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v6.13.7
  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
 27const struct of_device_id of_default_bus_match_table[] = {
 28	{ .compatible = "simple-bus", },
 29	{ .compatible = "simple-mfd", },
 30	{ .compatible = "isa", },
 31#ifdef CONFIG_ARM_AMBA
 32	{ .compatible = "arm,amba-bus", },
 33#endif /* CONFIG_ARM_AMBA */
 34	{} /* Empty terminated list */
 35};
 36
 
 
 
 
 
 37/**
 38 * of_find_device_by_node - Find the platform_device associated with a node
 39 * @np: Pointer to device tree node
 40 *
 41 * Takes a reference to the embedded struct device which needs to be dropped
 42 * after use.
 43 *
 44 * Return: platform_device pointer, or NULL if not found
 45 */
 46struct platform_device *of_find_device_by_node(struct device_node *np)
 47{
 48	struct device *dev;
 49
 50	dev = bus_find_device_by_of_node(&platform_bus_type, np);
 51	return dev ? to_platform_device(dev) : NULL;
 52}
 53EXPORT_SYMBOL(of_find_device_by_node);
 54
 55int of_device_add(struct platform_device *ofdev)
 56{
 57	BUG_ON(ofdev->dev.of_node == NULL);
 58
 59	/* name and id have to be set so that the platform bus doesn't get
 60	 * confused on matching */
 61	ofdev->name = dev_name(&ofdev->dev);
 62	ofdev->id = PLATFORM_DEVID_NONE;
 63
 64	/*
 65	 * If this device has not binding numa node in devicetree, that is
 66	 * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this
 67	 * device is on the same node as the parent.
 68	 */
 69	set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
 70
 71	return device_add(&ofdev->dev);
 72}
 73
 74int of_device_register(struct platform_device *pdev)
 75{
 76	device_initialize(&pdev->dev);
 77	return of_device_add(pdev);
 78}
 79EXPORT_SYMBOL(of_device_register);
 80
 81void of_device_unregister(struct platform_device *ofdev)
 82{
 83	device_unregister(&ofdev->dev);
 84}
 85EXPORT_SYMBOL(of_device_unregister);
 86
 87#ifdef CONFIG_OF_ADDRESS
 88static const struct of_device_id of_skipped_node_table[] = {
 89	{ .compatible = "operating-points-v2", },
 90	{} /* Empty terminated list */
 91};
 92
 93/*
 94 * The following routines scan a subtree and registers a device for
 95 * each applicable node.
 96 *
 97 * Note: sparc doesn't use these routines because it has a different
 98 * mechanism for creating devices from device tree nodes.
 99 */
100
101/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
102 * of_device_alloc - Allocate and initialize an of_device
103 * @np: device node to assign to device
104 * @bus_id: Name to assign to the device.  May be null to use default name.
105 * @parent: Parent device.
106 */
107struct platform_device *of_device_alloc(struct device_node *np,
108				  const char *bus_id,
109				  struct device *parent)
110{
111	struct platform_device *dev;
112	int rc, i, num_reg = 0;
113	struct resource *res;
114
115	dev = platform_device_alloc("", PLATFORM_DEVID_NONE);
116	if (!dev)
117		return NULL;
118
119	/* count the io resources */
120	num_reg = of_address_count(np);
 
 
121
122	/* Populate the resource table */
123	if (num_reg) {
124		res = kcalloc(num_reg, sizeof(*res), GFP_KERNEL);
125		if (!res) {
126			platform_device_put(dev);
127			return NULL;
128		}
129
130		dev->num_resources = num_reg;
131		dev->resource = res;
132		for (i = 0; i < num_reg; i++, res++) {
133			rc = of_address_to_resource(np, i, res);
134			WARN_ON(rc);
135		}
 
 
 
136	}
137
138	/* setup generic device info */
139	device_set_node(&dev->dev, of_fwnode_handle(of_node_get(np)));
140	dev->dev.parent = parent ? : &platform_bus;
141
142	if (bus_id)
143		dev_set_name(&dev->dev, "%s", bus_id);
144	else
145		of_device_make_bus_id(&dev->dev);
146
147	return dev;
148}
149EXPORT_SYMBOL(of_device_alloc);
150
151/**
152 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
153 * @np: pointer to node to create device for
154 * @bus_id: name to assign device
155 * @platform_data: pointer to populate platform_data pointer with
156 * @parent: Linux device model parent device.
157 *
158 * Return: Pointer to created platform device, or NULL if a device was not
159 * registered.  Unavailable devices will not get registered.
160 */
161static struct platform_device *of_platform_device_create_pdata(
162					struct device_node *np,
163					const char *bus_id,
164					void *platform_data,
165					struct device *parent)
166{
167	struct platform_device *dev;
168
169	pr_debug("create platform device: %pOF\n", np);
170
171	if (!of_device_is_available(np) ||
172	    of_node_test_and_set_flag(np, OF_POPULATED))
173		return NULL;
174
175	dev = of_device_alloc(np, bus_id, parent);
176	if (!dev)
177		goto err_clear_flag;
178
179	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
180	if (!dev->dev.dma_mask)
181		dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
182	dev->dev.bus = &platform_bus_type;
183	dev->dev.platform_data = platform_data;
184	of_msi_configure(&dev->dev, dev->dev.of_node);
185
186	if (of_device_add(dev) != 0) {
187		platform_device_put(dev);
188		goto err_clear_flag;
189	}
190
191	return dev;
192
193err_clear_flag:
194	of_node_clear_flag(np, OF_POPULATED);
195	return NULL;
196}
197
198/**
199 * of_platform_device_create - Alloc, initialize and register an of_device
200 * @np: pointer to node to create device for
201 * @bus_id: name to assign device
202 * @parent: Linux device model parent device.
203 *
204 * Return: Pointer to created platform device, or NULL if a device was not
205 * registered.  Unavailable devices will not get registered.
206 */
207struct platform_device *of_platform_device_create(struct device_node *np,
208					    const char *bus_id,
209					    struct device *parent)
210{
211	return of_platform_device_create_pdata(np, bus_id, NULL, parent);
212}
213EXPORT_SYMBOL(of_platform_device_create);
214
215#ifdef CONFIG_ARM_AMBA
216static struct amba_device *of_amba_device_create(struct device_node *node,
217						 const char *bus_id,
218						 void *platform_data,
219						 struct device *parent)
220{
221	struct amba_device *dev;
222	int ret;
 
