1 files changed, 127 insertions, 0 deletions
diff --git a/arch/mips/dec/kn02-irq.c b/arch/mips/dec/kn02-irq.c
new file mode 100644
index 00000000000..e0bfcd1521e
--- /dev/null
+++ b/arch/mips/dec/kn02-irq.c
@@ -0,0 +1,127 @@
+/*
+ *	linux/arch/mips/dec/kn02-irq.c
+ *
+ *	DECstation 5000/200 (KN02) Control and Status Register
+ *	interrupts.
+ *
+ *	Copyright (c) 2002, 2003  Maciej W. Rozycki
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include <asm/dec/kn02.h>
+
+
+/*
+ * Bits 7:0 of the Control Register are write-only -- the
+ * corresponding bits of the Status Register have a different
+ * meaning.  Hence we use a cache.  It speeds up things a bit
+ * as well.
+ *
+ * There is no default value -- it has to be initialized.
+ */
+u32 cached_kn02_csr;
+DEFINE_SPINLOCK(kn02_lock);
+
+
+static int kn02_irq_base;
+
+
+static inline void unmask_kn02_irq(unsigned int irq)
+{
+	volatile u32 *csr = (volatile u32 *)KN02_CSR_BASE;
+
+	cached_kn02_csr |= (1 << (irq - kn02_irq_base + 16));
+	*csr = cached_kn02_csr;
+}
+
+static inline void mask_kn02_irq(unsigned int irq)
+{
+	volatile u32 *csr = (volatile u32 *)KN02_CSR_BASE;
+
+	cached_kn02_csr &= ~(1 << (irq - kn02_irq_base + 16));
+	*csr = cached_kn02_csr;
+}
+
+static inline void enable_kn02_irq(unsigned int irq)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&kn02_lock, flags);
+	unmask_kn02_irq(irq);
+	spin_unlock_irqrestore(&kn02_lock, flags);
+}
+
+static inline void disable_kn02_irq(unsigned int irq)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&kn02_lock, flags);
+	mask_kn02_irq(irq);
+	spin_unlock_irqrestore(&kn02_lock, flags);
+}
+
+
+static unsigned int startup_kn02_irq(unsigned int irq)
+{
+	enable_kn02_irq(irq);
+	return 0;
+}
+
+#define shutdown_kn02_irq disable_kn02_irq
+
+static void ack_kn02_irq(unsigned int irq)
+{
+	spin_lock(&kn02_lock);
+	mask_kn02_irq(irq);
+	spin_unlock(&kn02_lock);
+	iob();
+}
+
+static void end_kn02_irq(unsigned int irq)
+{
+	if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS)))
+		enable_kn02_irq(irq);
+}
+
+static struct hw_interrupt_type kn02_irq_type = {
+	.typename = "KN02-CSR",
+	.startup = startup_kn02_irq,
+	.shutdown = shutdown_kn02_irq,
+	.enable = enable_kn02_irq,
+	.disable = disable_kn02_irq,
+	.ack = ack_kn02_irq,
+	.end = end_kn02_irq,
+};
+
+
+void __init init_kn02_irqs(int base)
+{
+	volatile u32 *csr = (volatile u32 *)KN02_CSR_BASE;
+	unsigned long flags;
+	int i;
+
+	/* Mask interrupts. */
+	spin_lock_irqsave(&kn02_lock, flags);
+	cached_kn02_csr &= ~KN03_CSR_IOINTEN;
+	*csr = cached_kn02_csr;
+	iob();
+	spin_unlock_irqrestore(&kn02_lock, flags);
+
+	for (i = base; i < base + KN02_IRQ_LINES; i++) {
+		irq_desc[i].status = IRQ_DISABLED;
+		irq_desc[i].action = 0;
+		irq_desc[i].depth = 1;
+		irq_desc[i].handler = &kn02_irq_type;
+	}
+
+	kn02_irq_base = base;
+}