irqchip: sunxi: Add irq controller driver

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
CC: Thomas Gleixner <tglx@linutronix.de>

2 files changed, 151 insertions, 0 deletions

diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 054321d..2444d07 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_ARCH_BCM2835) += irq-bcm2835.o
+obj-$(CONFIG_ARCH_SUNXI)   += irq-sunxi.o
diff --git a/drivers/irqchip/irq-sunxi.c b/drivers/irqchip/irq-sunxi.c
new file mode 100644
index 0000000..eef41a4
--- /dev/null
+++ b/drivers/irqchip/irq-sunxi.c
@@ -0,0 +1,150 @@
+/*
+ * Allwinner A1X SoCs IRQ chip driver.
+ *
+ * Copyright (C) 2012 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * Based on code from
+ * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
+ * Benn Huang <benn@allwinnertech.com>
+ *
+ * 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/io.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#include <linux/irqchip/sunxi.h>
+
+#define SUNXI_IRQ_VECTOR_REG		0x00
+#define SUNXI_IRQ_PROTECTION_REG	0x08
+#define SUNXI_IRQ_NMI_CTRL_REG		0x0c
+#define SUNXI_IRQ_PENDING_REG(x)	(0x10 + 0x4 * x)
+#define SUNXI_IRQ_FIQ_PENDING_REG(x)	(0x20 + 0x4 * x)
+#define SUNXI_IRQ_ENABLE_REG(x)		(0x40 + 0x4 * x)
+#define SUNXI_IRQ_MASK_REG(x)		(0x50 + 0x4 * x)
+
+static void __iomem *sunxi_irq_base;
+static struct irq_domain *sunxi_irq_domain;
+
+void sunxi_irq_ack(struct irq_data *irqd)
+{
+	unsigned int irq = irqd_to_hwirq(irqd);
+	unsigned int irq_off = irq % 32;
+	int reg = irq / 32;
+	u32 val;
+
+	val = readl(sunxi_irq_base + SUNXI_IRQ_PENDING_REG(reg));
+	writel(val | (1 << irq_off),
+	       sunxi_irq_base + SUNXI_IRQ_PENDING_REG(reg));
+}
+
+static void sunxi_irq_mask(struct irq_data *irqd)
+{
+	unsigned int irq = irqd_to_hwirq(irqd);
+	unsigned int irq_off = irq % 32;
+	int reg = irq / 32;
+	u32 val;
+
+	val = readl(sunxi_irq_base + SUNXI_IRQ_ENABLE_REG(reg));
+	writel(val & ~(1 << irq_off),
+	       sunxi_irq_base + SUNXI_IRQ_ENABLE_REG(reg));
+}
+
+static void sunxi_irq_unmask(struct irq_data *irqd)
+{
+	unsigned int irq = irqd_to_hwirq(irqd);
+	unsigned int irq_off = irq % 32;
+	int reg = irq / 32;
+	u32 val;
+
+	val = readl(sunxi_irq_base + SUNXI_IRQ_ENABLE_REG(reg));
+	writel(val | (1 << irq_off),
+	       sunxi_irq_base + SUNXI_IRQ_ENABLE_REG(reg));
+}
+
+static struct irq_chip sunxi_irq_chip = {
+	.name		= "sunxi_irq",
+	.irq_ack	= sunxi_irq_ack,
+	.irq_mask	= sunxi_irq_mask,
+	.irq_unmask	= sunxi_irq_unmask,
+};
+
+static int sunxi_irq_map(struct irq_domain *d, unsigned int virq,
+			 irq_hw_number_t hw)
+{
+	irq_set_chip_and_handler(virq, &sunxi_irq_chip,
+				 handle_level_irq);
+	set_irq_flags(virq, IRQF_VALID | IRQF_PROBE);
+
+	return 0;
+}
+
+static struct irq_domain_ops sunxi_irq_ops = {
+	.map = sunxi_irq_map,
+	.xlate = irq_domain_xlate_onecell,
+};
+
+static int __init sunxi_of_init(struct device_node *node,
+				struct device_node *parent)
+{
+	sunxi_irq_base = of_iomap(node, 0);
+	if (!sunxi_irq_base)
+		panic("%s: unable to map IC registers\n",
+			node->full_name);
+
+	/* Disable all interrupts */
+	writel(0, sunxi_irq_base + SUNXI_IRQ_ENABLE_REG(0));
+	writel(0, sunxi_irq_base + SUNXI_IRQ_ENABLE_REG(1));
+	writel(0, sunxi_irq_base + SUNXI_IRQ_ENABLE_REG(2));
+
+	/* Mask all the interrupts */
+	writel(0, sunxi_irq_base + SUNXI_IRQ_MASK_REG(0));
+	writel(0, sunxi_irq_base + SUNXI_IRQ_MASK_REG(1));
+	writel(0, sunxi_irq_base + SUNXI_IRQ_MASK_REG(2));
+
+	/* Clear all the pending interrupts */
+	writel(0xffffffff, sunxi_irq_base + SUNXI_IRQ_PENDING_REG(0));
+	writel(0xffffffff, sunxi_irq_base + SUNXI_IRQ_PENDING_REG(1));
+	writel(0xffffffff, sunxi_irq_base + SUNXI_IRQ_PENDING_REG(2));
+
+	/* Enable protection mode */
+	writel(0x01, sunxi_irq_base + SUNXI_IRQ_PROTECTION_REG);
+
+	/* Configure the external interrupt source type */
+	writel(0x00, sunxi_irq_base + SUNXI_IRQ_NMI_CTRL_REG);
+
+	sunxi_irq_domain = irq_domain_add_linear(node, 3 * 32,
+						 &sunxi_irq_ops, NULL);
+	if (!sunxi_irq_domain)
+		panic("%s: unable to create IRQ domain\n", node->full_name);
+
+	return 0;
+}
+
+static struct of_device_id sunxi_irq_dt_ids[] __initconst = {
+	{ .compatible = "allwinner,sunxi-ic", .data = sunxi_of_init }
+};
+
+void __init sunxi_init_irq(void)
+{
+	of_irq_init(sunxi_irq_dt_ids);
+}
+
+asmlinkage void __exception_irq_entry sunxi_handle_irq(struct pt_regs *regs)
+{
+	u32 irq, hwirq;
+
+	hwirq = readl(sunxi_irq_base + SUNXI_IRQ_VECTOR_REG) >> 2;
+	while (hwirq != 0) {
+		irq = irq_find_mapping(sunxi_irq_domain, hwirq);
+		handle_IRQ(irq, regs);
+		hwirq = readl(sunxi_irq_base + SUNXI_IRQ_VECTOR_REG) >> 2;
+	}
+}