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Paul Mackerrasf9bd1702005-10-26 16:47:42 +10001/*
2 * i8259 interrupt controller driver.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 */
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +10009#undef DEBUG
10
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#include <linux/ioport.h>
12#include <linux/interrupt.h>
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +100013#include <linux/kernel.h>
14#include <linux/delay.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <asm/io.h>
16#include <asm/i8259.h>
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +100017#include <asm/prom.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018
Paul Mackerrasf9bd1702005-10-26 16:47:42 +100019static volatile void __iomem *pci_intack; /* RO, gives us the irq vector */
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
Paul Mackerrasf9bd1702005-10-26 16:47:42 +100021static unsigned char cached_8259[2] = { 0xff, 0xff };
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#define cached_A1 (cached_8259[0])
23#define cached_21 (cached_8259[1])
24
Thomas Gleixner47e3c902010-02-18 02:23:11 +000025static DEFINE_RAW_SPINLOCK(i8259_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
Grant Likelybae1d8f2012-02-14 14:06:50 -070027static struct irq_domain *i8259_host;
Linus Torvalds1da177e2005-04-16 15:20:36 -070028
29/*
30 * Acknowledge the IRQ using either the PCI host bridge's interrupt
31 * acknowledge feature or poll. How i8259_init() is called determines
32 * which is called. It should be noted that polling is broken on some
33 * IBM and Motorola PReP boxes so we must use the int-ack feature on them.
34 */
Olaf Hering35a84c22006-10-07 22:08:26 +100035unsigned int i8259_irq(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070036{
37 int irq;
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +100038 int lock = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
40 /* Either int-ack or poll for the IRQ */
41 if (pci_intack)
Paul Mackerrasf9bd1702005-10-26 16:47:42 +100042 irq = readb(pci_intack);
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 else {
Thomas Gleixner47e3c902010-02-18 02:23:11 +000044 raw_spin_lock(&i8259_lock);
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +100045 lock = 1;
46
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 /* Perform an interrupt acknowledge cycle on controller 1. */
48 outb(0x0C, 0x20); /* prepare for poll */
49 irq = inb(0x20) & 7;
50 if (irq == 2 ) {
51 /*
52 * Interrupt is cascaded so perform interrupt
53 * acknowledge on controller 2.
54 */
55 outb(0x0C, 0xA0); /* prepare for poll */
56 irq = (inb(0xA0) & 7) + 8;
57 }
58 }
59
60 if (irq == 7) {
61 /*
62 * This may be a spurious interrupt.
63 *
64 * Read the interrupt status register (ISR). If the most
65 * significant bit is not set then there is no valid
66 * interrupt.
67 */
68 if (!pci_intack)
69 outb(0x0B, 0x20); /* ISR register */
70 if(~inb(0x20) & 0x80)
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +100071 irq = NO_IRQ;
72 } else if (irq == 0xff)
73 irq = NO_IRQ;
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +100075 if (lock)
Thomas Gleixner47e3c902010-02-18 02:23:11 +000076 raw_spin_unlock(&i8259_lock);
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +100077 return irq;
Paul Mackerrasf9bd1702005-10-26 16:47:42 +100078}
79
Lennert Buytenhekd4201182011-03-07 13:59:56 +000080static void i8259_mask_and_ack_irq(struct irq_data *d)
Linus Torvalds1da177e2005-04-16 15:20:36 -070081{
82 unsigned long flags;
83
Thomas Gleixner47e3c902010-02-18 02:23:11 +000084 raw_spin_lock_irqsave(&i8259_lock, flags);
Lennert Buytenhekd4201182011-03-07 13:59:56 +000085 if (d->irq > 7) {
86 cached_A1 |= 1 << (d->irq-8);
Paul Mackerrasf9bd1702005-10-26 16:47:42 +100087 inb(0xA1); /* DUMMY */
88 outb(cached_A1, 0xA1);
89 outb(0x20, 0xA0); /* Non-specific EOI */
90 outb(0x20, 0x20); /* Non-specific EOI to cascade */
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 } else {
Lennert Buytenhekd4201182011-03-07 13:59:56 +000092 cached_21 |= 1 << d->irq;
Paul Mackerrasf9bd1702005-10-26 16:47:42 +100093 inb(0x21); /* DUMMY */
94 outb(cached_21, 0x21);
95 outb(0x20, 0x20); /* Non-specific EOI */
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 }
Thomas Gleixner47e3c902010-02-18 02:23:11 +000097 raw_spin_unlock_irqrestore(&i8259_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098}
99
