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v6.2
  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
 24const struct of_device_id of_default_bus_match_table[] = {
 25	{ .compatible = "simple-bus", },
 26	{ .compatible = "simple-mfd", },
 27	{ .compatible = "isa", },
 28#ifdef CONFIG_ARM_AMBA
 29	{ .compatible = "arm,amba-bus", },
 30#endif /* CONFIG_ARM_AMBA */
 31	{} /* Empty terminated list */
 32};
 33
 34static const struct of_device_id of_skipped_node_table[] = {
 35	{ .compatible = "operating-points-v2", },
 36	{} /* Empty terminated list */
 37};
 38
 39/**
 40 * of_find_device_by_node - Find the platform_device associated with a node
 41 * @np: Pointer to device tree node
 42 *
 43 * Takes a reference to the embedded struct device which needs to be dropped
 44 * after use.
 45 *
 46 * Return: platform_device pointer, or NULL if not found
 47 */
 48struct platform_device *of_find_device_by_node(struct device_node *np)
 49{
 50	struct device *dev;
 51
 52	dev = bus_find_device_by_of_node(&platform_bus_type, np);
 53	return dev ? to_platform_device(dev) : NULL;
 54}
 55EXPORT_SYMBOL(of_find_device_by_node);
 56
 57#ifdef CONFIG_OF_ADDRESS
 58/*
 59 * The following routines scan a subtree and registers a device for
 60 * each applicable node.
 61 *
 62 * Note: sparc doesn't use these routines because it has a different
 63 * mechanism for creating devices from device tree nodes.
 64 */
 65
 66/**
 67 * of_device_make_bus_id - Use the device node data to assign a unique name
 68 * @dev: pointer to device structure that is linked to a device tree node
 69 *
 70 * This routine will first try using the translated bus address to
 71 * derive a unique name. If it cannot, then it will prepend names from
 72 * parent nodes until a unique name can be derived.
 73 */
 74static void of_device_make_bus_id(struct device *dev)
 75{
 76	struct device_node *node = dev->of_node;
 77	const __be32 *reg;
 78	u64 addr;
 79	u32 mask;
 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			if (!of_property_read_u32(node, "mask", &mask))
 90				dev_set_name(dev, dev_name(dev) ? "%llx.%x.%pOFn:%s" : "%llx.%x.%pOFn",
 91					     addr, ffs(mask) - 1, node, dev_name(dev));
 92
 93			else
 94				dev_set_name(dev, dev_name(dev) ? "%llx.%pOFn:%s" : "%llx.%pOFn",
 95					     addr, node, dev_name(dev));
 96			return;
 97		}
 98
 99		/* format arguments only used if dev_name() resolves to NULL */
100		dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
101			     kbasename(node->full_name), dev_name(dev));
102		node = node->parent;
103	}
104}
105
106/**
107 * of_device_alloc - Allocate and initialize an of_device
108 * @np: device node to assign to device
109 * @bus_id: Name to assign to the device.  May be null to use default name.
110 * @parent: Parent device.
111 */
112struct platform_device *of_device_alloc(struct device_node *np,
113				  const char *bus_id,
114				  struct device *parent)
115{
116	struct platform_device *dev;
117	int rc, i, num_reg = 0;
118	struct resource *res;
119
120	dev = platform_device_alloc("", PLATFORM_DEVID_NONE);
121	if (!dev)
122		return NULL;
123
124	/* count the io resources */
125	num_reg = of_address_count(np);
 
 
126
127	/* Populate the resource table */
128	if (num_reg) {
129		res = kcalloc(num_reg, sizeof(*res), GFP_KERNEL);
130		if (!res) {
131			platform_device_put(dev);
132			return NULL;
133		}
134
135		dev->num_resources = num_reg;
136		dev->resource = res;
137		for (i = 0; i < num_reg; i++, res++) {
138			rc = of_address_to_resource(np, i, res);
139			WARN_ON(rc);
140		}
 
 
 
141	}
142
143	dev->dev.of_node = of_node_get(np);
144	dev->dev.fwnode = &np->fwnode;
145	dev->dev.parent = parent ? : &platform_bus;
146
147	if (bus_id)
148		dev_set_name(&dev->dev, "%s", bus_id);
149	else
150		of_device_make_bus_id(&dev->dev);
151
152	return dev;
153}
154EXPORT_SYMBOL(of_device_alloc);
155
156/**
157 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
158 * @np: pointer to node to create device for
159 * @bus_id: name to assign device
160 * @platform_data: pointer to populate platform_data pointer with
161 * @parent: Linux device model parent device.
162 *
163 * Return: Pointer to created platform device, or NULL if a device was not
164 * registered.  Unavailable devices will not get registered.
165 */
166static struct platform_device *of_platform_device_create_pdata(
167					struct device_node *np,
168					const char *bus_id,
169					void *platform_data,
170					struct device *parent)
171{
172	struct platform_device *dev;
173
174	if (!of_device_is_available(np) ||
175	    of_node_test_and_set_flag(np, OF_POPULATED))
176		return NULL;
177
178	dev = of_device_alloc(np, bus_id, parent);
179	if (!dev)
180		goto err_clear_flag;
181
182	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
183	if (!dev->dev.dma_mask)
184		dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
185	dev->dev.bus = &platform_bus_type;
186	dev->dev.platform_data = platform_data;
187	of_msi_configure(&dev->dev, dev->dev.of_node);
188
189	if (of_device_add(dev) != 0) {
190		platform_device_put(dev);
191		goto err_clear_flag;
192	}
193
194	return dev;
195
196err_clear_flag:
197	of_node_clear_flag(np, OF_POPULATED);
198	return NULL;
199}
200
201/**
202 * of_platform_device_create - Alloc, initialize and register an of_device
203 * @np: pointer to node to create device for
204 * @bus_id: name to assign device
205 * @parent: Linux device model parent device.
206 *
207 * Return: Pointer to created platform device, or NULL if a device was not
208 * registered.  Unavailable devices will not get registered.
209 */
210struct platform_device *of_platform_device_create(struct device_node *np,
211					    const char *bus_id,
212					    struct device *parent)
213{
214	return of_platform_device_create_pdata(np, bus_id, NULL, parent);
215}
216EXPORT_SYMBOL(of_platform_device_create);
217
218#ifdef CONFIG_ARM_AMBA
219static struct amba_device *of_amba_device_create(struct device_node *node,
220						 const char *bus_id,
221						 void *platform_data,
222						 struct device *parent)
223{
224	struct amba_device *dev;
225	const void *prop;
226	int ret;
227
228	pr_debug("Creating amba device %pOF\n", node);
229
230	if (!of_device_is_available(node) ||
231	    of_node_test_and_set_flag(node, OF_POPULATED))
232		return NULL;
233
234	dev = amba_device_alloc(NULL, 0, 0);
235	if (!dev)
236		goto err_clear_flag;
237
238	/* AMBA devices only support a single DMA mask */
239	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
240	dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
241
242	/* setup generic device info */
243	dev->dev.of_node = of_node_get(node);
244	dev->dev.fwnode = &node->fwnode;
245	dev->dev.parent = parent ? : &platform_bus;
246	dev->dev.platform_data = platform_data;
247	if (bus_id)
248		dev_set_name(&dev->dev, "%s", bus_id);
249	else
250		of_device_make_bus_id(&dev->dev);
251
252	/* Allow the HW Peripheral ID to be overridden */
253	prop = of_get_property(node, "arm,primecell-periphid", NULL);
254	if (prop)
255		dev->periphid = of_read_ulong(prop, 1);
256
 
