summaryrefslogtreecommitdiff
path: root/drivers/of/platform.c
blob: b3faf89744aaa19d4b9595b4d55491f949ef2a05 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
// SPDX-License-Identifier: GPL-2.0+
/*
 *    Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
 *			 <benh@kernel.crashing.org>
 *    and		 Arnd Bergmann, IBM Corp.
 *    Merged from powerpc/kernel/of_platform.c and
 *    sparc{,64}/kernel/of_device.c by Stephen Rothwell
 */

#define pr_fmt(fmt)	"OF: " fmt

#include <linux/errno.h>
#include <linux/module.h>
#include <linux/amba/bus.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>

const struct of_device_id of_default_bus_match_table[] = {
	{ .compatible = "simple-bus", },
	{ .compatible = "simple-mfd", },
	{ .compatible = "isa", },
#ifdef CONFIG_ARM_AMBA
	{ .compatible = "arm,amba-bus", },
#endif /* CONFIG_ARM_AMBA */
	{} /* Empty terminated list */
};

static const struct of_device_id of_skipped_node_table[] = {
	{ .compatible = "operating-points-v2", },
	{} /* Empty terminated list */
};

/**
 * of_find_device_by_node - Find the platform_device associated with a node
 * @np: Pointer to device tree node
 *
 * Takes a reference to the embedded struct device which needs to be dropped
 * after use.
 *
 * Return: platform_device pointer, or NULL if not found
 */
struct platform_device *of_find_device_by_node(struct device_node *np)
{
	struct device *dev;

	dev = bus_find_device_by_of_node(&platform_bus_type, np);
	return dev ? to_platform_device(dev) : NULL;
}
EXPORT_SYMBOL(of_find_device_by_node);

#ifdef CONFIG_OF_ADDRESS
/*
 * The following routines scan a subtree and registers a device for
 * each applicable node.
 *
 * Note: sparc doesn't use these routines because it has a different
 * mechanism for creating devices from device tree nodes.
 */

/**
 * of_device_make_bus_id - Use the device node data to assign a unique name
 * @dev: pointer to device structure that is linked to a device tree node
 *
 * This routine will first try using the translated bus address to
 * derive a unique name. If it cannot, then it will prepend names from
 * parent nodes until a unique name can be derived.
 */
static void of_device_make_bus_id(struct device *dev)
{
	struct device_node *node = dev->of_node;
	const __be32 *reg;
	u64 addr;
	u32 mask;

	/* Construct the name, using parent nodes if necessary to ensure uniqueness */
	while (node->parent) {
		/*
		 * If the address can be translated, then that is as much
		 * uniqueness as we need. Make it the first component and return
		 */
		reg = of_get_property(node, "reg", NULL);
		if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
			if (!of_property_read_u32(node, "mask", &mask))
				dev_set_name(dev, dev_name(dev) ? "%llx.%x.%pOFn:%s" : "%llx.%x.%pOFn",
					     addr, ffs(mask) - 1, node, dev_name(dev));

			else
				dev_set_name(dev, dev_name(dev) ? "%llx.%pOFn:%s" : "%llx.%pOFn",
					     addr, node, dev_name(dev));
			return;
		}

		/* format arguments only used if dev_name() resolves to NULL */
		dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
			     kbasename(node->full_name), dev_name(dev));
		node = node->parent;
	}
}

/**
 * of_device_alloc - Allocate and initialize an of_device
 * @np: device node to assign to device
 * @bus_id: Name to assign to the device.  May be null to use default name.
 * @parent: Parent device.
 */
struct platform_device *of_device_alloc(struct device_node *np,
				  const char *bus_id,
				  struct device *parent)
{
	struct platform_device *dev;
	int rc, i, num_reg = 0, num_irq;
	struct resource *res, temp_res;

	dev = platform_device_alloc("", PLATFORM_DEVID_NONE);
	if (!dev)
		return NULL;

	/* count the io and irq resources */
	while (of_address_to_resource(np, num_reg, &temp_res) == 0)
		num_reg++;
	num_irq = of_irq_count(np);

