1 files changed, 132 insertions, 0 deletions
diff --git a/arch/i386/lib/pcat_interrupts.c b/arch/i386/lib/pcat_interrupts.c
new file mode 100644
index 0000000..67e6e97
--- /dev/null
+++ b/arch/i386/lib/pcat_interrupts.c
@@ -0,0 +1,132 @@
+/*
+ * (C) Copyright 2009
+ * Graeme Russ, graeme.russ@gmail.com
+ *
+ * (C) Copyright 2002
+ * Daniel Engström, Omicron Ceti AB, daniel@omicron.se.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/*
+ * This file provides the interrupt handling functionality for systems
+ * based on the standard PC/AT architecture using two cascaded i8259
+ * Programmable Interrupt Controllers.
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/i8259.h>
+#include <asm/ibmpc.h>
+#include <asm/interrupt.h>
+
+#if CONFIG_SYS_NUM_IRQS != 16
+#error "CONFIG_SYS_NUM_IRQS must equal 16 if CONFIG_SYS_NUM_IRQS is defined"
+#endif
+
+int interrupt_init(void)
+{
+	u8 i;
+
+	disable_interrupts();
+
+	/* Mask all interrupts */
+	outb(0xff, MASTER_PIC + IMR);
+	outb(0xff, SLAVE_PIC + IMR);
+
+	/* Master PIC */
+	/* Place master PIC interrupts at INT20 */
+	/* ICW3, One slave PIC is present */
+	outb(ICW1_SEL|ICW1_EICW4, MASTER_PIC + ICW1);
+	outb(0x20, MASTER_PIC + ICW2);
+	outb(IR2, MASTER_PIC + ICW3);
+	outb(ICW4_PM, MASTER_PIC + ICW4);
+
+	for (i = 0; i < 8; i++)
+		outb(OCW2_SEOI | i, MASTER_PIC + OCW2);
+
+	/* Slave PIC */
+	/* Place slave PIC interrupts at INT28 */
+	/* Slave ID */
+	outb(ICW1_SEL|ICW1_EICW4, SLAVE_PIC + ICW1);
+	outb(0x28, SLAVE_PIC + ICW2);
+	outb(0x02, SLAVE_PIC + ICW3);
+	outb(ICW4_PM, SLAVE_PIC + ICW4);
+
+	for (i = 0; i < 8; i++)
+		outb(OCW2_SEOI | i, SLAVE_PIC + OCW2);
+
+	/*
+	 * Enable cascaded interrupts by unmasking the cascade IRQ pin of
+	 * the master PIC
+	 */
+	unmask_irq (2);
+
+	enable_interrupts();
+
+	return 0;
+}
+
+void mask_irq(int irq)
+{
+	int imr_port;
+
+	if (irq >= CONFIG_SYS_NUM_IRQS)
+		return;
+
+	if (irq > 7)
+		imr_port = SLAVE_PIC + IMR;
+	else
+		imr_port = MASTER_PIC + IMR;
+
+	outb(inb(imr_port) | (1 << (irq & 7)), imr_port);
+}
+
+void unmask_irq(int irq)
+{
+	int imr_port;
+
+	if (irq >= CONFIG_SYS_NUM_IRQS)
+		return;
+
+	if (irq > 7)
+		imr_port = SLAVE_PIC + IMR;
+	else
+		imr_port = MASTER_PIC + IMR;
+
+	outb(inb(imr_port) & ~(1 << (irq & 7)), imr_port);
+}
+
+void specific_eoi(int irq)
+{
+	if (irq >= CONFIG_SYS_NUM_IRQS)
+		return;
+
+	if (irq > 7) {
+		/*
+		 *  IRQ is on the slave - Issue a corresponding EOI to the
+		 *  slave PIC and an EOI for IRQ2 (the cascade interrupt)
+		 *  on the master PIC
+		 */
+		outb(OCW2_SEOI | (irq & 7), SLAVE_PIC + OCW2);
+		irq = SEOI_IR2;
+	}
+
+	outb(OCW2_SEOI | irq, MASTER_PIC + OCW2);
+}