1 // SPDX-License-Identifier: GPL-2.0+
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
10 #define pr_fmt(fmt) "OF: " fmt
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>
25 #include "of_private.h"
27 const 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 */
38 * of_find_device_by_node - Find the platform_device associated with a node
39 * @np: Pointer to device tree node
41 * Takes a reference to the embedded struct device which needs to be dropped
44 * Return: platform_device pointer, or NULL if not found
46 struct platform_device *of_find_device_by_node(struct device_node *np)
50 dev = bus_find_device_by_of_node(&platform_bus_type, np);
51 return dev ? to_platform_device(dev) : NULL;
53 EXPORT_SYMBOL(of_find_device_by_node);
55 int of_device_add(struct platform_device *ofdev)
57 BUG_ON(ofdev->dev.of_node == NULL);
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;
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.
69 set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
71 return device_add(&ofdev->dev);
74 int of_device_register(struct platform_device *pdev)
76 device_initialize(&pdev->dev);
77 return of_device_add(pdev);
79 EXPORT_SYMBOL(of_device_register);
81 void of_device_unregister(struct platform_device *ofdev)
83 device_unregister(&ofdev->dev);
85 EXPORT_SYMBOL(of_device_unregister);
87 #ifdef CONFIG_OF_ADDRESS
88 static const struct of_device_id of_skipped_node_table[] = {
89 { .compatible = "operating-points-v2", },
90 {} /* Empty terminated list */
94 * The following routines scan a subtree and registers a device for
95 * each applicable node.
97 * Note: sparc doesn't use these routines because it has a different
98 * mechanism for creating devices from device tree nodes.
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.
107 struct platform_device *of_device_alloc(struct device_node *np,
109 struct device *parent)
111 struct platform_device *dev;
112 int rc, i, num_reg = 0;
113 struct resource *res;
115 dev = platform_device_alloc("", PLATFORM_DEVID_NONE);
119 /* count the io resources */
120 num_reg = of_address_count(np);
122 /* Populate the resource table */
124 res = kcalloc(num_reg, sizeof(*res), GFP_KERNEL);
126 platform_device_put(dev);
130 dev->num_resources = num_reg;
132 for (i = 0; i < num_reg; i++, res++) {
133 rc = of_address_to_resource(np, i, res);
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;
143 dev_set_name(&dev->dev, "%s", bus_id);
145 of_device_make_bus_id(&dev->dev);
149 EXPORT_SYMBOL(of_device_alloc);
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.
158 * Return: Pointer to created platform device, or NULL if a device was not
159 * registered. Unavailable devices will not get registered.
161 static struct platform_device *of_platform_device_create_pdata(
162 struct device_node *np,
165 struct device *parent)
167 struct platform_device *dev;
169 if (!of_device_is_available(np) ||
170 of_node_test_and_set_flag(np, OF_POPULATED))
173 dev = of_device_alloc(np, bus_id, parent);
177 dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
178 if (!dev->dev.dma_mask)
179 dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
180 dev->dev.bus = &platform_bus_type;
181 dev->dev.platform_data = platform_data;
182 of_msi_configure(&dev->dev, dev->dev.of_node);
184 if (of_device_add(dev) != 0) {
185 platform_device_put(dev);
192 of_node_clear_flag(np, OF_POPULATED);
197 * of_platform_device_create - Alloc, initialize and register an of_device
198 * @np: pointer to node to create device for
199 * @bus_id: name to assign device
200 * @parent: Linux device model parent device.
202 * Return: Pointer to created platform device, or NULL if a device was not
203 * registered. Unavailable devices will not get registered.
