xref: /kernel/linux/linux-6.6/drivers/of/platform.c (revision 62306a36)
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
24#include "of_private.h"
25
26const struct of_device_id of_default_bus_match_table[] = {
27	{ .compatible = "simple-bus", },
28	{ .compatible = "simple-mfd", },
29	{ .compatible = "isa", },
30#ifdef CONFIG_ARM_AMBA
31	{ .compatible = "arm,amba-bus", },
32#endif /* CONFIG_ARM_AMBA */
33	{} /* Empty terminated list */
34};
35
36/**
37 * of_find_device_by_node - Find the platform_device associated with a node
38 * @np: Pointer to device tree node
39 *
40 * Takes a reference to the embedded struct device which needs to be dropped
41 * after use.
42 *
43 * Return: platform_device pointer, or NULL if not found
44 */
45struct platform_device *of_find_device_by_node(struct device_node *np)
46{
47	struct device *dev;
48
49	dev = bus_find_device_by_of_node(&platform_bus_type, np);
50	return dev ? to_platform_device(dev) : NULL;
51}
52EXPORT_SYMBOL(of_find_device_by_node);
53
54int of_device_add(struct platform_device *ofdev)
55{
56	BUG_ON(ofdev->dev.of_node == NULL);
57
58	/* name and id have to be set so that the platform bus doesn't get
59	 * confused on matching */
60	ofdev->name = dev_name(&ofdev->dev);
61	ofdev->id = PLATFORM_DEVID_NONE;
62
63	/*
64	 * If this device has not binding numa node in devicetree, that is
65	 * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this
66	 * device is on the same node as the parent.
67	 */
68	set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
69
70	return device_add(&ofdev->dev);
71}
72
73int of_device_register(struct platform_device *pdev)
74{
75	device_initialize(&pdev->dev);
76	return of_device_add(pdev);
77}
78EXPORT_SYMBOL(of_device_register);
79
80void of_device_unregister(struct platform_device *ofdev)
81{
82	device_unregister(&ofdev->dev);
83}
84EXPORT_SYMBOL(of_device_unregister);
85
86#ifdef CONFIG_OF_ADDRESS
87static const struct of_device_id of_skipped_node_table[] = {
88	{ .compatible = "operating-points-v2", },
89	{} /* Empty terminated list */
90};
91
92/*
93 * The following routines scan a subtree and registers a device for
94 * each applicable node.
95 *
96 * Note: sparc doesn't use these routines because it has a different
97 * mechanism for creating devices from device tree nodes.
98 */
99
100/**
101 * of_device_make_bus_id - Use the device node data to assign a unique name
102 * @dev: pointer to device structure that is linked to a device tree node
103 *
104 * This routine will first try using the translated bus address to
105 * derive a unique name. If it cannot, then it will prepend names from
106 * parent nodes until a unique name can be derived.
107 */
108static void of_device_make_bus_id(struct device *dev)
109{
110	struct device_node *node = dev->of_node;
111	const __be32 *reg;
112	u64 addr;
113	u32 mask;
114
115	/* Construct the name, using parent nodes if necessary to ensure uniqueness */
116	while (node->parent) {
117		/*
118		 * If the address can be translated, then that is as much
119		 * uniqueness as we need. Make it the first component and return
120		 */
121		reg = of_get_property(node, "reg", NULL);
122		if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
123			if (!of_property_read_u32(node, "mask", &mask))
124				dev_set_name(dev, dev_name(dev) ? "%llx.%x.%pOFn:%s" : "%llx.%x.%pOFn",
125					     addr, ffs(mask) - 1, node, dev_name(dev));
126
127			else
128				dev_set_name(dev, dev_name(dev) ? "%llx.%pOFn:%s" : "%llx.%pOFn",
129					     addr, node, dev_name(dev));
130			return;
131		}
132
133		/* format arguments only used if dev_name() resolves to NULL */
134		dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
135			     kbasename(node->full_name), dev_name(dev));
136		node = node->parent;
137	}
138}
139
140/**
141 * of_device_alloc - Allocate and initialize an of_device
142 * @np: device node to assign to device
143 * @bus_id: Name to assign to the device.  May be null to use default name.
144 * @parent: Parent device.
