microblaze/irqchip: Move intc driver to irqchip

The Xilinx AXI Interrupt Controller IP block is used by the MIPS
based xilfpga platform and a few PowerPC based platforms.

Move the interrupt controller code out of arch/microblaze so that
it can be used by everyone

Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

3 files changed, 201 insertions, 0 deletions

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index bc0af3307bbf..ae96731cd2fb 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -211,6 +211,10 @@ config XTENSA_MX
 	bool
 	select IRQ_DOMAIN
 
+config XILINX_INTC
+	bool
+	select IRQ_DOMAIN
+
 config IRQ_CROSSBAR
 	bool
 	help
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index e4dbfc85abdb..0e55d94065bf 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_TB10X_IRQC)		+= irq-tb10x.o
 obj-$(CONFIG_TS4800_IRQ)		+= irq-ts4800.o
 obj-$(CONFIG_XTENSA)			+= irq-xtensa-pic.o
 obj-$(CONFIG_XTENSA_MX)			+= irq-xtensa-mx.o
+obj-$(CONFIG_XILINX_INTC)		+= irq-xilinx-intc.o
 obj-$(CONFIG_IRQ_CROSSBAR)		+= irq-crossbar.o
 obj-$(CONFIG_SOC_VF610)			+= irq-vf610-mscm-ir.o
 obj-$(CONFIG_BCM6345_L1_IRQ)		+= irq-bcm6345-l1.o
diff --git a/drivers/irqchip/irq-xilinx-intc.c b/drivers/irqchip/irq-xilinx-intc.c
new file mode 100644
index 000000000000..90bec7d71f85
--- /dev/null
+++ b/drivers/irqchip/irq-xilinx-intc.c
@@ -0,0 +1,196 @@
+/*
+ * Copyright (C) 2007-2013 Michal Simek <monstr@monstr.eu>
+ * Copyright (C) 2012-2013 Xilinx, Inc.
+ * Copyright (C) 2007-2009 PetaLogix
+ * Copyright (C) 2006 Atmark Techno, Inc.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/irqdomain.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/of_address.h>
+#include <linux/io.h>
+#include <linux/bug.h>
+
+static void __iomem *intc_baseaddr;
+
+/* No one else should require these constants, so define them locally here. */
+#define ISR 0x00			/* Interrupt Status Register */
+#define IPR 0x04			/* Interrupt Pending Register */
+#define IER 0x08			/* Interrupt Enable Register */
+#define IAR 0x0c			/* Interrupt Acknowledge Register */
+#define SIE 0x10			/* Set Interrupt Enable bits */
+#define CIE 0x14			/* Clear Interrupt Enable bits */
+#define IVR 0x18			/* Interrupt Vector Register */
+#define MER 0x1c			/* Master Enable Register */
+
+#define MER_ME (1<<0)
+#define MER_HIE (1<<1)
+
+static unsigned int (*read_fn)(void __iomem *);
+static void (*write_fn)(u32, void __iomem *);
+
+static void intc_write32(u32 val, void __iomem *addr)
+{
+	iowrite32(val, addr);
+}
+
+static unsigned int intc_read32(void __iomem *addr)
+{
+	return ioread32(addr);
+}
+
+static void intc_write32_be(u32 val, void __iomem *addr)
+{
+	iowrite32be(val, addr);
+}
+
+static unsigned int intc_read32_be(void __iomem *addr)
+{
+	return ioread32be(addr);
+}
+
+static void intc_enable_or_unmask(struct irq_data *d)
+{
+	unsigned long mask = 1 << d->hwirq;
+
+	pr_debug("enable_or_unmask: %ld\n", d->hwirq);
+
+	/* ack level irqs because they can't be acked during
+	 * ack function since the handle_level_irq function
+	 * acks the irq before calling the interrupt handler
+	 */
+	if (irqd_is_level_type(d))
+		write_fn(mask, intc_baseaddr + IAR);
+
+	write_fn(mask, intc_baseaddr + SIE);
+}
+