205 struct platform_device *of_platform_device_create(struct device_node *np,
207 struct device *parent)
209 return of_platform_device_create_pdata(np, bus_id, NULL, parent);
211 EXPORT_SYMBOL(of_platform_device_create);
213 #ifdef CONFIG_ARM_AMBA
214 static struct amba_device *of_amba_device_create(struct device_node *node,
217 struct device *parent)
219 struct amba_device *dev;
222 pr_debug("Creating amba device %pOF\n", node);
224 if (!of_device_is_available(node) ||
225 of_node_test_and_set_flag(node, OF_POPULATED))
228 dev = amba_device_alloc(NULL, 0, 0);
232 /* AMBA devices only support a single DMA mask */
233 dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
234 dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
236 /* setup generic device info */
237 device_set_node(&dev->dev, of_fwnode_handle(node));
238 dev->dev.parent = parent ? : &platform_bus;
239 dev->dev.platform_data = platform_data;
241 dev_set_name(&dev->dev, "%s", bus_id);
243 of_device_make_bus_id(&dev->dev);
245 /* Allow the HW Peripheral ID to be overridden */
246 of_property_read_u32(node, "arm,primecell-periphid", &dev->periphid);
248 ret = of_address_to_resource(node, 0, &dev->res);
250 pr_err("amba: of_address_to_resource() failed (%d) for %pOF\n",
255 ret = amba_device_add(dev, &iomem_resource);
257 pr_err("amba_device_add() failed (%d) for %pOF\n",
265 amba_device_put(dev);
267 of_node_clear_flag(node, OF_POPULATED);
270 #else /* CONFIG_ARM_AMBA */
271 static struct amba_device *of_amba_device_create(struct device_node *node,
274 struct device *parent)
278 #endif /* CONFIG_ARM_AMBA */
281 * of_dev_lookup() - Given a device node, lookup the preferred Linux name
283 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
284 struct device_node *np)
286 const struct of_dev_auxdata *auxdata;
294 for (; auxdata->compatible; auxdata++) {
295 if (!of_device_is_compatible(np, auxdata->compatible))
298 if (!of_address_to_resource(np, 0, &res))
299 if (res.start != auxdata->phys_addr)
301 pr_debug("%pOF: devname=%s\n", np, auxdata->name);
308 /* Try compatible match if no phys_addr and name are specified */
310 for (; auxdata->compatible; auxdata++) {
311 if (!of_device_is_compatible(np, auxdata->compatible))
313 if (!auxdata->phys_addr && !auxdata->name) {
314 pr_debug("%pOF: compatible match\n", np);
323 * of_platform_bus_create() - Create a device for a node and its children.
324 * @bus: device node of the bus to instantiate
325 * @matches: match table for bus nodes
326 * @lookup: auxdata table for matching id and platform_data with device nodes
327 * @parent: parent for new device, or NULL for top level.
328 * @strict: require compatible property
330 * Creates a platform_device for the provided device_node, and optionally
331 * recursively create devices for all the child nodes.
333 static int of_platform_bus_create(struct device_node *bus,
334 const struct of_device_id *matches,
335 const struct of_dev_auxdata *lookup,
336 struct device *parent, bool strict)
338 const struct of_dev_auxdata *auxdata;
339 struct device_node *child;
340 struct platform_device *dev;
341 const char *bus_id = NULL;
342 void *platform_data = NULL;
345 /* Make sure it has a compatible property */
346 if (strict && (!of_get_property(bus, "compatible", NULL))) {
347 pr_debug("%s() - skipping %pOF, no compatible prop\n",
352 /* Skip nodes for which we don't want to create devices */
353 if (unlikely(of_match_node(of_skipped_node_table, bus))) {
354 pr_debug("%s() - skipping %pOF node\n", __func__, bus);
358 if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
359 pr_debug("%s() - skipping %pOF, already populated\n",
364 auxdata = of_dev_lookup(lookup, bus);
366 bus_id = auxdata->name;
367 platform_data = auxdata->platform_data;
370 if (of_device_is_compatible(bus, "arm,primecell")) {
372 * Don't return an error here to keep compatibility with older
375 of_amba_device_create(bus, bus_id, platform_data, parent);
379 dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
380 if (!dev || !of_match_node(matches, bus))
383 for_each_child_of_node(bus, child) {
384 pr_debug(" create child: %pOF\n", child);
385 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
391 of_node_set_flag(bus, OF_POPULATED_BUS);
396 * of_platform_bus_probe() - Probe the device-tree for platform buses
397 * @root: parent of the first level to probe or NULL for the root of the tree
398 * @matches: match table for bus nodes
399 * @parent: parent to hook devices from, NULL for toplevel
401 * Note that children of the provided root are not instantiated as devices
402 * unless the specified root itself matches the bus list and is not NULL.
404 int of_platform_bus_probe(struct device_node *root,
405 const struct of_device_id *matches,
406 struct device *parent)
408 struct device_node *child;
411 root = root ? of_node_get(root) : of_find_node_by_path("/");
415 pr_debug("%s()\n", __func__);
416 pr_debug(" starting at: %pOF\n", root);
418 /* Do a self check of bus type, if there's a match, create children */
419 if (of_match_node(matches, root)) {
420 rc = of_platform_bus_create(root, matches, NULL, parent, false);
421 } else for_each_child_of_node(root, child) {
422 if (!of_match_node(matches, child))
424 rc = of_platform_bus_create(child, matches, NULL, parent, false);
434 EXPORT_SYMBOL(of_platform_bus_probe);
437 * of_platform_populate() - Populate platform_devices from device tree data
438 * @root: parent of the first level to probe or NULL for the root of the tree
439 * @matches: match table, NULL to use the default
440 * @lookup: auxdata table for matching id and platform_data with device nodes
441 * @parent: parent to hook devices from, NULL for toplevel
443 * Similar to of_platform_bus_probe(), this function walks the device tree
444 * and creates devices from nodes. It differs in that it follows the modern
445 * convention of requiring all device nodes to have a 'compatible' property,
446 * and it is suitable for creating devices which are children of the root
447 * node (of_platform_bus_probe will only create children of the root which
448 * are selected by the @matches argument).