145 */
146struct platform_device *of_device_alloc(struct device_node *np,
147				  const char *bus_id,
148				  struct device *parent)
149{
150	struct platform_device *dev;
151	int rc, i, num_reg = 0;
152	struct resource *res;
153
154	dev = platform_device_alloc("", PLATFORM_DEVID_NONE);
155	if (!dev)
156		return NULL;
157
158	/* count the io resources */
159	num_reg = of_address_count(np);
160
161	/* Populate the resource table */
162	if (num_reg) {
163		res = kcalloc(num_reg, sizeof(*res), GFP_KERNEL);
164		if (!res) {
165			platform_device_put(dev);
166			return NULL;
167		}
168
169		dev->num_resources = num_reg;
170		dev->resource = res;
171		for (i = 0; i < num_reg; i++, res++) {
172			rc = of_address_to_resource(np, i, res);
173			WARN_ON(rc);
174		}
175	}
176
177	/* setup generic device info */
178	device_set_node(&dev->dev, of_fwnode_handle(of_node_get(np)));
179	dev->dev.parent = parent ? : &platform_bus;
180
181	if (bus_id)
182		dev_set_name(&dev->dev, "%s", bus_id);
183	else
184		of_device_make_bus_id(&dev->dev);
185
186	return dev;
187}
188EXPORT_SYMBOL(of_device_alloc);
189
190/**
191 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
192 * @np: pointer to node to create device for
193 * @bus_id: name to assign device
194 * @platform_data: pointer to populate platform_data pointer with
195 * @parent: Linux device model parent device.
196 *
197 * Return: Pointer to created platform device, or NULL if a device was not
198 * registered.  Unavailable devices will not get registered.
199 */
200static struct platform_device *of_platform_device_create_pdata(
201					struct device_node *np,
202					const char *bus_id,
203					void *platform_data,
204					struct device *parent)
205{
206	struct platform_device *dev;
207
208	if (!of_device_is_available(np) ||
209	    of_node_test_and_set_flag(np, OF_POPULATED))
210		return NULL;
211
212	dev = of_device_alloc(np, bus_id, parent);
213	if (!dev)
214		goto err_clear_flag;
215
216	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
217	if (!dev->dev.dma_mask)
218		dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
219	dev->dev.bus = &platform_bus_type;
220	dev->dev.platform_data = platform_data;
221	of_msi_configure(&dev->dev, dev->dev.of_node);
222
223	if (of_device_add(dev) != 0) {
224		platform_device_put(dev);
225		goto err_clear_flag;
226	}
227
228	return dev;
229
230err_clear_flag:
231	of_node_clear_flag(np, OF_POPULATED);
232	return NULL;
233}
234
235/**
236 * of_platform_device_create - Alloc, initialize and register an of_device
237 * @np: pointer to node to create device for
238 * @bus_id: name to assign device
239 * @parent: Linux device model parent device.
240 *
241 * Return: Pointer to created platform device, or NULL if a device was not
242 * registered.  Unavailable devices will not get registered.
243 */
244struct platform_device *of_platform_device_create(struct device_node *np,
245					    const char *bus_id,
246					    struct device *parent)
247{
248	return of_platform_device_create_pdata(np, bus_id, NULL, parent);
249}
250EXPORT_SYMBOL(of_platform_device_create);
251
252#ifdef CONFIG_ARM_AMBA
253static struct amba_device *of_amba_device_create(struct device_node *node,
254						 const char *bus_id,
255						 void *platform_data,
256						 struct device *parent)
257{
258	struct amba_device *dev;
259	int ret;
260
261	pr_debug("Creating amba device %pOF\n", node);
262
263	if (!of_device_is_available(node) ||
264	    of_node_test_and_set_flag(node, OF_POPULATED))
265		return NULL;
266
267	dev = amba_device_alloc(NULL, 0, 0);
268	if (!dev)
269		goto err_clear_flag;
270
271	/* AMBA devices only support a single DMA mask */
272	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
273	dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
274
275	/* setup generic device info */
276	device_set_node(&dev->dev, of_fwnode_handle(of_node_get(node)));
277	dev->dev.parent = parent ? : &platform_bus;
