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>
24 const 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 */
34 static const struct of_device_id of_skipped_node_table[] = {
35 { .compatible = "operating-points-v2", },
36 {} /* Empty terminated list */
40 * of_find_device_by_node - Find the platform_device associated with a node
41 * @np: Pointer to device tree node
43 * Takes a reference to the embedded struct device which needs to be dropped
46 * Return: platform_device pointer, or NULL if not found
48 struct platform_device *of_find_device_by_node(struct device_node *np)
52 dev = bus_find_device_by_of_node(&platform_bus_type, np);
53 return dev ? to_platform_device(dev) : NULL;
55 EXPORT_SYMBOL(of_find_device_by_node);
57 #ifdef CONFIG_OF_ADDRESS
59 * The following routines scan a subtree and registers a device for
60 * each applicable node.
62 * Note: sparc doesn't use these routines because it has a different
63 * mechanism for creating devices from device tree nodes.
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
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.
74 static void of_device_make_bus_id(struct device *dev)
76 struct device_node *node = dev->of_node;
81 /* Construct the name, using parent nodes if necessary to ensure uniqueness */
82 while (node->parent) {
84 * If the address can be translated, then that is as much
85 * uniqueness as we need. Make it the first component and return
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));
94 dev_set_name(dev, dev_name(dev) ? "%llx.%pOFn:%s" : "%llx.%pOFn",
95 addr, node, dev_name(dev));
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));
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.
112 struct platform_device *of_device_alloc(struct device_node *np,
114 struct device *parent)
116 struct platform_device *dev;
117 int rc, i, num_reg = 0;
118 struct resource *res;
120 dev = platform_device_alloc("", PLATFORM_DEVID_NONE);
124 /* count the io resources */
125 num_reg = of_address_count(np);
127 /* Populate the resource table */
129 res = kcalloc(num_reg, sizeof(*res), GFP_KERNEL);
131 platform_device_put(dev);
135 dev->num_resources = num_reg;
137 for (i = 0; i < num_reg; i++, res++) {
138 rc = of_address_to_resource(np, i, res);
143 dev->dev.of_node = of_node_get(np);
144 dev->dev.fwnode = &np->fwnode;
145 dev->dev.parent = parent ? : &platform_bus;
148 dev_set_name(&dev->dev, "%s", bus_id);
150 of_device_make_bus_id(&dev->dev);
154 EXPORT_SYMBOL(of_device_alloc);
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.
163 * Return: Pointer to created platform device, or NULL if a device was not
164 * registered. Unavailable devices will not get registered.
166 static struct platform_device *of_platform_device_create_pdata(
167 struct device_node *np,
170 struct device *parent)
172 struct platform_device *dev;
174 if (!of_device_is_available(np) ||
175 of_node_test_and_set_flag(np, OF_POPULATED))
178 dev = of_device_alloc(np, bus_id, parent);
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);
189 if (of_device_add(dev) != 0) {
190 platform_device_put(dev);
197 of_node_clear_flag(np, OF_POPULATED);
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.
207 * Return: Pointer to created platform device, or NULL if a device was not
208 * registered. Unavailable devices will not get registered.