223
224	pr_debug("Creating amba device %pOF\n", node);
225
226	if (!of_device_is_available(node) ||
227	    of_node_test_and_set_flag(node, OF_POPULATED))
228		return NULL;
229
230	dev = amba_device_alloc(NULL, 0, 0);
231	if (!dev)
232		goto err_clear_flag;
233
234	/* AMBA devices only support a single DMA mask */
235	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
236	dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
237
238	/* setup generic device info */
239	device_set_node(&dev->dev, of_fwnode_handle(node));
 
240	dev->dev.parent = parent ? : &platform_bus;
241	dev->dev.platform_data = platform_data;
242	if (bus_id)
243		dev_set_name(&dev->dev, "%s", bus_id);
244	else
245		of_device_make_bus_id(&dev->dev);
246
247	/* Allow the HW Peripheral ID to be overridden */
248	of_property_read_u32(node, "arm,primecell-periphid", &dev->periphid);
 
 
 
 
 
 
249
250	ret = of_address_to_resource(node, 0, &dev->res);
251	if (ret) {
252		pr_err("amba: of_address_to_resource() failed (%d) for %pOF\n",
253		       ret, node);
254		goto err_free;
255	}
256
257	ret = amba_device_add(dev, &iomem_resource);
258	if (ret) {
259		pr_err("amba_device_add() failed (%d) for %pOF\n",
260		       ret, node);
261		goto err_free;
262	}
263
264	return dev;
265
266err_free:
267	amba_device_put(dev);
268err_clear_flag:
269	of_node_clear_flag(node, OF_POPULATED);
270	return NULL;
271}
272#else /* CONFIG_ARM_AMBA */
273static struct amba_device *of_amba_device_create(struct device_node *node,
274						 const char *bus_id,
275						 void *platform_data,
276						 struct device *parent)
277{
278	return NULL;
279}
280#endif /* CONFIG_ARM_AMBA */
281
282/*
283 * of_dev_lookup() - Given a device node, lookup the preferred Linux name
284 */
285static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
286				 struct device_node *np)
287{
288	const struct of_dev_auxdata *auxdata;
289	struct resource res;
290	int compatible = 0;
291
292	if (!lookup)
293		return NULL;
294
295	auxdata = lookup;
296	for (; auxdata->compatible; auxdata++) {
297		if (!of_device_is_compatible(np, auxdata->compatible))
298			continue;
299		compatible++;
300		if (!of_address_to_resource(np, 0, &res))
301			if (res.start != auxdata->phys_addr)
302				continue;
303		pr_debug("%pOF: devname=%s\n", np, auxdata->name);
304		return auxdata;
305	}
306
307	if (!compatible)
308		return NULL;
309
310	/* Try compatible match if no phys_addr and name are specified */
311	auxdata = lookup;
312	for (; auxdata->compatible; auxdata++) {
313		if (!of_device_is_compatible(np, auxdata->compatible))
314			continue;
315		if (!auxdata->phys_addr && !auxdata->name) {
316			pr_debug("%pOF: compatible match\n", np);
317			return auxdata;
318		}
319	}
320
321	return NULL;
322}
323
324/**
325 * of_platform_bus_create() - Create a device for a node and its children.
326 * @bus: device node of the bus to instantiate
327 * @matches: match table for bus nodes
328 * @lookup: auxdata table for matching id and platform_data with device nodes
329 * @parent: parent for new device, or NULL for top level.
330 * @strict: require compatible property
331 *
332 * Creates a platform_device for the provided device_node, and optionally
333 * recursively create devices for all the child nodes.
334 */
335static int of_platform_bus_create(struct device_node *bus,
336				  const struct of_device_id *matches,
337				  const struct of_dev_auxdata *lookup,
338				  struct device *parent, bool strict)
339{
340	const struct of_dev_auxdata *auxdata;
 
341	struct platform_device *dev;
342	const char *bus_id = NULL;
343	void *platform_data = NULL;
344	int rc = 0;
345
346	/* Make sure it has a compatible property */
347	if (strict && (!of_get_property(bus, "compatible", NULL))) {
348		pr_debug("%s() - skipping %pOF, no compatible prop\n",
349			 __func__, bus);
350		return 0;
351	}
352
353	/* Skip nodes for which we don't want to create devices */
354	if (unlikely(of_match_node(of_skipped_node_table, bus))) {
355		pr_debug("%s() - skipping %pOF node\n", __func__, bus);
356		return 0;
357	}
358
359	if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
360		pr_debug("%s() - skipping %pOF, already populated\n",
361			__func__, bus);
362		return 0;
363	}
364
365	auxdata = of_dev_lookup(lookup, bus);
366	if (auxdata) {
367		bus_id = auxdata->name;
368		platform_data = auxdata->platform_data;
369	}
370
371	if (of_device_is_compatible(bus, "arm,primecell")) {
372		/*
373		 * Don't return an error here to keep compatibility with older
374		 * device tree files.
375		 */
376		of_amba_device_create(bus, bus_id, platform_data, parent);
377		return 0;
378	}
379
380	dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
381	if (!dev || !of_match_node(matches, bus))
382		return 0;
383
384	for_each_child_of_node_scoped(bus, child) {
385		pr_debug("   create child: %pOF\n", child);
386		rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
387		if (rc)
 
388			break;
 