 
 
 
257	ret = of_address_to_resource(node, 0, &dev->res);
258	if (ret) {
259		pr_err("amba: of_address_to_resource() failed (%d) for %pOF\n",
260		       ret, node);
261		goto err_free;
262	}
263
264	ret = amba_device_add(dev, &iomem_resource);
265	if (ret) {
266		pr_err("amba_device_add() failed (%d) for %pOF\n",
267		       ret, node);
268		goto err_free;
269	}
270
271	return dev;
272
273err_free:
274	amba_device_put(dev);
275err_clear_flag:
276	of_node_clear_flag(node, OF_POPULATED);
277	return NULL;
278}
279#else /* CONFIG_ARM_AMBA */
280static struct amba_device *of_amba_device_create(struct device_node *node,
281						 const char *bus_id,
282						 void *platform_data,
283						 struct device *parent)
284{
285	return NULL;
286}
287#endif /* CONFIG_ARM_AMBA */
288
289/*
290 * of_dev_lookup() - Given a device node, lookup the preferred Linux name
291 */
292static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
293				 struct device_node *np)
294{
295	const struct of_dev_auxdata *auxdata;
296	struct resource res;
297	int compatible = 0;
298
299	if (!lookup)
300		return NULL;
301
302	auxdata = lookup;
303	for (; auxdata->compatible; auxdata++) {
304		if (!of_device_is_compatible(np, auxdata->compatible))
305			continue;
306		compatible++;
307		if (!of_address_to_resource(np, 0, &res))
308			if (res.start != auxdata->phys_addr)
309				continue;
310		pr_debug("%pOF: devname=%s\n", np, auxdata->name);
311		return auxdata;
312	}
313
314	if (!compatible)
315		return NULL;
316
317	/* Try compatible match if no phys_addr and name are specified */
318	auxdata = lookup;
319	for (; auxdata->compatible; auxdata++) {
320		if (!of_device_is_compatible(np, auxdata->compatible))
321			continue;
322		if (!auxdata->phys_addr && !auxdata->name) {
323			pr_debug("%pOF: compatible match\n", np);
324			return auxdata;
325		}
326	}
327
328	return NULL;
329}
330
331/**
332 * of_platform_bus_create() - Create a device for a node and its children.
333 * @bus: device node of the bus to instantiate
334 * @matches: match table for bus nodes
335 * @lookup: auxdata table for matching id and platform_data with device nodes
336 * @parent: parent for new device, or NULL for top level.
337 * @strict: require compatible property
338 *
339 * Creates a platform_device for the provided device_node, and optionally
340 * recursively create devices for all the child nodes.
341 */
342static int of_platform_bus_create(struct device_node *bus,
343				  const struct of_device_id *matches,
344				  const struct of_dev_auxdata *lookup,
345				  struct device *parent, bool strict)
346{
347	const struct of_dev_auxdata *auxdata;
348	struct device_node *child;
349	struct platform_device *dev;
350	const char *bus_id = NULL;
351	void *platform_data = NULL;
352	int rc = 0;
353
354	/* Make sure it has a compatible property */
355	if (strict && (!of_get_property(bus, "compatible", NULL))) {
356		pr_debug("%s() - skipping %pOF, no compatible prop\n",
357			 __func__, bus);
358		return 0;
359	}
360
361	/* Skip nodes for which we don't want to create devices */
362	if (unlikely(of_match_node(of_skipped_node_table, bus))) {
363		pr_debug("%s() - skipping %pOF node\n", __func__, bus);
364		return 0;
365	}
366
367	if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
368		pr_debug("%s() - skipping %pOF, already populated\n",
369			__func__, bus);
370		return 0;
371	}
372
373	auxdata = of_dev_lookup(lookup, bus);
374	if (auxdata) {
375		bus_id = auxdata->name;
376		platform_data = auxdata->platform_data;
377	}
378
379	if (of_device_is_compatible(bus, "arm,primecell")) {
380		/*
381		 * Don't return an error here to keep compatibility with older
382		 * device tree files.
383		 */
384		of_amba_device_create(bus, bus_id, platform_data, parent);
385		return 0;
386	}
387
388	dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
389	if (!dev || !of_match_node(matches, bus))
390		return 0;
391
392	for_each_child_of_node(bus, child) {
393		pr_debug("   create child: %pOF\n", child);
394		rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
395		if (rc) {
396			of_node_put(child);
397			break;
398		}
399	}
400	of_node_set_flag(bus, OF_POPULATED_BUS);
401	return rc;
402}
403
404/**
405 * of_platform_bus_probe() - Probe the device-tree for platform buses
406 * @root: parent of the first level to probe or NULL for the root of the tree
407 * @matches: match table for bus nodes
408 * @parent: parent to hook devices from, NULL for toplevel
409 *
410 * Note that children of the provided root are not instantiated as devices
411 * unless the specified root itself matches the bus list and is not NULL.
412 */
413int of_platform_bus_probe(struct device_node *root,
414			  const struct of_device_id *matches,
415			  struct device *parent)
416{
417	struct device_node *child;
418	int rc = 0;
419
420	root = root ? of_node_get(root) : of_find_node_by_path("/");
421	if (!root)
422		return -EINVAL;
423
424	pr_debug("%s()\n", __func__);
425	pr_debug(" starting at: %pOF\n", root);
426
427	/* Do a self check of bus type, if there's a match, create children */
428	if (of_match_node(matches, root)) {
429		rc = of_platform_bus_create(root, matches, NULL, parent, false);
430	} else for_each_child_of_node(root, child) {
431		if (!of_match_node(matches, child))
432			continue;
433		rc = of_platform_bus_create(child, matches, NULL, parent, false);
434		if (rc) {
435			of_node_put(child);
436			break;
437		}
438	}
439
440	of_node_put(root);
441	return rc;
442}
443EXPORT_SYMBOL(of_platform_bus_probe);
444
445/**
446 * of_platform_populate() - Populate platform_devices from device tree data
447 * @root: parent of the first level to probe or NULL for the root of the tree
448 * @matches: match table, NULL to use the default
449 * @lookup: auxdata table for matching id and platform_data with device nodes
450 * @parent: parent to hook devices from, NULL for toplevel
451 *
452 * Similar to of_platform_bus_probe(), this function walks the device tree
453 * and creates devices from nodes.  It differs in that it follows the modern
454 * convention of requiring all device nodes to have a 'compatible' property,
455 * and it is suitable for creating devices which are children of the root
456 * node (of_platform_bus_probe will only create children of the root which
457 * are selected by the @matches argument).
458 *
459 * New board support should be using this function instead of
460 * of_platform_bus_probe().
461 *
462 * Return: 0 on success, < 0 on failure.
463 */
464int of_platform_populate(struct device_node *root,
465			const struct of_device_id *matches,
466			const struct of_dev_auxdata *lookup,
467			struct device *parent)
468{
469	struct device_node *child;
470	int rc = 0;
471
472	root = root ? of_node_get(root) : of_find_node_by_path("/");
473	if (!root)
474		return -EINVAL;
475
476	pr_debug("%s()\n", __func__);
477	pr_debug(" starting at: %pOF\n", root);
478
479	device_links_supplier_sync_state_pause();
480	for_each_child_of_node(root, child) {
481		rc = of_platform_bus_create(child, matches, lookup, parent, true);
482		if (rc) {
483			of_node_put(child);
484			break;
485		}
486	}
487	device_links_supplier_sync_state_resume();
488
489	of_node_set_flag(root, OF_POPULATED_BUS);
490
491	of_node_put(root);
492	return rc;
493}
494EXPORT_SYMBOL_GPL(of_platform_populate);
495
496int of_platform_default_populate(struct device_node *root,
497				 const struct of_dev_auxdata *lookup,
498				 struct device *parent)
499{
500	return of_platform_populate(root, of_default_bus_match_table, lookup,
501				    parent);
502}
503EXPORT_SYMBOL_GPL(of_platform_default_populate);
504
 