210 struct platform_device *of_platform_device_create(struct device_node *np,
212 struct device *parent)
214 return of_platform_device_create_pdata(np, bus_id, NULL, parent);
216 EXPORT_SYMBOL(of_platform_device_create);
218 #ifdef CONFIG_ARM_AMBA
219 static struct amba_device *of_amba_device_create(struct device_node *node,
222 struct device *parent)
224 struct amba_device *dev;
228 pr_debug("Creating amba device %pOF\n", node);
230 if (!of_device_is_available(node) ||
231 of_node_test_and_set_flag(node, OF_POPULATED))
234 dev = amba_device_alloc(NULL, 0, 0);
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;
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;
248 dev_set_name(&dev->dev, "%s", bus_id);
250 of_device_make_bus_id(&dev->dev);
252 /* Allow the HW Peripheral ID to be overridden */
253 prop = of_get_property(node, "arm,primecell-periphid", NULL);
255 dev->periphid = of_read_ulong(prop, 1);
257 ret = of_address_to_resource(node, 0, &dev->res);
259 pr_err("amba: of_address_to_resource() failed (%d) for %pOF\n",
264 ret = amba_device_add(dev, &iomem_resource);
266 pr_err("amba_device_add() failed (%d) for %pOF\n",
274 amba_device_put(dev);
276 of_node_clear_flag(node, OF_POPULATED);
279 #else /* CONFIG_ARM_AMBA */
280 static struct amba_device *of_amba_device_create(struct device_node *node,
283 struct device *parent)
287 #endif /* CONFIG_ARM_AMBA */
290 * of_dev_lookup() - Given a device node, lookup the preferred Linux name
292 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
293 struct device_node *np)
295 const struct of_dev_auxdata *auxdata;
303 for (; auxdata->compatible; auxdata++) {
304 if (!of_device_is_compatible(np, auxdata->compatible))
307 if (!of_address_to_resource(np, 0, &res))
308 if (res.start != auxdata->phys_addr)
310 pr_debug("%pOF: devname=%s\n", np, auxdata->name);
317 /* Try compatible match if no phys_addr and name are specified */
319 for (; auxdata->compatible; auxdata++) {
320 if (!of_device_is_compatible(np, auxdata->compatible))
322 if (!auxdata->phys_addr && !auxdata->name) {
323 pr_debug("%pOF: compatible match\n", np);
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
339 * Creates a platform_device for the provided device_node, and optionally
340 * recursively create devices for all the child nodes.
342 static 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)
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;
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",
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);
367 if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
368 pr_debug("%s() - skipping %pOF, already populated\n",
373 auxdata = of_dev_lookup(lookup, bus);
375 bus_id = auxdata->name;
376 platform_data = auxdata->platform_data;
379 if (of_device_is_compatible(bus, "arm,primecell")) {
381 * Don't return an error here to keep compatibility with older
384 of_amba_device_create(bus, bus_id, platform_data, parent);
388 dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
389 if (!dev || !of_match_node(matches, bus))
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);
400 of_node_set_flag(bus, OF_POPULATED_BUS);
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
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.
413 int of_platform_bus_probe(struct device_node *root,
414 const struct of_device_id *matches,
415 struct device *parent)
417 struct device_node *child;
420 root = root ? of_node_get(root) : of_find_node_by_path("/");
424 pr_debug("%s()\n", __func__);
425 pr_debug(" starting at: %pOF\n", root);
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))
433 rc = of_platform_bus_create(child, matches, NULL, parent, false);
443 EXPORT_SYMBOL(of_platform_bus_probe);
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
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).
459 * New board support should be using this function instead of
460 * of_platform_bus_probe().
462 * Return: 0 on success, < 0 on failure.
464 int 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)
469 struct device_node *child;
472 root = root ? of_node_get(root) : of_find_node_by_path("/");
476 pr_debug("%s()\n", __func__);
477 pr_debug(" starting at: %pOF\n", root);
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);
487 device_links_supplier_sync_state_resume();
489 of_node_set_flag(root, OF_POPULATED_BUS);
494 EXPORT_SYMBOL_GPL(of_platform_populate);
496 int of_platform_default_populate(struct device_node *root,
497 const struct of_dev_auxdata *lookup,
498 struct device *parent)
500 return of_platform_populate(root, of_default_bus_match_table, lookup,
503 EXPORT_SYMBOL_GPL(of_platform_default_populate);
505 static 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" },
516 static int __init of_platform_default_populate_init(void)
518 struct device_node *node;
520 device_links_supplier_sync_state_pause();
522 if (!of_have_populated_dt())
525 if (IS_ENABLED(CONFIG_PPC)) {
526 struct device_node *boot_display = NULL;
527 struct platform_device *dev;
528 int display_number = 0;
531 /* Check if we have a MacOS display without a node spec */
532 if (of_get_property(of_chosen, "linux,bootx-noscreen", NULL)) {
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).
540 dev = platform_device_alloc("bootx-noscreen", 0);
543 ret = platform_device_add(dev);
545 platform_device_put(dev);
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.
