1 /*
2 * Derived from arch/i386/kernel/irq.c
3 * Copyright (C) 1992 Linus Torvalds
4 * Adapted from arch/i386 by Gary Thomas
5 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
6 * Updated and modified by Cort Dougan <cort@fsmlabs.com>
7 * Copyright (C) 1996-2001 Cort Dougan
8 * Adapted for Power Macintosh by Paul Mackerras
9 * Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
15 *
16 * This file contains the code used to make IRQ descriptions in the
17 * device tree to actual irq numbers on an interrupt controller
18 * driver.
19 */
20
21 #include <linux/errno.h>
22 #include <linux/list.h>
23 #include <linux/module.h>
24 #include <linux/of.h>
25 #include <linux/of_irq.h>
26 #include <linux/string.h>
27 #include <linux/slab.h>
28
29 /**
30 * irq_of_parse_and_map - Parse and map an interrupt into linux virq space
31 * @dev: Device node of the device whose interrupt is to be mapped
32 * @index: Index of the interrupt to map
33 *
34 * This function is a wrapper that chains of_irq_parse_one() and
35 * irq_create_of_mapping() to make things easier to callers
36 */
irq_of_parse_and_map(struct device_node * dev,int index)37 unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
38 {
39 struct of_phandle_args oirq;
40
41 if (of_irq_parse_one(dev, index, &oirq))
42 return 0;
43
44 return irq_create_of_mapping(&oirq);
45 }
46 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
47
48 /**
49 * of_irq_find_parent - Given a device node, find its interrupt parent node
50 * @child: pointer to device node
51 *
52 * Returns a pointer to the interrupt parent node, or NULL if the interrupt
53 * parent could not be determined.
54 */
of_irq_find_parent(struct device_node * child)55 struct device_node *of_irq_find_parent(struct device_node *child)
56 {
57 struct device_node *p;
58 const __be32 *parp;
59
60 if (!of_node_get(child))
61 return NULL;
62
63 do {
64 parp = of_get_property(child, "interrupt-parent", NULL);
65 if (parp == NULL)
66 p = of_get_parent(child);
67 else {
68 if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
69 p = of_node_get(of_irq_dflt_pic);
70 else
71 p = of_find_node_by_phandle(be32_to_cpup(parp));
72 }
73 of_node_put(child);
74 child = p;
75 } while (p && of_get_property(p, "#interrupt-cells", NULL) == NULL);
76
77 return p;
78 }
79
80 /**
81 * of_irq_parse_raw - Low level interrupt tree parsing
82 * @parent: the device interrupt parent
83 * @addr: address specifier (start of "reg" property of the device) in be32 format
84 * @out_irq: structure of_irq updated by this function
85 *
86 * Returns 0 on success and a negative number on error
87 *
88 * This function is a low-level interrupt tree walking function. It
89 * can be used to do a partial walk with synthetized reg and interrupts
90 * properties, for example when resolving PCI interrupts when no device
91 * node exist for the parent. It takes an interrupt specifier structure as
92 * input, walks the tree looking for any interrupt-map properties, translates
93 * the specifier for each map, and then returns the translated map.
