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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 */
v5.9
  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 const struct of_device_id of_skipped_node_table[] = {
 36	{ .compatible = "operating-points-v2", },
 37	{} /* Empty terminated list */
 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_by_of_node(&platform_bus_type, np);
 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.%pOFn:%s" : "%llx.%pOFn",
 90				     addr, node, dev_name(dev));
 91			return;
 92		}
 93
 94		/* format arguments only used if dev_name() resolves to NULL */
 95		dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
 96			     kbasename(node->full_name), dev_name(dev));
 97		node = node->parent;
 98	}
 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, num_irq;
113	struct resource *res, temp_res;
114
115	dev = platform_device_alloc("", PLATFORM_DEVID_NONE);
116	if (!dev)
117		return NULL;
118
119	/* count the io and irq resources */
120	while (of_address_to_resource(np, num_reg, &temp_res) == 0)
121		num_reg++;
122	num_irq = of_irq_count(np);
123
124	/* Populate the resource table */
125	if (num_irq || num_reg) {
126		res = kcalloc(num_irq + num_reg, sizeof(*res), GFP_KERNEL);
127		if (!res) {
128			platform_device_put(dev);
129			return NULL;
130		}
131
132		dev->num_resources = num_reg + num_irq;
133		dev->resource = res;
134		for (i = 0; i < num_reg; i++, res++) {
135			rc = of_address_to_resource(np, i, res);
136			WARN_ON(rc);
137		}
138		if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
139			pr_debug("not all legacy IRQ resources mapped for %pOFn\n",
140				 np);
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 * Returns 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 * Returns 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 i, 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	/* Decode the IRQs and address ranges */
258	for (i = 0; i < AMBA_NR_IRQS; i++)
259		dev->irq[i] = irq_of_parse_and_map(node, i);
260
261	ret = of_address_to_resource(node, 0, &dev->res);
262	if (ret) {
263		pr_err("amba: of_address_to_resource() failed (%d) for %pOF\n",
264		       ret, node);
265		goto err_free;
266	}
267
268	ret = amba_device_add(dev, &iomem_resource);
269	if (ret) {
270		pr_err("amba_device_add() failed (%d) for %pOF\n",
271		       ret, node);
272		goto err_free;
273	}
274
275	return dev;
276
277err_free:
278	amba_device_put(dev);
279err_clear_flag:
280	of_node_clear_flag(node, OF_POPULATED);
281	return NULL;
282}
283#else /* CONFIG_ARM_AMBA */
284static struct amba_device *of_amba_device_create(struct device_node *node,
285						 const char *bus_id,
286						 void *platform_data,
287						 struct device *parent)
288{
289	return NULL;
290}
291#endif /* CONFIG_ARM_AMBA */
292
293/**
294 * of_dev_lookup() - Given a device node, lookup the preferred Linux name
295 */
296static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
297				 struct device_node *np)
298{
299	const struct of_dev_auxdata *auxdata;
300	struct resource res;
301	int compatible = 0;
302
303	if (!lookup)
304		return NULL;
305
306	auxdata = lookup;
307	for (; auxdata->compatible; auxdata++) {
308		if (!of_device_is_compatible(np, auxdata->compatible))
309			continue;
310		compatible++;
311		if (!of_address_to_resource(np, 0, &res))
312			if (res.start != auxdata->phys_addr)
313				continue;
314		pr_debug("%pOF: devname=%s\n", np, auxdata->name);
315		return auxdata;
316	}
317
318	if (!compatible)
319		return NULL;
320
321	/* Try compatible match if no phys_addr and name are specified */
322	auxdata = lookup;
323	for (; auxdata->compatible; auxdata++) {
324		if (!of_device_is_compatible(np, auxdata->compatible))
325			continue;
326		if (!auxdata->phys_addr && !auxdata->name) {
327			pr_debug("%pOF: compatible match\n", np);
328			return auxdata;
329		}
330	}
331
332	return NULL;
333}
334
335/**
336 * of_platform_bus_create() - Create a device for a node and its children.
337 * @bus: device node of the bus to instantiate
338 * @matches: match table for bus nodes
339 * @lookup: auxdata table for matching id and platform_data with device nodes
340 * @parent: parent for new device, or NULL for top level.
341 * @strict: require compatible property
342 *
343 * Creates a platform_device for the provided device_node, and optionally
344 * recursively create devices for all the child nodes.
345 */
346static int of_platform_bus_create(struct device_node *bus,
347				  const struct of_device_id *matches,
348				  const struct of_dev_auxdata *lookup,
349				  struct device *parent, bool strict)
350{
351	const struct of_dev_auxdata *auxdata;
352	struct device_node *child;
353	struct platform_device *dev;
354	const char *bus_id = NULL;
355	void *platform_data = NULL;
356	int rc = 0;
357
358	/* Make sure it has a compatible property */
