Initial import

1 files changed, 160 insertions, 0 deletions

diff --git a/drivers/irqchip/irq-sun4i.c b/drivers/irqchip/irq-sun4i.c
new file mode 100644
index 000000000..64155b686
--- /dev/null
+++ b/drivers/irqchip/irq-sun4i.c
@@ -0,0 +1,160 @@
+/*
+ * 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 <asm/exception.h>
+#include <asm/mach/irq.h>
+
+#include "irqchip.h"
+
+#define SUN4I_IRQ_VECTOR_REG		0x00
+#define SUN4I_IRQ_PROTECTION_REG	0x08
+#define SUN4I_IRQ_NMI_CTRL_REG		0x0c
+#define SUN4I_IRQ_PENDING_REG(x)	(0x10 + 0x4 * x)
+#define SUN4I_IRQ_FIQ_PENDING_REG(x)	(0x20 + 0x4 * x)
+#define SUN4I_IRQ_ENABLE_REG(x)		(0x40 + 0x4 * x)
+#define SUN4I_IRQ_MASK_REG(x)		(0x50 + 0x4 * x)
+
+static void __iomem *sun4i_irq_base;
+static struct irq_domain *sun4i_irq_domain;
+
+static void __exception_irq_entry sun4i_handle_irq(struct pt_regs *regs);
+
+static void sun4i_irq_ack(struct irq_data *irqd)
+{
+	unsigned int irq = irqd_to_hwirq(irqd);
+
+	if (irq != 0)
+		return; /* Only IRQ 0 / the ENMI needs to be acked */
+
+	writel(BIT(0), sun4i_irq_base + SUN4I_IRQ_PENDING_REG(0));
+}
+
+static void sun4i_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(sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg));
+	writel(val & ~(1 << irq_off),
+	       sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg));
+}
+
+static void sun4i_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(sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg));
+	writel(val | (1 << irq_off),
+	       sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(reg));
+}
+
+static struct irq_chip sun4i_irq_chip = {
+	.name		= "sun4i_irq",
+	.irq_eoi	= sun4i_irq_ack,
+	.irq_mask	= sun4i_irq_mask,
+	.irq_unmask	= sun4i_irq_unmask,
+	.flags		= IRQCHIP_EOI_THREADED | IRQCHIP_EOI_IF_HANDLED,
+};
+
+static int sun4i_irq_map(struct irq_domain *d, unsigned int virq,
+			 irq_hw_number_t hw)
+{
+	irq_set_chip_and_handler(virq, &sun4i_irq_chip, handle_fasteoi_irq);
+	set_irq_flags(virq, IRQF_VALID | IRQF_PROBE);
+
+	return 0;
+}
+
+static struct irq_domain_ops sun4i_irq_ops = {
+	.map = sun4i_irq_map,
+	.xlate = irq_domain_xlate_onecell,
+};
+
+static int __init sun4i_of_init(struct device_node *node,
+				struct device_node *parent)
+{
+	sun4i_irq_base = of_iomap(node, 0);
+	if (!sun4i_irq_base)
+		panic("%s: unable to map IC registers\n",
+			node->full_name);
+
+	/* Disable all interrupts */
+	writel(0, sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(0));
+	writel(0, sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(1));
+	writel(0, sun4i_irq_base + SUN4I_IRQ_ENABLE_REG(2));
+
+	/* Unmask all the interrupts, ENABLE_REG(x) is used for masking */
+	writel(0, sun4i_irq_base + SUN4I_IRQ_MASK_REG(0));
+	writel(0, sun4i_irq_base + SUN4I_IRQ_MASK_REG(1));
+	writel(0, sun4i_irq_base + SUN4I_IRQ_MASK_REG(2));
+
+	/* Clear all the pending interrupts */
+	writel(0xffffffff, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(0));
+	writel(0xffffffff, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(1));
+	writel(0xffffffff, sun4i_irq_base + SUN4I_IRQ_PENDING_REG(2));
+
+	/* Enable protection mode */
+	writel(0x01, sun4i_irq_base + SUN4I_IRQ_PROTECTION_REG);
+
+	/* Configure the external interrupt source type */
+	writel(0x00, sun4i_irq_base + SUN4I_IRQ_NMI_CTRL_REG);
+
+	sun4i_irq_domain = irq_domain_add_linear(node, 3 * 32,
+						 &sun4i_irq_ops, NULL);
+	if (!sun4i_irq_domain)
+		panic("%s: unable to create IRQ domain\n", node->full_name);
+
+	set_handle_irq(sun4i_handle_irq);
+
+	return 0;
+}
+IRQCHIP_DECLARE(allwinner_sun4i_ic, "allwinner,sun4i-a10-ic", sun4i_of_init);
+
+static void __exception_irq_entry sun4i_handle_irq(struct pt_regs *regs)
+{
+	u32 hwirq;
+
+	/*
+	 * hwirq == 0 can mean one of 3 things:
+	 * 1) no more irqs pending
+	 * 2) irq 0 pending
+	 * 3) spurious irq
+	 * So if we immediately get a reading of 0, check the irq-pending reg
+	 * to differentiate between 2 and 3. We only do this once to avoid
+	 * the extra check in the common case of 1 hapening after having
+	 * read the vector-reg once.
+	 */
+	hwirq = readl(sun4i_irq_base + SUN4I_IRQ_VECTOR_REG) >> 2;
+	if (hwirq == 0 &&
+		  !(readl(sun4i_irq_base + SUN4I_IRQ_PENDING_REG(0)) & BIT(0)))
+		return;
+
+	do {
+		handle_domain_irq(sun4i_irq_domain, hwirq, regs);
+		hwirq = readl(sun4i_irq_base + SUN4I_IRQ_VECTOR_REG) >> 2;
+	} while (hwirq != 0);
+}