100static void i8259_set_irq_mask(int irq_nr)
101{
102 outb(cached_A1,0xA1);
103 outb(cached_21,0x21);
104}
105
Lennert Buytenhekd4201182011-03-07 13:59:56 +0000106static void i8259_mask_irq(struct irq_data *d)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107{
108 unsigned long flags;
109
Lennert Buytenhekd4201182011-03-07 13:59:56 +0000110 pr_debug("i8259_mask_irq(%d)\n", d->irq);
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000111
Thomas Gleixner47e3c902010-02-18 02:23:11 +0000112 raw_spin_lock_irqsave(&i8259_lock, flags);
Lennert Buytenhekd4201182011-03-07 13:59:56 +0000113 if (d->irq < 8)
114 cached_21 |= 1 << d->irq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 else
Lennert Buytenhekd4201182011-03-07 13:59:56 +0000116 cached_A1 |= 1 << (d->irq-8);
117 i8259_set_irq_mask(d->irq);
Thomas Gleixner47e3c902010-02-18 02:23:11 +0000118 raw_spin_unlock_irqrestore(&i8259_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119}
120
Lennert Buytenhekd4201182011-03-07 13:59:56 +0000121static void i8259_unmask_irq(struct irq_data *d)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122{
123 unsigned long flags;
124
Lennert Buytenhekd4201182011-03-07 13:59:56 +0000125 pr_debug("i8259_unmask_irq(%d)\n", d->irq);
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000126
Thomas Gleixner47e3c902010-02-18 02:23:11 +0000127 raw_spin_lock_irqsave(&i8259_lock, flags);
Lennert Buytenhekd4201182011-03-07 13:59:56 +0000128 if (d->irq < 8)
129 cached_21 &= ~(1 << d->irq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 else
Lennert Buytenhekd4201182011-03-07 13:59:56 +0000131 cached_A1 &= ~(1 << (d->irq-8));
132 i8259_set_irq_mask(d->irq);
Thomas Gleixner47e3c902010-02-18 02:23:11 +0000133 raw_spin_unlock_irqrestore(&i8259_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134}
135
Benjamin Herrenschmidtb9e5b4e2006-07-03 19:32:51 +1000136static struct irq_chip i8259_pic = {
Anton Blanchardfc380c02010-01-31 20:33:41 +0000137 .name = "i8259",
Lennert Buytenhekd4201182011-03-07 13:59:56 +0000138 .irq_mask = i8259_mask_irq,
139 .irq_disable = i8259_mask_irq,
140 .irq_unmask = i8259_unmask_irq,
141 .irq_mask_ack = i8259_mask_and_ack_irq,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142};
143
144static struct resource pic1_iores = {
145 .name = "8259 (master)",
146 .start = 0x20,
147 .end = 0x21,
148 .flags = IORESOURCE_BUSY,
149};
150
151static struct resource pic2_iores = {
152 .name = "8259 (slave)",
153 .start = 0xa0,
154 .end = 0xa1,
155 .flags = IORESOURCE_BUSY,
156};
157
158static struct resource pic_edgectrl_iores = {
159 .name = "8259 edge control",
160 .start = 0x4d0,
161 .end = 0x4d1,
162 .flags = IORESOURCE_BUSY,
163};
164
Marc Zyngierad3aedf2015-07-28 14:46:08 +0100165static int i8259_host_match(struct irq_domain *h, struct device_node *node,
166 enum irq_domain_bus_token bus_token)
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000167{
Marc Zyngier5d4c9bc2015-10-13 12:51:29 +0100168 struct device_node *of_node = irq_domain_get_of_node(h);
169 return of_node == NULL || of_node == node;
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000170}
171
Grant Likelybae1d8f2012-02-14 14:06:50 -0700172static int i8259_host_map(struct irq_domain *h, unsigned int virq,
Benjamin Herrenschmidt6e99e452006-07-10 04:44:42 -0700173 irq_hw_number_t hw)
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000174{
175 pr_debug("i8259_host_map(%d, 0x%lx)\n", virq, hw);
176
177 /* We block the internal cascade */
178 if (hw == 2)
Thomas Gleixner98488db2011-03-25 15:43:57 +0100179 irq_set_status_flags(virq, IRQ_NOREQUEST);
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000180
Benjamin Herrenschmidt6e99e452006-07-10 04:44:42 -0700181 /* We use the level handler only for now, we might want to
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000182 * be more cautious here but that works for now
183 */
Thomas Gleixner98488db2011-03-25 15:43:57 +0100184 irq_set_status_flags(virq, IRQ_LEVEL);
Thomas Gleixnerec775d02011-03-25 16:45:20 +0100185 irq_set_chip_and_handler(virq, &i8259_pic, handle_level_irq);
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000186 return 0;
187}
188
Grant Likelybae1d8f2012-02-14 14:06:50 -0700189static int i8259_host_xlate(struct irq_domain *h, struct device_node *ct,
Roman Fietze40d50cf2009-12-08 02:39:50 +0000190 const u32 *intspec, unsigned int intsize,
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000191 irq_hw_number_t *out_hwirq, unsigned int *out_flags)
