1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
4 * <benh@kernel.crashing.org>
5 * and Arnd Bergmann, IBM Corp.
6 * Merged from powerpc/kernel/of_platform.c and
7 * sparc{,64}/kernel/of_device.c by Stephen Rothwell
8 */
9
10#define pr_fmt(fmt) "OF: " fmt
11
12#include <linux/errno.h>
13#include <linux/module.h>
14#include <linux/amba/bus.h>
15#include <linux/device.h>
16#include <linux/dma-mapping.h>
17#include <linux/slab.h>
18#include <linux/of_address.h>
19#include <linux/of_device.h>
20#include <linux/of_irq.h>
21#include <linux/of_platform.h>
22#include <linux/platform_device.h>
23#include <linux/sysfb.h>
24
25#include "of_private.h"
26
27/**
28 * of_find_device_by_node - Find the platform_device associated with a node
29 * @np: Pointer to device tree node
30 *
31 * Takes a reference to the embedded struct device which needs to be dropped
32 * after use.
33 *
34 * Return: platform_device pointer, or NULL if not found
35 */
36struct platform_device *of_find_device_by_node(struct device_node *np)
37{
38 struct device *dev;
39
40 dev = bus_find_device_by_of_node(bus: &platform_bus_type, np);
41 return dev ? to_platform_device(dev) : NULL;
42}
43EXPORT_SYMBOL(of_find_device_by_node);
44
45int of_device_add(struct platform_device *ofdev)
46{
47 BUG_ON(ofdev->dev.of_node == NULL);
48
49 /* name and id have to be set so that the platform bus doesn't get
50 * confused on matching */
51 ofdev->name = dev_name(dev: &ofdev->dev);
52 ofdev->id = PLATFORM_DEVID_NONE;
53
54 /*
55 * If this device has not binding numa node in devicetree, that is
56 * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this
57 * device is on the same node as the parent.
58 */
59 set_dev_node(dev: &ofdev->dev, node: of_node_to_nid(np: ofdev->dev.of_node));
60
61 return device_add(dev: &ofdev->dev);
62}
63
64int of_device_register(struct platform_device *pdev)
65{
66 device_initialize(dev: &pdev->dev);
67 return of_device_add(ofdev: pdev);
68}
69EXPORT_SYMBOL(of_device_register);
70
71void of_device_unregister(struct platform_device *ofdev)
72{
73 device_unregister(dev: &ofdev->dev);
74}
75EXPORT_SYMBOL(of_device_unregister);
76
77#ifdef CONFIG_OF_ADDRESS
78static const struct of_device_id of_skipped_node_table[] = {
79 { .compatible = "operating-points-v2", },
80 {} /* Empty terminated list */
81};
82
83/*
84 * The following routines scan a subtree and registers a device for
85 * each applicable node.
86 *
87 * Note: sparc doesn't use these routines because it has a different
88 * mechanism for creating devices from device tree nodes.
89 */
90
91/**
92 * of_device_alloc - Allocate and initialize an of_device
93 * @np: device node to assign to device
94 * @bus_id: Name to assign to the device. May be null to use default name.
95 * @parent: Parent device.
96 */
97struct platform_device *of_device_alloc(struct device_node *np,
98 const char *bus_id,
99 struct device *parent)
100{
101 struct platform_device *dev;
102 int rc, i, num_reg = 0;
103 struct resource *res;
104
105 dev = platform_device_alloc(name: "", PLATFORM_DEVID_NONE);
106 if (!dev)
107 return NULL;
108
109 /* count the io resources */
110 num_reg = of_address_count(np);
111
112 /* Populate the resource table */
113 if (num_reg) {
114 res = kcalloc(num_reg, sizeof(*res), GFP_KERNEL);
115 if (!res) {
116 platform_device_put(pdev: dev);
117 return NULL;
118 }
119
120 dev->num_resources = num_reg;
121 dev->resource = res;
122 for (i = 0; i < num_reg; i++, res++) {
123 rc = of_address_to_resource(dev: np, index: i, r: res);
124 WARN_ON(rc);
125 }
126 }
127
128 /* setup generic device info */
129 device_set_node(dev: &dev->dev, of_fwnode_handle(of_node_get(np)));
130 dev->dev.parent = parent ? : &platform_bus;
131
132 if (bus_id)
133 dev_set_name(dev: &dev->dev, name: "%s", bus_id);
134 else
135 of_device_make_bus_id(dev: &dev->dev);
136
137 return dev;
138}
139EXPORT_SYMBOL(of_device_alloc);
140
141/**
142 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
143 * @np: pointer to node to create device for
144 * @bus_id: name to assign device
145 * @platform_data: pointer to populate platform_data pointer with
146 * @parent: Linux device model parent device.