505static const struct of_device_id reserved_mem_matches[] = {
506	{ .compatible = "phram" },
507	{ .compatible = "qcom,rmtfs-mem" },
508	{ .compatible = "qcom,cmd-db" },
509	{ .compatible = "qcom,smem" },
510	{ .compatible = "ramoops" },
511	{ .compatible = "nvmem-rmem" },
512	{ .compatible = "google,open-dice" },
513	{}
514};
515
516static int __init of_platform_default_populate_init(void)
517{
518	struct device_node *node;
519
520	device_links_supplier_sync_state_pause();
521
522	if (!of_have_populated_dt())
523		return -ENODEV;
524
525	if (IS_ENABLED(CONFIG_PPC)) {
526		struct device_node *boot_display = NULL;
527		struct platform_device *dev;
528		int display_number = 0;
529		int ret;
530
531		/* Check if we have a MacOS display without a node spec */
532		if (of_get_property(of_chosen, "linux,bootx-noscreen", NULL)) {
533			/*
534			 * The old code tried to work out which node was the MacOS
535			 * display based on the address. I'm dropping that since the
536			 * lack of a node spec only happens with old BootX versions
537			 * (users can update) and with this code, they'll still get
538			 * a display (just not the palette hacks).
539			 */
540			dev = platform_device_alloc("bootx-noscreen", 0);
541			if (WARN_ON(!dev))
542				return -ENOMEM;
543			ret = platform_device_add(dev);
544			if (WARN_ON(ret)) {
545				platform_device_put(dev);
546				return ret;
547			}
548		}
549
550		/*
551		 * For OF framebuffers, first create the device for the boot display,
552		 * then for the other framebuffers. Only fail for the boot display;
553		 * ignore errors for the rest.
554		 */
555		for_each_node_by_type(node, "display") {
556			if (!of_get_property(node, "linux,opened", NULL) ||
557			    !of_get_property(node, "linux,boot-display", NULL))
558				continue;
559			dev = of_platform_device_create(node, "of-display.0", NULL);
560			of_node_put(node);
561			if (WARN_ON(!dev))
562				return -ENOMEM;
563			boot_display = node;
564			display_number++;
565			break;
566		}
567		for_each_node_by_type(node, "display") {
568			char buf[14];
569			const char *of_display_format = "of-display.%d";
570
571			if (!of_get_property(node, "linux,opened", NULL) || node == boot_display)
572				continue;
573			ret = snprintf(buf, sizeof(buf), of_display_format, display_number++);
574			if (ret < sizeof(buf))
575				of_platform_device_create(node, buf, NULL);
576		}
577
578	} else {
579		/*
580		 * Handle certain compatibles explicitly, since we don't want to create
581		 * platform_devices for every node in /reserved-memory with a
582		 * "compatible",
583		 */
584		for_each_matching_node(node, reserved_mem_matches)
585			of_platform_device_create(node, NULL, NULL);
586
587		node = of_find_node_by_path("/firmware");
588		if (node) {
589			of_platform_populate(node, NULL, NULL, NULL);
590			of_node_put(node);
591		}
592
593		node = of_get_compatible_child(of_chosen, "simple-framebuffer");
594		of_platform_device_create(node, NULL, NULL);
595		of_node_put(node);
596
597		/* Populate everything else. */
598		of_platform_default_populate(NULL, NULL, NULL);
 
