Add a skeleton for the interrupt controller

2022-06-27 17:04:55 +01:00
parent d6a2a77303
commit 37e4b219d4
2 changed files with 135 additions and 0 deletions
--- a/source/peripherals/interrupt_controller.c
+++ b/source/peripherals/interrupt_controller.c
@@ -0,0 +1,103 @@
+/*******************************************************************************
+ * 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
+
+    }
+}