akutest.c

#include <stdio.h>
#include <stdlib.h>

#include <proto/exec.h>

#include <exec/types.h>
#include <exec/memory.h>
#include <exec/interrupts.h>

#include <hardware/intbits.h>

#define CLOCKPORT_BASE		0xD80001
#define CLOCKPORT_STRIDE	4

#define I2CSTA			0
#define I2CTO			0
#define I2CDAT			2
#define I2CADR			1
#define I2CCON			3

#define I2CCON_CR0		(1 << 0)
#define I2CCON_CR1		(1 << 1)
#define I2CCON_CR2		(1 << 2)
#define I2CCON_CR_88KHZ		(0x4)
#define I2CCON_CR_59KHZ		(0x5)
#define I2CCON_CR_MASK		(0x7)
#define I2CCON_SI		(1 << 3)
#define I2CCON_STO		(1 << 4)
#define I2CCON_STA		(1 << 5)
#define I2CCON_ENSIO		(1 << 6)
#define I2CCON_AA		(1 << 7)

#pragma dontwarn 113

UBYTE clockport_read(UBYTE reg);
void clockport_write(UBYTE reg, UBYTE val);
void pca9564_isr(void);

static UBYTE *cp = CLOCKPORT_BASE;
static const BOOL debug = TRUE;
static int inttest = 0;

UBYTE
clockport_read(UBYTE reg) 
{
	UBYTE v;
	UBYTE *ptr;

	ptr = cp + (reg * CLOCKPORT_STRIDE);
	v = *ptr;
	if (debug)
		printf("DEBUG: read %x from %p\n", (int) v, (void*) ptr);

	return v;
}

void
clockport_write(UBYTE reg, UBYTE value)
{
	UBYTE *ptr;

	ptr = cp + (reg * CLOCKPORT_STRIDE);
	if (debug)
		printf("DEBUG: write %x to %p\n", (int) value, (void*) ptr);
	*ptr = value;
}

int main(void)
{
	struct Interrupt *int6;
	UBYTE ctrl;
	UBYTE void_data;

	if (int6 = AllocMem(sizeof(struct Interrupt), MEMF_PUBLIC|MEMF_CLEAR)) {
		int6->is_Node.ln_Type = NT_INTERRUPT;
		int6->is_Node.ln_Pri = -60;
		int6->is_Node.ln_Name = "PCA9564";
		int6->is_Data = (APTR)&void_data;
		int6->is_Code = pca9564_isr;

		AddIntServer(INTB_EXTER, int6); 
	} else {
		printf("Can't allocate memory for interrupt node\n");
		return 1;
	}

	ctrl = I2CCON_CR_59KHZ | I2CCON_ENSIO;

	clockport_write(I2CCON, ctrl);
	Delay(50);
	printf("gonna send start\n");

	ctrl |= I2CCON_STA;
	clockport_write(I2CCON, ctrl);	/* send START condition */

	/* Wait for signal here */
	/* then do things... */

	Delay(50);
	ctrl = clockport_read(I2CCON);
	printf("I2CCON is now: %x\n", ctrl);

	RemIntServer(INTB_EXTER, int6);
	FreeMem(int6, sizeof(struct Interrupt));

	printf("ISR was called %d times\n", inttest);
    
    return 0;
}

/* Interrupt service routine. */
void
pca9564_isr(void) 
{
	UBYTE *conptr;

	/*
	 * so lame,
 	 * instead, acknowledge hw interrupt here, then signal the main program,
	 * continue there
         */
	conptr = cp + (I2CCON * CLOCKPORT_STRIDE);
	*conptr = 0;

	inttest++; 
}