1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Derived from arch/i386/kernel/irq.c
4 * Copyright (C) 1992 Linus Torvalds
5 * Adapted from arch/i386 by Gary Thomas
6 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
7 * Updated and modified by Cort Dougan <cort@fsmlabs.com>
8 * Copyright (C) 1996-2001 Cort Dougan
9 * Adapted for Power Macintosh by Paul Mackerras
10 * Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
11 *
12 * This file contains the code used to make IRQ descriptions in the
13 * device tree to actual irq numbers on an interrupt controller
14 * driver.
15 */
16
17#define pr_fmt(fmt) "OF: " fmt
18
19#include <linux/device.h>
20#include <linux/errno.h>
21#include <linux/list.h>
22#include <linux/module.h>
23#include <linux/of.h>
24#include <linux/of_irq.h>
25#include <linux/string.h>
26#include <linux/slab.h>
27
28/**
29 * irq_of_parse_and_map - Parse and map an interrupt into linux virq space
30 * @dev: Device node of the device whose interrupt is to be mapped
31 * @index: Index of the interrupt to map
32 *
33 * This function is a wrapper that chains of_irq_parse_one() and
34 * irq_create_of_mapping() to make things easier to callers
35 */
36unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
37{
38 struct of_phandle_args oirq;
39
40 if (of_irq_parse_one(device: dev, index, out_irq: &oirq))
41 return 0;
42
43 return irq_create_of_mapping(irq_data: &oirq);
44}
45EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
46
47/**
48 * of_irq_find_parent - Given a device node, find its interrupt parent node
49 * @child: pointer to device node
50 *
51 * Return: A pointer to the interrupt parent node, or NULL if the interrupt
52 * parent could not be determined.
53 */
54struct device_node *of_irq_find_parent(struct device_node *child)
55{
56 struct device_node *p;
57 phandle parent;
58
59 if (!of_node_get(node: child))
60 return NULL;
61
62 do {
63 if (of_property_read_u32(np: child, propname: "interrupt-parent", out_value: &parent)) {
64 p = of_get_parent(node: child);
65 } else {
66 if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
67 p = of_node_get(of_irq_dflt_pic);
68 else
69 p = of_find_node_by_phandle(handle: parent);
70 }
71 of_node_put(node: child);
72 child = p;
73 } while (p && of_get_property(node: p, name: "#interrupt-cells", NULL) == NULL);
74
75 return p;
76}
77EXPORT_SYMBOL_GPL(of_irq_find_parent);
78
79/*
80 * These interrupt controllers abuse interrupt-map for unspeakable
81 * reasons and rely on the core code to *ignore* it (the drivers do
82 * their own parsing of the property).
83 *
84 * If you think of adding to the list for something *new*, think
85 * again. There is a high chance that you will be sent back to the
86 * drawing board.
87 */
88static const char * const of_irq_imap_abusers[] = {
89 "CBEA,platform-spider-pic",
90 "sti,platform-spider-pic",
91 "realtek,rtl-intc",
92 "fsl,ls1021a-extirq",
93 "fsl,ls1043a-extirq",
94 "fsl,ls1088a-extirq",
95 "renesas,rza1-irqc",
96 NULL,
97};
98
99/**
100 * of_irq_parse_raw - Low level interrupt tree parsing
101 * @addr: address specifier (start of "reg" property of the device) in be32 format
102 * @out_irq: structure of_phandle_args updated by this function
103 *
104 * This function is a low-level interrupt tree walking function. It
105 * can be used to do a partial walk with synthetized reg and interrupts
106 * properties, for example when resolving PCI interrupts when no device
107 * node exist for the parent. It takes an interrupt specifier structure as
108 * input, walks the tree looking for any interrupt-map properties, translates
109 * the specifier for each map, and then returns the translated map.