278	dev->dev.platform_data = platform_data;
279	if (bus_id)
280		dev_set_name(&dev->dev, "%s", bus_id);
281	else
282		of_device_make_bus_id(&dev->dev);
283
284	/* Allow the HW Peripheral ID to be overridden */
285	of_property_read_u32(node, "arm,primecell-periphid", &dev->periphid);
286
287	ret = of_address_to_resource(node, 0, &dev->res);
288	if (ret) {
289		pr_err("amba: of_address_to_resource() failed (%d) for %pOF\n",
290		       ret, node);
291		goto err_free;
292	}
293
294	ret = amba_device_add(dev, &iomem_resource);
295	if (ret) {
296		pr_err("amba_device_add() failed (%d) for %pOF\n",
297		       ret, node);
298		goto err_free;
299	}
300
301	return dev;
302
303err_free:
304	amba_device_put(dev);
305err_clear_flag:
306	of_node_clear_flag(node, OF_POPULATED);
307	return NULL;
308}
309#else /* CONFIG_ARM_AMBA */
310static struct amba_device *of_amba_device_create(struct device_node *node,
311						 const char *bus_id,
312						 void *platform_data,
313						 struct device *parent)
314{
315	return NULL;
316}
317#endif /* CONFIG_ARM_AMBA */
318
319/*
320 * of_dev_lookup() - Given a device node, lookup the preferred Linux name
321 */
322static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
323				 struct device_node *np)
324{
325	const struct of_dev_auxdata *auxdata;
326	struct resource res;
327	int compatible = 0;
328
329	if (!lookup)
330		return NULL;
331
332	auxdata = lookup;
333	for (; auxdata->compatible; auxdata++) {
334		if (!of_device_is_compatible(np, auxdata->compatible))
335			continue;
336		compatible++;
337		if (!of_address_to_resource(np, 0, &res))
338			if (res.start != auxdata->phys_addr)
339				continue;
340		pr_debug("%pOF: devname=%s\n", np, auxdata->name);
341		return auxdata;
342	}
343
344	if (!compatible)
345		return NULL;
346
347	/* Try compatible match if no phys_addr and name are specified */
348	auxdata = lookup;
349	for (; auxdata->compatible; auxdata++) {
350		if (!of_device_is_compatible(np, auxdata->compatible))
351			continue;
352		if (!auxdata->phys_addr && !auxdata->name) {
353			pr_debug("%pOF: compatible match\n", np);
354			return auxdata;
355		}
356	}
357
358	return NULL;
359}
360
361/**
362 * of_platform_bus_create() - Create a device for a node and its children.
363 * @bus: device node of the bus to instantiate
364 * @matches: match table for bus nodes
365 * @lookup: auxdata table for matching id and platform_data with device nodes
366 * @parent: parent for new device, or NULL for top level.
367 * @strict: require compatible property
368 *
369 * Creates a platform_device for the provided device_node, and optionally
370 * recursively create devices for all the child nodes.
371 */
372static int of_platform_bus_create(struct device_node *bus,
373				  const struct of_device_id *matches,
374				  const struct of_dev_auxdata *lookup,
375				  struct device *parent, bool strict)
376{
377	const struct of_dev_auxdata *auxdata;
378	struct device_node *child;
379	struct platform_device *dev;
380	const char *bus_id = NULL;
381	void *platform_data = NULL;
382	int rc = 0;
383
384	/* Make sure it has a compatible property */
385	if (strict && (!of_get_property(bus, "compatible", NULL))) {
386		pr_debug("%s() - skipping %pOF, no compatible prop\n",
387			 __func__, bus);
388		return 0;
389	}
390
391	/* Skip nodes for which we don't want to create devices */
392	if (unlikely(of_match_node(of_skipped_node_table, bus))) {
393		pr_debug("%s() - skipping %pOF node\n", __func__, bus);
394		return 0;
395	}
396
397	if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
398		pr_debug("%s() - skipping %pOF, already populated\n",
399			__func__, bus);
400		return 0;
401	}
402
403	auxdata = of_dev_lookup(lookup, bus);
404	if (auxdata) {
405		bus_id = auxdata->name;
406		platform_data = auxdata->platform_data;
407	}
408
409	if (of_device_is_compatible(bus, "arm,primecell")) {
410		/*
411		 * Don't return an error here to keep compatibility with older
412		 * device tree files.