389	}
390	of_node_set_flag(bus, OF_POPULATED_BUS);
391	return rc;
392}
393
394/**
395 * of_platform_bus_probe() - Probe the device-tree for platform buses
396 * @root: parent of the first level to probe or NULL for the root of the tree
397 * @matches: match table for bus nodes
398 * @parent: parent to hook devices from, NULL for toplevel
399 *
400 * Note that children of the provided root are not instantiated as devices
401 * unless the specified root itself matches the bus list and is not NULL.
402 */
403int of_platform_bus_probe(struct device_node *root,
404			  const struct of_device_id *matches,
405			  struct device *parent)
406{
407	struct device_node *child;
408	int rc = 0;
409
410	root = root ? of_node_get(root) : of_find_node_by_path("/");
411	if (!root)
412		return -EINVAL;
413
414	pr_debug("%s()\n", __func__);
415	pr_debug(" starting at: %pOF\n", root);
416
417	/* Do a self check of bus type, if there's a match, create children */
418	if (of_match_node(matches, root)) {
419		rc = of_platform_bus_create(root, matches, NULL, parent, false);
420	} else for_each_child_of_node(root, child) {
421		if (!of_match_node(matches, child))
422			continue;
423		rc = of_platform_bus_create(child, matches, NULL, parent, false);
424		if (rc) {
425			of_node_put(child);
426			break;
427		}
428	}
429
430	of_node_put(root);
431	return rc;
432}
433EXPORT_SYMBOL(of_platform_bus_probe);
434
435/**
436 * of_platform_populate() - Populate platform_devices from device tree data
437 * @root: parent of the first level to probe or NULL for the root of the tree
438 * @matches: match table, NULL to use the default
439 * @lookup: auxdata table for matching id and platform_data with device nodes
440 * @parent: parent to hook devices from, NULL for toplevel
441 *
442 * Similar to of_platform_bus_probe(), this function walks the device tree
443 * and creates devices from nodes.  It differs in that it follows the modern
444 * convention of requiring all device nodes to have a 'compatible' property,
445 * and it is suitable for creating devices which are children of the root
446 * node (of_platform_bus_probe will only create children of the root which
447 * are selected by the @matches argument).
448 *
449 * New board support should be using this function instead of
450 * of_platform_bus_probe().
451 *
452 * Return: 0 on success, < 0 on failure.
453 */
454int of_platform_populate(struct device_node *root,
455			const struct of_device_id *matches,
456			const struct of_dev_auxdata *lookup,
457			struct device *parent)
458{
 
459	int rc = 0;
460
461	root = root ? of_node_get(root) : of_find_node_by_path("/");
462	if (!root)
463		return -EINVAL;
464
465	pr_debug("%s()\n", __func__);
466	pr_debug(" starting at: %pOF\n", root);
467
468	device_links_supplier_sync_state_pause();
469	for_each_child_of_node_scoped(root, child) {
470		rc = of_platform_bus_create(child, matches, lookup, parent, true);
471		if (rc)
 
472			break;
 
473	}
474	device_links_supplier_sync_state_resume();
475
476	of_node_set_flag(root, OF_POPULATED_BUS);
477
478	of_node_put(root);
479	return rc;
480}
481EXPORT_SYMBOL_GPL(of_platform_populate);
482
483int of_platform_default_populate(struct device_node *root,
484				 const struct of_dev_auxdata *lookup,
485				 struct device *parent)
486{
487	return of_platform_populate(root, of_default_bus_match_table, lookup,
488				    parent);
489}
490EXPORT_SYMBOL_GPL(of_platform_default_populate);
491
 
492static const struct of_device_id reserved_mem_matches[] = {
493	{ .compatible = "phram" },
494	{ .compatible = "qcom,rmtfs-mem" },
495	{ .compatible = "qcom,cmd-db" },
496	{ .compatible = "qcom,smem" },
497	{ .compatible = "ramoops" },
498	{ .compatible = "nvmem-rmem" },
499	{ .compatible = "google,open-dice" },
500	{}
501};
502
503static int __init of_platform_default_populate_init(void)
504{
505	struct device_node *node;
506
507	device_links_supplier_sync_state_pause();
508
509	if (IS_ENABLED(CONFIG_PPC)) {
510		struct device_node *boot_display = NULL;
511		struct platform_device *dev;
512		int display_number = 0;
513		int ret;
514
515		/* Check if we have a MacOS display without a node spec */
516		if (of_property_present(of_chosen, "linux,bootx-noscreen")) {
517			/*
518			 * The old code tried to work out which node was the MacOS
519			 * display based on the address. I'm dropping that since the
520			 * lack of a node spec only happens with old BootX versions
521			 * (users can update) and with this code, they'll still get
522			 * a display (just not the palette hacks).
523			 */
524			dev = platform_device_alloc("bootx-noscreen", 0);
525			if (WARN_ON(!dev))
526				return -ENOMEM;
527			ret = platform_device_add(dev);
528			if (WARN_ON(ret)) {
529				platform_device_put(dev);
530				return ret;
531			}
532		}
533
534		/*
535		 * For OF framebuffers, first create the device for the boot display,
536		 * then for the other framebuffers. Only fail for the boot display;
537		 * ignore errors for the rest.
538		 */
539		for_each_node_by_type(node, "display") {
540			if (!of_get_property(node, "linux,opened", NULL) ||
541			    !of_get_property(node, "linux,boot-display", NULL))
542				continue;
543			dev = of_platform_device_create(node, "of-display", NULL);
544			of_node_put(node);
545			if (WARN_ON(!dev))
546				return -ENOMEM;
547			boot_display = node;
548			display_number++;
549			break;
550		}
551		for_each_node_by_type(node, "display") {
552			char buf[14];
553			const char *of_display_format = "of-display.%d";
554
555			if (!of_get_property(node, "linux,opened", NULL) || node == boot_display)
556				continue;
557			ret = snprintf(buf, sizeof(buf), of_display_format, display_number++);
558			if (ret < sizeof(buf))
559				of_platform_device_create(node, buf, NULL);
560		}
561
562	} else {
563		/*
564		 * Handle certain compatibles explicitly, since we don't want to create
565		 * platform_devices for every node in /reserved-memory with a
566		 * "compatible",
567		 */
568		for_each_matching_node(node, reserved_mem_matches)
569			of_platform_device_create(node, NULL, NULL);
570
571		node = of_find_node_by_path("/firmware");
572		if (node) {
573			of_platform_populate(node, NULL, NULL, NULL);
574			of_node_put(node);
575		}
576
577		node = of_get_compatible_child(of_chosen, "simple-framebuffer");
578		if (node) {
579			/*
580			 * Since a "simple-framebuffer" device is already added
581			 * here, disable the Generic System Framebuffers (sysfb)
582			 * to prevent it from registering another device for the
583			 * system framebuffer later (e.g: using the screen_info
584			 * data that may had been filled as well).
585			 *
586			 * This can happen for example on DT systems that do EFI
587			 * booting and may provide a GOP handle to the EFI stub.
588			 */
589			sysfb_disable(NULL);
590			of_platform_device_create(node, NULL, NULL);
591			of_node_put(node);
592		}
593
594		/* Populate everything else. */
595		of_platform_default_populate(NULL, NULL, NULL);
 