 
599	}
600
 
 
 
601	return 0;
602}
603arch_initcall_sync(of_platform_default_populate_init);
604
605static int __init of_platform_sync_state_init(void)
606{
607	device_links_supplier_sync_state_resume();
608	return 0;
609}
610late_initcall_sync(of_platform_sync_state_init);
 
611
612int of_platform_device_destroy(struct device *dev, void *data)
613{
614	/* Do not touch devices not populated from the device tree */
615	if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
616		return 0;
617
618	/* Recurse for any nodes that were treated as busses */
619	if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
620		device_for_each_child(dev, NULL, of_platform_device_destroy);
621
622	of_node_clear_flag(dev->of_node, OF_POPULATED);
623	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
624
625	if (dev->bus == &platform_bus_type)
626		platform_device_unregister(to_platform_device(dev));
627#ifdef CONFIG_ARM_AMBA
628	else if (dev->bus == &amba_bustype)
629		amba_device_unregister(to_amba_device(dev));
630#endif
631
632	return 0;
633}
634EXPORT_SYMBOL_GPL(of_platform_device_destroy);
635
636/**
637 * of_platform_depopulate() - Remove devices populated from device tree
638 * @parent: device which children will be removed
639 *
640 * Complementary to of_platform_populate(), this function removes children
641 * of the given device (and, recurrently, their children) that have been
642 * created from their respective device tree nodes (and only those,
643 * leaving others - eg. manually created - unharmed).
644 */
645void of_platform_depopulate(struct device *parent)
646{
647	if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
648		device_for_each_child_reverse(parent, NULL, of_platform_device_destroy);
649		of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
650	}
651}
652EXPORT_SYMBOL_GPL(of_platform_depopulate);
653
654static void devm_of_platform_populate_release(struct device *dev, void *res)
655{
656	of_platform_depopulate(*(struct device **)res);
657}
658
659/**
660 * devm_of_platform_populate() - Populate platform_devices from device tree data
661 * @dev: device that requested to populate from device tree data
662 *
663 * Similar to of_platform_populate(), but will automatically call
664 * of_platform_depopulate() when the device is unbound from the bus.
665 *
666 * Return: 0 on success, < 0 on failure.
667 */
668int devm_of_platform_populate(struct device *dev)
669{
670	struct device **ptr;
671	int ret;
672
673	if (!dev)
674		return -EINVAL;
675
676	ptr = devres_alloc(devm_of_platform_populate_release,
677			   sizeof(*ptr), GFP_KERNEL);
678	if (!ptr)
679		return -ENOMEM;
680
681	ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
682	if (ret) {
683		devres_free(ptr);
684	} else {
685		*ptr = dev;
686		devres_add(dev, ptr);
687	}
688
689	return ret;
690}
691EXPORT_SYMBOL_GPL(devm_of_platform_populate);
692
693static int devm_of_platform_match(struct device *dev, void *res, void *data)
694{
695	struct device **ptr = res;
696
697	if (!ptr) {
698		WARN_ON(!ptr);
699		return 0;
700	}
701
702	return *ptr == data;
703}
704
705/**
706 * devm_of_platform_depopulate() - Remove devices populated from device tree
707 * @dev: device that requested to depopulate from device tree data
708 *
709 * Complementary to devm_of_platform_populate(), this function removes children
710 * of the given device (and, recurrently, their children) that have been
711 * created from their respective device tree nodes (and only those,
712 * leaving others - eg. manually created - unharmed).
713 */
714void devm_of_platform_depopulate(struct device *dev)
715{
716	int ret;
717
718	ret = devres_release(dev, devm_of_platform_populate_release,
719			     devm_of_platform_match, dev);
720
721	WARN_ON(ret);
722}
723EXPORT_SYMBOL_GPL(devm_of_platform_depopulate);
724
725#ifdef CONFIG_OF_DYNAMIC
726static int of_platform_notify(struct notifier_block *nb,
727				unsigned long action, void *arg)
728{
729	struct of_reconfig_data *rd = arg;
730	struct platform_device *pdev_parent, *pdev;
731	bool children_left;
732
733	switch (of_reconfig_get_state_change(action, rd)) {
734	case OF_RECONFIG_CHANGE_ADD:
735		/* verify that the parent is a bus */
736		if (!of_node_check_flag(rd->dn->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		/* pdev_parent may be NULL when no bus platform device */
744		pdev_parent = of_find_device_by_node(rd->dn->parent);
745		pdev = of_platform_device_create(rd->dn, NULL,
746				pdev_parent ? &pdev_parent->dev : NULL);
747		platform_device_put(pdev_parent);
748
749		if (pdev == NULL) {
750			pr_err("%s: failed to create for '%pOF'\n",
751					__func__, rd->dn);
752			/* of_platform_device_create tosses the error code */
753			return notifier_from_errno(-EINVAL);
754		}
755		break;
756
757	case OF_RECONFIG_CHANGE_REMOVE:
758
759		/* already depopulated? */
760		if (!of_node_check_flag(rd->dn, OF_POPULATED))
761			return NOTIFY_OK;
762
763		/* find our device by node */
764		pdev = of_find_device_by_node(rd->dn);
765		if (pdev == NULL)
766			return NOTIFY_OK;	/* no? not meant for us */
767
768		/* unregister takes one ref away */
769		of_platform_device_destroy(&pdev->dev, &children_left);
770
771		/* and put the reference of the find */
772		platform_device_put(pdev);
773		break;
774	}
775
776	return NOTIFY_OK;
777}
778
779static struct notifier_block platform_of_notifier = {
780	.notifier_call = of_platform_notify,
781};
782
783void of_platform_register_reconfig_notifier(void)
784{
785	WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
786}
787#endif /* CONFIG_OF_DYNAMIC */
788
789#endif /* CONFIG_OF_ADDRESS */
v5.14.15
  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
 24const struct of_device_id of_default_bus_match_table[] = {
 25	{ .compatible = "simple-bus", },
 26	{ .compatible = "simple-mfd", },
 27	{ .compatible = "isa", },
 28#ifdef CONFIG_ARM_AMBA
 29	{ .compatible = "arm,amba-bus", },
 30#endif /* CONFIG_ARM_AMBA */
 31	{} /* Empty terminated list */
 32};
 33
 34static const struct of_device_id of_skipped_node_table[] = {
 35	{ .compatible = "operating-points-v2", },
 36	{} /* Empty terminated list */
 37};
 38
 39/**
 40 * of_find_device_by_node - Find the platform_device associated with a node
 41 * @np: Pointer to device tree node
 42 *
 43 * Takes a reference to the embedded struct device which needs to be dropped
 44 * after use.
 45 *
 46 * Return: platform_device pointer, or NULL if not found
 47 */
 48struct platform_device *of_find_device_by_node(struct device_node *np)
 49{
 50	struct device *dev;
 51
 52	dev = bus_find_device_by_of_node(&platform_bus_type, np);
 53	return dev ? to_platform_device(dev) : NULL;
 54}
 55EXPORT_SYMBOL(of_find_device_by_node);
 56
 57#ifdef CONFIG_OF_ADDRESS
 58/*
 59 * The following routines scan a subtree and registers a device for
 60 * each applicable node.
 61 *
 62 * Note: sparc doesn't use these routines because it has a different
 63 * mechanism for creating devices from device tree nodes.
 64 */
 65
 66/**
 67 * of_device_make_bus_id - Use the device node data to assign a unique name
 68 * @dev: pointer to device structure that is linked to a device tree node
 69 *
 70 * This routine will first try using the translated bus address to
 71 * derive a unique name. If it cannot, then it will prepend names from
 72 * parent nodes until a unique name can be derived.
 73 */
 74static void of_device_make_bus_id(struct device *dev)
 75{
 76	struct device_node *node = dev->of_node;
 77	const __be32 *reg;
 78	u64 addr;
 