413		 */
414		of_amba_device_create(bus, bus_id, platform_data, parent);
415		return 0;
416	}
417
418	dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
419	if (!dev || !of_match_node(matches, bus))
420		return 0;
421
422	for_each_child_of_node(bus, child) {
423		pr_debug("   create child: %pOF\n", child);
424		rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
425		if (rc) {
426			of_node_put(child);
427			break;
428		}
429	}
430	of_node_set_flag(bus, OF_POPULATED_BUS);
431	return rc;
432}
433
434/**
435 * of_platform_bus_probe() - Probe the device-tree for platform buses
436 * @root: parent of the first level to probe or NULL for the root of the tree
437 * @matches: match table for bus nodes
438 * @parent: parent to hook devices from, NULL for toplevel
439 *
440 * Note that children of the provided root are not instantiated as devices
441 * unless the specified root itself matches the bus list and is not NULL.
442 */
443int of_platform_bus_probe(struct device_node *root,
444			  const struct of_device_id *matches,
445			  struct device *parent)
446{
447	struct device_node *child;
448	int rc = 0;
449
450	root = root ? of_node_get(root) : of_find_node_by_path("/");
451	if (!root)
452		return -EINVAL;
453
454	pr_debug("%s()\n", __func__);
455	pr_debug(" starting at: %pOF\n", root);
456
457	/* Do a self check of bus type, if there's a match, create children */
458	if (of_match_node(matches, root)) {
459		rc = of_platform_bus_create(root, matches, NULL, parent, false);
460	} else for_each_child_of_node(root, child) {
461		if (!of_match_node(matches, child))
462			continue;
463		rc = of_platform_bus_create(child, matches, NULL, parent, false);
464		if (rc) {
465			of_node_put(child);
466			break;
467		}
468	}
469
470	of_node_put(root);
471	return rc;
472}
473EXPORT_SYMBOL(of_platform_bus_probe);
474
475/**
476 * of_platform_populate() - Populate platform_devices from device tree data
477 * @root: parent of the first level to probe or NULL for the root of the tree
478 * @matches: match table, NULL to use the default
479 * @lookup: auxdata table for matching id and platform_data with device nodes
480 * @parent: parent to hook devices from, NULL for toplevel
481 *
482 * Similar to of_platform_bus_probe(), this function walks the device tree
483 * and creates devices from nodes.  It differs in that it follows the modern
484 * convention of requiring all device nodes to have a 'compatible' property,
485 * and it is suitable for creating devices which are children of the root
486 * node (of_platform_bus_probe will only create children of the root which
487 * are selected by the @matches argument).
488 *
489 * New board support should be using this function instead of
490 * of_platform_bus_probe().
491 *
492 * Return: 0 on success, < 0 on failure.
493 */
494int of_platform_populate(struct device_node *root,
495			const struct of_device_id *matches,
496			const struct of_dev_auxdata *lookup,
497			struct device *parent)
498{
499	struct device_node *child;
500	int rc = 0;
501
502	root = root ? of_node_get(root) : of_find_node_by_path("/");
503	if (!root)
504		return -EINVAL;
505
506	pr_debug("%s()\n", __func__);
507	pr_debug(" starting at: %pOF\n", root);
508
509	device_links_supplier_sync_state_pause();
510	for_each_child_of_node(root, child) {
511		rc = of_platform_bus_create(child, matches, lookup, parent, true);
512		if (rc) {
513			of_node_put(child);
514			break;
515		}
516	}
517	device_links_supplier_sync_state_resume();
518
519	of_node_set_flag(root, OF_POPULATED_BUS);
520
521	of_node_put(root);
522	return rc;
523}
524EXPORT_SYMBOL_GPL(of_platform_populate);
525
526int of_platform_default_populate(struct device_node *root,
527				 const struct of_dev_auxdata *lookup,
528				 struct device *parent)
529{
530	return of_platform_populate(root, of_default_bus_match_table, lookup,
531				    parent);
532}
533EXPORT_SYMBOL_GPL(of_platform_default_populate);
534
535static const struct of_device_id reserved_mem_matches[] = {
536	{ .compatible = "phram" },
537	{ .compatible = "qcom,rmtfs-mem" },
538	{ .compatible = "qcom,cmd-db" },
539	{ .compatible = "qcom,smem" },
540	{ .compatible = "ramoops" },
541	{ .compatible = "nvmem-rmem" },
542	{ .compatible = "google,open-dice" },
543	{}
544};
545
546static int __init of_platform_default_populate_init(void)
547{
548	struct device_node *node;
549
550	device_links_supplier_sync_state_pause();
551
552	if (!of_have_populated_dt())
553		return -ENODEV;
554
555	if (IS_ENABLED(CONFIG_PPC)) {
556		struct device_node *boot_display = NULL;
557		struct platform_device *dev;
558		int display_number = 0;
559		int ret;
560
561		/* Check if we have a MacOS display without a node spec */
562		if (of_property_present(of_chosen, "linux,bootx-noscreen")) {
563			/*
564			 * The old code tried to work out which node was the MacOS
565			 * display based on the address. I'm dropping that since the
566			 * lack of a node spec only happens with old BootX versions
567			 * (users can update) and with this code, they'll still get
568			 * a display (just not the palette hacks).
