From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001
From: root <root@artemis.panaceas.org>
Date: Fri, 25 Dec 2015 04:40:36 +0000
Subject: initial_commit

---
 arch/arm/mach-shark/irq.c | 108 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 108 insertions(+)
 create mode 100644 arch/arm/mach-shark/irq.c

(limited to 'arch/arm/mach-shark/irq.c')

diff --git a/arch/arm/mach-shark/irq.c b/arch/arm/mach-shark/irq.c
new file mode 100644
index 00000000..5dce13e4
--- /dev/null
+++ b/arch/arm/mach-shark/irq.c
@@ -0,0 +1,108 @@
+/*
+ *  linux/arch/arm/mach-shark/irq.c
+ *
+ * by Alexander Schulz
+ *
+ * derived from linux/arch/ppc/kernel/i8259.c and:
+ * arch/arm/mach-ebsa110/include/mach/irq.h
+ * Copyright (C) 1996-1998 Russell King
+ */
+
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+
+#include <asm/irq.h>
+#include <asm/mach/irq.h>
+
+/*
+ * 8259A PIC functions to handle ISA devices:
+ */
+
+/*
+ * This contains the irq mask for both 8259A irq controllers,
+ * Let through the cascade-interrupt no. 2 (ff-(1<<2)==fb)
+ */
+static unsigned char cached_irq_mask[2] = { 0xfb, 0xff };
+
+/*
+ * These have to be protected by the irq controller spinlock
+ * before being called.
+ */
+static void shark_disable_8259A_irq(struct irq_data *d)
+{
+	unsigned int mask;
+	if (d->irq<8) {
+	  mask = 1 << d->irq;
+	  cached_irq_mask[0] |= mask;
+	  outb(cached_irq_mask[1],0xA1);
+	} else {
+	  mask = 1 << (d->irq-8);
+	  cached_irq_mask[1] |= mask;
+	  outb(cached_irq_mask[0],0x21);
+	}
+}
+
+static void shark_enable_8259A_irq(struct irq_data *d)
+{
+	unsigned int mask;
+	if (d->irq<8) {
+	  mask = ~(1 << d->irq);
+	  cached_irq_mask[0] &= mask;
+	  outb(cached_irq_mask[0],0x21);
+	} else {
+	  mask = ~(1 << (d->irq-8));
+	  cached_irq_mask[1] &= mask;
+	  outb(cached_irq_mask[1],0xA1);
+	}
+}
+
+static void shark_ack_8259A_irq(struct irq_data *d){}
+
+static irqreturn_t bogus_int(int irq, void *dev_id)
+{
+	printk("Got interrupt %i!\n",irq);
+	return IRQ_NONE;
+}
+
+static struct irqaction cascade;
+
+static struct irq_chip fb_chip = {
+	.name		= "XT-PIC",
+	.irq_ack	= shark_ack_8259A_irq,
+	.irq_mask	= shark_disable_8259A_irq,
+	.irq_unmask	= shark_enable_8259A_irq,
+};
+
+void __init shark_init_irq(void)
+{
+	int irq;
+
+	for (irq = 0; irq < NR_IRQS; irq++) {
+		irq_set_chip_and_handler(irq, &fb_chip, handle_edge_irq);
+		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
+	}
+
+	/* init master interrupt controller */
+	outb(0x11, 0x20); /* Start init sequence, edge triggered (level: 0x19)*/
+	outb(0x00, 0x21); /* Vector base */
+	outb(0x04, 0x21); /* Cascade (slave) on IRQ2 */
+	outb(0x03, 0x21); /* Select 8086 mode , auto eoi*/
+	outb(0x0A, 0x20);
+	/* init slave interrupt controller */
+	outb(0x11, 0xA0); /* Start init sequence, edge triggered */
+	outb(0x08, 0xA1); /* Vector base */
+	outb(0x02, 0xA1); /* Cascade (slave) on IRQ2 */
+	outb(0x03, 0xA1); /* Select 8086 mode, auto eoi */
+	outb(0x0A, 0xA0);
+	outb(cached_irq_mask[1],0xA1);
+	outb(cached_irq_mask[0],0x21);
+	//request_region(0x20,0x2,"pic1");
+	//request_region(0xA0,0x2,"pic2");
+
+	cascade.handler = bogus_int;
+	cascade.name = "cascade";
+	setup_irq(2,&cascade);
+}
+
-- 
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