#include "7seg.h"

#include <stdio.h>

static device_vtable_t const seg7_vtable = {
	seg7_read,
	seg7_write,
	seg7_deinit
};

void seg7_init( seg7_t *seg, uint16_t addr, bool initialize )
{
	device_init( &seg->base, "seg7" );
	seg->base.vtable = (device_vtable_t *)&seg7_vtable;

	seg->addr = addr;
	seg->debug = false;
	
	if( initialize ) {
		seg->latch = 0x0000;
		seg->shift = 0x0000;
	}
}

uint8_t seg7_read( void *obj, uint16_t addr )
{
	return 0;
}

void seg7_write( void *obj, uint16_t addr, uint8_t data )
{
	seg7_t *seg = (seg7_t *)obj;
	
	switch( addr - seg->addr ) {
		case DDRA:
			seg->ddr = data;
			break;
		
		case PORTA:
			// write bits from SER into shift register on positive SRCLK
			if( ( seg->ddr | ( SRCLK & SER ) ) && ( data & SRCLK ) ) {
				seg->shift = ( seg->shift << 1 ) | ( data & SER );
				if( seg->debug ) {
					fprintf( stderr, "7seg shifting data, data is now %02X\n", seg->shift );
				}
			}
			
			// copy shift to latch register on positive RCLK
			if( ( seg->ddr | RCLK ) && ( data & RCLK ) ) {
				seg->latch = seg->shift;
				if( seg->debug ) {
					fprintf( stderr, "7seg copying %02X from shift to latch\n", seg->latch );
				}
			}
			
			break;
		
		// ignore writes to other addresses
	}
}

void seg7_deinit( void *obj )
{
	seg7_t *seg = (seg7_t *)obj;

	device_deinit( &seg->base );
}