 79
 80	/* Construct the name, using parent nodes if necessary to ensure uniqueness */
 81	while (node->parent) {
 82		/*
 83		 * If the address can be translated, then that is as much
 84		 * uniqueness as we need. Make it the first component and return
 85		 */
 86		reg = of_get_property(node, "reg", NULL);
 87		if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
 88			dev_set_name(dev, dev_name(dev) ? "%llx.%pOFn:%s" : "%llx.%pOFn",
 89				     addr, node, dev_name(dev));
 
 
 
 
 
 90			return;
 91		}
 92
 93		/* format arguments only used if dev_name() resolves to NULL */
 94		dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
 95			     kbasename(node->full_name), dev_name(dev));
 96		node = node->parent;
 97	}
 98}
 99
100/**
101 * of_device_alloc - Allocate and initialize an of_device
102 * @np: device node to assign to device
103 * @bus_id: Name to assign to the device.  May be null to use default name.
104 * @parent: Parent device.
105 */
106struct platform_device *of_device_alloc(struct device_node *np,
107				  const char *bus_id,
108				  struct device *parent)
109{
110	struct platform_device *dev;
111	int rc, i, num_reg = 0, num_irq;
112	struct resource *res, temp_res;
113
114	dev = platform_device_alloc("", PLATFORM_DEVID_NONE);
115	if (!dev)
116		return NULL;
117
118	/* count the io and irq resources */
119	while (of_address_to_resource(np, num_reg, &temp_res) == 0)
120		num_reg++;
121	num_irq = of_irq_count(np);
122
123	/* Populate the resource table */
124	if (num_irq || num_reg) {
125		res = kcalloc(num_irq + num_reg, sizeof(*res), GFP_KERNEL);
126		if (!res) {
127			platform_device_put(dev);
128			return NULL;
129		}
130
131		dev->num_resources = num_reg + num_irq;
132		dev->resource = res;
133		for (i = 0; i < num_reg; i++, res++) {
134			rc = of_address_to_resource(np, i, res);
135			WARN_ON(rc);
136		}
137		if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
138			pr_debug("not all legacy IRQ resources mapped for %pOFn\n",
139				 np);
140	}
141
142	dev->dev.of_node = of_node_get(np);
143	dev->dev.fwnode = &np->fwnode;
144	dev->dev.parent = parent ? : &platform_bus;
145
146	if (bus_id)
147		dev_set_name(&dev->dev, "%s", bus_id);
148	else
149		of_device_make_bus_id(&dev->dev);
150
151	return dev;
152}
153EXPORT_SYMBOL(of_device_alloc);
154
155/**
156 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
157 * @np: pointer to node to create device for
158 * @bus_id: name to assign device
159 * @platform_data: pointer to populate platform_data pointer with
160 * @parent: Linux device model parent device.
161 *
162 * Return: Pointer to created platform device, or NULL if a device was not
163 * registered.  Unavailable devices will not get registered.
164 */
165static struct platform_device *of_platform_device_create_pdata(
166					struct device_node *np,
167					const char *bus_id,
168					void *platform_data,
169					struct device *parent)
170{
171	struct platform_device *dev;
172
173	if (!of_device_is_available(np) ||
174	    of_node_test_and_set_flag(np, OF_POPULATED))
175		return NULL;
176
177	dev = of_device_alloc(np, bus_id, parent);
178	if (!dev)
179		goto err_clear_flag;
180
181	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
182	if (!dev->dev.dma_mask)
183		dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
184	dev->dev.bus = &platform_bus_type;
185	dev->dev.platform_data = platform_data;
186	of_msi_configure(&dev->dev, dev->dev.of_node);
187
188	if (of_device_add(dev) != 0) {
189		platform_device_put(dev);
190		goto err_clear_flag;
191	}
192
193	return dev;
194
195err_clear_flag:
196	of_node_clear_flag(np, OF_POPULATED);
197	return NULL;
198}
199
200/**
201 * of_platform_device_create - Alloc, initialize and register an of_device
202 * @np: pointer to node to create device for
203 * @bus_id: name to assign device
204 * @parent: Linux device model parent device.
205 *
206 * Return: Pointer to created platform device, or NULL if a device was not
207 * registered.  Unavailable devices will not get registered.
208 */
209struct platform_device *of_platform_device_create(struct device_node *np,
210					    const char *bus_id,
211					    struct device *parent)
212{
213	return of_platform_device_create_pdata(np, bus_id, NULL, parent);
214}
215EXPORT_SYMBOL(of_platform_device_create);
216
217#ifdef CONFIG_ARM_AMBA
218static struct amba_device *of_amba_device_create(struct device_node *node,
219						 const char *bus_id,
