Cleanup handling of interrupt controller (PIC).

[seabios.git] / src / pic.h

diff --git a/src/pic.h b/src/pic.h
new file mode 100644 (file)
index 0000000..0eb70ee
--- /dev/null
+++ b/src/pic.h
@@ -0,0 +1,77 @@
+// Helpers for working with i8259 interrupt controller.
+//
+// Copyright (C) 2008  Kevin O'Connor <kevin@koconnor.net>
+// Copyright (C) 2002  MandrakeSoft S.A.
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
+#include "ioport.h" // PORT_PIC*
+#include "util.h" // dprintf
+
+// PORT_PIC1 bitdefs
+#define PIC1_IRQ0  (1<<0)
+#define PIC1_IRQ1  (1<<1)
+#define PIC1_IRQ2  (1<<2)
+#define PIC1_IRQ5  (1<<5)
+#define PIC1_IRQ6  (1<<6)
+// PORT_PIC2 bitdefs
+#define PIC2_IRQ8  (1<<0)
+#define PIC2_IRQ12 (1<<4)
+#define PIC2_IRQ13 (1<<5)
+#define PIC2_IRQ14 (1<<6)
+
+static inline void
+eoi_pic1()
+{
+    // Send eoi (select OCW2 + eoi)
+    outb(0x20, PORT_PIC1_CMD);
+}
+
+static inline void
+eoi_pic2()
+{
+    // Send eoi (select OCW2 + eoi)
+    outb(0x20, PORT_PIC2_CMD);
+    eoi_pic1();
+}
+
+static inline void
+unmask_pic1(u8 irq)
+{
+    outb(inb(PORT_PIC1_DATA) & ~irq, PORT_PIC1_DATA);
+}
+
+static inline void
+unmask_pic2(u8 irq)
+{
+    outb(inb(PORT_PIC2_DATA) & ~irq, PORT_PIC2_DATA);
+}
+
+static inline u8
+get_pic1_isr()
+{
+    // 0x0b == select OCW1 + read ISR
+    outb(0x0b, PORT_PIC1_CMD);
+    return inb(PORT_PIC1_CMD);
+}
+
+static inline void
+pic_setup()
+{
+    dprintf(3, "init pic\n");
+    // Send ICW1 (select OCW1 + will send ICW4)
+    outb(0x11, PORT_PIC1_CMD);
+    outb(0x11, PORT_PIC2_CMD);
+    // Send ICW2 (base irqs: 0x08-0x0f for irq0-7, 0x70-0x78 for irq8-15)
+    outb(0x08, PORT_PIC1_DATA);
+    outb(0x70, PORT_PIC2_DATA);
+    // Send ICW3 (cascaded pic ids)
+    outb(0x04, PORT_PIC1_DATA);
+    outb(0x02, PORT_PIC2_DATA);
+    // Send ICW4 (enable 8086 mode)
+    outb(0x01, PORT_PIC1_DATA);
+    outb(0x01, PORT_PIC2_DATA);
+    // Mask all irqs (except cascaded PIC2 irq)
+    outb(~PIC1_IRQ2, PORT_PIC1_DATA);
+    outb(~0, PORT_PIC2_DATA);
+}