147 *
148 * Return: Pointer to created platform device, or NULL if a device was not
149 * registered. Unavailable devices will not get registered.
150 */
151static struct platform_device *of_platform_device_create_pdata(
152 struct device_node *np,
153 const char *bus_id,
154 void *platform_data,
155 struct device *parent)
156{
157 struct platform_device *dev;
158
159 pr_debug("create platform device: %pOF\n", np);
160
161 if (!of_device_is_available(device: np) ||
162 of_node_test_and_set_flag(n: np, OF_POPULATED))
163 return NULL;
164
165 dev = of_device_alloc(np, bus_id, parent);
166 if (!dev)
167 goto err_clear_flag;
168
169 dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
170 if (!dev->dev.dma_mask)
171 dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
172 dev->dev.bus = &platform_bus_type;
173 dev->dev.platform_data = platform_data;
174 of_msi_configure(dev: &dev->dev, np: dev->dev.of_node);
175
176 if (of_device_add(ofdev: dev) != 0) {
177 platform_device_put(pdev: dev);
178 goto err_clear_flag;
179 }
180
181 return dev;
182
183err_clear_flag:
184 of_node_clear_flag(n: np, OF_POPULATED);
185 return NULL;
186}
187
188/**
189 * of_platform_device_create - Alloc, initialize and register an of_device
190 * @np: pointer to node to create device for
191 * @bus_id: name to assign device
192 * @parent: Linux device model parent device.
193 *
194 * Return: Pointer to created platform device, or NULL if a device was not
195 * registered. Unavailable devices will not get registered.
196 */
197struct platform_device *of_platform_device_create(struct device_node *np,
198 const char *bus_id,
199 struct device *parent)
200{
201 return of_platform_device_create_pdata(np, bus_id, NULL, parent);
202}
203EXPORT_SYMBOL(of_platform_device_create);
204
205#ifdef CONFIG_ARM_AMBA
206static struct amba_device *of_amba_device_create(struct device_node *node,
207 const char *bus_id,
208 void *platform_data,
209 struct device *parent)
210{
211 struct amba_device *dev;
212 int ret;
213
214 pr_debug("Creating amba device %pOF\n", node);
215
216 if (!of_device_is_available(node) ||
217 of_node_test_and_set_flag(node, OF_POPULATED))
218 return NULL;
219
220 dev = amba_device_alloc(NULL, 0, 0);
221 if (!dev)
222 goto err_clear_flag;
223
224 /* AMBA devices only support a single DMA mask */
225 dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
226 dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
227
228 /* setup generic device info */
229 device_set_node(&dev->dev, of_fwnode_handle(node));
230 dev->dev.parent = parent ? : &platform_bus;
231 dev->dev.platform_data = platform_data;
232 if (bus_id)
233 dev_set_name(&dev->dev, "%s", bus_id);
234 else
235 of_device_make_bus_id(&dev->dev);
236
237 /* Allow the HW Peripheral ID to be overridden */
238 of_property_read_u32(node, "arm,primecell-periphid", &dev->periphid);
239
240 ret = of_address_to_resource(node, 0, &dev->res);
241 if (ret) {
242 pr_err("amba: of_address_to_resource() failed (%d) for %pOF\n",
243 ret, node);
244 goto err_free;
245 }
246
247 ret = amba_device_add(dev, &iomem_resource);
248 if (ret) {
249 pr_err("amba_device_add() failed (%d) for %pOF\n",
250 ret, node);
251 goto err_free;
252 }
253
254 return dev;
255
256err_free:
257 amba_device_put(dev);
258err_clear_flag:
259 of_node_clear_flag(node, OF_POPULATED);
260 return NULL;
261}
262#else /* CONFIG_ARM_AMBA */
263static struct amba_device *of_amba_device_create(struct device_node *node,
264 const char *bus_id,
265 void *platform_data,
266 struct device *parent)
267{
268 return NULL;
269}
270#endif /* CONFIG_ARM_AMBA */
271
272/*
273 * of_dev_lookup() - Given a device node, lookup the preferred Linux name
274 */
275static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
276 struct device_node *np)
277{
278 const struct of_dev_auxdata *auxdata;
279 struct resource res;
280 int compatible = 0;
281
282 if (!lookup)
283 return NULL;
284
285 auxdata = lookup;
286 for (; auxdata->compatible; auxdata++) {
287 if (!of_device_is_compatible(device: np, auxdata->compatible))
288 continue;
289 compatible++;
290 if (!of_address_to_resource(dev: np, index: 0, r: &res))
291 if (res.start != auxdata->phys_addr)
292 continue;
293 pr_debug("%pOF: devname=%s\n", np, auxdata->name);
294 return auxdata;
295 }
296
297 if (!compatible)
298 return NULL;
299
300 /* Try compatible match if no phys_addr and name are specified */
301 auxdata = lookup;
302 for (; auxdata->compatible; auxdata++) {
303 if (!of_device_is_compatible(device: np, auxdata->compatible))
304 continue;
305 if (!auxdata->phys_addr && !auxdata->name) {
306 pr_debug("%pOF: compatible match\n", np);
307 return auxdata;
308 }
309 }
310
311 return NULL;
312}
313
314/**
315 * of_platform_bus_create() - Create a device for a node and its children.