+static void intc_disable_or_mask(struct irq_data *d)
+{
+	pr_debug("disable: %ld\n", d->hwirq);
+	write_fn(1 << d->hwirq, intc_baseaddr + CIE);
+}
+
+static void intc_ack(struct irq_data *d)
+{
+	pr_debug("ack: %ld\n", d->hwirq);
+	write_fn(1 << d->hwirq, intc_baseaddr + IAR);
+}
+
+static void intc_mask_ack(struct irq_data *d)
+{
+	unsigned long mask = 1 << d->hwirq;
+
+	pr_debug("disable_and_ack: %ld\n", d->hwirq);
+	write_fn(mask, intc_baseaddr + CIE);
+	write_fn(mask, intc_baseaddr + IAR);
+}
+
+static struct irq_chip intc_dev = {
+	.name = "Xilinx INTC",
+	.irq_unmask = intc_enable_or_unmask,
+	.irq_mask = intc_disable_or_mask,
+	.irq_ack = intc_ack,
+	.irq_mask_ack = intc_mask_ack,
+};
+
+static struct irq_domain *root_domain;
+
+unsigned int get_irq(void)
+{
+	unsigned int hwirq, irq = -1;
+
+	hwirq = read_fn(intc_baseaddr + IVR);
+	if (hwirq != -1U)
+		irq = irq_find_mapping(root_domain, hwirq);
+
+	pr_debug("get_irq: hwirq=%d, irq=%d\n", hwirq, irq);
+
+	return irq;
+}
+
+static int xintc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
+{
+	u32 intr_mask = (u32)d->host_data;
+
+	if (intr_mask & (1 << hw)) {
+		irq_set_chip_and_handler_name(irq, &intc_dev,
+						handle_edge_irq, "edge");
+		irq_clear_status_flags(irq, IRQ_LEVEL);
+	} else {
+		irq_set_chip_and_handler_name(irq, &intc_dev,
+						handle_level_irq, "level");
+		irq_set_status_flags(irq, IRQ_LEVEL);
+	}
+	return 0;
+}
+
+static const struct irq_domain_ops xintc_irq_domain_ops = {
+	.xlate = irq_domain_xlate_onetwocell,
+	.map = xintc_map,
+};
+
+static int __init xilinx_intc_of_init(struct device_node *intc,
+					     struct device_node *parent)
+{
+	u32 nr_irq, intr_mask;
+	int ret;
+
+	intc_baseaddr = of_iomap(intc, 0);
+	BUG_ON(!intc_baseaddr);
+
+	ret = of_property_read_u32(intc, "xlnx,num-intr-inputs", &nr_irq);
+	if (ret < 0) {
+		pr_err("%s: unable to read xlnx,num-intr-inputs\n", __func__);
+		return ret;
+	}
+
+	ret = of_property_read_u32(intc, "xlnx,kind-of-intr", &intr_mask);
+	if (ret < 0) {
+		pr_err("%s: unable to read xlnx,kind-of-intr\n", __func__);
+		return ret;
+	}
+
+	if (intr_mask >> nr_irq)
+		pr_warn("%s: mismatch in kind-of-intr param\n", __func__);
+
+	pr_info("%s: num_irq=%d, edge=0x%x\n",
+		intc->full_name, nr_irq, intr_mask);
+
+	write_fn = intc_write32;
+	read_fn = intc_read32;
+
+	/*
+	 * Disable all external interrupts until they are
+	 * explicity requested.
+	 */
+	write_fn(0, intc_baseaddr + IER);
+
+	/* Acknowledge any pending interrupts just in case. */
+	write_fn(0xffffffff, intc_baseaddr + IAR);
+
+	/* Turn on the Master Enable. */
+	write_fn(MER_HIE | MER_ME, intc_baseaddr + MER);
+	if (!(read_fn(intc_baseaddr + MER) & (MER_HIE | MER_ME))) {
+		write_fn = intc_write32_be;
+		read_fn = intc_read32_be;
+		write_fn(MER_HIE | MER_ME, intc_baseaddr + MER);
+	}
+
+	/* Yeah, okay, casting the intr_mask to a void* is butt-ugly, but I'm
+	 * lazy and Michal can clean it up to something nicer when he tests
+	 * and commits this patch.  ~~gcl */
+	root_domain = irq_domain_add_linear(intc, nr_irq, &xintc_irq_domain_ops,
+							(void *)intr_mask);
+
+	irq_set_default_host(root_domain);
+
+	return 0;
+}
+
+IRQCHIP_DECLARE(xilinx_intc, "xlnx,xps-intc-1.00.a", xilinx_intc_of_init);