450 * New board support should be using this function instead of
451 * of_platform_bus_probe().
453 * Return: 0 on success, < 0 on failure.
455 int of_platform_populate(struct device_node *root,
456 const struct of_device_id *matches,
457 const struct of_dev_auxdata *lookup,
458 struct device *parent)
460 struct device_node *child;
463 root = root ? of_node_get(root) : of_find_node_by_path("/");
467 pr_debug("%s()\n", __func__);
468 pr_debug(" starting at: %pOF\n", root);
470 device_links_supplier_sync_state_pause();
471 for_each_child_of_node(root, child) {
472 rc = of_platform_bus_create(child, matches, lookup, parent, true);
478 device_links_supplier_sync_state_resume();
480 of_node_set_flag(root, OF_POPULATED_BUS);
485 EXPORT_SYMBOL_GPL(of_platform_populate);
487 int of_platform_default_populate(struct device_node *root,
488 const struct of_dev_auxdata *lookup,
489 struct device *parent)
491 return of_platform_populate(root, of_default_bus_match_table, lookup,
494 EXPORT_SYMBOL_GPL(of_platform_default_populate);
496 static const struct of_device_id reserved_mem_matches[] = {
497 { .compatible = "phram" },
498 { .compatible = "qcom,rmtfs-mem" },
499 { .compatible = "qcom,cmd-db" },
500 { .compatible = "qcom,smem" },
501 { .compatible = "ramoops" },
502 { .compatible = "nvmem-rmem" },
503 { .compatible = "google,open-dice" },
507 static int __init of_platform_default_populate_init(void)
509 struct device_node *node;
511 device_links_supplier_sync_state_pause();
513 if (!of_have_populated_dt())
516 if (IS_ENABLED(CONFIG_PPC)) {
517 struct device_node *boot_display = NULL;
518 struct platform_device *dev;
519 int display_number = 0;
522 /* Check if we have a MacOS display without a node spec */
523 if (of_property_present(of_chosen, "linux,bootx-noscreen")) {
525 * The old code tried to work out which node was the MacOS
526 * display based on the address. I'm dropping that since the
527 * lack of a node spec only happens with old BootX versions
528 * (users can update) and with this code, they'll still get
529 * a display (just not the palette hacks).
531 dev = platform_device_alloc("bootx-noscreen", 0);
534 ret = platform_device_add(dev);
536 platform_device_put(dev);
542 * For OF framebuffers, first create the device for the boot display,
543 * then for the other framebuffers. Only fail for the boot display;
544 * ignore errors for the rest.
546 for_each_node_by_type(node, "display") {
547 if (!of_get_property(node, "linux,opened", NULL) ||
548 !of_get_property(node, "linux,boot-display", NULL))
550 dev = of_platform_device_create(node, "of-display", NULL);
558 for_each_node_by_type(node, "display") {
560 const char *of_display_format = "of-display.%d";
562 if (!of_get_property(node, "linux,opened", NULL) || node == boot_display)
564 ret = snprintf(buf, sizeof(buf), of_display_format, display_number++);
565 if (ret < sizeof(buf))
566 of_platform_device_create(node, buf, NULL);
571 * Handle certain compatibles explicitly, since we don't want to create
572 * platform_devices for every node in /reserved-memory with a
575 for_each_matching_node(node, reserved_mem_matches)
576 of_platform_device_create(node, NULL, NULL);
578 node = of_find_node_by_path("/firmware");
580 of_platform_populate(node, NULL, NULL, NULL);
584 node = of_get_compatible_child(of_chosen, "simple-framebuffer");
587 * Since a "simple-framebuffer" device is already added
588 * here, disable the Generic System Framebuffers (sysfb)
589 * to prevent it from registering another device for the
590 * system framebuffer later (e.g: using the screen_info
591 * data that may had been filled as well).
593 * This can happen for example on DT systems that do EFI
594 * booting and may provide a GOP handle to the EFI stub.
