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8
9#undef DEBUG
10
11#include <linux/init.h>
12#include <linux/ioport.h>
13#include <linux/interrupt.h>
14#include <linux/kernel.h>
15#include <linux/delay.h>
16#include <asm/io.h>
17#include <asm/i8259.h>
18#include <asm/prom.h>
19
20static volatile void __iomem *pci_intack;
21
22static unsigned char cached_8259[2] = { 0xff, 0xff };
23#define cached_A1 (cached_8259[0])
24#define cached_21 (cached_8259[1])
25
26static DEFINE_RAW_SPINLOCK(i8259_lock);
27
28static struct irq_domain *i8259_host;
29
30
31
32
33
34
35
36unsigned int i8259_irq(void)
37{
38 int irq;
39 int lock = 0;
40
41
42 if (pci_intack)
43 irq = readb(pci_intack);
44 else {
45 raw_spin_lock(&i8259_lock);
46 lock = 1;
47
48
49 outb(0x0C, 0x20);
50 irq = inb(0x20) & 7;
51 if (irq == 2 ) {
52
53
54
55
56 outb(0x0C, 0xA0);
57 irq = (inb(0xA0) & 7) + 8;
58 }
59 }
60
61 if (irq == 7) {
62
63
64
65
66
67
68
69 if (!pci_intack)
70 outb(0x0B, 0x20);
71 if(~inb(0x20) & 0x80)
72 irq = NO_IRQ;
73 } else if (irq == 0xff)
74 irq = NO_IRQ;
75
76 if (lock)
77 raw_spin_unlock(&i8259_lock);
78 return irq;
79}
80
81static void i8259_mask_and_ack_irq(struct irq_data *d)
82{
83 unsigned long flags;
84
85 raw_spin_lock_irqsave(&i8259_lock, flags);
86 if (d->irq > 7) {
87 cached_A1 |= 1 << (d->irq-8);
88 inb(0xA1);
89 outb(cached_A1, 0xA1);
90 outb(0x20, 0xA0);
91 outb(0x20, 0x20);
92 } else {
93 cached_21 |= 1 << d->irq;
94 inb(0x21);
95 outb(cached_21, 0x21);
96 outb(0x20, 0x20);
97 }
98 raw_spin_unlock_irqrestore(&i8259_lock, flags);
99}
100
101static void i8259_set_irq_mask(int irq_nr)
102{
103 outb(cached_A1,0xA1);
104 outb(cached_21,0x21);
105}
106
107static void i8259_mask_irq(struct irq_data *d)
108{
109 unsigned long flags;
110
111 pr_debug("i8259_mask_irq(%d)\n", d->irq);
112
113 raw_spin_lock_irqsave(&i8259_lock, flags);
114 if (d->irq < 8)
115 cached_21 |= 1 << d->irq;
116 else
117 cached_A1 |= 1 << (d->irq-8);
118 i8259_set_irq_mask(d->irq);
119 raw_spin_unlock_irqrestore(&i8259_lock, flags);
120}
121
122static void i8259_unmask_irq(struct irq_data *d)
123{
124 unsigned long flags;
125
126 pr_debug("i8259_unmask_irq(%d)\n", d->irq);
127
128 raw_spin_lock_irqsave(&i8259_lock, flags);
129 if (d->irq < 8)
130 cached_21 &= ~(1 << d->irq);
131 else
132 cached_A1 &= ~(1 << (d->irq-8));
133 i8259_set_irq_mask(d->irq);
134 raw_spin_unlock_irqrestore(&i8259_lock, flags);
135}
136
137static struct irq_chip i8259_pic = {
138 .name = "i8259",
139 .irq_mask = i8259_mask_irq,
140 .irq_disable = i8259_mask_irq,
141 .irq_unmask = i8259_unmask_irq,
142 .irq_mask_ack = i8259_mask_and_ack_irq,
143};
144
145static struct resource pic1_iores = {
146 .name = "8259 (master)",
147 .start = 0x20,
148 .end = 0x21,
149 .flags = IORESOURCE_BUSY,
150};
151
152static struct resource pic2_iores = {