359	if (strict && (!of_get_property(bus, "compatible", NULL))) {
360		pr_debug("%s() - skipping %pOF, no compatible prop\n",
361			 __func__, bus);
362		return 0;
363	}
364
365	/* Skip nodes for which we don't want to create devices */
366	if (unlikely(of_match_node(of_skipped_node_table, bus))) {
367		pr_debug("%s() - skipping %pOF node\n", __func__, bus);
368		return 0;
369	}
370
371	if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
372		pr_debug("%s() - skipping %pOF, already populated\n",
373			__func__, bus);
374		return 0;
375	}
376
377	auxdata = of_dev_lookup(lookup, bus);
378	if (auxdata) {
379		bus_id = auxdata->name;
380		platform_data = auxdata->platform_data;
381	}
382
383	if (of_device_is_compatible(bus, "arm,primecell")) {
384		/*
385		 * Don't return an error here to keep compatibility with older
386		 * device tree files.
387		 */
388		of_amba_device_create(bus, bus_id, platform_data, parent);
389		return 0;
390	}
391
392	dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
393	if (!dev || !of_match_node(matches, bus))
394		return 0;
395
396	for_each_child_of_node(bus, child) {
397		pr_debug("   create child: %pOF\n", child);
398		rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
399		if (rc) {
400			of_node_put(child);
401			break;
402		}
403	}
404	of_node_set_flag(bus, OF_POPULATED_BUS);
405	return rc;
406}
407
408/**
409 * of_platform_bus_probe() - Probe the device-tree for platform buses
410 * @root: parent of the first level to probe or NULL for the root of the tree
411 * @matches: match table for bus nodes
412 * @parent: parent to hook devices from, NULL for toplevel
413 *
414 * Note that children of the provided root are not instantiated as devices
415 * unless the specified root itself matches the bus list and is not NULL.
416 */
417int of_platform_bus_probe(struct device_node *root,
418			  const struct of_device_id *matches,
419			  struct device *parent)
420{
421	struct device_node *child;
422	int rc = 0;
423
424	root = root ? of_node_get(root) : of_find_node_by_path("/");
425	if (!root)
426		return -EINVAL;
427
428	pr_debug("%s()\n", __func__);
429	pr_debug(" starting at: %pOF\n", root);
430
431	/* Do a self check of bus type, if there's a match, create children */
432	if (of_match_node(matches, root)) {
433		rc = of_platform_bus_create(root, matches, NULL, parent, false);
434	} else for_each_child_of_node(root, child) {
435		if (!of_match_node(matches, child))
436			continue;
437		rc = of_platform_bus_create(child, matches, NULL, parent, false);
438		if (rc) {
439			of_node_put(child);
440			break;
441		}
442	}
443
444	of_node_put(root);
445	return rc;
446}
447EXPORT_SYMBOL(of_platform_bus_probe);
448
449/**
450 * of_platform_populate() - Populate platform_devices from device tree data
451 * @root: parent of the first level to probe or NULL for the root of the tree
452 * @matches: match table, NULL to use the default
453 * @lookup: auxdata table for matching id and platform_data with device nodes
454 * @parent: parent to hook devices from, NULL for toplevel
455 *
456 * Similar to of_platform_bus_probe(), this function walks the device tree
457 * and creates devices from nodes.  It differs in that it follows the modern
458 * convention of requiring all device nodes to have a 'compatible' property,
459 * and it is suitable for creating devices which are children of the root
460 * node (of_platform_bus_probe will only create children of the root which
461 * are selected by the @matches argument).
462 *
463 * New board support should be using this function instead of
464 * of_platform_bus_probe().
465 *
466 * Returns 0 on success, < 0 on failure.
467 */
468int of_platform_populate(struct device_node *root,
469			const struct of_device_id *matches,
470			const struct of_dev_auxdata *lookup,
471			struct device *parent)
472{
473	struct device_node *child;
474	int rc = 0;
475
476	root = root ? of_node_get(root) : of_find_node_by_path("/");
477	if (!root)
478		return -EINVAL;
479
480	pr_debug("%s()\n", __func__);
481	pr_debug(" starting at: %pOF\n", root);
482
483	device_links_supplier_sync_state_pause();
484	for_each_child_of_node(root, child) {
485		rc = of_platform_bus_create(child, matches, lookup, parent, true);
486		if (rc) {
487			of_node_put(child);
488			break;
489		}
490	}
491	device_links_supplier_sync_state_resume();
492
493	of_node_set_flag(root, OF_POPULATED_BUS);
494
495	of_node_put(root);
496	return rc;
497}
498EXPORT_SYMBOL_GPL(of_platform_populate);
499
500int of_platform_default_populate(struct device_node *root,
501				 const struct of_dev_auxdata *lookup,
502				 struct device *parent)
503{
504	return of_platform_populate(root, of_default_bus_match_table, lookup,
505				    parent);
506}
507EXPORT_SYMBOL_GPL(of_platform_default_populate);
508
509#ifndef CONFIG_PPC
510static const struct of_device_id reserved_mem_matches[] = {
 
