newoswan/source/peripherals/interrupt_controller.c

103 lines
2.4 KiB
C

/*******************************************************************************
* NewOswan
* interrupt_controller.c:
*
* Created by mlt on 14/03/2022.
* Copyright (c) 2022 986-Studio. All rights reserved.
*
******************************************************************************/
#include <stdio.h>
#include <stdint.h>
#include <device.h>
#include <io.h>
#include <interrupt_controller.h>
/* device internal parameters */
typedef struct ic_params_t
{
uint8_t address_base;
uint8_t int_enable_mask;
uint8_t int_status;
} ic_params_t;
static ic_params_t interrupt_controller;
static uint8_t IC_IO_read(void *pdata, uint8_t port)
{
ic_params_t *params = (ic_params_t *)pdata;
switch(port)
{
case 0xB0: return params->address_base;
case 0xB2: return params->int_enable_mask;
case 0xB4: return params->int_status;
}
return 0x00;
}
static void IC_IO_write(void *pdata, uint8_t port, uint8_t value)
{
ic_params_t *params = (ic_params_t *)pdata;
switch(port)
{
case 0xB0: params->address_base = value; break;
case 0xB2: params->int_enable_mask = value; break;
}
}
static void IC_IO_write_ack(void *pdata, uint8_t port, uint8_t value)
{
ic_params_t *params = (ic_params_t *)pdata;
// De-assert CPU interrupt accordingly to the mask in value
}
static void IC_init(void *params)
{
UNUSED_PARAMETER(params);
register_io_hook(0xB0, IC_IO_read, IC_IO_write, &interrupt_controller);
register_io_hook(0xB2, IC_IO_read, IC_IO_write, &interrupt_controller);
register_io_hook(0xB4, IC_IO_read, NULL, &interrupt_controller);
register_io_hook(0xB6, NULL, IC_IO_write_ack, &interrupt_controller);
}
static void IC_reset()
{
interrupt_controller.int_enable_mask = 0;
interrupt_controller.address_base = 0;
}
static void IC_free()
{
}
device_t InterruptController =
{
.init = IC_init,
.reset = IC_reset,
.free = IC_free,
.deviceType = DT_INTERRUPT_CONTROLLER,
};
/* Exported functions */
void trigger_interrupt(hw_interrupt_type_t type)
{
uint16_t int_vector = interrupt_controller.address_base & 0xF8 + (uint8_t)type;
/* Check that the INT is enabled */
if ((interrupt_controller.int_enable_mask >> type) & 0x1)
{
/* TODO: Do we have to enable that even if the int is not enabled? */
interrupt_controller.int_status |= (1 << type);
// Fire the NEC interrupt
}
}