT91C_BASE_PMC;
AT91PS_AIC aicp = AT91C_BASE_AIC;
/*
* Flash Memory: 1 wait state, about 50 cycles in a microsecond.
*/
AT91C_BASE_MC->MC_FMR = (AT91C_MC_FMCN & (50 << 16)) | AT91C_MC_FWS_1FWS;
/*
* Watchdog disabled.
*/
AT91C_BASE_WDTC->WDTC_WDMR = AT91C_WDTC_WDDIS;
/*
* Enables the main oscillator and waits 56 slow cycles as startup time.
*/
pmcp->PMC_MOR = (AT91C_CKGR_OSCOUNT & (7 << 8)) | AT91C_CKGR_MOSCEN;
while (!(pmcp->PMC_SR & AT91C_PMC_MOSCS))
;
/*
* PLL setup: DIV = 14, MUL = 72, PLLCOUNT = 10
* PLLfreq = 96109714 Hz (rounded)
*/
pmcp->PMC_PLLR = (AT91C_CKGR_DIV & 14) |
(AT91C_CKGR_PLLCOUNT & (10 << 8)) |
(AT91C_CKGR_MUL & (72 << 16));
while (!(pmcp->PMC_SR & (AT91C_PMC_LOCK)))
;
/*
* Master clock = PLLfreq / 2 = 48054858 Hz (rounded)
*/
pmcp->PMC_MCKR = AT91C_PMC_CSS_PLL_CLK | AT91C_PMC_PRES_CLK_2;
while (!(pmcp->PMC_SR & (AT91C_PMC_MCKRDY)))
;
/*
* Default AIC setup, the device drivers will modify it as needed.
*/
aicp->AIC_SVR[0] = (AT91_REG)FiqHandler;
for (i = 1; i < 31; i++) {
aicp->AIC_SVR[i] = (AT91_REG)NULL;
aicp->AIC_EOICR = (AT91_REG)i;
}
aicp->AIC_SPU = (AT91_REG)SpuriousHandler;
/*
* I/O setup, enable clocks, initially all pins are inputs with pullups.
*/
pmcp->PMC_PCER = (1 << AT91C_ID_PIOA) | (1 << AT91C_ID_PIOB);
AT91C_BASE_PIOA->PIO_PER = 0xFFFFFFFF;
}