kn02-irq.c (1678B)
1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * DECstation 5000/200 (KN02) Control and Status Register 4 * interrupts. 5 * 6 * Copyright (c) 2002, 2003, 2005 Maciej W. Rozycki 7 */ 8 9#include <linux/init.h> 10#include <linux/irq.h> 11#include <linux/types.h> 12 13#include <asm/dec/kn02.h> 14 15 16/* 17 * Bits 7:0 of the Control Register are write-only -- the 18 * corresponding bits of the Status Register have a different 19 * meaning. Hence we use a cache. It speeds up things a bit 20 * as well. 21 * 22 * There is no default value -- it has to be initialized. 23 */ 24u32 cached_kn02_csr; 25 26static int kn02_irq_base; 27 28static void unmask_kn02_irq(struct irq_data *d) 29{ 30 volatile u32 *csr = (volatile u32 *)CKSEG1ADDR(KN02_SLOT_BASE + 31 KN02_CSR); 32 33 cached_kn02_csr |= (1 << (d->irq - kn02_irq_base + 16)); 34 *csr = cached_kn02_csr; 35} 36 37static void mask_kn02_irq(struct irq_data *d) 38{ 39 volatile u32 *csr = (volatile u32 *)CKSEG1ADDR(KN02_SLOT_BASE + 40 KN02_CSR); 41 42 cached_kn02_csr &= ~(1 << (d->irq - kn02_irq_base + 16)); 43 *csr = cached_kn02_csr; 44} 45 46static void ack_kn02_irq(struct irq_data *d) 47{ 48 mask_kn02_irq(d); 49 iob(); 50} 51 52static struct irq_chip kn02_irq_type = { 53 .name = "KN02-CSR", 54 .irq_ack = ack_kn02_irq, 55 .irq_mask = mask_kn02_irq, 56 .irq_mask_ack = ack_kn02_irq, 57 .irq_unmask = unmask_kn02_irq, 58}; 59 60void __init init_kn02_irqs(int base) 61{ 62 volatile u32 *csr = (volatile u32 *)CKSEG1ADDR(KN02_SLOT_BASE + 63 KN02_CSR); 64 int i; 65 66 /* Mask interrupts. */ 67 cached_kn02_csr &= ~KN02_CSR_IOINTEN; 68 *csr = cached_kn02_csr; 69 iob(); 70 71 for (i = base; i < base + KN02_IRQ_LINES; i++) 72 irq_set_chip_and_handler(i, &kn02_irq_type, handle_level_irq); 73 74 kn02_irq_base = base; 75}