110 *
111 * Return: 0 on success and a negative number on error
112 */
113int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
114{
115 struct device_node *ipar, *tnode, *old = NULL, *newpar = NULL;
116 __be32 initial_match_array[MAX_PHANDLE_ARGS];
117 const __be32 *match_array = initial_match_array;
118 const __be32 *tmp, *imap, *imask, dummy_imask[] = { [0 ... MAX_PHANDLE_ARGS] = cpu_to_be32(~0) };
119 u32 intsize = 1, addrsize, newintsize = 0, newaddrsize = 0;
120 int imaplen, match, i, rc = -EINVAL;
121
122#ifdef DEBUG
123 of_print_phandle_args("of_irq_parse_raw: ", out_irq);
124#endif
125
126 ipar = of_node_get(node: out_irq->np);
127
128 /* First get the #interrupt-cells property of the current cursor
129 * that tells us how to interpret the passed-in intspec. If there
130 * is none, we are nice and just walk up the tree
131 */
132 do {
133 if (!of_property_read_u32(np: ipar, propname: "#interrupt-cells", out_value: &intsize))
134 break;
135 tnode = ipar;
136 ipar = of_irq_find_parent(ipar);
137 of_node_put(node: tnode);
138 } while (ipar);
139 if (ipar == NULL) {
140 pr_debug(" -> no parent found !\n");
141 goto fail;
142 }
143
144 pr_debug("of_irq_parse_raw: ipar=%pOF, size=%d\n", ipar, intsize);
145
146 if (out_irq->args_count != intsize)
147 goto fail;
148
149 /* Look for this #address-cells. We have to implement the old linux
150 * trick of looking for the parent here as some device-trees rely on it
151 */
152 old = of_node_get(node: ipar);
153 do {
154 tmp = of_get_property(node: old, name: "#address-cells", NULL);
155 tnode = of_get_parent(node: old);
156 of_node_put(node: old);
157 old = tnode;
158 } while (old && tmp == NULL);
159 of_node_put(node: old);
160 old = NULL;
161 addrsize = (tmp == NULL) ? 2 : be32_to_cpu(*tmp);
162
163 pr_debug(" -> addrsize=%d\n", addrsize);
164
165 /* Range check so that the temporary buffer doesn't overflow */
166 if (WARN_ON(addrsize + intsize > MAX_PHANDLE_ARGS)) {
167 rc = -EFAULT;
168 goto fail;
169 }
170
171 /* Precalculate the match array - this simplifies match loop */
172 for (i = 0; i < addrsize; i++)
173 initial_match_array[i] = addr ? addr[i] : 0;
174 for (i = 0; i < intsize; i++)
175 initial_match_array[addrsize + i] = cpu_to_be32(out_irq->args[i]);
176
177 /* Now start the actual "proper" walk of the interrupt tree */
178 while (ipar != NULL) {
179 /*
180 * Now check if cursor is an interrupt-controller and
181 * if it is then we are done, unless there is an
182 * interrupt-map which takes precedence except on one
183 * of these broken platforms that want to parse
184 * interrupt-map themselves for $reason.
185 */
186 bool intc = of_property_read_bool(np: ipar, propname: "interrupt-controller");
187
188 imap = of_get_property(node: ipar, name: "interrupt-map", lenp: &imaplen);
189 if (intc &&
190 (!imap || of_device_compatible_match(device: ipar, compat: of_irq_imap_abusers))) {
191 pr_debug(" -> got it !\n");
192 return 0;
193 }
194
195 /*
196 * interrupt-map parsing does not work without a reg
197 * property when #address-cells != 0
198 */
199 if (addrsize && !addr) {
200 pr_debug(" -> no reg passed in when needed !\n");
201 goto fail;
202 }
203
204 /* No interrupt map, check for an interrupt parent */
205 if (imap == NULL) {
206 pr_debug(" -> no map, getting parent\n");
207 newpar = of_irq_find_parent(ipar);
208 goto skiplevel;
209 }
210 imaplen /= sizeof(u32);
211
212 /* Look for a mask */
213 imask = of_get_property(node: ipar, name: "interrupt-map-mask", NULL);
214 if (!imask)
215 imask = dummy_imask;
216
217 /* Parse interrupt-map */
218 match = 0;
219 while (imaplen > (addrsize + intsize + 1) && !match) {
220 /* Compare specifiers */
221 match = 1;
222 for (i = 0; i < (addrsize + intsize); i++, imaplen--)
223 match &= !((match_array[i] ^ *imap++) & imask[i]);
224
225 pr_debug(" -> match=%d (imaplen=%d)\n", match, imaplen);
226
227 /* Get the interrupt parent */
228 if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
229 newpar = of_node_get(of_irq_dflt_pic);
230 else
231 newpar = of_find_node_by_phandle(be32_to_cpup(p: imap));
232 imap++;
233 --imaplen;
234
235 /* Check if not found */
236 if (newpar == NULL) {
237 pr_debug(" -> imap parent not found !\n");
238 goto fail;
239 }
240
241 if (!of_device_is_available(device: newpar))
242 match = 0;
243
244 /* Get #interrupt-cells and #address-cells of new
245 * parent
246 */
247 if (of_property_read_u32(np: newpar, propname: "#interrupt-cells",
248 out_value: &newintsize)) {
249 pr_debug(" -> parent lacks #interrupt-cells!\n");
250 goto fail;
251 }
252 if (of_property_read_u32(np: newpar, propname: "#address-cells",
253 out_value: &newaddrsize))
254 newaddrsize = 0;
255
256 pr_debug(" -> newintsize=%d, newaddrsize=%d\n",
257 newintsize, newaddrsize);
258
259 /* Check for malformed properties */
260 if (WARN_ON(newaddrsize + newintsize > MAX_PHANDLE_ARGS)
261 || (imaplen < (newaddrsize + newintsize))) {
262 rc = -EFAULT;
263 goto fail;
264 }
265
266 imap += newaddrsize + newintsize;
267 imaplen -= newaddrsize + newintsize;
268
269 pr_debug(" -> imaplen=%d\n", imaplen);
270 }
271 if (!match) {
272 if (intc) {
273 /*
274 * The PASEMI Nemo is a known offender, so
275 * let's only warn for anyone else.
