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-rw-r--r--arch/mips/dec/kn02-irq.c127
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 000000000000..e0bfcd1521e2
--- /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;
+}