 
596	}
597
598	return 0;
599}
600arch_initcall_sync(of_platform_default_populate_init);
601
602static int __init of_platform_sync_state_init(void)
603{
604	device_links_supplier_sync_state_resume();
605	return 0;
606}
607late_initcall_sync(of_platform_sync_state_init);
 
608
609int of_platform_device_destroy(struct device *dev, void *data)
610{
611	/* Do not touch devices not populated from the device tree */
612	if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
613		return 0;
614
615	/* Recurse for any nodes that were treated as busses */
616	if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
617		device_for_each_child(dev, NULL, of_platform_device_destroy);
618
619	of_node_clear_flag(dev->of_node, OF_POPULATED);
620	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
621
622	if (dev->bus == &platform_bus_type)
623		platform_device_unregister(to_platform_device(dev));
624#ifdef CONFIG_ARM_AMBA
625	else if (dev->bus == &amba_bustype)
626		amba_device_unregister(to_amba_device(dev));
627#endif
628
 
 
629	return 0;
630}
631EXPORT_SYMBOL_GPL(of_platform_device_destroy);
632
633/**
634 * of_platform_depopulate() - Remove devices populated from device tree
635 * @parent: device which children will be removed
636 *
637 * Complementary to of_platform_populate(), this function removes children
638 * of the given device (and, recursively, their children) that have been
639 * created from their respective device tree nodes (and only those,
640 * leaving others - eg. manually created - unharmed).
641 */
642void of_platform_depopulate(struct device *parent)
643{
644	if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
645		device_for_each_child_reverse(parent, NULL, of_platform_device_destroy);
646		of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
647	}
648}
649EXPORT_SYMBOL_GPL(of_platform_depopulate);
650
651static void devm_of_platform_populate_release(struct device *dev, void *res)
652{
653	of_platform_depopulate(*(struct device **)res);
654}
655
656/**
657 * devm_of_platform_populate() - Populate platform_devices from device tree data
658 * @dev: device that requested to populate from device tree data
659 *
660 * Similar to of_platform_populate(), but will automatically call
661 * of_platform_depopulate() when the device is unbound from the bus.
662 *
663 * Return: 0 on success, < 0 on failure.
664 */
665int devm_of_platform_populate(struct device *dev)
666{
667	struct device **ptr;
668	int ret;
669
670	if (!dev)
671		return -EINVAL;
672
673	ptr = devres_alloc(devm_of_platform_populate_release,
674			   sizeof(*ptr), GFP_KERNEL);
675	if (!ptr)
676		return -ENOMEM;
677
678	ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
679	if (ret) {
680		devres_free(ptr);
681	} else {
682		*ptr = dev;
683		devres_add(dev, ptr);
684	}
685
686	return ret;
687}
688EXPORT_SYMBOL_GPL(devm_of_platform_populate);
689
690static int devm_of_platform_match(struct device *dev, void *res, void *data)
691{
692	struct device **ptr = res;
693
694	if (!ptr) {
695		WARN_ON(!ptr);
696		return 0;
697	}
698
699	return *ptr == data;
700}
701
702/**
703 * devm_of_platform_depopulate() - Remove devices populated from device tree
704 * @dev: device that requested to depopulate from device tree data
705 *
706 * Complementary to devm_of_platform_populate(), this function removes children
707 * of the given device (and, recursively, their children) that have been
708 * created from their respective device tree nodes (and only those,
709 * leaving others - eg. manually created - unharmed).
710 */
711void devm_of_platform_depopulate(struct device *dev)
712{
713	int ret;
714
715	ret = devres_release(dev, devm_of_platform_populate_release,
716			     devm_of_platform_match, dev);
717
718	WARN_ON(ret);
719}
720EXPORT_SYMBOL_GPL(devm_of_platform_depopulate);
721
722#ifdef CONFIG_OF_DYNAMIC
723static int of_platform_notify(struct notifier_block *nb,
724				unsigned long action, void *arg)
725{
726	struct of_reconfig_data *rd = arg;
727	struct platform_device *pdev_parent, *pdev;
728	bool children_left;
729	struct device_node *parent;
730
731	switch (of_reconfig_get_state_change(action, rd)) {
732	case OF_RECONFIG_CHANGE_ADD:
733		parent = rd->dn->parent;
734		/* verify that the parent is a bus (or the root node) */
735		if (!of_node_is_root(parent) &&
736		    !of_node_check_flag(parent, OF_POPULATED_BUS))
737			return NOTIFY_OK;	/* not for us */
738
739		/* already populated? (driver using of_populate manually) */
740		if (of_node_check_flag(rd->dn, OF_POPULATED))
741			return NOTIFY_OK;
742
743		/*
744		 * Clear the flag before adding the device so that fw_devlink
745		 * doesn't skip adding consumers to this device.
746		 */
747		rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
748		/* pdev_parent may be NULL when no bus platform device */
749		pdev_parent = of_find_device_by_node(parent);
750		pdev = of_platform_device_create(rd->dn, NULL,
751				pdev_parent ? &pdev_parent->dev : NULL);
752		platform_device_put(pdev_parent);
753
754		if (pdev == NULL) {
755			pr_err("%s: failed to create for '%pOF'\n",
756					__func__, rd->dn);
757			/* of_platform_device_create tosses the error code */
758			return notifier_from_errno(-EINVAL);
759		}
760		break;
761
762	case OF_RECONFIG_CHANGE_REMOVE:
763
764		/* already depopulated? */
765		if (!of_node_check_flag(rd->dn, OF_POPULATED))
766			return NOTIFY_OK;
767
768		/* find our device by node */
769		pdev = of_find_device_by_node(rd->dn);
770		if (pdev == NULL)
771			return NOTIFY_OK;	/* no? not meant for us */
772
773		/* unregister takes one ref away */
774		of_platform_device_destroy(&pdev->dev, &children_left);
775
776		/* and put the reference of the find */
777		platform_device_put(pdev);
778		break;
779	}
780
781	return NOTIFY_OK;
782}
783
784static struct notifier_block platform_of_notifier = {
785	.notifier_call = of_platform_notify,
786};
787
788void of_platform_register_reconfig_notifier(void)
789{
790	WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
791}
792#endif /* CONFIG_OF_DYNAMIC */
793
794#endif /* CONFIG_OF_ADDRESS */
v4.17
  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_iommu.h>
 21#include <linux/of_irq.h>
 22#include <linux/of_platform.h>
 23#include <linux/platform_device.h>
 