153 .name = "8259 (slave)",
154 .start = 0xa0,
155 .end = 0xa1,
156 .flags = IORESOURCE_BUSY,
157};
158
159static struct resource pic_edgectrl_iores = {
160 .name = "8259 edge control",
161 .start = 0x4d0,
162 .end = 0x4d1,
163 .flags = IORESOURCE_BUSY,
164};
165
166static int i8259_host_match(struct irq_domain *h, struct device_node *node)
167{
168 return h->of_node == NULL || h->of_node == node;
169}
170
171static int i8259_host_map(struct irq_domain *h, unsigned int virq,
172 irq_hw_number_t hw)
173{
174 pr_debug("i8259_host_map(%d, 0x%lx)\n", virq, hw);
175
176
177 if (hw == 2)
178 irq_set_status_flags(virq, IRQ_NOREQUEST);
179
180
181
182
183 irq_set_status_flags(virq, IRQ_LEVEL);
184 irq_set_chip_and_handler(virq, &i8259_pic, handle_level_irq);
185 return 0;
186}
187
188static int i8259_host_xlate(struct irq_domain *h, struct device_node *ct,
189 const u32 *intspec, unsigned int intsize,
190 irq_hw_number_t *out_hwirq, unsigned int *out_flags)
191{
192 static unsigned char map_isa_senses[4] = {
193 IRQ_TYPE_LEVEL_LOW,
194 IRQ_TYPE_LEVEL_HIGH,
195 IRQ_TYPE_EDGE_FALLING,
196 IRQ_TYPE_EDGE_RISING,
197 };
198
199 *out_hwirq = intspec[0];
200 if (intsize > 1 && intspec[1] < 4)
201 *out_flags = map_isa_senses[intspec[1]];
202 else
203 *out_flags = IRQ_TYPE_NONE;
204
205 return 0;
206}
207
208static struct irq_domain_ops i8259_host_ops = {
209 .match = i8259_host_match,
210 .map = i8259_host_map,
211 .xlate = i8259_host_xlate,
212};
213
214struct irq_domain *i8259_get_host(void)
215{
216 return i8259_host;
217}
218
219
220
221
222
223
224
225
226void i8259_init(struct device_node *node, unsigned long intack_addr)
227{
228 unsigned long flags;
229
230
231 raw_spin_lock_irqsave(&i8259_lock, flags);
232
233
234 outb(0xff, 0xA1);
235 outb(0xff, 0x21);
236
237
238 outb(0x11, 0x20);
239 outb(0x00, 0x21);
240 outb(0x04, 0x21);
241 outb(0x01, 0x21);
242
243
244 outb(0x11, 0xA0);
245 outb(0x08, 0xA1);
246 outb(0x02, 0xA1);
247 outb(0x01, 0xA1);
248
249
250 udelay(100);
251
252
253 outb(0x0B, 0x20);
254 outb(0x0B, 0xA0);
255
256
257 cached_21 &= ~(1 << 2);
258
259
260 outb(cached_A1, 0xA1);
261 outb(cached_21, 0x21);
262
263 raw_spin_unlock_irqrestore(&i8259_lock, flags);
264
265
266 i8259_host = irq_domain_add_legacy_isa(node, &i8259_host_ops, NULL);
267 if (i8259_host == NULL) {
268 printk(KERN_ERR "i8259: failed to allocate irq host !\n");
269 return;
270 }
271
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273
274
275
276
277 request_resource(&ioport_resource, &pic1_iores);
278 request_resource(&ioport_resource, &pic2_iores);
279 request_resource(&ioport_resource, &pic_edgectrl_iores);
280
281 if (intack_addr != 0)
282 pci_intack = ioremap(intack_addr, 1);
283
284 printk(KERN_INFO "i8259 legacy interrupt controller initialized\n");
285}
286