/***************************************************************************
 *   sam7fc - System Interrupt Dispatcher                                  *
 *                                                                         *
 *   Copyright (C) 01/2008 by Olaf Rempel                                  *
 *   razzor@kopf-tisch.de                                                  *
 *                                                                         *
 *   This program 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; version 2 of the License                *
 *                                                                         *
 *   This program 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, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#include "AT91SAM7S256.h"
#include "at91_sysc.h"
#include "board.h"

static SYSCISR *sysc_isrs[AT91_SYSIRQ_COUNT];

struct _irq_regs {
	AT91_REG *mask_register;
	uint32_t mask;
	AT91_REG *status_register;
	uint32_t status;
};

/* same IDs as sysc_isrs enum! */
static const struct _irq_regs irq_regs[] = {
	/*
	 * PIT (Periodic Intervall Timer)
	 * ISR must read AT91C_PITC_PIVR to clear interrupt
	 * - PITIEN (Periodic Intervall Timer Interrupt Enable)
	 */
	{	AT91C_PITC_PIMR, AT91C_PITC_PITIEN,
		AT91C_PITC_PISR, AT91C_PITC_PITS
	},

	/*
	 * DBGU (Debug Unit)
	 * TODO: must use AT91C_DBGU_IDR to fault disable interrupt
	 * - 12 Interrupt sources
	 */
	{	AT91C_DBGU_IMR, (AT91C_US_RXRDY | AT91C_US_TXRDY |
				AT91C_US_ENDRX | AT91C_US_ENDTX |
				AT91C_US_OVRE | AT91C_US_FRAME |
				AT91C_US_PARE | AT91C_US_TXEMPTY |
				AT91C_US_TXBUFE | AT91C_US_RXBUFF |
				AT91C_US_COMM_TX | AT91C_US_COMM_RX),
		AT91C_DBGU_CSR, (AT91C_US_RXRDY | AT91C_US_TXRDY |
				AT91C_US_ENDRX | AT91C_US_ENDTX |
				AT91C_US_OVRE | AT91C_US_FRAME |
				AT91C_US_PARE | AT91C_US_TXEMPTY |
				AT91C_US_TXBUFE | AT91C_US_RXBUFF |
				AT91C_US_COMM_TX | AT91C_US_COMM_RX)
	},

	/*
	 * EFC (Embedded Flash Controller / Memory Controller)
	 */
	{	AT91C_MC_FMR, (AT91C_MC_FRDY | AT91C_MC_LOCKE | AT91C_MC_PROGE),
		AT91C_MC_FSR, (AT91C_MC_FRDY | AT91C_MC_LOCKE | AT91C_MC_PROGE)
	},

	/*
	 * WDT (Watchdog Timer)
	 * WDMR can be written only once (no fault disable)
	 * - WDFIEN (Watchdog Fault Interrupt Enable)
	 */
	{	AT91C_WDTC_WDMR, AT91C_WDTC_WDFIEN,
		AT91C_WDTC_WDSR, (AT91C_WDTC_WDUNF | AT91C_WDTC_WDERR)
	},

	/*
	 * RTT (Real-Time Timer)
	 * Interrupts must be disabled during ISR?!
	 * - ALMIEN (Alarm Interrupt Enable)
	 * - RTTCINCIEN (Real-Time Timer Increment Interrupt Enable)
	 */
	{	AT91C_RTTC_RTMR, (AT91C_RTTC_ALMIEN | AT91C_RTTC_RTTINCIEN),
		AT91C_RTTC_RTSR, (AT91C_RTTC_ALMS | AT91C_RTTC_RTTINC)
	},

	/*
	 * RSTC (Reset Controller)
	 * - AT91C_RSTC_URSTIEN (User Reset Interrupt Enable)
	 * - AT91C_RSTC_BODIEN (Brownout Detection Interrupt Enable)
	 */
	{	AT91C_RSTC_RMR, (AT91C_RSTC_URSTIEN | AT91C_RSTC_BODIEN),
		AT91C_RSTC_RSR, (AT91C_RSTC_URSTS | AT91C_RSTC_BODSTS)
	},

	/*
	 * PMC (Power Managment Controller)
	 * TODO: must use AT91C_PMC_IDR to fault disable interrupt
	 * - 6 Interrupt sources
	 */
	{	AT91C_PMC_IMR, (AT91C_PMC_MOSCS | AT91C_PMC_LOCK |
				AT91C_PMC_MCKRDY | AT91C_PMC_PCK0RDY |
				AT91C_PMC_PCK1RDY | AT91C_PMC_PCK2RDY),
		AT91C_PMC_SR, (AT91C_PMC_MOSCS | AT91C_PMC_LOCK |
				AT91C_PMC_MCKRDY | AT91C_PMC_PCK0RDY |
				AT91C_PMC_PCK1RDY | AT91C_PMC_PCK2RDY)
	},
};

/* check Interrupts from internal hardware */
static void at91_sysc_isr(void)
{
	uint32_t id;
	for (id = 0; id < AT91_SYSIRQ_COUNT; id++) {

		/* check if interrups are enabled */
		if (*(irq_regs[id].mask_register) & irq_regs[id].mask) {

			/* check if interrupts are active */
			uint32_t status = *(irq_regs[id].status_register);
			if (status & irq_regs[id].status) {

				/* execute handler */
				if (sysc_isrs[id]) {
					sysc_isrs[id](status);

				} else {
					/* disable interrupts */
					*(irq_regs[id].mask_register) &= ~irq_regs[id].mask;
				}
			}
		}
	}
}

void at91_sysc_init(void)
{
	/* high priority, level triggered, own vector */
	AT91S_AIC *aic = AT91C_BASE_AIC;
	aic->AIC_SMR[AT91C_ID_SYS] = IRQPRIO_SYSC |
				     AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL;

	aic->AIC_SVR[AT91C_ID_SYS] = (uint32_t)at91_sysc_isr;
	aic->AIC_IECR = (1<<AT91C_ID_SYS);
}

void sysc_register_isr(enum syscirqs irq, SYSCISR *isr)
{
	if (irq >= AT91_SYSIRQ_COUNT)
		return;

	sysc_isrs[irq] = isr;
}