276 */
277 WARN(!IS_ENABLED(CONFIG_PPC_PASEMI),
278 "%pOF interrupt-map failed, using interrupt-controller\n",
279 ipar);
280 return 0;
281 }
282
283 goto fail;
284 }
285
286 /*
287 * Successfully parsed an interrupt-map translation; copy new
288 * interrupt specifier into the out_irq structure
289 */
290 match_array = imap - newaddrsize - newintsize;
291 for (i = 0; i < newintsize; i++)
292 out_irq->args[i] = be32_to_cpup(p: imap - newintsize + i);
293 out_irq->args_count = intsize = newintsize;
294 addrsize = newaddrsize;
295
296 if (ipar == newpar) {
297 pr_debug("%pOF interrupt-map entry to self\n", ipar);
298 return 0;
299 }
300
301 skiplevel:
302 /* Iterate again with new parent */
303 out_irq->np = newpar;
304 pr_debug(" -> new parent: %pOF\n", newpar);
305 of_node_put(node: ipar);
306 ipar = newpar;
307 newpar = NULL;
308 }
309 rc = -ENOENT; /* No interrupt-map found */
310
311 fail:
312 of_node_put(node: ipar);
313 of_node_put(node: newpar);
314
315 return rc;
316}
317EXPORT_SYMBOL_GPL(of_irq_parse_raw);
318
319/**
320 * of_irq_parse_one - Resolve an interrupt for a device
321 * @device: the device whose interrupt is to be resolved
322 * @index: index of the interrupt to resolve
323 * @out_irq: structure of_phandle_args filled by this function
324 *
325 * This function resolves an interrupt for a node by walking the interrupt tree,
326 * finding which interrupt controller node it is attached to, and returning the
327 * interrupt specifier that can be used to retrieve a Linux IRQ number.
328 */
329int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_args *out_irq)
330{
331 struct device_node *p;
332 const __be32 *addr;
333 u32 intsize;
334 int i, res;
335
336 pr_debug("of_irq_parse_one: dev=%pOF, index=%d\n", device, index);
337
338 /* OldWorld mac stuff is "special", handle out of line */
339 if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
340 return of_irq_parse_oldworld(device, index, out_irq);
341
342 /* Get the reg property (if any) */
343 addr = of_get_property(node: device, name: "reg", NULL);
344
345 /* Try the new-style interrupts-extended first */
346 res = of_parse_phandle_with_args(np: device, list_name: "interrupts-extended",
347 cells_name: "#interrupt-cells", index, out_args: out_irq);
348 if (!res)
349 return of_irq_parse_raw(addr, out_irq);
350
351 /* Look for the interrupt parent. */
352 p = of_irq_find_parent(device);
353 if (p == NULL)
354 return -EINVAL;
355
356 /* Get size of interrupt specifier */
357 if (of_property_read_u32(np: p, propname: "#interrupt-cells", out_value: &intsize)) {
358 res = -EINVAL;
359 goto out;
360 }
361
362 pr_debug(" parent=%pOF, intsize=%d\n", p, intsize);
363
364 /* Copy intspec into irq structure */
365 out_irq->np = p;
366 out_irq->args_count = intsize;
367 for (i = 0; i < intsize; i++) {
368 res = of_property_read_u32_index(np: device, propname: "interrupts",
369 index: (index * intsize) + i,
370 out_value: out_irq->args + i);
371 if (res)
372 goto out;
373 }
374
375 pr_debug(" intspec=%d\n", *out_irq->args);
376
377
378 /* Check if there are any interrupt-map translations to process */
379 res = of_irq_parse_raw(addr, out_irq);
380 out:
381 of_node_put(node: p);
382 return res;
383}
384EXPORT_SYMBOL_GPL(of_irq_parse_one);
385
386/**
387 * of_irq_to_resource - Decode a node's IRQ and return it as a resource
388 * @dev: pointer to device tree node
389 * @index: zero-based index of the irq
390 * @r: pointer to resource structure to return result into.