597 of_platform_device_create(node, NULL, NULL);
601 /* Populate everything else. */
602 of_platform_default_populate(NULL, NULL, NULL);
607 arch_initcall_sync(of_platform_default_populate_init);
609 static int __init of_platform_sync_state_init(void)
611 device_links_supplier_sync_state_resume();
614 late_initcall_sync(of_platform_sync_state_init);
616 int of_platform_device_destroy(struct device *dev, void *data)
618 /* Do not touch devices not populated from the device tree */
619 if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
622 /* Recurse for any nodes that were treated as busses */
623 if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
624 device_for_each_child(dev, NULL, of_platform_device_destroy);
626 of_node_clear_flag(dev->of_node, OF_POPULATED);
627 of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
629 if (dev->bus == &platform_bus_type)
630 platform_device_unregister(to_platform_device(dev));
631 #ifdef CONFIG_ARM_AMBA
632 else if (dev->bus == &amba_bustype)
633 amba_device_unregister(to_amba_device(dev));
638 EXPORT_SYMBOL_GPL(of_platform_device_destroy);
641 * of_platform_depopulate() - Remove devices populated from device tree
642 * @parent: device which children will be removed
644 * Complementary to of_platform_populate(), this function removes children
645 * of the given device (and, recursively, their children) that have been
646 * created from their respective device tree nodes (and only those,
647 * leaving others - eg. manually created - unharmed).
649 void of_platform_depopulate(struct device *parent)
651 if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
652 device_for_each_child_reverse(parent, NULL, of_platform_device_destroy);
653 of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
656 EXPORT_SYMBOL_GPL(of_platform_depopulate);
658 static void devm_of_platform_populate_release(struct device *dev, void *res)
660 of_platform_depopulate(*(struct device **)res);
664 * devm_of_platform_populate() - Populate platform_devices from device tree data
665 * @dev: device that requested to populate from device tree data
667 * Similar to of_platform_populate(), but will automatically call
668 * of_platform_depopulate() when the device is unbound from the bus.
670 * Return: 0 on success, < 0 on failure.
672 int devm_of_platform_populate(struct device *dev)
680 ptr = devres_alloc(devm_of_platform_populate_release,
681 sizeof(*ptr), GFP_KERNEL);
685 ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
690 devres_add(dev, ptr);
695 EXPORT_SYMBOL_GPL(devm_of_platform_populate);
697 static int devm_of_platform_match(struct device *dev, void *res, void *data)
699 struct device **ptr = res;
710 * devm_of_platform_depopulate() - Remove devices populated from device tree
711 * @dev: device that requested to depopulate from device tree data
713 * Complementary to devm_of_platform_populate(), this function removes children
714 * of the given device (and, recursively, their children) that have been
715 * created from their respective device tree nodes (and only those,
716 * leaving others - eg. manually created - unharmed).
718 void devm_of_platform_depopulate(struct device *dev)
722 ret = devres_release(dev, devm_of_platform_populate_release,
723 devm_of_platform_match, dev);
727 EXPORT_SYMBOL_GPL(devm_of_platform_depopulate);
729 #ifdef CONFIG_OF_DYNAMIC
730 static int of_platform_notify(struct notifier_block *nb,
731 unsigned long action, void *arg)
733 struct of_reconfig_data *rd = arg;
734 struct platform_device *pdev_parent, *pdev;
737 switch (of_reconfig_get_state_change(action, rd)) {
738 case OF_RECONFIG_CHANGE_ADD:
739 /* verify that the parent is a bus */
740 if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
741 return NOTIFY_OK; /* not for us */
743 /* already populated? (driver using of_populate manually) */
744 if (of_node_check_flag(rd->dn, OF_POPULATED))
748 * Clear the flag before adding the device so that fw_devlink
749 * doesn't skip adding consumers to this device.
751 rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
752 /* pdev_parent may be NULL when no bus platform device */
753 pdev_parent = of_find_device_by_node(rd->dn->parent);
754 pdev = of_platform_device_create(rd->dn, NULL,
755 pdev_parent ? &pdev_parent->dev : NULL);
756 platform_device_put(pdev_parent);
759 pr_err("%s: failed to create for '%pOF'\n",
761 /* of_platform_device_create tosses the error code */
762 return notifier_from_errno(-EINVAL);
766 case OF_RECONFIG_CHANGE_REMOVE:
768 /* already depopulated? */
769 if (!of_node_check_flag(rd->dn, OF_POPULATED))
772 /* find our device by node */
773 pdev = of_find_device_by_node(rd->dn);
775 return NOTIFY_OK; /* no? not meant for us */
777 /* unregister takes one ref away */
778 of_platform_device_destroy(&pdev->dev, &children_left);
780 /* and put the reference of the find */
781 platform_device_put(pdev);
788 static struct notifier_block platform_of_notifier = {
789 .notifier_call = of_platform_notify,
792 void of_platform_register_reconfig_notifier(void)
794 WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
796 #endif /* CONFIG_OF_DYNAMIC */
798 #endif /* CONFIG_OF_ADDRESS */