511	{ .compatible = "qcom,rmtfs-mem" },
512	{ .compatible = "qcom,cmd-db" },
 
513	{ .compatible = "ramoops" },
 
 
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	fw_devlink_pause();
542	of_platform_default_populate(NULL, NULL, NULL);
543	fw_devlink_resume();
544
545	return 0;
546}
547arch_initcall_sync(of_platform_default_populate_init);
548
549static int __init of_platform_sync_state_init(void)
550{
551	device_links_supplier_sync_state_resume();
552	return 0;
553}
554late_initcall_sync(of_platform_sync_state_init);
555#endif
556
557int of_platform_device_destroy(struct device *dev, void *data)
558{
559	/* Do not touch devices not populated from the device tree */
560	if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
561		return 0;
562
563	/* Recurse for any nodes that were treated as busses */
564	if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
565		device_for_each_child(dev, NULL, of_platform_device_destroy);
566
567	of_node_clear_flag(dev->of_node, OF_POPULATED);
568	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
569
570	if (dev->bus == &platform_bus_type)
571		platform_device_unregister(to_platform_device(dev));
572#ifdef CONFIG_ARM_AMBA
573	else if (dev->bus == &amba_bustype)
574		amba_device_unregister(to_amba_device(dev));
575#endif
576
577	return 0;
578}
579EXPORT_SYMBOL_GPL(of_platform_device_destroy);
580
581/**
582 * of_platform_depopulate() - Remove devices populated from device tree
583 * @parent: device which children will be removed
584 *
585 * Complementary to of_platform_populate(), this function removes children
586 * of the given device (and, recurrently, their children) that have been
587 * created from their respective device tree nodes (and only those,
588 * leaving others - eg. manually created - unharmed).
589 */
590void of_platform_depopulate(struct device *parent)
591{
592	if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
593		device_for_each_child(parent, NULL, of_platform_device_destroy);
594		of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
595	}
596}
597EXPORT_SYMBOL_GPL(of_platform_depopulate);
598
599static void devm_of_platform_populate_release(struct device *dev, void *res)
600{
601	of_platform_depopulate(*(struct device **)res);
602}
603
604/**
605 * devm_of_platform_populate() - Populate platform_devices from device tree data
606 * @dev: device that requested to populate from device tree data
607 *
608 * Similar to of_platform_populate(), but will automatically call
609 * of_platform_depopulate() when the device is unbound from the bus.
610 *
611 * Returns 0 on success, < 0 on failure.
612 */
613int devm_of_platform_populate(struct device *dev)
614{
615	struct device **ptr;
616	int ret;
617
618	if (!dev)
619		return -EINVAL;
620
621	ptr = devres_alloc(devm_of_platform_populate_release,
622			   sizeof(*ptr), GFP_KERNEL);
623	if (!ptr)
624		return -ENOMEM;
625
626	ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
627	if (ret) {
628		devres_free(ptr);
629	} else {
630		*ptr = dev;
631		devres_add(dev, ptr);
632	}
633
634	return ret;
635}
636EXPORT_SYMBOL_GPL(devm_of_platform_populate);
637
638static int devm_of_platform_match(struct device *dev, void *res, void *data)
639{
640	struct device **ptr = res;
641
642	if (!ptr) {
643		WARN_ON(!ptr);
644		return 0;
645	}
646
647	return *ptr == data;
648}
649
650/**
651 * devm_of_platform_depopulate() - Remove devices populated from device tree
652 * @dev: device that requested to depopulate from device tree data
653 *
654 * Complementary to devm_of_platform_populate(), this function removes children
655 * of the given device (and, recurrently, their children) that have been
656 * created from their respective device tree nodes (and only those,
657 * leaving others - eg. manually created - unharmed).
658 */
659void devm_of_platform_depopulate(struct device *dev)
660{
661	int ret;
662
663	ret = devres_release(dev, devm_of_platform_populate_release,
664			     devm_of_platform_match, dev);
665
666	WARN_ON(ret);
667}
668EXPORT_SYMBOL_GPL(devm_of_platform_depopulate);
669
670#ifdef CONFIG_OF_DYNAMIC
671static int of_platform_notify(struct notifier_block *nb,
672				unsigned long action, void *arg)
673{
674	struct of_reconfig_data *rd = arg;
675	struct platform_device *pdev_parent, *pdev;
676	bool children_left;
 