94 */
of_irq_parse_raw(const __be32 * addr,struct of_phandle_args * out_irq)95 int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
96 {
97 struct device_node *ipar, *tnode, *old = NULL, *newpar = NULL;
98 __be32 initial_match_array[MAX_PHANDLE_ARGS];
99 const __be32 *match_array = initial_match_array;
100 const __be32 *tmp, *imap, *imask, dummy_imask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
101 u32 intsize = 1, addrsize, newintsize = 0, newaddrsize = 0;
102 int imaplen, match, i;
103
104 #ifdef DEBUG
105 of_print_phandle_args("of_irq_parse_raw: ", out_irq);
106 #endif
107
108 ipar = of_node_get(out_irq->np);
109
110 /* First get the #interrupt-cells property of the current cursor
111 * that tells us how to interpret the passed-in intspec. If there
112 * is none, we are nice and just walk up the tree
113 */
114 do {
115 tmp = of_get_property(ipar, "#interrupt-cells", NULL);
116 if (tmp != NULL) {
117 intsize = be32_to_cpu(*tmp);
118 break;
119 }
120 tnode = ipar;
121 ipar = of_irq_find_parent(ipar);
122 of_node_put(tnode);
123 } while (ipar);
124 if (ipar == NULL) {
125 pr_debug(" -> no parent found !\n");
126 goto fail;
127 }
128
129 pr_debug("of_irq_parse_raw: ipar=%s, size=%d\n", of_node_full_name(ipar), intsize);
130
131 if (out_irq->args_count != intsize)
132 return -EINVAL;
133
134 /* Look for this #address-cells. We have to implement the old linux
135 * trick of looking for the parent here as some device-trees rely on it
136 */
137 old = of_node_get(ipar);
138 do {
139 tmp = of_get_property(old, "#address-cells", NULL);
140 tnode = of_get_parent(old);
141 of_node_put(old);
142 old = tnode;
143 } while (old && tmp == NULL);
144 of_node_put(old);
145 old = NULL;
146 addrsize = (tmp == NULL) ? 2 : be32_to_cpu(*tmp);
147
148 pr_debug(" -> addrsize=%d\n", addrsize);
149
150 /* Range check so that the temporary buffer doesn't overflow */
151 if (WARN_ON(addrsize + intsize > MAX_PHANDLE_ARGS))
152 goto fail;
153
154 /* Precalculate the match array - this simplifies match loop */
155 for (i = 0; i < addrsize; i++)
156 initial_match_array[i] = addr ? addr[i] : 0;
157 for (i = 0; i < intsize; i++)
158 initial_match_array[addrsize + i] = cpu_to_be32(out_irq->args[i]);
159
160 /* Now start the actual "proper" walk of the interrupt tree */
161 while (ipar != NULL) {
162 /* Now check if cursor is an interrupt-controller and if it is
163 * then we are done
164 */
165 if (of_get_property(ipar, "interrupt-controller", NULL) !=
166 NULL) {
167 pr_debug(" -> got it !\n");
168 return 0;
169 }
170
171 /*
172 * interrupt-map parsing does not work without a reg
173 * property when #address-cells != 0
174 */
175 if (addrsize && !addr) {
176 pr_debug(" -> no reg passed in when needed !\n");
177 goto fail;
178 }
179
180 /* Now look for an interrupt-map */
181 imap = of_get_property(ipar, "interrupt-map", &imaplen);
182 /* No interrupt map, check for an interrupt parent */
183 if (imap == NULL) {
184 pr_debug(" -> no map, getting parent\n");
185 newpar = of_irq_find_parent(ipar);
186 goto skiplevel;
187 }
188 imaplen /= sizeof(u32);
189
190 /* Look for a mask */
191 imask = of_get_property(ipar, "interrupt-map-mask", NULL);
192 if (!imask)
193 imask = dummy_imask;
194
195 /* Parse interrupt-map */
196 match = 0;
197 while (imaplen > (addrsize + intsize + 1) && !match) {
198 /* Compare specifiers */
199 match = 1;
200 for (i = 0; i < (addrsize + intsize); i++, imaplen--)
201 match &= !((match_array[i] ^ *imap++) & imask[i]);
202
203 pr_debug(" -> match=%d (imaplen=%d)\n", match, imaplen);
204
205 /* Get the interrupt parent */
206 if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
207 newpar = of_node_get(of_irq_dflt_pic);
208 else
209 newpar = of_find_node_by_phandle(be32_to_cpup(imap));
210 imap++;
211 --imaplen;
212
213 /* Check if not found */
214 if (newpar == NULL) {
215 pr_debug(" -> imap parent not found !\n");
216 goto fail;
217 }
218
219 if (!of_device_is_available(newpar))
220 match = 0;
221
222 /* Get #interrupt-cells and #address-cells of new
223 * parent
224 */
225 tmp = of_get_property(newpar, "#interrupt-cells", NULL);
226 if (tmp == NULL) {