	/* Populate the resource table */
	if (num_irq || num_reg) {
		res = kcalloc(num_irq + num_reg, sizeof(*res), GFP_KERNEL);
		if (!res) {
			platform_device_put(dev);
			return NULL;
		}

		dev->num_resources = num_reg + num_irq;
		dev->resource = res;
		for (i = 0; i < num_reg; i++, res++) {
			rc = of_address_to_resource(np, i, res);
			WARN_ON(rc);
		}
		if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
			pr_debug("not all legacy IRQ resources mapped for %pOFn\n",
				 np);
	}

	dev->dev.of_node = of_node_get(np);
	dev->dev.fwnode = &np->fwnode;
	dev->dev.parent = parent ? : &platform_bus;

	if (bus_id)
		dev_set_name(&dev->dev, "%s", bus_id);
	else
		of_device_make_bus_id(&dev->dev);

	return dev;
}
EXPORT_SYMBOL(of_device_alloc);

/**
 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
 * @np: pointer to node to create device for
 * @bus_id: name to assign device
 * @platform_data: pointer to populate platform_data pointer with
 * @parent: Linux device model parent device.
 *
 * Return: Pointer to created platform device, or NULL if a device was not
 * registered.  Unavailable devices will not get registered.
 */
static struct platform_device *of_platform_device_create_pdata(
					struct device_node *np,
					const char *bus_id,
					void *platform_data,
					struct device *parent)
{
	struct platform_device *dev;

	if (!of_device_is_available(np) ||
	    of_node_test_and_set_flag(np, OF_POPULATED))
		return NULL;

	dev = of_device_alloc(np, bus_id, parent);
	if (!dev)
		goto err_clear_flag;

	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
	if (!dev->dev.dma_mask)
		dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
	dev->dev.bus = &platform_bus_type;
	dev->dev.platform_data = platform_data;
	of_msi_configure(&dev->dev, dev->dev.of_node);

	if (of_device_add(dev) != 0) {
		platform_device_put(dev);
		goto err_clear_flag;
	}

	return dev;

err_clear_flag:
	of_node_clear_flag(np, OF_POPULATED);
	return NULL;
}

/**
 * of_platform_device_create - Alloc, initialize and register an of_device
 * @np: pointer to node to create device for
 * @bus_id: name to assign device
 * @parent: Linux device model parent device.
 *
 * Return: Pointer to created platform device, or NULL if a device was not
 * registered.  Unavailable devices will not get registered.
 */
struct platform_device *of_platform_device_create(struct device_node *np,
					    const char *bus_id,
					    struct device *parent)
{
	return of_platform_device_create_pdata(np, bus_id, NULL, parent);
}
EXPORT_SYMBOL(of_platform_device_create);

#ifdef CONFIG_ARM_AMBA
static struct amba_device *of_amba_device_create(struct device_node *node,
						 const char *bus_id,
						 void *platform_data,
						 struct device *parent)
{
	struct amba_device *dev;
	const void *prop;
	int ret;

	pr_debug("Creating amba device %pOF\n", node);

	if (!of_device_is_available(node) ||
	    of_node_test_and_set_flag(node, OF_POPULATED))
		return NULL;

	dev = amba_device_alloc(NULL, 0, 0);
	if (!dev)
		goto err_clear_flag;

	/* AMBA devices only support a single DMA mask */
	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
	dev->dev.dma_mask = &dev->dev.coherent_dma_mask;

	/* setup generic device info */
	dev->dev.of_node = of_node_get(node);
	dev->dev.fwnode = &node->fwnode;
	dev->dev.parent = parent ? : &platform_bus;
	dev->dev.platform_data = platform_data;
	if (bus_id)
		dev_set_name(&dev->dev, "%s", bus_id);
	else
		of_device_make_bus_id(&dev->dev);

	/* Allow the HW Peripheral ID to be overridden */
	prop = of_get_property(node, "arm,primecell-periphid", NULL);
	if (prop)
		dev->periphid = of_read_ulong(prop, 1);

	ret = of_address_to_resource(node, 0, &dev->res);
	if (ret) {
		pr_err("amba: of_address_to_resource() failed (%d) for %pOF\n",
		       ret, node);
		goto err_free;
	}

	ret = amba_device_add(dev, &iomem_resource);
	if (ret) {
		pr_err("amba_device_add() failed (%d) for %pOF\n",
		       ret, node);
		goto err_free;
	}

	return dev;

err_free:
	amba_device_put(dev);
err_clear_flag:
	of_node_clear_flag(node, OF_POPULATED);
	return NULL;
}
#else /* CONFIG_ARM_AMBA */
static struct amba_device *of_amba_device_create(struct device_node *node,
						 const char *bus_id,
						 void *platform_data,
						 struct device *parent)
{
	return NULL;
}
#endif /* CONFIG_ARM_AMBA */

