xtensa: move built-in PIC to drivers/irqchip

Extract xtensa built-in interrupt controller implementation from
xtensa/kernel/irq.c and move it to other irqchips, providing way to
instantiate it from the device tree.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>

2 files changed, 109 insertions, 0 deletions

diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index c60b9010b152..c81a7f3f6506 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -22,3 +22,4 @@ obj-$(CONFIG_RENESAS_IRQC)		+= irq-renesas-irqc.o
 obj-$(CONFIG_VERSATILE_FPGA_IRQ)	+= irq-versatile-fpga.o
 obj-$(CONFIG_ARCH_VT8500)		+= irq-vt8500.o
 obj-$(CONFIG_TB10X_IRQC)		+= irq-tb10x.o
+obj-$(CONFIG_XTENSA)			+= irq-xtensa-pic.o
diff --git a/drivers/irqchip/irq-xtensa-pic.c b/drivers/irqchip/irq-xtensa-pic.c
new file mode 100644
index 000000000000..7d71126d1ce5
--- /dev/null
+++ b/drivers/irqchip/irq-xtensa-pic.c
@@ -0,0 +1,108 @@
+/*
+ * Xtensa built-in interrupt controller
+ *
+ * Copyright (C) 2002 - 2013 Tensilica, Inc.
+ * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
+ *
+ * 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.
+ *
+ * Chris Zankel <chris@zankel.net>
+ * Kevin Chea
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+
+#include "irqchip.h"
+
+unsigned int cached_irq_mask;
+
+/*
+ * Device Tree IRQ specifier translation function which works with one or
+ * two cell bindings. First cell value maps directly to the hwirq number.
+ * Second cell if present specifies whether hwirq number is external (1) or
+ * internal (0).
+ */
+static int xtensa_pic_irq_domain_xlate(struct irq_domain *d,
+		struct device_node *ctrlr,
+		const u32 *intspec, unsigned int intsize,
+		unsigned long *out_hwirq, unsigned int *out_type)
+{
+	return xtensa_irq_domain_xlate(intspec, intsize,
+			intspec[0], intspec[0],
+			out_hwirq, out_type);
+}
+
+static const struct irq_domain_ops xtensa_irq_domain_ops = {
+	.xlate = xtensa_pic_irq_domain_xlate,
+	.map = xtensa_irq_map,
+};
+
+static void xtensa_irq_mask(struct irq_data *d)
+{
+	cached_irq_mask &= ~(1 << d->hwirq);
+	set_sr(cached_irq_mask, intenable);
+}
+
+static void xtensa_irq_unmask(struct irq_data *d)
+{
+	cached_irq_mask |= 1 << d->hwirq;
+	set_sr(cached_irq_mask, intenable);
+}
+
+static void xtensa_irq_enable(struct irq_data *d)
+{
+	variant_irq_enable(d->hwirq);
+	xtensa_irq_unmask(d);
+}
+
+static void xtensa_irq_disable(struct irq_data *d)
+{
+	xtensa_irq_mask(d);
+	variant_irq_disable(d->hwirq);
+}
+
+static void xtensa_irq_ack(struct irq_data *d)
+{
+	set_sr(1 << d->hwirq, intclear);
+}
+
+static int xtensa_irq_retrigger(struct irq_data *d)
+{
+	set_sr(1 << d->hwirq, intset);
+	return 1;
+}
+
+static struct irq_chip xtensa_irq_chip = {
+	.name		= "xtensa",
+	.irq_enable	= xtensa_irq_enable,
+	.irq_disable	= xtensa_irq_disable,
+	.irq_mask	= xtensa_irq_mask,
+	.irq_unmask	= xtensa_irq_unmask,
+	.irq_ack	= xtensa_irq_ack,
+	.irq_retrigger	= xtensa_irq_retrigger,
+};
+
+int __init xtensa_pic_init_legacy(struct device_node *interrupt_parent)
+{
+	struct irq_domain *root_domain =
+		irq_domain_add_legacy(NULL, NR_IRQS, 0, 0,
+				&xtensa_irq_domain_ops, &xtensa_irq_chip);
+	irq_set_default_host(root_domain);
+	return 0;
+}
+
+static int __init xtensa_pic_init(struct device_node *np,
+		struct device_node *interrupt_parent)
+{
+	struct irq_domain *root_domain =
+		irq_domain_add_linear(np, NR_IRQS, &xtensa_irq_domain_ops,
+				&xtensa_irq_chip);
+	irq_set_default_host(root_domain);
+	return 0;
+}
+IRQCHIP_DECLARE(xtensa_irq_chip, "cdns,xtensa-pic", xtensa_pic_init);