192{
193 static unsigned char map_isa_senses[4] = {
194 IRQ_TYPE_LEVEL_LOW,
195 IRQ_TYPE_LEVEL_HIGH,
196 IRQ_TYPE_EDGE_FALLING,
197 IRQ_TYPE_EDGE_RISING,
198 };
199
200 *out_hwirq = intspec[0];
201 if (intsize > 1 && intspec[1] < 4)
202 *out_flags = map_isa_senses[intspec[1]];
203 else
204 *out_flags = IRQ_TYPE_NONE;
205
206 return 0;
207}
208
Krzysztof Kozlowski202648a2015-04-27 21:48:47 +0900209static const struct irq_domain_ops i8259_host_ops = {
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000210 .match = i8259_host_match,
211 .map = i8259_host_map,
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000212 .xlate = i8259_host_xlate,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213};
214
Grant Likelybae1d8f2012-02-14 14:06:50 -0700215struct irq_domain *i8259_get_host(void)
Benjamin Herrenschmidtf4d4c352006-10-25 13:22:27 +1000216{
217 return i8259_host;
218}
219
Michael Ellerman40681b92006-08-02 11:13:50 +1000220/**
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000221 * i8259_init - Initialize the legacy controller
222 * @node: device node of the legacy PIC (can be NULL, but then, it will match
223 * all interrupts, so beware)
224 * @intack_addr: PCI interrupt acknowledge (real) address which will return
225 * the active irq from the 8259
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 */
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000227void i8259_init(struct device_node *node, unsigned long intack_addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228{
229 unsigned long flags;
230
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000231 /* initialize the controller */
Thomas Gleixner47e3c902010-02-18 02:23:11 +0000232 raw_spin_lock_irqsave(&i8259_lock, flags);
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000233
234 /* Mask all first */
235 outb(0xff, 0xA1);
236 outb(0xff, 0x21);
Paul Mackerrasf9bd1702005-10-26 16:47:42 +1000237
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 /* init master interrupt controller */
239 outb(0x11, 0x20); /* Start init sequence */
240 outb(0x00, 0x21); /* Vector base */
Adam Buchbinder446957b2016-02-24 10:51:11 -0800241 outb(0x04, 0x21); /* edge triggered, Cascade (slave) on IRQ2 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 outb(0x01, 0x21); /* Select 8086 mode */
243
244 /* init slave interrupt controller */
245 outb(0x11, 0xA0); /* Start init sequence */
246 outb(0x08, 0xA1); /* Vector base */
247 outb(0x02, 0xA1); /* edge triggered, Cascade (slave) on IRQ2 */
248 outb(0x01, 0xA1); /* Select 8086 mode */
249
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000250 /* That thing is slow */
251 udelay(100);
252
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 /* always read ISR */
254 outb(0x0B, 0x20);
255 outb(0x0B, 0xA0);
256
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000257 /* Unmask the internal cascade */
258 cached_21 &= ~(1 << 2);
259
260 /* Set interrupt masks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 outb(cached_A1, 0xA1);
262 outb(cached_21, 0x21);
263
Thomas Gleixner47e3c902010-02-18 02:23:11 +0000264 raw_spin_unlock_irqrestore(&i8259_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000266 /* create a legacy host */
Grant Likely1bc04f22012-02-14 14:06:55 -0700267 i8259_host = irq_domain_add_legacy_isa(node, &i8259_host_ops, NULL);
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000268 if (i8259_host == NULL) {
269 printk(KERN_ERR "i8259: failed to allocate irq host !\n");
270 return;
Benjamin Herrenschmidtb9e5b4e2006-07-03 19:32:51 +1000271 }
David Woodhouse9d2ba6f2005-11-05 17:54:22 +0000272
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 /* reserve our resources */
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000274 /* XXX should we continue doing that ? it seems to cause problems
275 * with further requesting of PCI IO resources for that range...
276 * need to look into it.
277 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 request_resource(&ioport_resource, &pic1_iores);
279 request_resource(&ioport_resource, &pic2_iores);
280 request_resource(&ioport_resource, &pic_edgectrl_iores);
281
282 if (intack_addr != 0)
283 pci_intack = ioremap(intack_addr, 1);
Paul Mackerrasf9bd1702005-10-26 16:47:42 +1000284
Benjamin Herrenschmidt0ebfff12006-07-03 21:36:01 +1000285 printk(KERN_INFO "i8259 legacy interrupt controller initialized\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286}