316 * @bus: device node of the bus to instantiate
317 * @matches: match table for bus nodes
318 * @lookup: auxdata table for matching id and platform_data with device nodes
319 * @parent: parent for new device, or NULL for top level.
320 * @strict: require compatible property
321 *
322 * Creates a platform_device for the provided device_node, and optionally
323 * recursively create devices for all the child nodes.
324 */
325static int of_platform_bus_create(struct device_node *bus,
326 const struct of_device_id *matches,
327 const struct of_dev_auxdata *lookup,
328 struct device *parent, bool strict)
329{
330 const struct of_dev_auxdata *auxdata;
331 struct platform_device *dev;
332 const char *bus_id = NULL;
333 void *platform_data = NULL;
334 int rc = 0;
335
336 /* Make sure it has a compatible property */
337 if (strict && (!of_property_present(np: bus, propname: "compatible"))) {
338 pr_debug("%s() - skipping %pOF, no compatible prop\n",
339 __func__, bus);
340 return 0;
341 }
342
343 /* Skip nodes for which we don't want to create devices */
344 if (unlikely(of_match_node(of_skipped_node_table, bus))) {
345 pr_debug("%s() - skipping %pOF node\n", __func__, bus);
346 return 0;
347 }
348
349 if (of_node_check_flag(n: bus, OF_POPULATED_BUS)) {
350 pr_debug("%s() - skipping %pOF, already populated\n",
351 __func__, bus);
352 return 0;
353 }
354
355 auxdata = of_dev_lookup(lookup, np: bus);
356 if (auxdata) {
357 bus_id = auxdata->name;
358 platform_data = auxdata->platform_data;
359 }
360
361 if (of_device_is_compatible(device: bus, "arm,primecell")) {
362 /*
363 * Don't return an error here to keep compatibility with older
364 * device tree files.
365 */
366 of_amba_device_create(node: bus, bus_id, platform_data, parent);
367 return 0;
368 }
369
370 dev = of_platform_device_create_pdata(np: bus, bus_id, platform_data, parent);
371 if (!dev || !of_match_node(matches, node: bus))
372 return 0;
373
374 for_each_child_of_node_scoped(bus, child) {
375 pr_debug(" create child: %pOF\n", child);
376 rc = of_platform_bus_create(bus: child, matches, lookup, parent: &dev->dev, strict);
377 if (rc)
378 break;
379 }
380 of_node_set_flag(n: bus, OF_POPULATED_BUS);
381 return rc;
382}
383
384/**
385 * of_platform_bus_probe() - Probe the device-tree for platform buses
386 * @root: parent of the first level to probe or NULL for the root of the tree
387 * @matches: match table for bus nodes
388 * @parent: parent to hook devices from, NULL for toplevel
389 *
390 * Note that children of the provided root are not instantiated as devices
391 * unless the specified root itself matches the bus list and is not NULL.