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))
559 dev = of_platform_device_create(node, "of-display.0", NULL);
567 for_each_node_by_type(node, "display") {
569 const char *of_display_format = "of-display.%d";
571 if (!of_get_property(node, "linux,opened", NULL) || node == boot_display)
573 ret = snprintf(buf, sizeof(buf), of_display_format, display_number++);
574 if (ret < sizeof(buf))
575 of_platform_device_create(node, buf, NULL);
580 * Handle certain compatibles explicitly, since we don't want to create
581 * platform_devices for every node in /reserved-memory with a
584 for_each_matching_node(node, reserved_mem_matches)
585 of_platform_device_create(node, NULL, NULL);
587 node = of_find_node_by_path("/firmware");
589 of_platform_populate(node, NULL, NULL, NULL);
593 node = of_get_compatible_child(of_chosen, "simple-framebuffer");
594 of_platform_device_create(node, NULL, NULL);
597 /* Populate everything else. */
598 of_platform_default_populate(NULL, NULL, NULL);
603 arch_initcall_sync(of_platform_default_populate_init);
605 static int __init of_platform_sync_state_init(void)
607 device_links_supplier_sync_state_resume();
610 late_initcall_sync(of_platform_sync_state_init);
612 int of_platform_device_destroy(struct device *dev, void *data)
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))
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);
622 of_node_clear_flag(dev->of_node, OF_POPULATED);
623 of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
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));
634 EXPORT_SYMBOL_GPL(of_platform_device_destroy);
637 * of_platform_depopulate() - Remove devices populated from device tree
638 * @parent: device which children will be removed
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).
645 void of_platform_depopulate(struct device *parent)
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);
652 EXPORT_SYMBOL_GPL(of_platform_depopulate);
654 static void devm_of_platform_populate_release(struct device *dev, void *res)
656 of_platform_depopulate(*(struct device **)res);
660 * devm_of_platform_populate() - Populate platform_devices from device tree data
661 * @dev: device that requested to populate from device tree data
663 * Similar to of_platform_populate(), but will automatically call
664 * of_platform_depopulate() when the device is unbound from the bus.
666 * Return: 0 on success, < 0 on failure.
668 int devm_of_platform_populate(struct device *dev)
676 ptr = devres_alloc(devm_of_platform_populate_release,
677 sizeof(*ptr), GFP_KERNEL);
681 ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
686 devres_add(dev, ptr);
691 EXPORT_SYMBOL_GPL(devm_of_platform_populate);
693 static int devm_of_platform_match(struct device *dev, void *res, void *data)
695 struct device **ptr = res;
706 * devm_of_platform_depopulate() - Remove devices populated from device tree
707 * @dev: device that requested to depopulate from device tree data
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).
714 void devm_of_platform_depopulate(struct device *dev)
718 ret = devres_release(dev, devm_of_platform_populate_release,
719 devm_of_platform_match, dev);
723 EXPORT_SYMBOL_GPL(devm_of_platform_depopulate);
725 #ifdef CONFIG_OF_DYNAMIC
726 static int of_platform_notify(struct notifier_block *nb,
727 unsigned long action, void *arg)
729 struct of_reconfig_data *rd = arg;
730 struct platform_device *pdev_parent, *pdev;
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 */
739 /* already populated? (driver using of_populate manually) */
740 if (of_node_check_flag(rd->dn, OF_POPULATED))
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);
750 pr_err("%s: failed to create for '%pOF'\n",
752 /* of_platform_device_create tosses the error code */
753 return notifier_from_errno(-EINVAL);
757 case OF_RECONFIG_CHANGE_REMOVE:
759 /* already depopulated? */
760 if (!of_node_check_flag(rd->dn, OF_POPULATED))
763 /* find our device by node */
764 pdev = of_find_device_by_node(rd->dn);
766 return NOTIFY_OK; /* no? not meant for us */
768 /* unregister takes one ref away */
769 of_platform_device_destroy(&pdev->dev, &children_left);
771 /* and put the reference of the find */
772 platform_device_put(pdev);
779 static struct notifier_block platform_of_notifier = {
780 .notifier_call = of_platform_notify,
783 void of_platform_register_reconfig_notifier(void)
785 WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
787 #endif /* CONFIG_OF_DYNAMIC */
789 #endif /* CONFIG_OF_ADDRESS */