220						 void *platform_data,
221						 struct device *parent)
222{
223	struct amba_device *dev;
224	const void *prop;
225	int i, ret;
226
227	pr_debug("Creating amba device %pOF\n", node);
228
229	if (!of_device_is_available(node) ||
230	    of_node_test_and_set_flag(node, OF_POPULATED))
231		return NULL;
232
233	dev = amba_device_alloc(NULL, 0, 0);
234	if (!dev)
235		goto err_clear_flag;
236
237	/* AMBA devices only support a single DMA mask */
238	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
239	dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
240
241	/* setup generic device info */
242	dev->dev.of_node = of_node_get(node);
243	dev->dev.fwnode = &node->fwnode;
244	dev->dev.parent = parent ? : &platform_bus;
245	dev->dev.platform_data = platform_data;
246	if (bus_id)
247		dev_set_name(&dev->dev, "%s", bus_id);
248	else
249		of_device_make_bus_id(&dev->dev);
250
251	/* Allow the HW Peripheral ID to be overridden */
252	prop = of_get_property(node, "arm,primecell-periphid", NULL);
253	if (prop)
254		dev->periphid = of_read_ulong(prop, 1);
255
256	/* Decode the IRQs and address ranges */
257	for (i = 0; i < AMBA_NR_IRQS; i++)
258		dev->irq[i] = irq_of_parse_and_map(node, i);
259
260	ret = of_address_to_resource(node, 0, &dev->res);
261	if (ret) {
262		pr_err("amba: of_address_to_resource() failed (%d) for %pOF\n",
263		       ret, node);
264		goto err_free;
265	}
266
267	ret = amba_device_add(dev, &iomem_resource);
268	if (ret) {
269		pr_err("amba_device_add() failed (%d) for %pOF\n",
270		       ret, node);
271		goto err_free;
272	}
273
274	return dev;
275
276err_free:
277	amba_device_put(dev);
278err_clear_flag:
279	of_node_clear_flag(node, OF_POPULATED);
280	return NULL;
281}
282#else /* CONFIG_ARM_AMBA */
283static struct amba_device *of_amba_device_create(struct device_node *node,
284						 const char *bus_id,
285						 void *platform_data,
286						 struct device *parent)
287{
288	return NULL;
289}
290#endif /* CONFIG_ARM_AMBA */
291
292/*
293 * of_dev_lookup() - Given a device node, lookup the preferred Linux name
294 */
295static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
296				 struct device_node *np)
297{
298	const struct of_dev_auxdata *auxdata;
299	struct resource res;
300	int compatible = 0;
301
302	if (!lookup)
303		return NULL;
304
305	auxdata = lookup;
306	for (; auxdata->compatible; auxdata++) {
307		if (!of_device_is_compatible(np, auxdata->compatible))
308			continue;
309		compatible++;
310		if (!of_address_to_resource(np, 0, &res))
311			if (res.start != auxdata->phys_addr)
312				continue;
313		pr_debug("%pOF: devname=%s\n", np, auxdata->name);
314		return auxdata;
315	}
316
317	if (!compatible)
318		return NULL;
319
320	/* Try compatible match if no phys_addr and name are specified */
321	auxdata = lookup;
322	for (; auxdata->compatible; auxdata++) {
323		if (!of_device_is_compatible(np, auxdata->compatible))
324			continue;
325		if (!auxdata->phys_addr && !auxdata->name) {
326			pr_debug("%pOF: compatible match\n", np);
327			return auxdata;
328		}
329	}
330
331	return NULL;
332}
333
334/**
335 * of_platform_bus_create() - Create a device for a node and its children.
336 * @bus: device node of the bus to instantiate
337 * @matches: match table for bus nodes
338 * @lookup: auxdata table for matching id and platform_data with device nodes
339 * @parent: parent for new device, or NULL for top level.
340 * @strict: require compatible property
341 *
342 * Creates a platform_device for the provided device_node, and optionally
343 * recursively create devices for all the child nodes.
344 */
345static int of_platform_bus_create(struct device_node *bus,
346				  const struct of_device_id *matches,
347				  const struct of_dev_auxdata *lookup,
348				  struct device *parent, bool strict)
349{
350	const struct of_dev_auxdata *auxdata;
351	struct device_node *child;
352	struct platform_device *dev;
353	const char *bus_id = NULL;
354	void *platform_data = NULL;
355	int rc = 0;
356
357	/* Make sure it has a compatible property */
358	if (strict && (!of_get_property(bus, "compatible", NULL))) {
359		pr_debug("%s() - skipping %pOF, no compatible prop\n",
360			 __func__, bus);
361		return 0;
362	}
363
364	/* Skip nodes for which we don't want to create devices */
365	if (unlikely(of_match_node(of_skipped_node_table, bus))) {
366		pr_debug("%s() - skipping %pOF node\n", __func__, bus);
367		return 0;
368	}
369
370	if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