392 */
393int of_platform_bus_probe(struct device_node *root,
394 const struct of_device_id *matches,
395 struct device *parent)
396{
397 struct device_node *child;
398 int rc = 0;
399
400 root = root ? of_node_get(node: root) : of_find_node_by_path(path: "/");
401 if (!root)
402 return -EINVAL;
403
404 pr_debug("%s()\n", __func__);
405 pr_debug(" starting at: %pOF\n", root);
406
407 /* Do a self check of bus type, if there's a match, create children */
408 if (of_match_node(matches, node: root)) {
409 rc = of_platform_bus_create(bus: root, matches, NULL, parent, strict: false);
410 } else for_each_child_of_node(root, child) {
411 if (!of_match_node(matches, node: child))
412 continue;
413 rc = of_platform_bus_create(bus: child, matches, NULL, parent, strict: false);
414 if (rc) {
415 of_node_put(node: child);
416 break;
417 }
418 }
419
420 of_node_put(node: root);
421 return rc;
422}
423EXPORT_SYMBOL(of_platform_bus_probe);
424
425/**
426 * of_platform_populate() - Populate platform_devices from device tree data
427 * @root: parent of the first level to probe or NULL for the root of the tree
428 * @matches: match table, NULL to use the default
429 * @lookup: auxdata table for matching id and platform_data with device nodes
430 * @parent: parent to hook devices from, NULL for toplevel
431 *
432 * Similar to of_platform_bus_probe(), this function walks the device tree
433 * and creates devices from nodes. It differs in that it follows the modern
434 * convention of requiring all device nodes to have a 'compatible' property,
435 * and it is suitable for creating devices which are children of the root
436 * node (of_platform_bus_probe will only create children of the root which
437 * are selected by the @matches argument).
438 *
439 * New board support should be using this function instead of
440 * of_platform_bus_probe().
441 *
442 * Return: 0 on success, < 0 on failure.
443 */
444int of_platform_populate(struct device_node *root,
445 const struct of_device_id *matches,
446 const struct of_dev_auxdata *lookup,
447 struct device *parent)
448{
449 int rc = 0;
450
451 root = root ? of_node_get(node: root) : of_find_node_by_path(path: "/");
452 if (!root)
453 return -EINVAL;
454
455 pr_debug("%s()\n", __func__);
456 pr_debug(" starting at: %pOF\n", root);
457
458 device_links_supplier_sync_state_pause();
459 for_each_child_of_node_scoped(root, child) {
460 rc = of_platform_bus_create(bus: child, matches, lookup, parent, strict: true);
461 if (rc)
462 break;
463 }
464 device_links_supplier_sync_state_resume();
465
466 of_node_set_flag(n: root, OF_POPULATED_BUS);
467
468 of_node_put(node: root);
469 return rc;
470}
471EXPORT_SYMBOL_GPL(of_platform_populate);
472
473int of_platform_default_populate(struct device_node *root,
474 const struct of_dev_auxdata *lookup,
475 struct device *parent)
476{
477 static const struct of_device_id match_table[] = {
478 { .compatible = "simple-bus", },
479 { .compatible = "simple-mfd", },
480 { .compatible = "isa", },
481#ifdef CONFIG_ARM_AMBA
482 { .compatible = "arm,amba-bus", },
483#endif /* CONFIG_ARM_AMBA */
484 {} /* Empty terminated list */
485 };
486
487 return of_platform_populate(root, match_table, lookup, parent);
488}
489EXPORT_SYMBOL_GPL(of_platform_default_populate);
490
491static const struct of_device_id reserved_mem_matches[] = {
492 { .compatible = "phram" },
493 { .compatible = "qcom,rmtfs-mem" },
494 { .compatible = "qcom,cmd-db" },
495 { .compatible = "qcom,smem" },
496 { .compatible = "ramoops" },
497 { .compatible = "nvmem-rmem" },
498 { .compatible = "google,open-dice" },
499 {}
500};
501
502static int __init of_platform_default_populate_init(void)
503{
504 struct device_node *node;
505
506 device_links_supplier_sync_state_pause();
507
508 if (IS_ENABLED(CONFIG_PPC)) {
509 struct device_node *boot_display = NULL;
510 struct platform_device *dev;
511 int display_number = 0;
512 int ret;
513
514 /* Check if we have a MacOS display without a node spec */
515 if (of_property_present(np: of_chosen, propname: "linux,bootx-noscreen")) {
516 /*
517 * The old code tried to work out which node was the MacOS
518 * display based on the address. I'm dropping that since the
519 * lack of a node spec only happens with old BootX versions
520 * (users can update) and with this code, they'll still get
521 * a display (just not the palette hacks).
522 */
523 dev = platform_device_alloc(name: "bootx-noscreen", id: 0);
524 if (WARN_ON(!dev))
525 return -ENOMEM;
526 ret = platform_device_add(pdev: dev);
527 if (WARN_ON(ret)) {
528 platform_device_put(pdev: dev);
529 return ret;
530 }
531 }
532
533 /*
534 * For OF framebuffers, first create the device for the boot display,
535 * then for the other framebuffers. Only fail for the boot display;
536 * ignore errors for the rest.