569			 */
570			dev = platform_device_alloc("bootx-noscreen", 0);
571			if (WARN_ON(!dev))
572				return -ENOMEM;
573			ret = platform_device_add(dev);
574			if (WARN_ON(ret)) {
575				platform_device_put(dev);
576				return ret;
577			}
578		}
579
580		/*
581		 * For OF framebuffers, first create the device for the boot display,
582		 * then for the other framebuffers. Only fail for the boot display;
583		 * ignore errors for the rest.
584		 */
585		for_each_node_by_type(node, "display") {
586			if (!of_get_property(node, "linux,opened", NULL) ||
587			    !of_get_property(node, "linux,boot-display", NULL))
588				continue;
589			dev = of_platform_device_create(node, "of-display", NULL);
590			of_node_put(node);
591			if (WARN_ON(!dev))
592				return -ENOMEM;
593			boot_display = node;
594			display_number++;
595			break;
596		}
597		for_each_node_by_type(node, "display") {
598			char buf[14];
599			const char *of_display_format = "of-display.%d";
600
601			if (!of_get_property(node, "linux,opened", NULL) || node == boot_display)
602				continue;
603			ret = snprintf(buf, sizeof(buf), of_display_format, display_number++);
604			if (ret < sizeof(buf))
605				of_platform_device_create(node, buf, NULL);
606		}
607
608	} else {
609		/*
610		 * Handle certain compatibles explicitly, since we don't want to create
611		 * platform_devices for every node in /reserved-memory with a
612		 * "compatible",
613		 */
614		for_each_matching_node(node, reserved_mem_matches)
615			of_platform_device_create(node, NULL, NULL);
616
617		node = of_find_node_by_path("/firmware");
618		if (node) {
619			of_platform_populate(node, NULL, NULL, NULL);
620			of_node_put(node);
621		}
622
623		node = of_get_compatible_child(of_chosen, "simple-framebuffer");
624		of_platform_device_create(node, NULL, NULL);
625		of_node_put(node);
626
627		/* Populate everything else. */
628		of_platform_default_populate(NULL, NULL, NULL);
629	}
630
631	return 0;
632}
633arch_initcall_sync(of_platform_default_populate_init);
634
635static int __init of_platform_sync_state_init(void)
636{
637	device_links_supplier_sync_state_resume();
638	return 0;
639}
640late_initcall_sync(of_platform_sync_state_init);
641
642int of_platform_device_destroy(struct device *dev, void *data)
643{
644	/* Do not touch devices not populated from the device tree */
645	if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
646		return 0;
647
648	/* Recurse for any nodes that were treated as busses */
649	if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
650		device_for_each_child(dev, NULL, of_platform_device_destroy);
651
652	of_node_clear_flag(dev->of_node, OF_POPULATED);
653	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
654
655	if (dev->bus == &platform_bus_type)
656		platform_device_unregister(to_platform_device(dev));
657#ifdef CONFIG_ARM_AMBA
658	else if (dev->bus == &amba_bustype)
659		amba_device_unregister(to_amba_device(dev));
660#endif
661
662	return 0;
663}
664EXPORT_SYMBOL_GPL(of_platform_device_destroy);
665
666/**
667 * of_platform_depopulate() - Remove devices populated from device tree
668 * @parent: device which children will be removed
669 *
670 * Complementary to of_platform_populate(), this function removes children
671 * of the given device (and, recurrently, their children) that have been
672 * created from their respective device tree nodes (and only those,
673 * leaving others - eg. manually created - unharmed).
674 */
675void of_platform_depopulate(struct device *parent)
676{
677	if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
678		device_for_each_child_reverse(parent, NULL, of_platform_device_destroy);
679		of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
680	}
681}
682EXPORT_SYMBOL_GPL(of_platform_depopulate);
683
684static void devm_of_platform_populate_release(struct device *dev, void *res)
685{
686	of_platform_depopulate(*(struct device **)res);
687}
688
689/**
690 * devm_of_platform_populate() - Populate platform_devices from device tree data
691 * @dev: device that requested to populate from device tree data
692 *
693 * Similar to of_platform_populate(), but will automatically call
694 * of_platform_depopulate() when the device is unbound from the bus.
