1/* linux/arch/arm/mach-s3c2410/bast-irq.c 2 * 3 * Copyright 2003-2005 Simtec Electronics 4 * Ben Dooks <ben@simtec.co.uk> 5 * 6 * http://www.simtec.co.uk/products/EB2410ITX/ 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21*/ 22 23 24#include <linux/init.h> 25#include <linux/module.h> 26#include <linux/ioport.h> 27#include <linux/device.h> 28#include <linux/io.h> 29 30#include <asm/mach-types.h> 31 32#include <mach/hardware.h> 33#include <asm/irq.h> 34 35#include <asm/mach/irq.h> 36 37#include <mach/regs-irq.h> 38#include <mach/bast-map.h> 39#include <mach/bast-irq.h> 40 41#include <plat/irq.h> 42 43#if 0 44#include <asm/debug-ll.h> 45#endif 46 47#define irqdbf(x...) 48#define irqdbf2(x...) 49 50 51/* handle PC104 ISA interrupts from the system CPLD */ 52 53/* table of ISA irq nos to the relevant mask... zero means 54 * the irq is not implemented 55*/ 56static unsigned char bast_pc104_irqmasks[] = { 57 0, /* 0 */ 58 0, /* 1 */ 59 0, /* 2 */ 60 1, /* 3 */ 61 0, /* 4 */ 62 2, /* 5 */ 63 0, /* 6 */ 64 4, /* 7 */ 65 0, /* 8 */ 66 0, /* 9 */ 67 8, /* 10 */ 68 0, /* 11 */ 69 0, /* 12 */ 70 0, /* 13 */ 71 0, /* 14 */ 72 0, /* 15 */ 73}; 74 75static unsigned char bast_pc104_irqs[] = { 3, 5, 7, 10 }; 76 77static void 78bast_pc104_mask(struct irq_data *data) 79{ 80 unsigned long temp; 81 82 temp = __raw_readb(BAST_VA_PC104_IRQMASK); 83 temp &= ~bast_pc104_irqmasks[data->irq]; 84 __raw_writeb(temp, BAST_VA_PC104_IRQMASK); 85} 86 87static void 88bast_pc104_maskack(struct irq_data *data) 89{ 90 struct irq_desc *desc = irq_desc + IRQ_ISA; 91 92 bast_pc104_mask(data); 93 desc->irq_data.chip->irq_ack(&desc->irq_data); 94} 95 96static void 97bast_pc104_unmask(struct irq_data *data) 98{ 99 unsigned long temp; 100 101 temp = __raw_readb(BAST_VA_PC104_IRQMASK); 102 temp |= bast_pc104_irqmasks[data->irq]; 103 __raw_writeb(temp, BAST_VA_PC104_IRQMASK); 104} 105 106static struct irq_chip bast_pc104_chip = { 107 .irq_mask = bast_pc104_mask, 108 .irq_unmask = bast_pc104_unmask, 109 .irq_ack = bast_pc104_maskack 110}; 111 112static void 113bast_irq_pc104_demux(unsigned int irq, 114 struct irq_desc *desc) 115{ 116 unsigned int stat; 117 unsigned int irqno; 118 int i; 119 120 stat = __raw_readb(BAST_VA_PC104_IRQREQ) & 0xf; 121 122 if (unlikely(stat == 0)) { 123 /* ack if we get an irq with nothing (ie, startup) */ 124 125 desc = irq_desc + IRQ_ISA; 126 desc->irq_data.chip->irq_ack(&desc->irq_data); 127 } else { 128 /* handle the IRQ */ 129 130 for (i = 0; stat != 0; i++, stat >>= 1) { 131 if (stat & 1) { 132 irqno = bast_pc104_irqs[i]; 133 generic_handle_irq(irqno); 134 } 135 } 136 } 137} 138 139static __init int bast_irq_init(void) 140{ 141 unsigned int i; 142 143 if (machine_is_bast()) { 144 printk(KERN_INFO "BAST PC104 IRQ routing, Copyright 2005 Simtec Electronics\n"); 145 146 /* zap all the IRQs */ 147 148 __raw_writeb(0x0, BAST_VA_PC104_IRQMASK); 149 150 irq_set_chained_handler(IRQ_ISA, bast_irq_pc104_demux); 151 152 /* register our IRQs */ 153 154 for (i = 0; i < 4; i++) { 155 unsigned int irqno = bast_pc104_irqs[i]; 156 157 irq_set_chip_and_handler(irqno, &bast_pc104_chip, 158 handle_level_irq); 159 set_irq_flags(irqno, IRQF_VALID); 160 } 161 } 162 163 return 0; 164} 165 166arch_initcall(bast_irq_init); 167