[ARM] tegra: add FIQ support

Signed-off-by: Iliyan Malchev <malchev@google.com>

arch/arm/Kconfig

@@ -578,6 +578,7 @@ config ARCH_TEGRA
 	select ARCH_HAS_BARRIERS if CACHE_L2X0
 	select ARCH_HAS_CPUFREQ
 	select ARCH_PROVIDES_UDELAY
+	select FIQ
 	help
 	  This enables support for NVIDIA Tegra based systems (Tegra APX,
 	  Tegra 6xx and Tegra 2 series).

arch/arm/mach-tegra/Makefile

@@ -10,6 +10,8 @@ obj-y                                   += delay.o
 obj-y                                   += powergate.o
 obj-y					+= suspend.o
 obj-y					+= fuse.o
+obj-$(CONFIG_FIQ)                       += fiq.o
+
 obj-$(CONFIG_ARCH_TEGRA_2x_SOC)         += clock.o
 obj-$(CONFIG_ARCH_TEGRA_2x_SOC)         += tegra2_clocks.o
 obj-$(CONFIG_ARCH_TEGRA_2x_SOC)         += tegra2_dvfs.o

arch/arm/mach-tegra/fiq.c

@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2010 Google, Inc.
+ *
+ * Author:
+ *	Brian Swetland <swetland@google.com>
+ *	Iliyan Malchev <malchev@google.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+#include <asm/hardware/gic.h>
+
+#include <mach/iomap.h>
+#include <mach/fiq.h>
+#include <mach/legacy_irq.h>
+
+#include "board.h"
+
+void tegra_fiq_enable(int irq)
+{
+	void __iomem *base = IO_ADDRESS(TEGRA_ARM_PERIF_BASE + 0x100);
+	/* enable FIQ */
+	u32 val = readl(base + GIC_CPU_CTRL);
+	val &= ~8; /* pass FIQs through */
+	val |= 2; /* enableNS */
+	writel(val, base + GIC_CPU_CTRL);
+	tegra_legacy_unmask_irq(irq);
+}
+
+void tegra_fiq_disable(int irq)
+{
+	tegra_legacy_mask_irq(irq);
+}
+
+void tegra_fiq_select(int irq, int on)
+{
+	tegra_legacy_select_fiq(irq, !!on);
+}

arch/arm/mach-tegra/include/mach/fiq.h

@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2010 Google, Inc.
+ *
+ * Author:
+ *	Iliyan Malchev <malchev@google.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#ifndef __ASM_ARCH_TEGRA_FIQ_H
+#define __ASM_ARCH_TEGRA_FIQ_H
+
+/* change an interrupt to be an FIQ instead of an IRQ */
+void tegra_fiq_select(int n, int on);
+
+/* enable/disable an interrupt that is an FIQ (safe from FIQ context?) */
+void tegra_fiq_enable(int n);
+void tegra_fiq_disable(int n);
+
+/* install an FIQ handler */
+int tegra_fiq_set_handler(void (*func)(void *data, void *regs, void *svc_sp),
+		void *data);
+
+#endif

arch/arm/mach-tegra/include/mach/irqs.h

@@ -172,6 +172,8 @@
 
 #define INT_GPIO_NR			(28 * 8)
 
+#define FIQ_START			INT_GIC_BASE
+
 #define TEGRA_NR_IRQS			(INT_GPIO_BASE + INT_GPIO_NR)
 
 #define INT_BOARD_BASE			TEGRA_NR_IRQS