391 */
392int of_irq_to_resource(struct device_node *dev, int index, struct resource *r)
393{
394 int irq = of_irq_get(dev, index);
395
396 if (irq < 0)
397 return irq;
398
399 /* Only dereference the resource if both the
400 * resource and the irq are valid. */
401 if (r && irq) {
402 const char *name = NULL;
403
404 memset(r, 0, sizeof(*r));
405 /*
406 * Get optional "interrupt-names" property to add a name
407 * to the resource.
408 */
409 of_property_read_string_index(np: dev, propname: "interrupt-names", index,
410 output: &name);
411
412 r->start = r->end = irq;
413 r->flags = IORESOURCE_IRQ | irqd_get_trigger_type(d: irq_get_irq_data(irq));
414 r->name = name ? name : of_node_full_name(np: dev);
415 }
416
417 return irq;
418}
419EXPORT_SYMBOL_GPL(of_irq_to_resource);
420
421/**
422 * of_irq_get - Decode a node's IRQ and return it as a Linux IRQ number
423 * @dev: pointer to device tree node
424 * @index: zero-based index of the IRQ
425 *
426 * Return: Linux IRQ number on success, or 0 on the IRQ mapping failure, or
427 * -EPROBE_DEFER if the IRQ domain is not yet created, or error code in case
428 * of any other failure.
429 */
430int of_irq_get(struct device_node *dev, int index)
431{
432 int rc;
433 struct of_phandle_args oirq;
434 struct irq_domain *domain;
435
436 rc = of_irq_parse_one(dev, index, &oirq);
437 if (rc)
438 return rc;
439
440 domain = irq_find_host(node: oirq.np);
441 if (!domain) {
442 rc = -EPROBE_DEFER;
443 goto out;
444 }
445
446 rc = irq_create_of_mapping(irq_data: &oirq);
447out:
448 of_node_put(node: oirq.np);
449
450 return rc;
451}
452EXPORT_SYMBOL_GPL(of_irq_get);
453
454/**
455 * of_irq_get_byname - Decode a node's IRQ and return it as a Linux IRQ number
456 * @dev: pointer to device tree node
457 * @name: IRQ name
458 *
459 * Return: Linux IRQ number on success, or 0 on the IRQ mapping failure, or
460 * -EPROBE_DEFER if the IRQ domain is not yet created, or error code in case
461 * of any other failure.
462 */
463int of_irq_get_byname(struct device_node *dev, const char *name)
464{
465 int index;
466
467 if (unlikely(!name))
468 return -EINVAL;
469
470 index = of_property_match_string(np: dev, propname: "interrupt-names", string: name);
471 if (index < 0)
472 return index;
473
474 return of_irq_get(dev, index);
475}
476EXPORT_SYMBOL_GPL(of_irq_get_byname);
477
478/**
479 * of_irq_count - Count the number of IRQs a node uses
480 * @dev: pointer to device tree node
481 */
482int of_irq_count(struct device_node *dev)
483{
484 struct of_phandle_args irq;
485 int nr = 0;
486
487 while (of_irq_parse_one(dev, nr, &irq) == 0)
488 nr++;
489
490 return nr;
491}
492
493/**
494 * of_irq_to_resource_table - Fill in resource table with node's IRQ info
495 * @dev: pointer to device tree node
496 * @res: array of resources to fill in
497 * @nr_irqs: the number of IRQs (and upper bound for num of @res elements)
498 *
499 * Return: The size of the filled in table (up to @nr_irqs).
