Loading...
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 */
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 */