diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/ppc/syslib/i8259.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/ppc/syslib/i8259.c')
-rw-r--r-- | arch/ppc/syslib/i8259.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/arch/ppc/syslib/i8259.c b/arch/ppc/syslib/i8259.c new file mode 100644 index 000000000000..b9391e650141 --- /dev/null +++ b/arch/ppc/syslib/i8259.c | |||
@@ -0,0 +1,211 @@ | |||
1 | #include <linux/init.h> | ||
2 | #include <linux/ioport.h> | ||
3 | #include <linux/interrupt.h> | ||
4 | #include <asm/io.h> | ||
5 | #include <asm/i8259.h> | ||
6 | |||
7 | static volatile unsigned char *pci_intack; /* RO, gives us the irq vector */ | ||
8 | |||
9 | unsigned char cached_8259[2] = { 0xff, 0xff }; | ||
10 | #define cached_A1 (cached_8259[0]) | ||
11 | #define cached_21 (cached_8259[1]) | ||
12 | |||
13 | static DEFINE_SPINLOCK(i8259_lock); | ||
14 | |||
15 | int i8259_pic_irq_offset; | ||
16 | |||
17 | /* | ||
18 | * Acknowledge the IRQ using either the PCI host bridge's interrupt | ||
19 | * acknowledge feature or poll. How i8259_init() is called determines | ||
20 | * which is called. It should be noted that polling is broken on some | ||
21 | * IBM and Motorola PReP boxes so we must use the int-ack feature on them. | ||
22 | */ | ||
23 | int | ||
24 | i8259_irq(struct pt_regs *regs) | ||
25 | { | ||
26 | int irq; | ||
27 | |||
28 | spin_lock(&i8259_lock); | ||
29 | |||
30 | /* Either int-ack or poll for the IRQ */ | ||
31 | if (pci_intack) | ||
32 | irq = *pci_intack; | ||
33 | else { | ||
34 | /* Perform an interrupt acknowledge cycle on controller 1. */ | ||
35 | outb(0x0C, 0x20); /* prepare for poll */ | ||
36 | irq = inb(0x20) & 7; | ||
37 | if (irq == 2 ) { | ||
38 | /* | ||
39 | * Interrupt is cascaded so perform interrupt | ||
40 | * acknowledge on controller 2. | ||
41 | */ | ||
42 | outb(0x0C, 0xA0); /* prepare for poll */ | ||
43 | irq = (inb(0xA0) & 7) + 8; | ||
44 | } | ||
45 | } | ||
46 | |||
47 | if (irq == 7) { | ||
48 | /* | ||
49 | * This may be a spurious interrupt. | ||
50 | * | ||
51 | * Read the interrupt status register (ISR). If the most | ||
52 | * significant bit is not set then there is no valid | ||
53 | * interrupt. | ||
54 | */ | ||
55 | if (!pci_intack) | ||
56 | outb(0x0B, 0x20); /* ISR register */ | ||
57 | if(~inb(0x20) & 0x80) | ||
58 | irq = -1; | ||
59 | } | ||
60 | |||
61 | spin_unlock(&i8259_lock); | ||
62 | return irq; | ||
63 | } | ||
64 | |||
65 | static void i8259_mask_and_ack_irq(unsigned int irq_nr) | ||
66 | { | ||
67 | unsigned long flags; | ||
68 | |||
69 | spin_lock_irqsave(&i8259_lock, flags); | ||
70 | if ( irq_nr >= i8259_pic_irq_offset ) | ||
71 | irq_nr -= i8259_pic_irq_offset; | ||
72 | |||
73 | if (irq_nr > 7) { | ||
74 | cached_A1 |= 1 << (irq_nr-8); | ||
75 | inb(0xA1); /* DUMMY */ | ||
76 | outb(cached_A1,0xA1); | ||
77 | outb(0x20,0xA0); /* Non-specific EOI */ | ||
78 | outb(0x20,0x20); /* Non-specific EOI to cascade */ | ||
79 | } else { | ||
80 | cached_21 |= 1 << irq_nr; | ||
81 | inb(0x21); /* DUMMY */ | ||
82 | outb(cached_21,0x21); | ||
83 | outb(0x20,0x20); /* Non-specific EOI */ | ||
84 | } | ||
85 | spin_unlock_irqrestore(&i8259_lock, flags); | ||
86 | } | ||
87 | |||
88 | static void i8259_set_irq_mask(int irq_nr) | ||
89 | { | ||
90 | outb(cached_A1,0xA1); | ||
91 | outb(cached_21,0x21); | ||
92 | } | ||
93 | |||
94 | static void i8259_mask_irq(unsigned int irq_nr) | ||
95 | { | ||
96 | unsigned long flags; | ||
97 | |||
98 | spin_lock_irqsave(&i8259_lock, flags); | ||
99 | if ( irq_nr >= i8259_pic_irq_offset ) | ||
100 | irq_nr -= i8259_pic_irq_offset; | ||
101 | if ( irq_nr < 8 ) | ||
