Espresso 0.0.2c

files/irq.c

@@ -0,0 +1,69 @@
+#include <stdio.h>
+#include <drivers/ps2_keyboard.h>
+#include <drivers/pit.h>
+#include <port_io.h>
+
+#include <drivers/irq.h>
+
+#define MAX_IRQ_HANDLERS 128 /* the maximum number of irq handlers */
+
+
+typedef struct {
+  uint32_t irq_no;
+  irq_func_t func;
+} irq_handler_t;
+
+uint32_t      num_irq_handlers = 0;
+irq_handler_t handler_list[MAX_IRQ_HANDLERS];
+
+static volatile uint32_t num_irqs_missed = 0;
+
+void irq_init(void)
+{
+  for (int i = 0; i < MAX_IRQ_HANDLERS; i++)
+  {
+    handler_list[i].irq_no = 0;
+    handler_list[i].func   = NULL;
+  }
+  set_irq_handler(0, (irq_func_t) pit_handler);
+  set_irq_handler(1, (irq_func_t) ps2_keyboard_handler);
+}
+
+void irq_handler(uint32_t irq, registers_t* regs)
+{
+  uint8_t funcs_called = 0;
+
+  if (num_irq_handlers > 0)
+  {  
+    for (unsigned int i = 0; i < num_irq_handlers; i++)
+    {
+      if (handler_list[i].irq_no == irq && handler_list[i].func != NULL)
+      {
+        handler_list[i].func(regs);
+        funcs_called++;
+        /* PIC IRQ acknowledgement happens in idt.c */
+      }
+    }
+  }
+  
+  if (funcs_called == 0)
+  {
+    num_irqs_missed++;
+  }
+}
+
+uint32_t get_interrupts_missed(void)
+{
+  return num_irqs_missed;
+}
+
+void set_irq_handler(uint32_t num, irq_func_t handler)
+{
+  if (num < MAX_IRQ_HANDLERS)
+  {
+    handler_list[num].irq_no = num;
+    handler_list[num].func   = handler;
+    
+    num_irq_handlers++;
+  }
+}