 
 
 24
 25const struct of_device_id of_default_bus_match_table[] = {
 26	{ .compatible = "simple-bus", },
 27	{ .compatible = "simple-mfd", },
 28	{ .compatible = "isa", },
 29#ifdef CONFIG_ARM_AMBA
 30	{ .compatible = "arm,amba-bus", },
 31#endif /* CONFIG_ARM_AMBA */
 32	{} /* Empty terminated list */
 33};
 34
 35static int of_dev_node_match(struct device *dev, void *data)
 36{
 37	return dev->of_node == data;
 38}
 39
 40/**
 41 * of_find_device_by_node - Find the platform_device associated with a node
 42 * @np: Pointer to device tree node
 43 *
 44 * Takes a reference to the embedded struct device which needs to be dropped
 45 * after use.
 46 *
 47 * Returns platform_device pointer, or NULL if not found
 48 */
 49struct platform_device *of_find_device_by_node(struct device_node *np)
 50{
 51	struct device *dev;
 52
 53	dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
 54	return dev ? to_platform_device(dev) : NULL;
 55}
 56EXPORT_SYMBOL(of_find_device_by_node);
 57
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 58#ifdef CONFIG_OF_ADDRESS
 
 
 
 
 
 59/*
 60 * The following routines scan a subtree and registers a device for
 61 * each applicable node.
 62 *
 63 * Note: sparc doesn't use these routines because it has a different
 64 * mechanism for creating devices from device tree nodes.
 65 */
 66
 67/**
 68 * of_device_make_bus_id - Use the device node data to assign a unique name
 69 * @dev: pointer to device structure that is linked to a device tree node
 70 *
 71 * This routine will first try using the translated bus address to
 72 * derive a unique name. If it cannot, then it will prepend names from
 73 * parent nodes until a unique name can be derived.
 74 */
 75static void of_device_make_bus_id(struct device *dev)
 76{
 77	struct device_node *node = dev->of_node;
 78	const __be32 *reg;
 79	u64 addr;
 80
 81	/* Construct the name, using parent nodes if necessary to ensure uniqueness */
 82	while (node->parent) {
 83		/*
 84		 * If the address can be translated, then that is as much
 85		 * uniqueness as we need. Make it the first component and return
 86		 */
 87		reg = of_get_property(node, "reg", NULL);
 88		if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
 89			dev_set_name(dev, dev_name(dev) ? "%llx.%s:%s" : "%llx.%s",
 90				     (unsigned long long)addr, node->name,
 91				     dev_name(dev));
 92			return;
 93		}
 94
 95		/* format arguments only used if dev_name() resolves to NULL */
 96		dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
 97			     kbasename(node->full_name), dev_name(dev));
 98		node = node->parent;
 99	}
100}
101
102/**
103 * of_device_alloc - Allocate and initialize an of_device
104 * @np: device node to assign to device
105 * @bus_id: Name to assign to the device.  May be null to use default name.
106 * @parent: Parent device.
107 */
108struct platform_device *of_device_alloc(struct device_node *np,
109				  const char *bus_id,
110				  struct device *parent)
111{
112	struct platform_device *dev;
113	int rc, i, num_reg = 0, num_irq;
114	struct resource *res, temp_res;
115
116	dev = platform_device_alloc("", PLATFORM_DEVID_NONE);
117	if (!dev)
118		return NULL;
119
120	/* count the io and irq resources */
121	while (of_address_to_resource(np, num_reg, &temp_res) == 0)
122		num_reg++;
123	num_irq = of_irq_count(np);
124
125	/* Populate the resource table */
126	if (num_irq || num_reg) {
127		res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
128		if (!res) {
129			platform_device_put(dev);
130			return NULL;
131		}
132
133		dev->num_resources = num_reg + num_irq;
134		dev->resource = res;
135		for (i = 0; i < num_reg; i++, res++) {
136			rc = of_address_to_resource(np, i, res);
137			WARN_ON(rc);
138		}
139		if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
140			pr_debug("not all legacy IRQ resources mapped for %s\n",
141				 np->name);
142	}
143
144	dev->dev.of_node = of_node_get(np);
145	dev->dev.fwnode = &np->fwnode;
146	dev->dev.parent = parent ? : &platform_bus;
147
148	if (bus_id)
149		dev_set_name(&dev->dev, "%s", bus_id);
150	else
151		of_device_make_bus_id(&dev->dev);
152
153	return dev;
154}
155EXPORT_SYMBOL(of_device_alloc);
156
157/**
158 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
159 * @np: pointer to node to create device for
160 * @bus_id: name to assign device
161 * @platform_data: pointer to populate platform_data pointer with
162 * @parent: Linux device model parent device.
163 *
164 * Returns pointer to created platform device, or NULL if a device was not
165 * registered.  Unavailable devices will not get registered.
166 */
167static struct platform_device *of_platform_device_create_pdata(
168					struct device_node *np,
169					const char *bus_id,
170					void *platform_data,
171					struct device *parent)
172{
173	struct platform_device *dev;
174
 