537 */
538 for_each_node_by_type(node, "display") {
539 if (!of_property_read_bool(np: node, propname: "linux,opened") ||
540 !of_property_read_bool(np: node, propname: "linux,boot-display"))
541 continue;
542 dev = of_platform_device_create(node, "of-display", NULL);
543 of_node_put(node);
544 if (WARN_ON(!dev))
545 return -ENOMEM;
546 boot_display = node;
547 display_number++;
548 break;
549 }
550 for_each_node_by_type(node, "display") {
551 char buf[14];
552 const char *of_display_format = "of-display.%d";
553
554 if (!of_property_read_bool(np: node, propname: "linux,opened") || node == boot_display)
555 continue;
556 ret = snprintf(buf, size: sizeof(buf), fmt: of_display_format, display_number++);
557 if (ret < sizeof(buf))
558 of_platform_device_create(node, buf, NULL);
559 }
560
561 } else {
562 /*
563 * Handle certain compatibles explicitly, since we don't want to create
564 * platform_devices for every node in /reserved-memory with a
565 * "compatible",
566 */
567 for_each_matching_node(node, reserved_mem_matches)
568 of_platform_device_create(node, NULL, NULL);
569
570 node = of_find_node_by_path(path: "/firmware");
571 if (node) {
572 of_platform_default_populate(node, NULL, NULL);
573 of_node_put(node);
574 }
575
576 node = of_get_compatible_child(parent: of_chosen, compatible: "simple-framebuffer");
577 if (node) {
578 /*
579 * Since a "simple-framebuffer" device is already added
580 * here, disable the Generic System Framebuffers (sysfb)
581 * to prevent it from registering another device for the
582 * system framebuffer later (e.g: using the screen_info
583 * data that may had been filled as well).
584 *
585 * This can happen for example on DT systems that do EFI
586 * booting and may provide a GOP handle to the EFI stub.
587 */
588 sysfb_disable(NULL);
589 of_platform_device_create(node, NULL, NULL);
590 of_node_put(node);
591 }
592
593 /* Populate everything else. */
594 of_platform_default_populate(NULL, NULL, NULL);
595 }
596
597 return 0;
598}
599arch_initcall_sync(of_platform_default_populate_init);
600
601static int __init of_platform_sync_state_init(void)
602{
603 device_links_supplier_sync_state_resume();
604 return 0;
605}
606late_initcall_sync(of_platform_sync_state_init);
607
608int of_platform_device_destroy(struct device *dev, void *data)
609{
610 /* Do not touch devices not populated from the device tree */
611 if (!dev->of_node || !of_node_check_flag(n: dev->of_node, OF_POPULATED))
612 return 0;
613
614 /* Recurse for any nodes that were treated as busses */
615 if (of_node_check_flag(n: dev->of_node, OF_POPULATED_BUS))
616 device_for_each_child(parent: dev, NULL, fn: of_platform_device_destroy);
617
618 of_node_clear_flag(n: dev->of_node, OF_POPULATED);
619 of_node_clear_flag(n: dev->of_node, OF_POPULATED_BUS);
620
621 if (dev->bus == &platform_bus_type)
622 platform_device_unregister(to_platform_device(dev));
623#ifdef CONFIG_ARM_AMBA
624 else if (dev->bus == &amba_bustype)
625 amba_device_unregister(to_amba_device(dev));
626#endif
627
628 return 0;
629}
630EXPORT_SYMBOL_GPL(of_platform_device_destroy);
631
632/**
633 * of_platform_depopulate() - Remove devices populated from device tree
634 * @parent: device which children will be removed
635 *
636 * Complementary to of_platform_populate(), this function removes children
637 * of the given device (and, recursively, their children) that have been
638 * created from their respective device tree nodes (and only those,
639 * leaving others - eg. manually created - unharmed).
640 */
641void of_platform_depopulate(struct device *parent)
642{
643 if (parent->of_node && of_node_check_flag(n: parent->of_node, OF_POPULATED_BUS)) {
644 device_for_each_child_reverse(parent, NULL, fn: of_platform_device_destroy);
645 of_node_clear_flag(n: parent->of_node, OF_POPULATED_BUS);
646 }
647}
648EXPORT_SYMBOL_GPL(of_platform_depopulate);
649
650static void devm_of_platform_populate_release(struct device *dev, void *res)
651{
652 of_platform_depopulate(*(struct device **)res);
653}
654
655/**
656 * devm_of_platform_populate() - Populate platform_devices from device tree data
657 * @dev: device that requested to populate from device tree data
658 *
659 * Similar to of_platform_populate(), but will automatically call
660 * of_platform_depopulate() when the device is unbound from the bus.