/*
 * of_dev_lookup() - Given a device node, lookup the preferred Linux name
 */
static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
				 struct device_node *np)
{
	const struct of_dev_auxdata *auxdata;
	struct resource res;
	int compatible = 0;

	if (!lookup)
		return NULL;

	auxdata = lookup;
	for (; auxdata->compatible; auxdata++) {
		if (!of_device_is_compatible(np, auxdata->compatible))
			continue;
		compatible++;
		if (!of_address_to_resource(np, 0, &res))
			if (res.start != auxdata->phys_addr)
				continue;
		pr_debug("%pOF: devname=%s\n", np, auxdata->name);
		return auxdata;
	}

	if (!compatible)
		return NULL;

	/* Try compatible match if no phys_addr and name are specified */
	auxdata = lookup;
	for (; auxdata->compatible; auxdata++) {
		if (!of_device_is_compatible(np, auxdata->compatible))
			continue;
		if (!auxdata->phys_addr && !auxdata->name) {
			pr_debug("%pOF: compatible match\n", np);
			return auxdata;
		}
	}

	return NULL;
}

/**
 * of_platform_bus_create() - Create a device for a node and its children.
 * @bus: device node of the bus to instantiate
 * @matches: match table for bus nodes
 * @lookup: auxdata table for matching id and platform_data with device nodes
 * @parent: parent for new device, or NULL for top level.
 * @strict: require compatible property
 *
 * Creates a platform_device for the provided device_node, and optionally
 * recursively create devices for all the child nodes.
 */
static int of_platform_bus_create(struct device_node *bus,
				  const struct of_device_id *matches,
				  const struct of_dev_auxdata *lookup,
				  struct device *parent, bool strict)
{
	const struct of_dev_auxdata *auxdata;
	struct device_node *child;
	struct platform_device *dev;
	const char *bus_id = NULL;
	void *platform_data = NULL;
	int rc = 0;

	/* Make sure it has a compatible property */
	if (strict && (!of_get_property(bus, "compatible", NULL))) {
		pr_debug("%s() - skipping %pOF, no compatible prop\n",
			 __func__, bus);
		return 0;
	}

	/* Skip nodes for which we don't want to create devices */
	if (unlikely(of_match_node(of_skipped_node_table, bus))) {
		pr_debug("%s() - skipping %pOF node\n", __func__, bus);
		return 0;
	}

	if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
		pr_debug("%s() - skipping %pOF, already populated\n",
			__func__, bus);
		return 0;
	}

	auxdata = of_dev_lookup(lookup, bus);
	if (auxdata) {
		bus_id = auxdata->name;
		platform_data = auxdata->platform_data;
	}

	if (of_device_is_compatible(bus, "arm,primecell")) {
		/*
		 * Don't return an error here to keep compatibility with older
		 * device tree files.
		 */
		of_amba_device_create(bus, bus_id, platform_data, parent);
		return 0;
	}

	dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
	if (!dev || !of_match_node(matches, bus))
		return 0;

	for_each_child_of_node(bus, child) {
		pr_debug("   create child: %pOF\n", child);
		rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
		if (rc) {
			of_node_put(child);
			break;
		}
	}
	of_node_set_flag(bus, OF_POPULATED_BUS);
	return rc;
}

/**
 * of_platform_bus_probe() - Probe the device-tree for platform buses
 * @root: parent of the first level to probe or NULL for the root of the tree
 * @matches: match table for bus nodes
 * @parent: parent to hook devices from, NULL for toplevel
 *
 * Note that children of the provided root are not instantiated as devices
 * unless the specified root itself matches the bus list and is not NULL.
 */
int of_platform_bus_probe(struct device_node *root,
			  const struct of_device_id *matches,
			  struct device *parent)
{
	struct device_node *child;
	int rc = 0;

	root = root ? of_node_get(root) : of_find_node_by_path("/");
	if (!root)
		return -EINVAL;

	pr_debug("%s()\n", __func__);
	pr_debug(" starting at: %pOF\n", root);

