2 * linux/arch/arm/mach-footbridge/irq.c
4 * Copyright (C) 1996-2000 Russell King
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
11 * 22-Aug-1998 RMK Restructured IRQ routines
12 * 03-Sep-1998 PJB Merged CATS support
13 * 20-Jan-1998 RMK Started merge of EBSA286, CATS and NetWinder
14 * 26-Jan-1999 PJB Don't use IACK on CATS
15 * 16-Mar-1999 RMK Added autodetect of ISA PICs
17 #include <linux/ioport.h>
18 #include <linux/interrupt.h>
19 #include <linux/list.h>
20 #include <linux/init.h>
22 #include <asm/mach/irq.h>
24 #include <asm/hardware.h>
25 #include <asm/hardware/dec21285.h>
28 #include <asm/mach-types.h>
30 static void isa_mask_pic_lo_irq(unsigned int irq
)
32 unsigned int mask
= 1 << (irq
& 7);
34 outb(inb(PIC_MASK_LO
) | mask
, PIC_MASK_LO
);
37 static void isa_ack_pic_lo_irq(unsigned int irq
)
39 unsigned int mask
= 1 << (irq
& 7);
41 outb(inb(PIC_MASK_LO
) | mask
, PIC_MASK_LO
);
45 static void isa_unmask_pic_lo_irq(unsigned int irq
)
47 unsigned int mask
= 1 << (irq
& 7);
49 outb(inb(PIC_MASK_LO
) & ~mask
, PIC_MASK_LO
);
52 static struct irqchip isa_lo_chip
= {
53 .ack
= isa_ack_pic_lo_irq
,
54 .mask
= isa_mask_pic_lo_irq
,
55 .unmask
= isa_unmask_pic_lo_irq
,
58 static void isa_mask_pic_hi_irq(unsigned int irq
)
60 unsigned int mask
= 1 << (irq
& 7);
62 outb(inb(PIC_MASK_HI
) | mask
, PIC_MASK_HI
);
65 static void isa_ack_pic_hi_irq(unsigned int irq
)
67 unsigned int mask
= 1 << (irq
& 7);
69 outb(inb(PIC_MASK_HI
) | mask
, PIC_MASK_HI
);
74 static void isa_unmask_pic_hi_irq(unsigned int irq
)
76 unsigned int mask
= 1 << (irq
& 7);
78 outb(inb(PIC_MASK_HI
) & ~mask
, PIC_MASK_HI
);
81 static struct irqchip isa_hi_chip
= {
82 .ack
= isa_ack_pic_hi_irq
,
83 .mask
= isa_mask_pic_hi_irq
,
84 .unmask
= isa_unmask_pic_hi_irq
,
88 isa_irq_handler(unsigned int irq
, struct irqdesc
*desc
)
90 unsigned int isa_irq
= *(unsigned char *)PCIIACK_BASE
;
92 if (isa_irq
< _ISA_IRQ(0) || isa_irq
>= _ISA_IRQ(16)) {
93 do_bad_IRQ(isa_irq
, desc
);
97 desc
= irq_desc
+ isa_irq
;
98 desc_handle_irq(isa_irq
, desc
);
101 static struct irqaction irq_cascade
= {
102 .handler
= no_action
,
106 static struct resource pic1_resource
= {
112 static struct resource pic2_resource
= {
118 void __init
isa_init_irq(unsigned int host_irq
)
123 * Setup, and then probe for an ISA PIC
124 * If the PIC is not there, then we
128 outb(_ISA_IRQ(0), PIC_MASK_LO
); /* IRQ number */
129 outb(0x04, PIC_MASK_LO
); /* Slave on Ch2 */
130 outb(0x01, PIC_MASK_LO
); /* x86 */
131 outb(0xf5, PIC_MASK_LO
); /* pattern: 11110101 */
134 outb(_ISA_IRQ(8), PIC_MASK_HI
); /* IRQ number */
135 outb(0x02, PIC_MASK_HI
); /* Slave on Ch1 */
136 outb(0x01, PIC_MASK_HI
); /* x86 */
137 outb(0xfa, PIC_MASK_HI
); /* pattern: 11111010 */
142 if (inb(PIC_MASK_LO
) == 0xf5 && inb(PIC_MASK_HI
) == 0xfa) {
143 outb(0xff, PIC_MASK_LO
);/* mask all IRQs */
144 outb(0xff, PIC_MASK_HI
);/* mask all IRQs */
146 printk(KERN_INFO
"IRQ: ISA PIC not found\n");
147 host_irq
= (unsigned int)-1;
150 if (host_irq
!= (unsigned int)-1) {
151 for (irq
= _ISA_IRQ(0); irq
< _ISA_IRQ(8); irq
++) {
152 set_irq_chip(irq
, &isa_lo_chip
);
153 set_irq_handler(irq
, do_level_IRQ
);
154 set_irq_flags(irq
, IRQF_VALID
| IRQF_PROBE
);
157 for (irq
= _ISA_IRQ(8); irq
< _ISA_IRQ(16); irq
++) {
158 set_irq_chip(irq
, &isa_hi_chip
);
159 set_irq_handler(irq
, do_level_IRQ
);
160 set_irq_flags(irq
, IRQF_VALID
| IRQF_PROBE
);
163 request_resource(&ioport_resource
, &pic1_resource
);
164 request_resource(&ioport_resource
, &pic2_resource
);
165 setup_irq(IRQ_ISA_CASCADE
, &irq_cascade
);
167 set_irq_chained_handler(host_irq
, isa_irq_handler
);
170 * On the NetWinder, don't automatically
171 * enable ISA IRQ11 when it is requested.
172 * There appears to be a missing pull-up
173 * resistor on this line.
175 if (machine_is_netwinder())
176 set_irq_flags(_ISA_IRQ(11), IRQF_VALID
|
177 IRQF_PROBE
| IRQF_NOAUTOEN
);