500 */
501int of_irq_to_resource_table(struct device_node *dev, struct resource *res,
502 int nr_irqs)
503{
504 int i;
505
506 for (i = 0; i < nr_irqs; i++, res++)
507 if (of_irq_to_resource(dev, i, res) <= 0)
508 break;
509
510 return i;
511}
512EXPORT_SYMBOL_GPL(of_irq_to_resource_table);
513
514struct of_intc_desc {
515 struct list_head list;
516 of_irq_init_cb_t irq_init_cb;
517 struct device_node *dev;
518 struct device_node *interrupt_parent;
519};
520
521/**
522 * of_irq_init - Scan and init matching interrupt controllers in DT
523 * @matches: 0 terminated array of nodes to match and init function to call
524 *
525 * This function scans the device tree for matching interrupt controller nodes,
526 * and calls their initialization functions in order with parents first.
527 */
528void __init of_irq_init(const struct of_device_id *matches)
529{
530 const struct of_device_id *match;
531 struct device_node *np, *parent = NULL;
532 struct of_intc_desc *desc, *temp_desc;
533 struct list_head intc_desc_list, intc_parent_list;
534
535 INIT_LIST_HEAD(list: &intc_desc_list);
536 INIT_LIST_HEAD(list: &intc_parent_list);
537
538 for_each_matching_node_and_match(np, matches, &match) {
539 if (!of_property_read_bool(np, propname: "interrupt-controller") ||
540 !of_device_is_available(device: np))
541 continue;
542
543 if (WARN(!match->data, "of_irq_init: no init function for %s\n",
544 match->compatible))
545 continue;
546
547 /*
548 * Here, we allocate and populate an of_intc_desc with the node
549 * pointer, interrupt-parent device_node etc.
550 */
551 desc = kzalloc(size: sizeof(*desc), GFP_KERNEL);
552 if (!desc) {
553 of_node_put(node: np);
554 goto err;
555 }
556
557 desc->irq_init_cb = match->data;
558 desc->dev = of_node_get(node: np);
559 /*
560 * interrupts-extended can reference multiple parent domains.
561 * Arbitrarily pick the first one; assume any other parents
562 * are the same distance away from the root irq controller.
563 */
564 desc->interrupt_parent = of_parse_phandle(np, phandle_name: "interrupts-extended", index: 0);
565 if (!desc->interrupt_parent)
566 desc->interrupt_parent = of_irq_find_parent(np);
567 if (desc->interrupt_parent == np) {
568 of_node_put(node: desc->interrupt_parent);
569 desc->interrupt_parent = NULL;
570 }
571 list_add_tail(new: &desc->list, head: &intc_desc_list);
572 }
573
574 /*
575 * The root irq controller is the one without an interrupt-parent.
576 * That one goes first, followed by the controllers that reference it,
577 * followed by the ones that reference the 2nd level controllers, etc.
578 */
579 while (!list_empty(head: &intc_desc_list)) {
580 /*
581 * Process all controllers with the current 'parent'.
582 * First pass will be looking for NULL as the parent.
583 * The assumption is that NULL parent means a root controller.
584 */
585 list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
586 int ret;
587
588 if (desc->interrupt_parent != parent)
589 continue;
590
591 list_del(entry: &desc->list);
592
593 of_node_set_flag(n: desc->dev, OF_POPULATED);
594
595 pr_debug("of_irq_init: init %pOF (%p), parent %p\n",
596 desc->dev,
597 desc->dev, desc->interrupt_parent);
598 ret = desc->irq_init_cb(desc->dev,
599 desc->interrupt_parent);
600 if (ret) {
601 pr_err("%s: Failed to init %pOF (%p), parent %p\n",
602 __func__, desc->dev, desc->dev,
603 desc->interrupt_parent);
604 of_node_clear_flag(n: desc->dev, OF_POPULATED);
605 kfree(objp: desc);
606 continue;
607 }
608
609 /*
610 * This one is now set up; add it to the parent list so
611 * its children can get processed in a subsequent pass.