	/* Do a self check of bus type, if there's a match, create children */
	if (of_match_node(matches, root)) {
		rc = of_platform_bus_create(root, matches, NULL, parent, false);
	} else for_each_child_of_node(root, child) {
		if (!of_match_node(matches, child))
			continue;
		rc = of_platform_bus_create(child, matches, NULL, parent, false);
		if (rc) {
			of_node_put(child);
			break;
		}
	}

	of_node_put(root);
	return rc;
}
EXPORT_SYMBOL(of_platform_bus_probe);

/**
 * of_platform_populate() - Populate platform_devices from device tree data
 * @root: parent of the first level to probe or NULL for the root of the tree
 * @matches: match table, NULL to use the default
 * @lookup: auxdata table for matching id and platform_data with device nodes
 * @parent: parent to hook devices from, NULL for toplevel
 *
 * Similar to of_platform_bus_probe(), this function walks the device tree
 * and creates devices from nodes.  It differs in that it follows the modern
 * convention of requiring all device nodes to have a 'compatible' property,
 * and it is suitable for creating devices which are children of the root
 * node (of_platform_bus_probe will only create children of the root which
 * are selected by the @matches argument).
 *
 * New board support should be using this function instead of
 * of_platform_bus_probe().
 *
 * Return: 0 on success, < 0 on failure.
 */
int of_platform_populate(struct device_node *root,
			const struct of_device_id *matches,
			const struct of_dev_auxdata *lookup,
			struct device *parent)
{
	struct device_node *child;
	int rc = 0;

	root = root ? of_node_get(root) : of_find_node_by_path("/");
	if (!root)
		return -EINVAL;

	pr_debug("%s()\n", __func__);
	pr_debug(" starting at: %pOF\n", root);

	device_links_supplier_sync_state_pause();
	for_each_child_of_node(root, child) {
		rc = of_platform_bus_create(child, matches, lookup, parent, true);
		if (rc) {
			of_node_put(child);
			break;
		}
	}
	device_links_supplier_sync_state_resume();

	of_node_set_flag(root, OF_POPULATED_BUS);

	of_node_put(root);
	return rc;
}
EXPORT_SYMBOL_GPL(of_platform_populate);

int of_platform_default_populate(struct device_node *root,
				 const struct of_dev_auxdata *lookup,
				 struct device *parent)
{
	return of_platform_populate(root, of_default_bus_match_table, lookup,
				    parent);
}
EXPORT_SYMBOL_GPL(of_platform_default_populate);

#ifndef CONFIG_PPC
static const struct of_device_id reserved_mem_matches[] = {
	{ .compatible = "qcom,rmtfs-mem" },
	{ .compatible = "qcom,cmd-db" },
	{ .compatible = "qcom,smem" },
	{ .compatible = "ramoops" },
	{ .compatible = "nvmem-rmem" },
	{}
};

static int __init of_platform_default_populate_init(void)
{
	struct device_node *node;

	device_links_supplier_sync_state_pause();

	if (!of_have_populated_dt())
		return -ENODEV;

	/*
	 * Handle certain compatibles explicitly, since we don't want to create
	 * platform_devices for every node in /reserved-memory with a
	 * "compatible",
	 */
	for_each_matching_node(node, reserved_mem_matches)
		of_platform_device_create(node, NULL, NULL);

	node = of_find_node_by_path("/firmware");
	if (node) {
		of_platform_populate(node, NULL, NULL, NULL);
		of_node_put(node);
	}

	/* Populate everything else. */
	of_platform_default_populate(NULL, NULL, NULL);

	return 0;
}
arch_initcall_sync(of_platform_default_populate_init);

static int __init of_platform_sync_state_init(void)
{
	device_links_supplier_sync_state_resume();
	return 0;
}
late_initcall_sync(of_platform_sync_state_init);
#endif

int of_platform_device_destroy(struct device *dev, void *data)
{
	/* Do not touch devices not populated from the device tree */
	if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
		return 0;

	/* Recurse for any nodes that were treated as busses */
	if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
		device_for_each_child(dev, NULL, of_platform_device_destroy);

	of_node_clear_flag(dev->of_node, OF_POPULATED);
	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);

	if (dev->bus == &platform_bus_type)
		platform_device_unregister(to_platform_device(dev));
#ifdef CONFIG_ARM_AMBA
	else if (dev->bus == &amba_bustype)
		amba_device_unregister(to_amba_device(dev));
#endif

	return 0;
}
EXPORT_SYMBOL_GPL(of_platform_device_destroy);