371		pr_debug("%s() - skipping %pOF, already populated\n",
372			__func__, bus);
373		return 0;
374	}
375
376	auxdata = of_dev_lookup(lookup, bus);
377	if (auxdata) {
378		bus_id = auxdata->name;
379		platform_data = auxdata->platform_data;
380	}
381
382	if (of_device_is_compatible(bus, "arm,primecell")) {
383		/*
384		 * Don't return an error here to keep compatibility with older
385		 * device tree files.
386		 */
387		of_amba_device_create(bus, bus_id, platform_data, parent);
388		return 0;
389	}
390
391	dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
392	if (!dev || !of_match_node(matches, bus))
393		return 0;
394
395	for_each_child_of_node(bus, child) {
396		pr_debug("   create child: %pOF\n", child);
397		rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
398		if (rc) {
399			of_node_put(child);
400			break;
401		}
402	}
403	of_node_set_flag(bus, OF_POPULATED_BUS);
404	return rc;
405}
406
407/**
408 * of_platform_bus_probe() - Probe the device-tree for platform buses
409 * @root: parent of the first level to probe or NULL for the root of the tree
410 * @matches: match table for bus nodes
411 * @parent: parent to hook devices from, NULL for toplevel
412 *
413 * Note that children of the provided root are not instantiated as devices
414 * unless the specified root itself matches the bus list and is not NULL.
415 */
416int of_platform_bus_probe(struct device_node *root,
417			  const struct of_device_id *matches,
418			  struct device *parent)
419{
420	struct device_node *child;
421	int rc = 0;
422
423	root = root ? of_node_get(root) : of_find_node_by_path("/");
424	if (!root)
425		return -EINVAL;
426
427	pr_debug("%s()\n", __func__);
428	pr_debug(" starting at: %pOF\n", root);
429
430	/* Do a self check of bus type, if there's a match, create children */
431	if (of_match_node(matches, root)) {
432		rc = of_platform_bus_create(root, matches, NULL, parent, false);
433	} else for_each_child_of_node(root, child) {
434		if (!of_match_node(matches, child))
435			continue;
436		rc = of_platform_bus_create(child, matches, NULL, parent, false);
437		if (rc) {
438			of_node_put(child);
439			break;
440		}
441	}
442
443	of_node_put(root);
444	return rc;
445}
446EXPORT_SYMBOL(of_platform_bus_probe);
447
448/**
449 * of_platform_populate() - Populate platform_devices from device tree data
450 * @root: parent of the first level to probe or NULL for the root of the tree
451 * @matches: match table, NULL to use the default
452 * @lookup: auxdata table for matching id and platform_data with device nodes
453 * @parent: parent to hook devices from, NULL for toplevel
454 *
455 * Similar to of_platform_bus_probe(), this function walks the device tree
456 * and creates devices from nodes.  It differs in that it follows the modern
457 * convention of requiring all device nodes to have a 'compatible' property,
458 * and it is suitable for creating devices which are children of the root
459 * node (of_platform_bus_probe will only create children of the root which
460 * are selected by the @matches argument).
461 *
462 * New board support should be using this function instead of
463 * of_platform_bus_probe().
464 *
465 * Return: 0 on success, < 0 on failure.
466 */
467int of_platform_populate(struct device_node *root,
468			const struct of_device_id *matches,
469			const struct of_dev_auxdata *lookup,
470			struct device *parent)
471{
472	struct device_node *child;
473	int rc = 0;
474
475	root = root ? of_node_get(root) : of_find_node_by_path("/");
476	if (!root)
477		return -EINVAL;
478
479	pr_debug("%s()\n", __func__);
480	pr_debug(" starting at: %pOF\n", root);
481
482	device_links_supplier_sync_state_pause();
483	for_each_child_of_node(root, child) {
484		rc = of_platform_bus_create(child, matches, lookup, parent, true);
485		if (rc) {
486			of_node_put(child);
487			break;
488		}
489	}
490	device_links_supplier_sync_state_resume();
491
492	of_node_set_flag(root, OF_POPULATED_BUS);
493
494	of_node_put(root);
495	return rc;
496}
497EXPORT_SYMBOL_GPL(of_platform_populate);
498
499int of_platform_default_populate(struct device_node *root,
500				 const struct of_dev_auxdata *lookup,
501				 struct device *parent)
502{
503	return of_platform_populate(root, of_default_bus_match_table, lookup,
504				    parent);
505}
506EXPORT_SYMBOL_GPL(of_platform_default_populate);
507
508#ifndef CONFIG_PPC
509static const struct of_device_id reserved_mem_matches[] = {
 