661 *
662 * Return: 0 on success, < 0 on failure.
663 */
664int devm_of_platform_populate(struct device *dev)
665{
666 struct device **ptr;
667 int ret;
668
669 if (!dev)
670 return -EINVAL;
671
672 ptr = devres_alloc(devm_of_platform_populate_release,
673 sizeof(*ptr), GFP_KERNEL);
674 if (!ptr)
675 return -ENOMEM;
676
677 ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
678 if (ret) {
679 devres_free(res: ptr);
680 } else {
681 *ptr = dev;
682 devres_add(dev, res: ptr);
683 }
684
685 return ret;
686}
687EXPORT_SYMBOL_GPL(devm_of_platform_populate);
688
689static int devm_of_platform_match(struct device *dev, void *res, void *data)
690{
691 struct device **ptr = res;
692
693 if (!ptr) {
694 WARN_ON(!ptr);
695 return 0;
696 }
697
698 return *ptr == data;
699}
700
701/**
702 * devm_of_platform_depopulate() - Remove devices populated from device tree
703 * @dev: device that requested to depopulate from device tree data
704 *
705 * Complementary to devm_of_platform_populate(), this function removes children
706 * of the given device (and, recursively, their children) that have been
707 * created from their respective device tree nodes (and only those,
708 * leaving others - eg. manually created - unharmed).
709 */
710void devm_of_platform_depopulate(struct device *dev)
711{
712 int ret;
713
714 ret = devres_release(dev, release: devm_of_platform_populate_release,
715 match: devm_of_platform_match, match_data: dev);
716
717 WARN_ON(ret);
718}
719EXPORT_SYMBOL_GPL(devm_of_platform_depopulate);
720
721#ifdef CONFIG_OF_DYNAMIC
722static int of_platform_notify(struct notifier_block *nb,
723 unsigned long action, void *arg)
724{
725 struct of_reconfig_data *rd = arg;
726 struct platform_device *pdev_parent, *pdev;
727 bool children_left;
728 struct device_node *parent;
729
730 switch (of_reconfig_get_state_change(action, arg: rd)) {
731 case OF_RECONFIG_CHANGE_ADD:
732 parent = rd->dn->parent;
733 /* verify that the parent is a bus (or the root node) */
734 if (!of_node_is_root(node: parent) &&
735 !of_node_check_flag(n: parent, OF_POPULATED_BUS))
736 return NOTIFY_OK; /* not for us */
737
738 /* already populated? (driver using of_populate manually) */
739 if (of_node_check_flag(n: rd->dn, OF_POPULATED))
740 return NOTIFY_OK;
741
742 /*
743 * Clear the flag before adding the device so that fw_devlink
744 * doesn't skip adding consumers to this device.
745 */
746 rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
747 /* pdev_parent may be NULL when no bus platform device */
748 pdev_parent = of_find_device_by_node(parent);
749 pdev = of_platform_device_create(rd->dn, NULL,
750 pdev_parent ? &pdev_parent->dev : NULL);
751 platform_device_put(pdev: pdev_parent);
752
753 if (pdev == NULL) {
754 pr_err("%s: failed to create for '%pOF'\n",
755 __func__, rd->dn);
756 /* of_platform_device_create tosses the error code */
757 return notifier_from_errno(err: -EINVAL);
758 }
759 break;
760
761 case OF_RECONFIG_CHANGE_REMOVE:
762
763 /* already depopulated? */
764 if (!of_node_check_flag(n: rd->dn, OF_POPULATED))
765 return NOTIFY_OK;
766
767 /* find our device by node */
768 pdev = of_find_device_by_node(rd->dn);
769 if (pdev == NULL)
770 return NOTIFY_OK; /* no? not meant for us */
771
772 /* unregister takes one ref away */
773 of_platform_device_destroy(&pdev->dev, &children_left);
774
775 /* and put the reference of the find */
776 platform_device_put(pdev);
777 break;
778 }
779
780 return NOTIFY_OK;
781}
782
783static struct notifier_block platform_of_notifier = {
784 .notifier_call = of_platform_notify,
785};
786
787void of_platform_register_reconfig_notifier(void)
788{
789 WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
790}
791#endif /* CONFIG_OF_DYNAMIC */
792
793#endif /* CONFIG_OF_ADDRESS */
794

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