102 | cached_21 |= 1 << irq_nr; | ||
103 | else | ||
104 | cached_A1 |= 1 << (irq_nr-8); | ||
105 | i8259_set_irq_mask(irq_nr); | ||
106 | spin_unlock_irqrestore(&i8259_lock, flags); | ||
107 | } | ||
108 | |||
109 | static void i8259_unmask_irq(unsigned int irq_nr) | ||
110 | { | ||
111 | unsigned long flags; | ||
112 | |||
113 | spin_lock_irqsave(&i8259_lock, flags); | ||
114 | if ( irq_nr >= i8259_pic_irq_offset ) | ||
115 | irq_nr -= i8259_pic_irq_offset; | ||
116 | if ( irq_nr < 8 ) | ||
117 | cached_21 &= ~(1 << irq_nr); | ||
118 | else | ||
119 | cached_A1 &= ~(1 << (irq_nr-8)); | ||
120 | i8259_set_irq_mask(irq_nr); | ||
121 | spin_unlock_irqrestore(&i8259_lock, flags); | ||
122 | } | ||
123 | |||
124 | static void i8259_end_irq(unsigned int irq) | ||
125 | { | ||
126 | if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)) | ||
127 | && irq_desc[irq].action) | ||
128 | i8259_unmask_irq(irq); | ||
129 | } | ||
130 | |||
131 | struct hw_interrupt_type i8259_pic = { | ||
132 | " i8259 ", | ||
133 | NULL, | ||
134 | NULL, | ||
135 | i8259_unmask_irq, | ||
136 | i8259_mask_irq, | ||
137 | i8259_mask_and_ack_irq, | ||
138 | i8259_end_irq, | ||
139 | NULL | ||
140 | }; | ||
141 | |||
142 | static struct resource pic1_iores = { | ||
143 | .name = "8259 (master)", | ||
144 | .start = 0x20, | ||
145 | .end = 0x21, | ||
146 | .flags = IORESOURCE_BUSY, | ||
147 | }; | ||
148 | |||
149 | static struct resource pic2_iores = { | ||
150 | .name = "8259 (slave)", | ||
151 | .start = 0xa0, | ||
152 | .end = 0xa1, | ||
153 | .flags = IORESOURCE_BUSY, | ||
154 | }; | ||
155 | |||
156 | static struct resource pic_edgectrl_iores = { | ||
157 | .name = "8259 edge control", | ||
158 | .start = 0x4d0, | ||
159 | .end = 0x4d1, | ||
160 | .flags = IORESOURCE_BUSY, | ||
161 | }; | ||
162 | |||
163 | static struct irqaction i8259_irqaction = { | ||
164 | .handler = no_action, | ||
165 | .flags = SA_INTERRUPT, | ||
166 | .mask = CPU_MASK_NONE, | ||
167 | .name = "82c59 secondary cascade", | ||
168 | }; | ||
169 | |||
170 | /* | ||
171 | * i8259_init() | ||
172 | * intack_addr - PCI interrupt acknowledge (real) address which will return | ||
173 | * the active irq from the 8259 | ||
174 | */ | ||
175 | void __init | ||
176 | i8259_init(long intack_addr) | ||
177 | { | ||
178 | unsigned long flags; | ||
179 | |||
180 | spin_lock_irqsave(&i8259_lock, flags); | ||
181 | /* init master interrupt controller */ | ||
182 | outb(0x11, 0x20); /* Start init sequence */ | ||
183 | outb(0x00, 0x21); /* Vector base */ | ||
184 | outb(0x04, 0x21); /* edge tiggered, Cascade (slave) on IRQ2 */ | ||
185 | outb(0x01, 0x21); /* Select 8086 mode */ | ||
186 | |||
187 | /* init slave interrupt controller */ | ||
188 | outb(0x11, 0xA0); /* Start init sequence */ | ||
189 | outb(0x08, 0xA1); /* Vector base */ | ||
190 | outb(0x02, 0xA1); /* edge triggered, Cascade (slave) on IRQ2 */ | ||
191 | outb(0x01, 0xA1); /* Select 8086 mode */ | ||
192 | |||
193 | /* always read ISR */ | ||
194 | outb(0x0B, 0x20); | ||
195 | outb(0x0B, 0xA0); | ||
196 | |||
197 | /* Mask all interrupts */ | ||
198 | outb(cached_A1, 0xA1); | ||
199 | outb(cached_21, 0x21); | ||
200 | |||
201 | spin_unlock_irqrestore(&i8259_lock, flags); | ||
202 | |||
203 | /* reserve our resources */ | ||
204 | setup_irq( i8259_pic_irq_offset + 2, &i8259_irqaction); | ||
205 | request_resource(&ioport_resource, &pic1_iores); | ||
206 | request_resource(&ioport_resource, &pic2_iores); | ||
207 | request_resource(&ioport_resource, &pic_edgectrl_iores); | ||
208 | |||
209 | if (intack_addr != 0) | ||
210 | pci_intack = ioremap(intack_addr, 1); | ||
211 | } | ||