• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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