227 pr_debug(" -> parent lacks #interrupt-cells!\n");
228 goto fail;
229 }
230 newintsize = be32_to_cpu(*tmp);
231 tmp = of_get_property(newpar, "#address-cells", NULL);
232 newaddrsize = (tmp == NULL) ? 0 : be32_to_cpu(*tmp);
233
234 pr_debug(" -> newintsize=%d, newaddrsize=%d\n",
235 newintsize, newaddrsize);
236
237 /* Check for malformed properties */
238 if (WARN_ON(newaddrsize + newintsize > MAX_PHANDLE_ARGS))
239 goto fail;
240 if (imaplen < (newaddrsize + newintsize))
241 goto fail;
242
243 imap += newaddrsize + newintsize;
244 imaplen -= newaddrsize + newintsize;
245
246 pr_debug(" -> imaplen=%d\n", imaplen);
247 }
248 if (!match)
249 goto fail;
250
251 /*
252 * Successfully parsed an interrrupt-map translation; copy new
253 * interrupt specifier into the out_irq structure
254 */
255 out_irq->np = newpar;
256
257 match_array = imap - newaddrsize - newintsize;
258 for (i = 0; i < newintsize; i++)
259 out_irq->args[i] = be32_to_cpup(imap - newintsize + i);
260 out_irq->args_count = intsize = newintsize;
261 addrsize = newaddrsize;
262
263 skiplevel:
264 /* Iterate again with new parent */
265 pr_debug(" -> new parent: %s\n", of_node_full_name(newpar));
266 of_node_put(ipar);
267 ipar = newpar;
268 newpar = NULL;
269 }
270 fail:
271 of_node_put(ipar);
272 of_node_put(newpar);
273
274 return -EINVAL;
275 }
276 EXPORT_SYMBOL_GPL(of_irq_parse_raw);
277
278 /**
279 * of_irq_parse_one - Resolve an interrupt for a device
280 * @device: the device whose interrupt is to be resolved
281 * @index: index of the interrupt to resolve
282 * @out_irq: structure of_irq filled by this function
283 *
284 * This function resolves an interrupt for a node by walking the interrupt tree,
285 * finding which interrupt controller node it is attached to, and returning the
286 * interrupt specifier that can be used to retrieve a Linux IRQ number.
287 */
of_irq_parse_one(struct device_node * device,int index,struct of_phandle_args * out_irq)288 int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_args *out_irq)
289 {
290 struct device_node *p;
291 const __be32 *intspec, *tmp, *addr;
292 u32 intsize, intlen;
293 int i, res;
294
295 pr_debug("of_irq_parse_one: dev=%s, index=%d\n", of_node_full_name(device), index);
296
297 /* OldWorld mac stuff is "special", handle out of line */
298 if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
299 return of_irq_parse_oldworld(device, index, out_irq);
300
301 /* Get the reg property (if any) */
302 addr = of_get_property(device, "reg", NULL);
303
304 /* Try the new-style interrupts-extended first */
305 res = of_parse_phandle_with_args(device, "interrupts-extended",
306 "#interrupt-cells", index, out_irq);
307 if (!res)
308 return of_irq_parse_raw(addr, out_irq);
309
310 /* Get the interrupts property */
311 intspec = of_get_property(device, "interrupts", &intlen);
312 if (intspec == NULL)
313 return -EINVAL;
314
315 intlen /= sizeof(*intspec);
316
317 pr_debug(" intspec=%d intlen=%d\n", be32_to_cpup(intspec), intlen);
318
319 /* Look for the interrupt parent. */
320 p = of_irq_find_parent(device);
321 if (p == NULL)
322 return -EINVAL;
323
324 /* Get size of interrupt specifier */
325 tmp = of_get_property(p, "#interrupt-cells", NULL);
326 if (tmp == NULL) {
327 res = -EINVAL;
328 goto out;
329 }
330 intsize = be32_to_cpu(*tmp);
331
332 pr_debug(" intsize=%d intlen=%d\n", intsize, intlen);
333
334 /* Check index */
335 if ((index + 1) * intsize > intlen) {
336 res = -EINVAL;
337 goto out;
338 }
339
340 /* Copy intspec into irq structure */
341 intspec += index * intsize;
342 out_irq->np = p;
343 out_irq->args_count = intsize;
344 for (i = 0; i < intsize; i++)
345 out_irq->args[i] = be32_to_cpup(intspec++);
346
347 /* Check if there are any interrupt-map translations to process */
348 res = of_irq_parse_raw(addr, out_irq);
349 out:
350 of_node_put(p);
351 return res;
352 }
353 EXPORT_SYMBOL_GPL(of_irq_parse_one);
354
355 /**
356 * of_irq_to_resource - Decode a node's IRQ and return it as a resource
357 * @dev: pointer to device tree node
358 * @index: zero-based index of the irq
359 * @r: pointer to resource structure to return result into.
