1/* 2 * Carsten Langgaard, carstenl@mips.com 3 * Copyright (C) 1999,2000 MIPS Technologies, Inc. All rights reserved. 4 * 5 * This program is free software; you can distribute it and/or modify it 6 * under the terms of the GNU General Public License (Version 2) as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * for more details. 13 * 14 * You should have received a copy of the GNU General Public License along 15 * with this program; if not, write to the Free Software Foundation, Inc., 16 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. 17 * 18 * Routines for generic manipulation of the interrupts found on the 19 * Lasat boards. 20 */ 21#include <linux/init.h> 22#include <linux/interrupt.h> 23#include <linux/irq.h> 24 25#include <asm/irq_cpu.h> 26#include <asm/lasat/lasat.h> 27#include <asm/lasat/lasatint.h> 28 29#include <irq.h> 30 31static volatile int *lasat_int_status; 32static volatile int *lasat_int_mask; 33static volatile int lasat_int_mask_shift; 34 35void disable_lasat_irq(unsigned int irq_nr) 36{ 37 irq_nr -= LASAT_IRQ_BASE; 38 *lasat_int_mask &= ~(1 << irq_nr) << lasat_int_mask_shift; 39} 40 41void enable_lasat_irq(unsigned int irq_nr) 42{ 43 irq_nr -= LASAT_IRQ_BASE; 44 *lasat_int_mask |= (1 << irq_nr) << lasat_int_mask_shift; 45} 46 47static struct irq_chip lasat_irq_type = { 48 .name = "Lasat", 49 .ack = disable_lasat_irq, 50 .mask = disable_lasat_irq, 51 .mask_ack = disable_lasat_irq, 52 .unmask = enable_lasat_irq, 53}; 54 55static inline int ls1bit32(unsigned int x) 56{ 57 int b = 31, s; 58 59 s = 16; if (x << 16 == 0) s = 0; b -= s; x <<= s; 60 s = 8; if (x << 8 == 0) s = 0; b -= s; x <<= s; 61 s = 4; if (x << 4 == 0) s = 0; b -= s; x <<= s; 62 s = 2; if (x << 2 == 0) s = 0; b -= s; x <<= s; 63 s = 1; if (x << 1 == 0) s = 0; b -= s; 64 65 return b; 66} 67 68static unsigned long (*get_int_status)(void); 69 70static unsigned long get_int_status_100(void) 71{ 72 return *lasat_int_status & *lasat_int_mask; 73} 74 75static unsigned long get_int_status_200(void) 76{ 77 unsigned long int_status; 78 79 int_status = *lasat_int_status; 80 int_status &= (int_status >> LASATINT_MASK_SHIFT_200) & 0xffff; 81 return int_status; 82} 83 84asmlinkage void plat_irq_dispatch(void) 85{ 86 unsigned long int_status; 87 unsigned int cause = read_c0_cause(); 88 int irq; 89 90 if (cause & CAUSEF_IP7) { /* R4000 count / compare IRQ */ 91 do_IRQ(7); 92 return; 93 } 94 95 int_status = get_int_status(); 96 97 /* if int_status == 0, then the interrupt has already been cleared */ 98 if (int_status) { 99 irq = LASAT_IRQ_BASE + ls1bit32(int_status); 100 101 do_IRQ(irq); 102 } 103} 104 105static struct irqaction cascade = { 106 .handler = no_action, 107 .name = "cascade", 108}; 109 110void __init arch_init_irq(void) 111{ 112 int i; 113 114 if (IS_LASAT_200()) { 115 lasat_int_status = (void *)LASAT_INT_STATUS_REG_200; 116 lasat_int_mask = (void *)LASAT_INT_MASK_REG_200; 117 lasat_int_mask_shift = LASATINT_MASK_SHIFT_200; 118 get_int_status = get_int_status_200; 119 *lasat_int_mask &= 0xffff; 120 } else { 121 lasat_int_status = (void *)LASAT_INT_STATUS_REG_100; 122 lasat_int_mask = (void *)LASAT_INT_MASK_REG_100; 123 lasat_int_mask_shift = LASATINT_MASK_SHIFT_100; 124 get_int_status = get_int_status_100; 125 *lasat_int_mask = 0; 126 } 127 128 mips_cpu_irq_init(); 129 130 for (i = LASAT_IRQ_BASE; i <= LASAT_IRQ_END; i++) 131 set_irq_chip_and_handler(i, &lasat_irq_type, handle_level_irq); 132 133 setup_irq(LASAT_CASCADE_IRQ, &cascade); 134} 135