677
678	switch (of_reconfig_get_state_change(action, rd)) {
679	case OF_RECONFIG_CHANGE_ADD:
680		/* verify that the parent is a bus */
681		if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
 
 
682			return NOTIFY_OK;	/* not for us */
683
684		/* already populated? (driver using of_populate manually) */
685		if (of_node_check_flag(rd->dn, OF_POPULATED))
686			return NOTIFY_OK;
687
 
 
 
 
 
688		/* pdev_parent may be NULL when no bus platform device */
689		pdev_parent = of_find_device_by_node(rd->dn->parent);
690		pdev = of_platform_device_create(rd->dn, NULL,
691				pdev_parent ? &pdev_parent->dev : NULL);
692		of_dev_put(pdev_parent);
693
694		if (pdev == NULL) {
695			pr_err("%s: failed to create for '%pOF'\n",
696					__func__, rd->dn);
697			/* of_platform_device_create tosses the error code */
698			return notifier_from_errno(-EINVAL);
699		}
700		break;
701
702	case OF_RECONFIG_CHANGE_REMOVE:
703
704		/* already depopulated? */
705		if (!of_node_check_flag(rd->dn, OF_POPULATED))
706			return NOTIFY_OK;
707
708		/* find our device by node */
709		pdev = of_find_device_by_node(rd->dn);
710		if (pdev == NULL)
711			return NOTIFY_OK;	/* no? not meant for us */
712
713		/* unregister takes one ref away */
714		of_platform_device_destroy(&pdev->dev, &children_left);
715
716		/* and put the reference of the find */
717		of_dev_put(pdev);
718		break;
719	}
720
721	return NOTIFY_OK;
722}
723
724static struct notifier_block platform_of_notifier = {
725	.notifier_call = of_platform_notify,
726};
727
728void of_platform_register_reconfig_notifier(void)
729{
730	WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
731}
732#endif /* CONFIG_OF_DYNAMIC */
733
734#endif /* CONFIG_OF_ADDRESS */