 
175	if (!of_device_is_available(np) ||
176	    of_node_test_and_set_flag(np, OF_POPULATED))
177		return NULL;
178
179	dev = of_device_alloc(np, bus_id, parent);
180	if (!dev)
181		goto err_clear_flag;
182
 
 
 
183	dev->dev.bus = &platform_bus_type;
184	dev->dev.platform_data = platform_data;
185	of_msi_configure(&dev->dev, dev->dev.of_node);
186
187	if (of_device_add(dev) != 0) {
188		platform_device_put(dev);
189		goto err_clear_flag;
190	}
191
192	return dev;
193
194err_clear_flag:
195	of_node_clear_flag(np, OF_POPULATED);
196	return NULL;
197}
198
199/**
200 * of_platform_device_create - Alloc, initialize and register an of_device
201 * @np: pointer to node to create device for
202 * @bus_id: name to assign device
203 * @parent: Linux device model parent device.
204 *
205 * Returns pointer to created platform device, or NULL if a device was not
206 * registered.  Unavailable devices will not get registered.
207 */
208struct platform_device *of_platform_device_create(struct device_node *np,
209					    const char *bus_id,
210					    struct device *parent)
211{
212	return of_platform_device_create_pdata(np, bus_id, NULL, parent);
213}
214EXPORT_SYMBOL(of_platform_device_create);
215
216#ifdef CONFIG_ARM_AMBA
217static struct amba_device *of_amba_device_create(struct device_node *node,
218						 const char *bus_id,
219						 void *platform_data,
220						 struct device *parent)
221{
222	struct amba_device *dev;
223	const void *prop;
224	int i, ret;
225
226	pr_debug("Creating amba device %pOF\n", node);
227
228	if (!of_device_is_available(node) ||
229	    of_node_test_and_set_flag(node, OF_POPULATED))
230		return NULL;
231
232	dev = amba_device_alloc(NULL, 0, 0);
233	if (!dev)
234		goto err_clear_flag;
235
 
 
 
 
236	/* setup generic device info */
237	dev->dev.of_node = of_node_get(node);
238	dev->dev.fwnode = &node->fwnode;
239	dev->dev.parent = parent ? : &platform_bus;
240	dev->dev.platform_data = platform_data;
241	if (bus_id)
242		dev_set_name(&dev->dev, "%s", bus_id);
243	else
244		of_device_make_bus_id(&dev->dev);
245
246	/* Allow the HW Peripheral ID to be overridden */
247	prop = of_get_property(node, "arm,primecell-periphid", NULL);
248	if (prop)
249		dev->periphid = of_read_ulong(prop, 1);
250
251	/* Decode the IRQs and address ranges */
252	for (i = 0; i < AMBA_NR_IRQS; i++)
253		dev->irq[i] = irq_of_parse_and_map(node, i);
254
255	ret = of_address_to_resource(node, 0, &dev->res);
256	if (ret) {
257		pr_err("amba: of_address_to_resource() failed (%d) for %pOF\n",
258		       ret, node);
259		goto err_free;
260	}
261
262	ret = amba_device_add(dev, &iomem_resource);
263	if (ret) {
264		pr_err("amba_device_add() failed (%d) for %pOF\n",
265		       ret, node);
266		goto err_free;
267	}
268
269	return dev;
270
271err_free:
272	amba_device_put(dev);
273err_clear_flag:
274	of_node_clear_flag(node, OF_POPULATED);
275	return NULL;
276}
277#else /* CONFIG_ARM_AMBA */
278static struct amba_device *of_amba_device_create(struct device_node *node,
279						 const char *bus_id,
280						 void *platform_data,
281						 struct device *parent)
282{
283	return NULL;
284}
285#endif /* CONFIG_ARM_AMBA */
286
287/**
288 * of_devname_lookup() - Given a device node, lookup the preferred Linux name
289 */
290static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
291				 struct device_node *np)
292{
293	const struct of_dev_auxdata *auxdata;
294	struct resource res;
295	int compatible = 0;
296
297	if (!lookup)
298		return NULL;
299
300	auxdata = lookup;
301	for (; auxdata->compatible; auxdata++) {
302		if (!of_device_is_compatible(np, auxdata->compatible))
303			continue;
304		compatible++;
305		if (!of_address_to_resource(np, 0, &res))
306			if (res.start != auxdata->phys_addr)
307				continue;
308		pr_debug("%pOF: devname=%s\n", np, auxdata->name);
309		return auxdata;
310	}
311
312	if (!compatible)
313		return NULL;
314
315	/* Try compatible match if no phys_addr and name are specified */
316	auxdata = lookup;
317	for (; auxdata->compatible; auxdata++) {
318		if (!of_device_is_compatible(np, auxdata->compatible))
319			continue;
320		if (!auxdata->phys_addr && !auxdata->name) {
321			pr_debug("%pOF: compatible match\n", np);
322			return auxdata;
323		}
324	}
325
326	return NULL;
327}
328
329/**
330 * of_platform_bus_create() - Create a device for a node and its children.
331 * @bus: device node of the bus to instantiate
332 * @matches: match table for bus nodes
333 * @lookup: auxdata table for matching id and platform_data with device nodes
334 * @parent: parent for new device, or NULL for top level.
335 * @strict: require compatible property
336 *
337 * Creates a platform_device for the provided device_node, and optionally
338 * recursively create devices for all the child nodes.
339 */
340static int of_platform_bus_create(struct device_node *bus,
341				  const struct of_device_id *matches,
342				  const struct of_dev_auxdata *lookup,
343				  struct device *parent, bool strict)
344{
345	const struct of_dev_auxdata *auxdata;
346	struct device_node *child;
347	struct platform_device *dev;
348	const char *bus_id = NULL;
349	void *platform_data = NULL;
350	int rc = 0;
351
352	/* Make sure it has a compatible property */
353	if (strict && (!of_get_property(bus, "compatible", NULL))) {
354		pr_debug("%s() - skipping %pOF, no compatible prop\n",
355			 __func__, bus);
356		return 0;
357	}
358
 