360 */
of_irq_to_resource(struct device_node * dev,int index,struct resource * r)361 int of_irq_to_resource(struct device_node *dev, int index, struct resource *r)
362 {
363 int irq = irq_of_parse_and_map(dev, index);
364
365 /* Only dereference the resource if both the
366 * resource and the irq are valid. */
367 if (r && irq) {
368 const char *name = NULL;
369
370 memset(r, 0, sizeof(*r));
371 /*
372 * Get optional "interrupt-names" property to add a name
373 * to the resource.
374 */
375 of_property_read_string_index(dev, "interrupt-names", index,
376 &name);
377
378 r->start = r->end = irq;
379 r->flags = IORESOURCE_IRQ | irqd_get_trigger_type(irq_get_irq_data(irq));
380 r->name = name ? name : of_node_full_name(dev);
381 }
382
383 return irq;
384 }
385 EXPORT_SYMBOL_GPL(of_irq_to_resource);
386
387 /**
388 * of_irq_get - Decode a node's IRQ and return it as a Linux IRQ number
389 * @dev: pointer to device tree node
390 * @index: zero-based index of the IRQ
391 *
392 * Returns Linux IRQ number on success, or 0 on the IRQ mapping failure, or
393 * -EPROBE_DEFER if the IRQ domain is not yet created, or error code in case
394 * of any other failure.
395 */
of_irq_get(struct device_node * dev,int index)396 int of_irq_get(struct device_node *dev, int index)
397 {
398 int rc;
399 struct of_phandle_args oirq;
400 struct irq_domain *domain;
401
402 rc = of_irq_parse_one(dev, index, &oirq);
403 if (rc)
404 return rc;
405
406 domain = irq_find_host(oirq.np);
407 if (!domain)
408 return -EPROBE_DEFER;
409
410 return irq_create_of_mapping(&oirq);
411 }
412
413 /**
414 * of_irq_get_byname - Decode a node's IRQ and return it as a Linux IRQ number
415 * @dev: pointer to device tree node
416 * @name: IRQ name
417 *
418 * Returns Linux IRQ number on success, or 0 on the IRQ mapping failure, or
419 * -EPROBE_DEFER if the IRQ domain is not yet created, or error code in case
420 * of any other failure.
421 */
of_irq_get_byname(struct device_node * dev,const char * name)422 int of_irq_get_byname(struct device_node *dev, const char *name)
423 {
424 int index;
425
426 if (unlikely(!name))
427 return -EINVAL;
428
429 index = of_property_match_string(dev, "interrupt-names", name);
430 if (index < 0)
431 return index;
432
433 return of_irq_get(dev, index);
434 }
435
436 /**
437 * of_irq_count - Count the number of IRQs a node uses
438 * @dev: pointer to device tree node
439 */
of_irq_count(struct device_node * dev)440 int of_irq_count(struct device_node *dev)
441 {
442 struct of_phandle_args irq;
443 int nr = 0;
444
445 while (of_irq_parse_one(dev, nr, &irq) == 0)
446 nr++;
447
448 return nr;
449 }
450
451 /**
452 * of_irq_to_resource_table - Fill in resource table with node's IRQ info
453 * @dev: pointer to device tree node
454 * @res: array of resources to fill in
455 * @nr_irqs: the number of IRQs (and upper bound for num of @res elements)
456 *
457 * Returns the size of the filled in table (up to @nr_irqs).
