/******************************************************************************
Copyright 2009, Freie Universitaet Berlin (FUB). All rights reserved.

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and Telematics group (http://cst.mi.fu-berlin.de).
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

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*******************************************************************************/

/**
 * @ingroup		lpc2387
 * @addtogroup	dev_gpioint
 * @{
 */

/**
 * @file
 * @brief		LPC2387 GPIO Interrupt Multiplexer implementation
 *
 * @author      Freie Universität Berlin, Computer Systems & Telematics, FeuerWhere project
 * @author		Michael Baar <michael.baar@fu-berlin.de>
 * @version     $Revision: 1508 $
 *
 * @note    	$Id: lpc2387-gpioint.c 1508 2009-10-26 15:10:02Z baar $
 * @see			dev_gpioint
 */

#include <stdio.h>
#include "lpc2387.h"
#include "gpioint.h"
#include "cpu.h"
#include <irq.h>

struct irq_callback {
	fp_irqcb	callback;
};

static struct irq_callback gpioint0[32];
static struct irq_callback gpioint2[32];


void gpioint_init(void) {
    extern void GPIO_IRQHandler(void);

   /* GPIO Init */
    INTWAKE |= GPIO0WAKE | GPIO2WAKE;                       // allow GPIO to wake up from power down
    install_irq(GPIO_INT, &GPIO_IRQHandler, IRQP_GPIO);     // install irq handler
}

/*---------------------------------------------------------------------------*/
bool
gpioint_set(int port, uint32_t bitmask, int flags, fp_irqcb callback)
{
	struct irq_callback*	cbdata;
	unsigned long bit;
	volatile unsigned long* en_f;
	volatile unsigned long* en_r;
	volatile unsigned long* en_clr;

	/* lookup registers */
	bit = number_of_highest_bit(bitmask);						// get irq mapping table index

	switch( port ) {
		case 0:													// PORT0
			cbdata = gpioint0;
			en_f = &IO0_INT_EN_F;
			en_r = &IO0_INT_EN_R;
			en_clr = &IO0_INT_CLR;
			break;

		case 2:													// PORT2
			cbdata = gpioint2;
			en_f = &IO2_INT_EN_F;
			en_r = &IO2_INT_EN_R;
			en_clr = &IO2_INT_CLR;
			break;

		default:												// unsupported
			return false;										// fail
	}

	/* reconfigure irq */
	unsigned long cpsr = disableIRQ();
	*en_clr |= bitmask; 										// clear interrupt

	if( (flags & GPIOINT_FALLING_EDGE) != 0 ) {
		*en_f |= bitmask; 										// enable falling edge
	} else {
		*en_f &= ~bitmask; 										// disable falling edge
	}

	if( (flags & GPIOINT_RISING_EDGE) != 0 ) {
		*en_r |= bitmask; 										// enable rising edge
	} else {
		*en_r &= ~bitmask; 										// disable rising edge
	}

	if( ((flags & (GPIOINT_FALLING_EDGE | GPIOINT_RISING_EDGE)) != 0) ) {
		cbdata[bit].callback = callback;

	} else {
		cbdata[bit].callback = NULL;							// remove from interrupt mapping table
	}
	restoreIRQ(cpsr);

	return true;												// success
}
/*---------------------------------------------------------------------------*/
static void test_irq(int port, unsigned long f_mask, unsigned long r_mask, struct irq_callback* pcb)
{
	/* Test each bit of rising and falling masks, if set trigger interrupt
	 * on corresponding device */
	do {
		if( (pcb->callback != NULL)  ) {
			if ((r_mask & 1) | (f_mask & 1)) {
				pcb->callback();			// pass to handler
			}
		}

		f_mask >>= 1UL;
		r_mask >>= 1UL;
		pcb++;
	} while( (f_mask != 0) || (r_mask != 0) );
}
/*---------------------------------------------------------------------------*/
void GPIO_IRQHandler(void) __attribute__((interrupt("IRQ")));
/**
 * @brief	GPIO Interrupt handler function
 * @internal
 *
 * Invoked whenever an activated gpio interrupt is triggered by a rising
 * or falling edge.
 */
void GPIO_IRQHandler(void) {
	if( IO_INT_STAT & BIT0 ) {										// interrupt(s) on PORT0 pending
		unsigned long int_stat_f = IO0_INT_STAT_F;					// save content
		unsigned long int_stat_r = IO0_INT_STAT_R;					// save content

		IO0_INT_CLR = int_stat_f;									// clear flags of fallen pins
		IO0_INT_CLR = int_stat_r;									// clear flags of risen pins

		test_irq(0, int_stat_f, int_stat_r, gpioint0);
	}

	if( IO_INT_STAT & BIT2 ) {										// interrupt(s) on PORT2 pending
		unsigned long int_stat_f = IO2_INT_STAT_F;					// save content
		unsigned long int_stat_r = IO2_INT_STAT_R;					// save content

		IO2_INT_CLR = int_stat_f;									// clear flags of fallen pins
		IO2_INT_CLR = int_stat_r;									// clear flags of risen pins

		test_irq(2, int_stat_f, int_stat_r, gpioint2);
	}
	VICVectAddr = 0;												// Acknowledge Interrupt
}
/*---------------------------------------------------------------------------*/
/** @} */