76 lines
1.6 KiB
C
76 lines
1.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* DECstation 5000/200 (KN02) Control and Status Register
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* interrupts.
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*
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* Copyright (c) 2002, 2003, 2005 Maciej W. Rozycki
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*/
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#include <linux/init.h>
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#include <linux/irq.h>
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#include <linux/types.h>
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#include <asm/dec/kn02.h>
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/*
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* Bits 7:0 of the Control Register are write-only -- the
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* corresponding bits of the Status Register have a different
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* meaning. Hence we use a cache. It speeds up things a bit
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* as well.
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*
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* There is no default value -- it has to be initialized.
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*/
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u32 cached_kn02_csr;
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static int kn02_irq_base;
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static void unmask_kn02_irq(struct irq_data *d)
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{
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volatile u32 *csr = (volatile u32 *)CKSEG1ADDR(KN02_SLOT_BASE +
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KN02_CSR);
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cached_kn02_csr |= (1 << (d->irq - kn02_irq_base + 16));
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*csr = cached_kn02_csr;
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}
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static void mask_kn02_irq(struct irq_data *d)
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{
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volatile u32 *csr = (volatile u32 *)CKSEG1ADDR(KN02_SLOT_BASE +
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KN02_CSR);
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cached_kn02_csr &= ~(1 << (d->irq - kn02_irq_base + 16));
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*csr = cached_kn02_csr;
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}
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static void ack_kn02_irq(struct irq_data *d)
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{
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mask_kn02_irq(d);
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iob();
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}
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static struct irq_chip kn02_irq_type = {
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.name = "KN02-CSR",
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.irq_ack = ack_kn02_irq,
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.irq_mask = mask_kn02_irq,
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.irq_mask_ack = ack_kn02_irq,
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.irq_unmask = unmask_kn02_irq,
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};
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void __init init_kn02_irqs(int base)
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{
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volatile u32 *csr = (volatile u32 *)CKSEG1ADDR(KN02_SLOT_BASE +
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KN02_CSR);
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int i;
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/* Mask interrupts. */
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cached_kn02_csr &= ~KN02_CSR_IOINTEN;
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*csr = cached_kn02_csr;
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iob();
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for (i = base; i < base + KN02_IRQ_LINES; i++)
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irq_set_chip_and_handler(i, &kn02_irq_type, handle_level_irq);
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kn02_irq_base = base;
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}
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