/**
 * of_platform_depopulate() - Remove devices populated from device tree
 * @parent: device which children will be removed
 *
 * Complementary to of_platform_populate(), this function removes children
 * of the given device (and, recurrently, their children) that have been
 * created from their respective device tree nodes (and only those,
 * leaving others - eg. manually created - unharmed).
 */
void of_platform_depopulate(struct device *parent)
{
	if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
		device_for_each_child_reverse(parent, NULL, of_platform_device_destroy);
		of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
	}
}
EXPORT_SYMBOL_GPL(of_platform_depopulate);

static void devm_of_platform_populate_release(struct device *dev, void *res)
{
	of_platform_depopulate(*(struct device **)res);
}

/**
 * devm_of_platform_populate() - Populate platform_devices from device tree data
 * @dev: device that requested to populate from device tree data
 *
 * Similar to of_platform_populate(), but will automatically call
 * of_platform_depopulate() when the device is unbound from the bus.
 *
 * Return: 0 on success, < 0 on failure.
 */
int devm_of_platform_populate(struct device *dev)
{
	struct device **ptr;
	int ret;

	if (!dev)
		return -EINVAL;

	ptr = devres_alloc(devm_of_platform_populate_release,
			   sizeof(*ptr), GFP_KERNEL);
	if (!ptr)
		return -ENOMEM;

	ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
	if (ret) {
		devres_free(ptr);
	} else {
		*ptr = dev;
		devres_add(dev, ptr);
	}

	return ret;
}
EXPORT_SYMBOL_GPL(devm_of_platform_populate);

static int devm_of_platform_match(struct device *dev, void *res, void *data)
{
	struct device **ptr = res;

	if (!ptr) {
		WARN_ON(!ptr);
		return 0;
	}

	return *ptr == data;
}

/**
 * devm_of_platform_depopulate() - Remove devices populated from device tree
 * @dev: device that requested to depopulate from device tree data
 *
 * Complementary to devm_of_platform_populate(), this function removes children
 * of the given device (and, recurrently, their children) that have been
 * created from their respective device tree nodes (and only those,
 * leaving others - eg. manually created - unharmed).
 */
void devm_of_platform_depopulate(struct device *dev)
{
	int ret;

	ret = devres_release(dev, devm_of_platform_populate_release,
			     devm_of_platform_match, dev);

	WARN_ON(ret);
}
EXPORT_SYMBOL_GPL(devm_of_platform_depopulate);

#ifdef CONFIG_OF_DYNAMIC
static int of_platform_notify(struct notifier_block *nb,
				unsigned long action, void *arg)
{
	struct of_reconfig_data *rd = arg;
	struct platform_device *pdev_parent, *pdev;
	bool children_left;

	switch (of_reconfig_get_state_change(action, rd)) {
	case OF_RECONFIG_CHANGE_ADD:
		/* verify that the parent is a bus */
		if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
			return NOTIFY_OK;	/* not for us */

		/* already populated? (driver using of_populate manually) */
		if (of_node_check_flag(rd->dn, OF_POPULATED))
			return NOTIFY_OK;

		/* pdev_parent may be NULL when no bus platform device */
		pdev_parent = of_find_device_by_node(rd->dn->parent);
		pdev = of_platform_device_create(rd->dn, NULL,
				pdev_parent ? &pdev_parent->dev : NULL);
		platform_device_put(pdev_parent);

		if (pdev == NULL) {
			pr_err("%s: failed to create for '%pOF'\n",
					__func__, rd->dn);
			/* of_platform_device_create tosses the error code */
			return notifier_from_errno(-EINVAL);
		}
		break;

	case OF_RECONFIG_CHANGE_REMOVE:

		/* already depopulated? */
		if (!of_node_check_flag(rd->dn, OF_POPULATED))
			return NOTIFY_OK;

		/* find our device by node */
		pdev = of_find_device_by_node(rd->dn);
		if (pdev == NULL)
			return NOTIFY_OK;	/* no? not meant for us */

		/* unregister takes one ref away */
		of_platform_device_destroy(&pdev->dev, &children_left);

		/* and put the reference of the find */
		platform_device_put(pdev);
		break;
	}

	return NOTIFY_OK;
}

static struct notifier_block platform_of_notifier = {
	.notifier_call = of_platform_notify,
};

void of_platform_register_reconfig_notifier(void)
{
	WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
}
#endif /* CONFIG_OF_DYNAMIC */

#endif /* CONFIG_OF_ADDRESS */