arm: mach-mvebu: add support for Armada 370 and Armada XP with DT

[ben.dooks@codethink.co.uk: ensure error check on of_property_read_u32]
[ben.dooks@codethink.co.uk: use mpic address instead of bus-unit's ]
[ben.dooks@codethink.co.uk: BUG_ON() if the of_iomap() fails for mpic]
[ben.dooks@codethink.co.uk: move mpic per-cpu register base ]
[ben.dooks@codethink.co.uk: number fetch should use irqd_to_hwirq()]

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Lior Amsalem <alior@marvell.com>
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Yehuda Yitschak <yehuday@marvell.com>
Tested-by: Lior Amsalem <alior@marvell.com>
diff --git a/arch/arm/mach-mvebu/irq-armada-370-xp.c b/arch/arm/mach-mvebu/irq-armada-370-xp.c
new file mode 100644
index 0000000..645a8d3
--- /dev/null
+++ b/arch/arm/mach-mvebu/irq-armada-370-xp.c
@@ -0,0 +1,130 @@
+/*
+ * Marvell Armada 370 and Armada XP SoC IRQ handling
+ *
+ * Copyright (C) 2012 Marvell
+ *
+ * Lior Amsalem <alior@marvell.com>
+ * Gregory CLEMENT <gregory.clement@free-electrons.com>
+ * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+ * Ben Dooks <ben.dooks@codethink.co.uk>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/irqdomain.h>
+#include <asm/mach/arch.h>
+#include <asm/exception.h>
+
+/* Interrupt Controller Registers Map */
+#define ARMADA_370_XP_INT_SET_MASK_OFFS		(0x48)
+#define ARMADA_370_XP_INT_CLEAR_MASK_OFFS	(0x4C)
+
+#define ARMADA_370_XP_INT_SET_ENABLE_OFFS	(0x30)
+#define ARMADA_370_XP_INT_CLEAR_ENABLE_OFFS	(0x34)
+
+#define ARMADA_370_XP_CPU_INTACK_OFFS		(0x44)
+
+#define ARMADA_370_XP_NR_IRQS			(115)
+
+static void __iomem *per_cpu_int_base;
+static void __iomem *main_int_base;
+static struct irq_domain *armada_370_xp_mpic_domain;
+
+static void armada_370_xp_irq_mask(struct irq_data *d)
+{
+	writel(irqd_to_hwirq(d),
+	       per_cpu_int_base + ARMADA_370_XP_INT_SET_MASK_OFFS);
+}
+
+static void armada_370_xp_irq_unmask(struct irq_data *d)
+{
+	writel(irqd_to_hwirq(d),
+	       per_cpu_int_base + ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
+}
+
+static struct irq_chip armada_370_xp_irq_chip = {
+	.name		= "armada_370_xp_irq",
+	.irq_mask       = armada_370_xp_irq_mask,
+	.irq_mask_ack   = armada_370_xp_irq_mask,
+	.irq_unmask     = armada_370_xp_irq_unmask,
+};
+
+static int armada_370_xp_mpic_irq_map(struct irq_domain *h,
+				      unsigned int virq, irq_hw_number_t hw)
+{
+	armada_370_xp_irq_mask(irq_get_irq_data(virq));
+	writel(hw, main_int_base + ARMADA_370_XP_INT_SET_ENABLE_OFFS);
+
+	irq_set_chip_and_handler(virq, &armada_370_xp_irq_chip,
+				 handle_level_irq);
+	irq_set_status_flags(virq, IRQ_LEVEL);
+	set_irq_flags(virq, IRQF_VALID | IRQF_PROBE);
+
+	return 0;
+}
+
+static struct irq_domain_ops armada_370_xp_mpic_irq_ops = {
+	.map = armada_370_xp_mpic_irq_map,
+	.xlate = irq_domain_xlate_onecell,
+};
+
+static int __init armada_370_xp_mpic_of_init(struct device_node *node,
+					     struct device_node *parent)
+{
+	main_int_base = of_iomap(node, 0);
+	per_cpu_int_base = of_iomap(node, 1);
+
+	BUG_ON(!main_int_base);
+	BUG_ON(!per_cpu_int_base);
+
+	armada_370_xp_mpic_domain =
+	    irq_domain_add_linear(node, ARMADA_370_XP_NR_IRQS,
+				  &armada_370_xp_mpic_irq_ops, NULL);
+
+	if (!armada_370_xp_mpic_domain)
+		panic("Unable to add Armada_370_Xp MPIC irq domain (DT)\n");
+
+	irq_set_default_host(armada_370_xp_mpic_domain);
+	return 0;
+}
+
+asmlinkage void __exception_irq_entry armada_370_xp_handle_irq(struct pt_regs
+							       *regs)
+{
+	u32 irqstat, irqnr;
+
+	do {
+		irqstat = readl_relaxed(per_cpu_int_base +
+					ARMADA_370_XP_CPU_INTACK_OFFS);
+		irqnr = irqstat & 0x3FF;
+
+		if (irqnr < 1023) {
+			irqnr =
+			    irq_find_mapping(armada_370_xp_mpic_domain, irqnr);
+			handle_IRQ(irqnr, regs);
+			continue;
+		}
+
+		break;
+	} while (1);
+}
+
+static const struct of_device_id mpic_of_match[] __initconst = {
+	{.compatible = "marvell,mpic", .data = armada_370_xp_mpic_of_init},
+	{},
+};
+
+void __init armada_370_xp_init_irq(void)
+{
+	of_irq_init(mpic_of_match);
+}