 
 
 
 
 
359	if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
360		pr_debug("%s() - skipping %pOF, already populated\n",
361			__func__, bus);
362		return 0;
363	}
364
365	auxdata = of_dev_lookup(lookup, bus);
366	if (auxdata) {
367		bus_id = auxdata->name;
368		platform_data = auxdata->platform_data;
369	}
370
371	if (of_device_is_compatible(bus, "arm,primecell")) {
372		/*
373		 * Don't return an error here to keep compatibility with older
374		 * device tree files.
375		 */
376		of_amba_device_create(bus, bus_id, platform_data, parent);
377		return 0;
378	}
379
380	dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
381	if (!dev || !of_match_node(matches, bus))
382		return 0;
383
384	for_each_child_of_node(bus, child) {
385		pr_debug("   create child: %pOF\n", child);
386		rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
387		if (rc) {
388			of_node_put(child);
389			break;
390		}
391	}
392	of_node_set_flag(bus, OF_POPULATED_BUS);
393	return rc;
394}
395
396/**
397 * of_platform_bus_probe() - Probe the device-tree for platform buses
398 * @root: parent of the first level to probe or NULL for the root of the tree
399 * @matches: match table for bus nodes
400 * @parent: parent to hook devices from, NULL for toplevel
401 *
402 * Note that children of the provided root are not instantiated as devices
403 * unless the specified root itself matches the bus list and is not NULL.
404 */
405int of_platform_bus_probe(struct device_node *root,
406			  const struct of_device_id *matches,
407			  struct device *parent)
408{
409	struct device_node *child;
410	int rc = 0;
411
412	root = root ? of_node_get(root) : of_find_node_by_path("/");
413	if (!root)
414		return -EINVAL;
415
416	pr_debug("%s()\n", __func__);
417	pr_debug(" starting at: %pOF\n", root);
418
419	/* Do a self check of bus type, if there's a match, create children */
420	if (of_match_node(matches, root)) {
421		rc = of_platform_bus_create(root, matches, NULL, parent, false);
422	} else for_each_child_of_node(root, child) {
423		if (!of_match_node(matches, child))
424			continue;
425		rc = of_platform_bus_create(child, matches, NULL, parent, false);
426		if (rc) {
427			of_node_put(child);
428			break;
429		}
430	}
431
432	of_node_put(root);
433	return rc;
434}
435EXPORT_SYMBOL(of_platform_bus_probe);
436
437/**
438 * of_platform_populate() - Populate platform_devices from device tree data
439 * @root: parent of the first level to probe or NULL for the root of the tree
440 * @matches: match table, NULL to use the default
441 * @lookup: auxdata table for matching id and platform_data with device nodes
442 * @parent: parent to hook devices from, NULL for toplevel
443 *
444 * Similar to of_platform_bus_probe(), this function walks the device tree
445 * and creates devices from nodes.  It differs in that it follows the modern
446 * convention of requiring all device nodes to have a 'compatible' property,
447 * and it is suitable for creating devices which are children of the root
448 * node (of_platform_bus_probe will only create children of the root which
449 * are selected by the @matches argument).
450 *
451 * New board support should be using this function instead of
452 * of_platform_bus_probe().
453 *
454 * Returns 0 on success, < 0 on failure.
455 */
456int of_platform_populate(struct device_node *root,
457			const struct of_device_id *matches,
458			const struct of_dev_auxdata *lookup,
459			struct device *parent)
460{
461	struct device_node *child;
462	int rc = 0;
463
464	root = root ? of_node_get(root) : of_find_node_by_path("/");
465	if (!root)
466		return -EINVAL;
467
468	pr_debug("%s()\n", __func__);
469	pr_debug(" starting at: %pOF\n", root);
470
471	for_each_child_of_node(root, child) {
 
472		rc = of_platform_bus_create(child, matches, lookup, parent, true);
473		if (rc) {
474			of_node_put(child);
475			break;
476		}
477	}
 
 
478	of_node_set_flag(root, OF_POPULATED_BUS);
479
480	of_node_put(root);
481	return rc;
482}
483EXPORT_SYMBOL_GPL(of_platform_populate);
484
485int of_platform_default_populate(struct device_node *root,
486				 const struct of_dev_auxdata *lookup,
487				 struct device *parent)
488{
489	return of_platform_populate(root, of_default_bus_match_table, lookup,
490				    parent);
491}
492EXPORT_SYMBOL_GPL(of_platform_default_populate);
493
494#ifndef CONFIG_PPC
495static const struct of_device_id reserved_mem_matches[] = {
 
496	{ .compatible = "qcom,rmtfs-mem" },
 
 
497	{ .compatible = "ramoops" },
 
 
498	{}
499};
500
501static int __init of_platform_default_populate_init(void)
502{
503	struct device_node *node;
504
505	if (!of_have_populated_dt())
506		return -ENODEV;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
507
508	/*
509	 * Handle certain compatibles explicitly, since we don't want to create
510	 * platform_devices for every node in /reserved-memory with a
511	 * "compatible",
512	 */
513	for_each_matching_node(node, reserved_mem_matches)
514		of_platform_device_create(node, NULL, NULL);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
515
516	node = of_find_node_by_path("/firmware");
517	if (node) {
518		of_platform_populate(node, NULL, NULL, NULL);
519		of_node_put(node);
520	}
521
522	/* Populate everything else. */
523	of_platform_default_populate(NULL, NULL, NULL);
 