458 */
of_irq_to_resource_table(struct device_node * dev,struct resource * res,int nr_irqs)459 int of_irq_to_resource_table(struct device_node *dev, struct resource *res,
460 int nr_irqs)
461 {
462 int i;
463
464 for (i = 0; i < nr_irqs; i++, res++)
465 if (!of_irq_to_resource(dev, i, res))
466 break;
467
468 return i;
469 }
470 EXPORT_SYMBOL_GPL(of_irq_to_resource_table);
471
472 struct intc_desc {
473 struct list_head list;
474 struct device_node *dev;
475 struct device_node *interrupt_parent;
476 };
477
478 /**
479 * of_irq_init - Scan and init matching interrupt controllers in DT
480 * @matches: 0 terminated array of nodes to match and init function to call
481 *
482 * This function scans the device tree for matching interrupt controller nodes,
483 * and calls their initialization functions in order with parents first.
484 */
of_irq_init(const struct of_device_id * matches)485 void __init of_irq_init(const struct of_device_id *matches)
486 {
487 struct device_node *np, *parent = NULL;
488 struct intc_desc *desc, *temp_desc;
489 struct list_head intc_desc_list, intc_parent_list;
490
491 INIT_LIST_HEAD(&intc_desc_list);
492 INIT_LIST_HEAD(&intc_parent_list);
493
494 for_each_matching_node(np, matches) {
495 if (!of_find_property(np, "interrupt-controller", NULL) ||
496 !of_device_is_available(np))
497 continue;
498 /*
499 * Here, we allocate and populate an intc_desc with the node
500 * pointer, interrupt-parent device_node etc.
501 */
502 desc = kzalloc(sizeof(*desc), GFP_KERNEL);
503 if (WARN_ON(!desc))
504 goto err;
505
506 desc->dev = np;
507 desc->interrupt_parent = of_irq_find_parent(np);
508 if (desc->interrupt_parent == np)
509 desc->interrupt_parent = NULL;
510 list_add_tail(&desc->list, &intc_desc_list);
511 }
512
513 /*
514 * The root irq controller is the one without an interrupt-parent.
515 * That one goes first, followed by the controllers that reference it,
516 * followed by the ones that reference the 2nd level controllers, etc.
517 */
518 while (!list_empty(&intc_desc_list)) {
519 /*
520 * Process all controllers with the current 'parent'.
521 * First pass will be looking for NULL as the parent.
522 * The assumption is that NULL parent means a root controller.
523 */
524 list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
525 const struct of_device_id *match;
526 int ret;
527 of_irq_init_cb_t irq_init_cb;
528
529 if (desc->interrupt_parent != parent)
530 continue;
531
532 list_del(&desc->list);
533 match = of_match_node(matches, desc->dev);
534 if (WARN(!match->data,
535 "of_irq_init: no init function for %s\n",
536 match->compatible)) {
537 kfree(desc);
538 continue;
539 }
540
541 pr_debug("of_irq_init: init %s @ %p, parent %p\n",
542 match->compatible,
543 desc->dev, desc->interrupt_parent);
544 irq_init_cb = (of_irq_init_cb_t)match->data;
545 ret = irq_init_cb(desc->dev, desc->interrupt_parent);
546 if (ret) {
547 kfree(desc);
548 continue;
549 }
550
551 /*
552 * This one is now set up; add it to the parent list so
553 * its children can get processed in a subsequent pass.
554 */
555 list_add_tail(&desc->list, &intc_parent_list);
556 }
557
558 /* Get the next pending parent that might have children */
559 desc = list_first_entry_or_null(&intc_parent_list,
560 typeof(*desc), list);
561 if (!desc) {
562 pr_err("of_irq_init: children remain, but no parents\n");
563 break;
564 }
565 list_del(&desc->list);
566 parent = desc->dev;
567 kfree(desc);
568 }
569
570 list_for_each_entry_safe(desc, temp_desc, &intc_parent_list, list) {
571 list_del(&desc->list);
572 kfree(desc);
573 }
574 err:
575 list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
576 list_del(&desc->list);
577 kfree(desc);
578 }
579 }
580