695 *
696 * Return: 0 on success, < 0 on failure.
697 */
698int devm_of_platform_populate(struct device *dev)
699{
700	struct device **ptr;
701	int ret;
702
703	if (!dev)
704		return -EINVAL;
705
706	ptr = devres_alloc(devm_of_platform_populate_release,
707			   sizeof(*ptr), GFP_KERNEL);
708	if (!ptr)
709		return -ENOMEM;
710
711	ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
712	if (ret) {
713		devres_free(ptr);
714	} else {
715		*ptr = dev;
716		devres_add(dev, ptr);
717	}
718
719	return ret;
720}
721EXPORT_SYMBOL_GPL(devm_of_platform_populate);
722
723static int devm_of_platform_match(struct device *dev, void *res, void *data)
724{
725	struct device **ptr = res;
726
727	if (!ptr) {
728		WARN_ON(!ptr);
729		return 0;
730	}
731
732	return *ptr == data;
733}
734
735/**
736 * devm_of_platform_depopulate() - Remove devices populated from device tree
737 * @dev: device that requested to depopulate from device tree data
738 *
739 * Complementary to devm_of_platform_populate(), this function removes children
740 * of the given device (and, recurrently, their children) that have been
741 * created from their respective device tree nodes (and only those,
742 * leaving others - eg. manually created - unharmed).
743 */
744void devm_of_platform_depopulate(struct device *dev)
745{
746	int ret;
747
748	ret = devres_release(dev, devm_of_platform_populate_release,
749			     devm_of_platform_match, dev);
750
751	WARN_ON(ret);
752}
753EXPORT_SYMBOL_GPL(devm_of_platform_depopulate);
754
755#ifdef CONFIG_OF_DYNAMIC
756static int of_platform_notify(struct notifier_block *nb,
757				unsigned long action, void *arg)
758{
759	struct of_reconfig_data *rd = arg;
760	struct platform_device *pdev_parent, *pdev;
761	bool children_left;
762
763	switch (of_reconfig_get_state_change(action, rd)) {
764	case OF_RECONFIG_CHANGE_ADD:
765		/* verify that the parent is a bus */
766		if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
767			return NOTIFY_OK;	/* not for us */
768
769		/* already populated? (driver using of_populate manually) */
770		if (of_node_check_flag(rd->dn, OF_POPULATED))
771			return NOTIFY_OK;
772
773		/*
774		 * Clear the flag before adding the device so that fw_devlink
775		 * doesn't skip adding consumers to this device.
776		 */
777		rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
778		/* pdev_parent may be NULL when no bus platform device */
779		pdev_parent = of_find_device_by_node(rd->dn->parent);
780		pdev = of_platform_device_create(rd->dn, NULL,
781				pdev_parent ? &pdev_parent->dev : NULL);
782		platform_device_put(pdev_parent);
783
784		if (pdev == NULL) {
785			pr_err("%s: failed to create for '%pOF'\n",
786					__func__, rd->dn);
787			/* of_platform_device_create tosses the error code */
788			return notifier_from_errno(-EINVAL);
789		}
790		break;
791
792	case OF_RECONFIG_CHANGE_REMOVE:
793
794		/* already depopulated? */
795		if (!of_node_check_flag(rd->dn, OF_POPULATED))
796			return NOTIFY_OK;
797
798		/* find our device by node */
799		pdev = of_find_device_by_node(rd->dn);
800		if (pdev == NULL)
801			return NOTIFY_OK;	/* no? not meant for us */
802
803		/* unregister takes one ref away */
804		of_platform_device_destroy(&pdev->dev, &children_left);
805
806		/* and put the reference of the find */
807		platform_device_put(pdev);
808		break;
809	}
810
811	return NOTIFY_OK;
812}
813
814static struct notifier_block platform_of_notifier = {
815	.notifier_call = of_platform_notify,
816};
817
818void of_platform_register_reconfig_notifier(void)
819{
820	WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
821}
822#endif /* CONFIG_OF_DYNAMIC */
823
824#endif /* CONFIG_OF_ADDRESS */
825