524
 
 
 
525	return 0;
526}
527arch_initcall_sync(of_platform_default_populate_init);
528#endif
529
530int of_platform_device_destroy(struct device *dev, void *data)
531{
532	/* Do not touch devices not populated from the device tree */
533	if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
534		return 0;
535
536	/* Recurse for any nodes that were treated as busses */
537	if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
538		device_for_each_child(dev, NULL, of_platform_device_destroy);
539
 
 
 
540	if (dev->bus == &platform_bus_type)
541		platform_device_unregister(to_platform_device(dev));
542#ifdef CONFIG_ARM_AMBA
543	else if (dev->bus == &amba_bustype)
544		amba_device_unregister(to_amba_device(dev));
545#endif
546
547	of_node_clear_flag(dev->of_node, OF_POPULATED);
548	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
549	return 0;
550}
551EXPORT_SYMBOL_GPL(of_platform_device_destroy);
552
553/**
554 * of_platform_depopulate() - Remove devices populated from device tree
555 * @parent: device which children will be removed
556 *
557 * Complementary to of_platform_populate(), this function removes children
558 * of the given device (and, recurrently, their children) that have been
559 * created from their respective device tree nodes (and only those,
560 * leaving others - eg. manually created - unharmed).
561 */
562void of_platform_depopulate(struct device *parent)
563{
564	if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
565		device_for_each_child(parent, NULL, of_platform_device_destroy);
566		of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
567	}
568}
569EXPORT_SYMBOL_GPL(of_platform_depopulate);
570
571static void devm_of_platform_populate_release(struct device *dev, void *res)
572{
573	of_platform_depopulate(*(struct device **)res);
574}
575
576/**
577 * devm_of_platform_populate() - Populate platform_devices from device tree data
578 * @dev: device that requested to populate from device tree data
579 *
580 * Similar to of_platform_populate(), but will automatically call
581 * of_platform_depopulate() when the device is unbound from the bus.
582 *
583 * Returns 0 on success, < 0 on failure.
584 */
585int devm_of_platform_populate(struct device *dev)
586{
587	struct device **ptr;
588	int ret;
589
590	if (!dev)
591		return -EINVAL;
592
593	ptr = devres_alloc(devm_of_platform_populate_release,
594			   sizeof(*ptr), GFP_KERNEL);
595	if (!ptr)
596		return -ENOMEM;
597
598	ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
599	if (ret) {
600		devres_free(ptr);
601	} else {
602		*ptr = dev;
603		devres_add(dev, ptr);
604	}
605
606	return ret;
607}
608EXPORT_SYMBOL_GPL(devm_of_platform_populate);
609
610static int devm_of_platform_match(struct device *dev, void *res, void *data)
611{
612	struct device **ptr = res;
613
614	if (!ptr) {
615		WARN_ON(!ptr);
616		return 0;
617	}
618
619	return *ptr == data;
620}
621
622/**
623 * devm_of_platform_depopulate() - Remove devices populated from device tree
624 * @dev: device that requested to depopulate from device tree data
625 *
626 * Complementary to devm_of_platform_populate(), this function removes children
627 * of the given device (and, recurrently, their children) that have been
628 * created from their respective device tree nodes (and only those,
629 * leaving others - eg. manually created - unharmed).
630 */
631void devm_of_platform_depopulate(struct device *dev)
632{
633	int ret;
634
635	ret = devres_release(dev, devm_of_platform_populate_release,
636			     devm_of_platform_match, dev);
637
638	WARN_ON(ret);
639}
640EXPORT_SYMBOL_GPL(devm_of_platform_depopulate);
641
642#ifdef CONFIG_OF_DYNAMIC
643static int of_platform_notify(struct notifier_block *nb,
644				unsigned long action, void *arg)
645{
646	struct of_reconfig_data *rd = arg;
647	struct platform_device *pdev_parent, *pdev;
648	bool children_left;
 
649
650	switch (of_reconfig_get_state_change(action, rd)) {
651	case OF_RECONFIG_CHANGE_ADD:
652		/* verify that the parent is a bus */
653		if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
 
 
654			return NOTIFY_OK;	/* not for us */
655
656		/* already populated? (driver using of_populate manually) */
657		if (of_node_check_flag(rd->dn, OF_POPULATED))
658			return NOTIFY_OK;
659
 
 
 
 
 
660		/* pdev_parent may be NULL when no bus platform device */
661		pdev_parent = of_find_device_by_node(rd->dn->parent);
662		pdev = of_platform_device_create(rd->dn, NULL,
663				pdev_parent ? &pdev_parent->dev : NULL);
664		of_dev_put(pdev_parent);
665
666		if (pdev == NULL) {
667			pr_err("%s: failed to create for '%pOF'\n",
668					__func__, rd->dn);
669			/* of_platform_device_create tosses the error code */
670			return notifier_from_errno(-EINVAL);
671		}
672		break;
673
674	case OF_RECONFIG_CHANGE_REMOVE:
675
676		/* already depopulated? */
677		if (!of_node_check_flag(rd->dn, OF_POPULATED))
678			return NOTIFY_OK;
679
680		/* find our device by node */
681		pdev = of_find_device_by_node(rd->dn);
682		if (pdev == NULL)
683			return NOTIFY_OK;	/* no? not meant for us */
684
685		/* unregister takes one ref away */
686		of_platform_device_destroy(&pdev->dev, &children_left);
687
688		/* and put the reference of the find */
689		of_dev_put(pdev);
690		break;
691	}
692
693	return NOTIFY_OK;
694}
695
696static struct notifier_block platform_of_notifier = {
697	.notifier_call = of_platform_notify,
698};
699
700void of_platform_register_reconfig_notifier(void)
701{
702	WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
703}
704#endif /* CONFIG_OF_DYNAMIC */
705
706#endif /* CONFIG_OF_ADDRESS */