510	{ .compatible = "qcom,rmtfs-mem" },
511	{ .compatible = "qcom,cmd-db" },
 
512	{ .compatible = "ramoops" },
513	{ .compatible = "nvmem-rmem" },
 
514	{}
515};
516
517static int __init of_platform_default_populate_init(void)
518{
519	struct device_node *node;
520
521	device_links_supplier_sync_state_pause();
522
523	if (!of_have_populated_dt())
524		return -ENODEV;
525
526	/*
527	 * Handle certain compatibles explicitly, since we don't want to create
528	 * platform_devices for every node in /reserved-memory with a
529	 * "compatible",
530	 */
531	for_each_matching_node(node, reserved_mem_matches)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
532		of_platform_device_create(node, NULL, NULL);
 
533
534	node = of_find_node_by_path("/firmware");
535	if (node) {
536		of_platform_populate(node, NULL, NULL, NULL);
537		of_node_put(node);
538	}
539
540	/* Populate everything else. */
541	of_platform_default_populate(NULL, NULL, NULL);
542
543	return 0;
544}
545arch_initcall_sync(of_platform_default_populate_init);
546
547static int __init of_platform_sync_state_init(void)
548{
549	device_links_supplier_sync_state_resume();
550	return 0;
551}
552late_initcall_sync(of_platform_sync_state_init);
553#endif
554
555int of_platform_device_destroy(struct device *dev, void *data)
556{
557	/* Do not touch devices not populated from the device tree */
558	if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
559		return 0;
560
561	/* Recurse for any nodes that were treated as busses */
562	if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
563		device_for_each_child(dev, NULL, of_platform_device_destroy);
564
565	of_node_clear_flag(dev->of_node, OF_POPULATED);
566	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
567
568	if (dev->bus == &platform_bus_type)
569		platform_device_unregister(to_platform_device(dev));
570#ifdef CONFIG_ARM_AMBA
571	else if (dev->bus == &amba_bustype)
572		amba_device_unregister(to_amba_device(dev));
573#endif
574
575	return 0;
576}
577EXPORT_SYMBOL_GPL(of_platform_device_destroy);
578
579/**
580 * of_platform_depopulate() - Remove devices populated from device tree
581 * @parent: device which children will be removed
582 *
583 * Complementary to of_platform_populate(), this function removes children
584 * of the given device (and, recurrently, their children) that have been
585 * created from their respective device tree nodes (and only those,
586 * leaving others - eg. manually created - unharmed).
587 */
588void of_platform_depopulate(struct device *parent)
589{
590	if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
591		device_for_each_child_reverse(parent, NULL, of_platform_device_destroy);
592		of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
593	}
594}
595EXPORT_SYMBOL_GPL(of_platform_depopulate);
596
597static void devm_of_platform_populate_release(struct device *dev, void *res)
598{
599	of_platform_depopulate(*(struct device **)res);
600}
601
602/**
603 * devm_of_platform_populate() - Populate platform_devices from device tree data
604 * @dev: device that requested to populate from device tree data
605 *
606 * Similar to of_platform_populate(), but will automatically call
607 * of_platform_depopulate() when the device is unbound from the bus.
608 *
609 * Return: 0 on success, < 0 on failure.
610 */
611int devm_of_platform_populate(struct device *dev)
612{
613	struct device **ptr;
614	int ret;
615
616	if (!dev)
617		return -EINVAL;
618
619	ptr = devres_alloc(devm_of_platform_populate_release,
620			   sizeof(*ptr), GFP_KERNEL);
621	if (!ptr)
622		return -ENOMEM;
623
624	ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
625	if (ret) {
626		devres_free(ptr);
627	} else {
628		*ptr = dev;
629		devres_add(dev, ptr);
630	}
631
632	return ret;
633}
634EXPORT_SYMBOL_GPL(devm_of_platform_populate);
635
636static int devm_of_platform_match(struct device *dev, void *res, void *data)
637{
638	struct device **ptr = res;
639
640	if (!ptr) {
641		WARN_ON(!ptr);
642		return 0;
643	}
644
645	return *ptr == data;
646}
647
648/**
649 * devm_of_platform_depopulate() - Remove devices populated from device tree
650 * @dev: device that requested to depopulate from device tree data
651 *
652 * Complementary to devm_of_platform_populate(), this function removes children
653 * of the given device (and, recurrently, their children) that have been
654 * created from their respective device tree nodes (and only those,
655 * leaving others - eg. manually created - unharmed).
656 */
657void devm_of_platform_depopulate(struct device *dev)
658{
659	int ret;
660
661	ret = devres_release(dev, devm_of_platform_populate_release,
662			     devm_of_platform_match, dev);
663
664	WARN_ON(ret);
665}
666EXPORT_SYMBOL_GPL(devm_of_platform_depopulate);
667
668#ifdef CONFIG_OF_DYNAMIC
669static int of_platform_notify(struct notifier_block *nb,
670				unsigned long action, void *arg)
671{
672	struct of_reconfig_data *rd = arg;
673	struct platform_device *pdev_parent, *pdev;
674	bool children_left;
675
676	switch (of_reconfig_get_state_change(action, rd)) {
677	case OF_RECONFIG_CHANGE_ADD:
678		/* verify that the parent is a bus */
679		if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
680			return NOTIFY_OK;	/* not for us */
681
682		/* already populated? (driver using of_populate manually) */
683		if (of_node_check_flag(rd->dn, OF_POPULATED))
684			return NOTIFY_OK;
685
686		/* pdev_parent may be NULL when no bus platform device */
687		pdev_parent = of_find_device_by_node(rd->dn->parent);
688		pdev = of_platform_device_create(rd->dn, NULL,
689				pdev_parent ? &pdev_parent->dev : NULL);
690		platform_device_put(pdev_parent);
691
692		if (pdev == NULL) {
693			pr_err("%s: failed to create for '%pOF'\n",
694					__func__, rd->dn);
695			/* of_platform_device_create tosses the error code */
696			return notifier_from_errno(-EINVAL);
697		}
698		break;
699
700	case OF_RECONFIG_CHANGE_REMOVE:
701
702		/* already depopulated? */
703		if (!of_node_check_flag(rd->dn, OF_POPULATED))
704			return NOTIFY_OK;
705
706		/* find our device by node */
707		pdev = of_find_device_by_node(rd->dn);
708		if (pdev == NULL)
709			return NOTIFY_OK;	/* no? not meant for us */
710
711		/* unregister takes one ref away */
712		of_platform_device_destroy(&pdev->dev, &children_left);
713
714		/* and put the reference of the find */
715		platform_device_put(pdev);
716		break;
717	}
718
719	return NOTIFY_OK;
720}
721
722static struct notifier_block platform_of_notifier = {
723	.notifier_call = of_platform_notify,
724};
725
726void of_platform_register_reconfig_notifier(void)
727{
728	WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
729}
730#endif /* CONFIG_OF_DYNAMIC */
731
732#endif /* CONFIG_OF_ADDRESS */