h8300: IRQ chip driver

Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
diff --git a/drivers/irqchip/irq-renesas-h8300h.c b/drivers/irqchip/irq-renesas-h8300h.c
new file mode 100644
index 0000000..1870e6b
--- /dev/null
+++ b/drivers/irqchip/irq-renesas-h8300h.c
@@ -0,0 +1,95 @@
+/*
+ * H8/300H interrupt controller driver
+ *
+ * Copyright 2015 Yoshinori Sato <ysato@users.sourceforge.jp>
+ */
+
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <asm/io.h>
+
+#include "irqchip.h"
+
+static const char ipr_bit[] = {
+	 7,  6,  5,  5,
+	 4,  4,  4,  4,  3,  3,  3,  3,
+	 2,  2,  2,  2,  1,  1,  1,  1,
+	 0,  0,  0,  0, 15, 15, 15, 15,
+	14, 14, 14, 14, 13, 13, 13, 13,
+	-1, -1, -1, -1, 11, 11, 11, 11,
+	10, 10, 10, 10,  9,  9,  9,  9,
+};
+
+static void *intc_baseaddr;
+
+#define IPR ((unsigned long)intc_baseaddr + 6)
+
+static void h8300h_disable_irq(struct irq_data *data)
+{
+	int bit;
+	int irq = data->irq - 12;
+
+	bit = ipr_bit[irq];
+	if (bit >= 0) {
+		if (bit < 8)
+			ctrl_bclr(bit & 7, IPR);
+		else
+			ctrl_bclr(bit & 7, (IPR+1));
+	}
+}
+
+static void h8300h_enable_irq(struct irq_data *data)
+{
+	int bit;
+	int irq = data->irq - 12;
+
+	bit = ipr_bit[irq];
+	if (bit >= 0) {
+		if (bit < 8)
+			ctrl_bset(bit & 7, IPR);
+		else
+			ctrl_bset(bit & 7, (IPR+1));
+	}
+}
+
+struct irq_chip h8300h_irq_chip = {
+	.name		= "H8/300H-INTC",
+	.irq_enable	= h8300h_enable_irq,
+	.irq_disable	= h8300h_disable_irq,
+};
+
+static int irq_map(struct irq_domain *h, unsigned int virq,
+		   irq_hw_number_t hw_irq_num)
+{
+       irq_set_chip_and_handler(virq, &h8300h_irq_chip, handle_simple_irq);
+
+       return 0;
+}
+
+static struct irq_domain_ops irq_ops = {
+       .map    = irq_map,
+       .xlate  = irq_domain_xlate_onecell,
+};
+
+static int __init h8300h_intc_of_init(struct device_node *intc,
+				      struct device_node *parent)
+{
+	struct irq_domain *domain;
+
+	intc_baseaddr = of_iomap(intc, 0);
+	BUG_ON(!intc_baseaddr);
+
+	/* All interrupt priority low */
+	ctrl_outb(0x00, IPR + 0);
+	ctrl_outb(0x00, IPR + 1);
+
+	domain = irq_domain_add_linear(intc, NR_IRQS, &irq_ops, NULL);
+	BUG_ON(!domain);
+	irq_set_default_host(domain);
+	return 0;
+}
+
+IRQCHIP_DECLARE(h8300h_intc, "renesas,h8300h-intc", h8300h_intc_of_init);