ARM: Add Gemini architecture v3

Adds support for Cortina Systems Gemini family CPUs:
http://www.cortina-systems.com/products/category/18

v3:
- fixed __io(a) to be defined as __typesafe_io(a)

v2:
- #include <asm/io.h> -> <linux/io.h>
- remove asm/system.h include
- revorked mm.c to use named initializers
- removed "empty" dma.h
- updated copyrights

Signed-off-by: Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
diff --git a/arch/arm/mach-gemini/irq.c b/arch/arm/mach-gemini/irq.c
new file mode 100644
index 0000000..9e613ca
--- /dev/null
+++ b/arch/arm/mach-gemini/irq.c
@@ -0,0 +1,102 @@
+/*
+ *  Interrupt routines for Gemini
+ *
+ *  Copyright (C) 2001-2006 Storlink, Corp.
+ *  Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
+ *
+ * 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.
+ */
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/stddef.h>
+#include <linux/list.h>
+#include <linux/sched.h>
+#include <asm/irq.h>
+#include <asm/mach/irq.h>
+#include <mach/hardware.h>
+
+#define IRQ_SOURCE(base_addr)	(base_addr + 0x00)
+#define IRQ_MASK(base_addr)	(base_addr + 0x04)
+#define IRQ_CLEAR(base_addr)	(base_addr + 0x08)
+#define IRQ_TMODE(base_addr)	(base_addr + 0x0C)
+#define IRQ_TLEVEL(base_addr)	(base_addr + 0x10)
+#define IRQ_STATUS(base_addr)	(base_addr + 0x14)
+#define FIQ_SOURCE(base_addr)	(base_addr + 0x20)
+#define FIQ_MASK(base_addr)	(base_addr + 0x24)
+#define FIQ_CLEAR(base_addr)	(base_addr + 0x28)
+#define FIQ_TMODE(base_addr)	(base_addr + 0x2C)
+#define FIQ_LEVEL(base_addr)	(base_addr + 0x30)
+#define FIQ_STATUS(base_addr)	(base_addr + 0x34)
+
+static void gemini_ack_irq(unsigned int irq)
+{
+	__raw_writel(1 << irq, IRQ_CLEAR(IO_ADDRESS(GEMINI_INTERRUPT_BASE)));
+}
+
+static void gemini_mask_irq(unsigned int irq)
+{
+	unsigned int mask;
+
+	mask = __raw_readl(IRQ_MASK(IO_ADDRESS(GEMINI_INTERRUPT_BASE)));
+	mask &= ~(1 << irq);
+	__raw_writel(mask, IRQ_MASK(IO_ADDRESS(GEMINI_INTERRUPT_BASE)));
+}
+
+static void gemini_unmask_irq(unsigned int irq)
+{
+	unsigned int mask;
+
+	mask = __raw_readl(IRQ_MASK(IO_ADDRESS(GEMINI_INTERRUPT_BASE)));
+	mask |= (1 << irq);
+	__raw_writel(mask, IRQ_MASK(IO_ADDRESS(GEMINI_INTERRUPT_BASE)));
+}
+
+static struct irq_chip gemini_irq_chip = {
+	.name	= "INTC",
+	.ack	= gemini_ack_irq,
+	.mask	= gemini_mask_irq,
+	.unmask	= gemini_unmask_irq,
+};
+
+static struct resource irq_resource = {
+	.name	= "irq_handler",
+	.start	= IO_ADDRESS(GEMINI_INTERRUPT_BASE),
+	.end	= IO_ADDRESS(FIQ_STATUS(GEMINI_INTERRUPT_BASE)) + 4,
+};
+
+void __init gemini_init_irq(void)
+{
+	unsigned int i, mode = 0, level = 0;
+
+	/*
+	 * Disable arch_idle() by default since it is buggy
+	 * For more info see arch/arm/mach-gemini/include/mach/system.h
+	 */
+	disable_hlt();
+
+	request_resource(&iomem_resource, &irq_resource);
+
+	for (i = 0; i < NR_IRQS; i++) {
+		set_irq_chip(i, &gemini_irq_chip);
+		if((i >= IRQ_TIMER1 && i <= IRQ_TIMER3) || (i >= IRQ_SERIRQ0 && i <= IRQ_SERIRQ1)) {
+			set_irq_handler(i, handle_edge_irq);
+			mode |= 1 << i;
+			level |= 1 << i;
+		} else {			
+			set_irq_handler(i, handle_level_irq);
+		}
+		set_irq_flags(i, IRQF_VALID | IRQF_PROBE);
+	}
+
+	/* Disable all interrupts */
+	__raw_writel(0, IRQ_MASK(IO_ADDRESS(GEMINI_INTERRUPT_BASE)));
+	__raw_writel(0, FIQ_MASK(IO_ADDRESS(GEMINI_INTERRUPT_BASE)));
+
+	/* Set interrupt mode */
+	__raw_writel(mode, IRQ_TMODE(IO_ADDRESS(GEMINI_INTERRUPT_BASE)));
+	__raw_writel(level, IRQ_TLEVEL(IO_ADDRESS(GEMINI_INTERRUPT_BASE)));
+}