Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6
[linux-2.6] / arch / arm / mach-footbridge / isa-irq.c
1 /*
2  *  linux/arch/arm/mach-footbridge/irq.c
3  *
4  *  Copyright (C) 1996-2000 Russell King
5  *
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.
9  *
10  *  Changelog:
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
16  */
17 #include <linux/ioport.h>
18 #include <linux/interrupt.h>
19 #include <linux/list.h>
20 #include <linux/init.h>
21
22 #include <asm/mach/irq.h>
23
24 #include <asm/hardware.h>
25 #include <asm/hardware/dec21285.h>
26 #include <asm/irq.h>
27 #include <asm/io.h>
28 #include <asm/mach-types.h>
29
30 static void isa_mask_pic_lo_irq(unsigned int irq)
31 {
32         unsigned int mask = 1 << (irq & 7);
33
34         outb(inb(PIC_MASK_LO) | mask, PIC_MASK_LO);
35 }
36
37 static void isa_ack_pic_lo_irq(unsigned int irq)
38 {
39         unsigned int mask = 1 << (irq & 7);
40
41         outb(inb(PIC_MASK_LO) | mask, PIC_MASK_LO);
42         outb(0x20, PIC_LO);
43 }
44
45 static void isa_unmask_pic_lo_irq(unsigned int irq)
46 {
47         unsigned int mask = 1 << (irq & 7);
48
49         outb(inb(PIC_MASK_LO) & ~mask, PIC_MASK_LO);
50 }
51
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,
56 };
57
58 static void isa_mask_pic_hi_irq(unsigned int irq)
59 {
60         unsigned int mask = 1 << (irq & 7);
61
62         outb(inb(PIC_MASK_HI) | mask, PIC_MASK_HI);
63 }
64
65 static void isa_ack_pic_hi_irq(unsigned int irq)
66 {
67         unsigned int mask = 1 << (irq & 7);
68
69         outb(inb(PIC_MASK_HI) | mask, PIC_MASK_HI);
70         outb(0x62, PIC_LO);
71         outb(0x20, PIC_HI);
72 }
73
74 static void isa_unmask_pic_hi_irq(unsigned int irq)
75 {
76         unsigned int mask = 1 << (irq & 7);
77
78         outb(inb(PIC_MASK_HI) & ~mask, PIC_MASK_HI);
79 }
80
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,
85 };
86
87 static void
88 isa_irq_handler(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs)
89 {
90         unsigned int isa_irq = *(unsigned char *)PCIIACK_BASE;
91
92         if (isa_irq < _ISA_IRQ(0) || isa_irq >= _ISA_IRQ(16)) {
93                 do_bad_IRQ(isa_irq, desc, regs);
94                 return;
95         }
96
97         desc = irq_desc + isa_irq;
98         desc_handle_irq(isa_irq, desc, regs);
99 }
100
101 static struct irqaction irq_cascade = { .handler = no_action, .name = "cascade", };
102 static struct resource pic1_resource = { "pic1", 0x20, 0x3f };
103 static struct resource pic2_resource = { "pic2", 0xa0, 0xbf };
104
105 void __init isa_init_irq(unsigned int host_irq)
106 {
107         unsigned int irq;
108
109         /*
110          * Setup, and then probe for an ISA PIC
111          * If the PIC is not there, then we
112          * ignore the PIC.
113          */
114         outb(0x11, PIC_LO);
115         outb(_ISA_IRQ(0), PIC_MASK_LO); /* IRQ number           */
116         outb(0x04, PIC_MASK_LO);        /* Slave on Ch2         */
117         outb(0x01, PIC_MASK_LO);        /* x86                  */
118         outb(0xf5, PIC_MASK_LO);        /* pattern: 11110101    */
119
120         outb(0x11, PIC_HI);
121         outb(_ISA_IRQ(8), PIC_MASK_HI); /* IRQ number           */
122         outb(0x02, PIC_MASK_HI);        /* Slave on Ch1         */
123         outb(0x01, PIC_MASK_HI);        /* x86                  */
124         outb(0xfa, PIC_MASK_HI);        /* pattern: 11111010    */
125
126         outb(0x0b, PIC_LO);
127         outb(0x0b, PIC_HI);
128
129         if (inb(PIC_MASK_LO) == 0xf5 && inb(PIC_MASK_HI) == 0xfa) {
130                 outb(0xff, PIC_MASK_LO);/* mask all IRQs        */
131                 outb(0xff, PIC_MASK_HI);/* mask all IRQs        */
132         } else {
133                 printk(KERN_INFO "IRQ: ISA PIC not found\n");
134                 host_irq = (unsigned int)-1;
135         }
136
137         if (host_irq != (unsigned int)-1) {
138                 for (irq = _ISA_IRQ(0); irq < _ISA_IRQ(8); irq++) {
139                         set_irq_chip(irq, &isa_lo_chip);
140                         set_irq_handler(irq, do_level_IRQ);
141                         set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
142                 }
143
144                 for (irq = _ISA_IRQ(8); irq < _ISA_IRQ(16); irq++) {
145                         set_irq_chip(irq, &isa_hi_chip);
146                         set_irq_handler(irq, do_level_IRQ);
147                         set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
148                 }
149
150                 request_resource(&ioport_resource, &pic1_resource);
151                 request_resource(&ioport_resource, &pic2_resource);
152                 setup_irq(IRQ_ISA_CASCADE, &irq_cascade);
153
154                 set_irq_chained_handler(host_irq, isa_irq_handler);
155
156                 /*
157                  * On the NetWinder, don't automatically
158                  * enable ISA IRQ11 when it is requested.
159                  * There appears to be a missing pull-up
160                  * resistor on this line.
161                  */
162                 if (machine_is_netwinder())
163                         set_irq_flags(_ISA_IRQ(11), IRQF_VALID |
164                                       IRQF_PROBE | IRQF_NOAUTOEN);
165         }
166 }
167
168