initial_commit

1 files changed, 124 insertions, 0 deletions

diff --git a/arch/arm/mach-exynos4/irq-combiner.c b/arch/arm/mach-exynos4/irq-combiner.c
new file mode 100644
index 00000000..5a2758ab
--- /dev/null
+++ b/arch/arm/mach-exynos4/irq-combiner.c
@@ -0,0 +1,124 @@
+/* linux/arch/arm/mach-exynos4/irq-combiner.c
+ *
+ * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * Based on arch/arm/common/gic.c
+ *
+ * IRQ COMBINER support
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#include <linux/io.h>
+
+#include <asm/mach/irq.h>
+
+#define COMBINER_ENABLE_SET	0x0
+#define COMBINER_ENABLE_CLEAR	0x4
+#define COMBINER_INT_STATUS	0xC
+
+static DEFINE_SPINLOCK(irq_controller_lock);
+
+struct combiner_chip_data {
+	unsigned int irq_offset;
+	unsigned int irq_mask;
+	void __iomem *base;
+};
+
+static struct combiner_chip_data combiner_data[MAX_COMBINER_NR];
+
+static inline void __iomem *combiner_base(struct irq_data *data)
+{
+	struct combiner_chip_data *combiner_data =
+		irq_data_get_irq_chip_data(data);
+
+	return combiner_data->base;
+}
+
+static void combiner_mask_irq(struct irq_data *data)
+{
+	u32 mask = 1 << (data->irq % 32);
+
+	__raw_writel(mask, combiner_base(data) + COMBINER_ENABLE_CLEAR);
+}
+
+static void combiner_unmask_irq(struct irq_data *data)
+{
+	u32 mask = 1 << (data->irq % 32);
+
+	__raw_writel(mask, combiner_base(data) + COMBINER_ENABLE_SET);
+}
+
+static void combiner_handle_cascade_irq(unsigned int irq, struct irq_desc *desc)
+{
+	struct combiner_chip_data *chip_data = irq_get_handler_data(irq);
+	struct irq_chip *chip = irq_get_chip(irq);
+	unsigned int cascade_irq, combiner_irq;
+	unsigned long status;
+
+	chained_irq_enter(chip, desc);
+
+	spin_lock(&irq_controller_lock);
+	status = __raw_readl(chip_data->base + COMBINER_INT_STATUS);
+	spin_unlock(&irq_controller_lock);
+	status &= chip_data->irq_mask;
+
+	if (status == 0)
+		goto out;
+
+	combiner_irq = __ffs(status);
+
+	cascade_irq = combiner_irq + (chip_data->irq_offset & ~31);
+	if (unlikely(cascade_irq >= NR_IRQS))
+		do_bad_IRQ(cascade_irq, desc);
+	else
+		generic_handle_irq(cascade_irq);
+
+ out:
+	chained_irq_exit(chip, desc);
+}
+
+static struct irq_chip combiner_chip = {
+	.name		= "COMBINER",
+	.irq_mask	= combiner_mask_irq,
+	.irq_unmask	= combiner_unmask_irq,
+};
+
+void __init combiner_cascade_irq(unsigned int combiner_nr, unsigned int irq)
+{
+	if (combiner_nr >= MAX_COMBINER_NR)
+		BUG();
+	if (irq_set_handler_data(irq, &combiner_data[combiner_nr]) != 0)
+		BUG();
+	irq_set_chained_handler(irq, combiner_handle_cascade_irq);
+}
+
+void __init combiner_init(unsigned int combiner_nr, void __iomem *base,
+			  unsigned int irq_start)
+{
+	unsigned int i;
+
+	if (combiner_nr >= MAX_COMBINER_NR)
+		BUG();
+
+	combiner_data[combiner_nr].base = base;
+	combiner_data[combiner_nr].irq_offset = irq_start;
+	combiner_data[combiner_nr].irq_mask = 0xff << ((combiner_nr % 4) << 3);
+
+	/* Disable all interrupts */
+
+	__raw_writel(combiner_data[combiner_nr].irq_mask,
+		     base + COMBINER_ENABLE_CLEAR);
+
+	/* Setup the Linux IRQ subsystem */
+
+	for (i = irq_start; i < combiner_data[combiner_nr].irq_offset
+				+ MAX_IRQ_IN_COMBINER; i++) {
+		irq_set_chip_and_handler(i, &combiner_chip, handle_level_irq);
+		irq_set_chip_data(i, &combiner_data[combiner_nr]);
+		set_irq_flags(i, IRQF_VALID | IRQF_PROBE);
+	}
+}