612 */
613 list_add_tail(new: &desc->list, head: &intc_parent_list);
614 }
615
616 /* Get the next pending parent that might have children */
617 desc = list_first_entry_or_null(&intc_parent_list,
618 typeof(*desc), list);
619 if (!desc) {
620 pr_err("of_irq_init: children remain, but no parents\n");
621 break;
622 }
623 list_del(entry: &desc->list);
624 parent = desc->dev;
625 kfree(objp: desc);
626 }
627
628 list_for_each_entry_safe(desc, temp_desc, &intc_parent_list, list) {
629 list_del(entry: &desc->list);
630 kfree(objp: desc);
631 }
632err:
633 list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
634 list_del(entry: &desc->list);
635 of_node_put(node: desc->dev);
636 kfree(objp: desc);
637 }
638}
639
640static u32 __of_msi_map_id(struct device *dev, struct device_node **np,
641 u32 id_in)
642{
643 struct device *parent_dev;
644 u32 id_out = id_in;
645
646 /*
647 * Walk up the device parent links looking for one with a
648 * "msi-map" property.
649 */
650 for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent)
651 if (!of_map_id(np: parent_dev->of_node, id: id_in, map_name: "msi-map",
652 map_mask_name: "msi-map-mask", target: np, id_out: &id_out))
653 break;
654 return id_out;
655}
656
657/**
658 * of_msi_map_id - Map a MSI ID for a device.
659 * @dev: device for which the mapping is to be done.
660 * @msi_np: device node of the expected msi controller.
661 * @id_in: unmapped MSI ID for the device.
662 *
663 * Walk up the device hierarchy looking for devices with a "msi-map"
664 * property. If found, apply the mapping to @id_in.
665 *
666 * Return: The mapped MSI ID.
667 */
668u32 of_msi_map_id(struct device *dev, struct device_node *msi_np, u32 id_in)
669{
670 return __of_msi_map_id(dev, np: &msi_np, id_in);
671}
672
673/**
674 * of_msi_map_get_device_domain - Use msi-map to find the relevant MSI domain
675 * @dev: device for which the mapping is to be done.
676 * @id: Device ID.
677 * @bus_token: Bus token
678 *
679 * Walk up the device hierarchy looking for devices with a "msi-map"
680 * property.
681 *
682 * Returns: the MSI domain for this device (or NULL on failure)
683 */
684struct irq_domain *of_msi_map_get_device_domain(struct device *dev, u32 id,
685 u32 bus_token)
686{
687 struct device_node *np = NULL;
688
689 __of_msi_map_id(dev, np: &np, id_in: id);
690 return irq_find_matching_host(node: np, bus_token);
691}
692
693/**
694 * of_msi_get_domain - Use msi-parent to find the relevant MSI domain
695 * @dev: device for which the domain is requested
696 * @np: device node for @dev
697 * @token: bus type for this domain
698 *
699 * Parse the msi-parent property (both the simple and the complex
700 * versions), and returns the corresponding MSI domain.
701 *
702 * Returns: the MSI domain for this device (or NULL on failure).
703 */
704struct irq_domain *of_msi_get_domain(struct device *dev,
705 struct device_node *np,
706 enum irq_domain_bus_token token)
707{
708 struct device_node *msi_np;
709 struct irq_domain *d;
710
711 /* Check for a single msi-parent property */
712 msi_np = of_parse_phandle(np, phandle_name: "msi-parent", index: 0);
713 if (msi_np && !of_property_read_bool(np: msi_np, propname: "#msi-cells")) {
714 d = irq_find_matching_host(node: msi_np, bus_token: token);
715 if (!d)
716 of_node_put(node: msi_np);
717 return d;
718 }
719
720 if (token == DOMAIN_BUS_PLATFORM_MSI) {
721 /* Check for the complex msi-parent version */
722 struct of_phandle_args args;
723 int index = 0;
724
725 while (!of_parse_phandle_with_args(np, list_name: "msi-parent",
726 cells_name: "#msi-cells",
727 index, out_args: &args)) {
728 d = irq_find_matching_host(node: args.np, bus_token: token);
729 if (d)
730 return d;
731
732 of_node_put(node: args.np);
733 index++;
734 }
735 }
736
737 return NULL;
738}
739EXPORT_SYMBOL_GPL(of_msi_get_domain);
740
741/**
742 * of_msi_configure - Set the msi_domain field of a device
743 * @dev: device structure to associate with an MSI irq domain
744 * @np: device node for that device
745 */
746void of_msi_configure(struct device *dev, struct device_node *np)
747{
748 dev_set_msi_domain(dev,
749 d: of_msi_get_domain(dev, np, DOMAIN_BUS_PLATFORM_MSI));
750}
751EXPORT_SYMBOL_GPL(of_msi_configure);
752

source code of linux/drivers/of/irq.c