[ARM] tegra: Add legacy irq support

The "legacy irq controller" duplicates the functionality of the GIC,
but remains powered during the cpu suspend and idle modes that power
down the CPU and the GIC.

Signed-off-by: Colin Cross <ccross@android.com>

arch/arm/mach-tegra/Makefile

@@ -1,6 +1,6 @@
 obj-y                                   += common.o
 obj-y                                   += io.o
-obj-y                                   += irq.o
+obj-y                                   += irq.o legacy_irq.o
 obj-y                                   += clock.o
 obj-y                                   += timer.o
 obj-y                                   += gpio.o

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

@@ -0,0 +1,31 @@
+/*
+ * arch/arm/mach-tegra/include/mach/legacy_irq.h
+ *
+ * Copyright (C) 2010 Google, Inc.
+ * Author: Colin Cross <ccross@android.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 _ARCH_ARM_MACH_TEGRA_LEGARY_IRQ_H
+#define _ARCH_ARM_MACH_TEGRA_LEGARY_IRQ_H
+
+void tegra_legacy_mask_irq(unsigned int irq);
+void tegra_legacy_unmask_irq(unsigned int irq);
+void tegra_legacy_select_fiq(unsigned int irq, bool fiq);
+void tegra_legacy_force_irq_set(unsigned int irq);
+void tegra_legacy_force_irq_clr(unsigned int irq);
+int tegra_legacy_force_irq_status(unsigned int irq);
+void tegra_legacy_select_fiq(unsigned int irq, bool fiq);
+unsigned long tegra_legacy_vfiq(int nr);
+unsigned long tegra_legacy_class(int nr);
+
+#endif

arch/arm/mach-tegra/legacy_irq.c

@@ -0,0 +1,114 @@
+/*
+ * arch/arm/mach-tegra/legacy_irq.c
+ *
+ * Copyright (C) 2010 Google, Inc.
+ * Author: Colin Cross <ccross@android.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/io.h>
+#include <linux/kernel.h>
+#include <mach/iomap.h>
+#include <mach/legacy_irq.h>
+
+#define ICTLR_CPU_IER		0x20
+#define ICTLR_CPU_IER_SET	0x24
+#define ICTLR_CPU_IER_CLR	0x28
+#define ICTLR_CPU_IEP_CLASS	0x2C
+#define ICTLR_CPU_IEP_VFIQ	0x08
+#define ICTLR_CPU_IEP_FIR	0x14
+#define ICTLR_CPU_IEP_FIR_SET	0x18
+#define ICTLR_CPU_IEP_FIR_CLR	0x1c
+
+static void __iomem *ictlr_reg_base[] = {
+	IO_ADDRESS(TEGRA_PRIMARY_ICTLR_BASE),
+	IO_ADDRESS(TEGRA_SECONDARY_ICTLR_BASE),
+	IO_ADDRESS(TEGRA_TERTIARY_ICTLR_BASE),
+	IO_ADDRESS(TEGRA_QUATERNARY_ICTLR_BASE),
+};
+
+/* When going into deep sleep, the CPU is powered down, taking the GIC with it
+   In order to wake, the wake interrupts need to be enabled in the legacy
+   interrupt controller. */
+void tegra_legacy_unmask_irq(unsigned int irq)
+{
+	void __iomem *base;
+	pr_debug("%s: %d\n", __func__, irq);
+
+	irq -= 32;
+	base = ictlr_reg_base[irq>>5];
+	writel(1 << (irq & 31), base + ICTLR_CPU_IER_SET);
+}
+
+void tegra_legacy_mask_irq(unsigned int irq)
+{
+	void __iomem *base;
+	pr_debug("%s: %d\n", __func__, irq);
+
+	irq -= 32;
+	base = ictlr_reg_base[irq>>5];
+	writel(1 << (irq & 31), base + ICTLR_CPU_IER_CLR);
+}
+
+void tegra_legacy_force_irq_set(unsigned int irq)
+{
+	void __iomem *base;
+	pr_debug("%s: %d\n", __func__, irq);
+
+	irq -= 32;
+	base = ictlr_reg_base[irq>>5];
+	writel(1 << (irq & 31), base + ICTLR_CPU_IEP_FIR_SET);
+}
+
+void tegra_legacy_force_irq_clr(unsigned int irq)
+{
+	void __iomem *base;
+	pr_debug("%s: %d\n", __func__, irq);
+
+	irq -= 32;
+	base = ictlr_reg_base[irq>>5];
+	writel(1 << (irq & 31), base + ICTLR_CPU_IEP_FIR_CLR);
+}
+
+int tegra_legacy_force_irq_status(unsigned int irq)
+{
+	void __iomem *base;
+	pr_debug("%s: %d\n", __func__, irq);
+
+	irq -= 32;
+	base = ictlr_reg_base[irq>>5];
+	return !!(readl(base + ICTLR_CPU_IEP_FIR) & (1 << (irq & 31)));
+}
+
+void tegra_legacy_select_fiq(unsigned int irq, bool fiq)
+{
+	void __iomem *base;
+	pr_debug("%s: %d\n", __func__, irq);
+
+	irq -= 32;
+	base = ictlr_reg_base[irq>>5];
+	writel(fiq << (irq & 31), base + ICTLR_CPU_IEP_CLASS);
+}
+
+unsigned long tegra_legacy_vfiq(int nr)
+{
+	void __iomem *base;
+	base = ictlr_reg_base[nr];
+	return readl(base + ICTLR_CPU_IEP_VFIQ);
+}
+
+unsigned long tegra_legacy_class(int nr)
+{
+	void __iomem *base;
+	base = ictlr_reg_base[nr];
+	return readl(base + ICTLR_CPU_IEP_CLASS);
+}