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_iommu.h>
21 #include <linux/of_irq.h>
22 #include <linux/of_platform.h>
23 #include <linux/platform_device.h>
25 const 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 */
35 static const struct of_device_id of_skipped_node_table[] = {
36 { .compatible = "operating-points-v2", },
37 {} /* Empty terminated list */
41 * of_find_device_by_node - Find the platform_device associated with a node
42 * @np: Pointer to device tree node
44 * Takes a reference to the embedded struct device which needs to be dropped
47 * Returns platform_device pointer, or NULL if not found
49 struct platform_device *of_find_device_by_node(struct device_node *np)
53 dev = bus_find_device_by_of_node(&platform_bus_type, np);
54 return dev ? to_platform_device(dev) : NULL;
56 EXPORT_SYMBOL(of_find_device_by_node);
58 #ifdef CONFIG_OF_ADDRESS
60 * The following routines scan a subtree and registers a device for
61 * each applicable node.
63 * Note: sparc doesn't use these routines because it has a different
64 * mechanism for creating devices from device tree nodes.
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
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.
75 static void of_device_make_bus_id(struct device *dev)
77 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 dev_set_name(dev, dev_name(dev) ? "%llx.%pOFn:%s" : "%llx.%pOFn",
90 addr, node, dev_name(dev));
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));
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, num_irq;
113 struct resource *res, temp_res;
115 dev = platform_device_alloc("", PLATFORM_DEVID_NONE);
119 /* count the io and irq resources */
120 while (of_address_to_resource(np, num_reg, &temp_res) == 0)
122 num_irq = of_irq_count(np);
124 /* Populate the resource table */
125 if (num_irq || num_reg) {
126 res = kcalloc(num_irq + num_reg, sizeof(*res), GFP_KERNEL);
128 platform_device_put(dev);
132 dev->num_resources = num_reg + num_irq;
134 for (i = 0; i < num_reg; i++, res++) {
135 rc = of_address_to_resource(np, i, res);
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",
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 * Returns 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 * Returns 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 /* 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);
261 ret = of_address_to_resource(node, 0, &dev->res);
263 pr_err("amba: of_address_to_resource() failed (%d) for %pOF\n",
268 ret = amba_device_add(dev, &iomem_resource);
270 pr_err("amba_device_add() failed (%d) for %pOF\n",
278 amba_device_put(dev);
280 of_node_clear_flag(node, OF_POPULATED);
283 #else /* CONFIG_ARM_AMBA */
284 static struct amba_device *of_amba_device_create(struct device_node *node,
287 struct device *parent)
291 #endif /* CONFIG_ARM_AMBA */
294 * of_dev_lookup() - Given a device node, lookup the preferred Linux name
296 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
297 struct device_node *np)
299 const struct of_dev_auxdata *auxdata;
307 for (; auxdata->compatible; auxdata++) {
308 if (!of_device_is_compatible(np, auxdata->compatible))
311 if (!of_address_to_resource(np, 0, &res))
312 if (res.start != auxdata->phys_addr)
314 pr_debug("%pOF: devname=%s\n", np, auxdata->name);
321 /* Try compatible match if no phys_addr and name are specified */
323 for (; auxdata->compatible; auxdata++) {
324 if (!of_device_is_compatible(np, auxdata->compatible))
326 if (!auxdata->phys_addr && !auxdata->name) {
327 pr_debug("%pOF: compatible match\n", np);
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
343 * Creates a platform_device for the provided device_node, and optionally
344 * recursively create devices for all the child nodes.
346 static 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)
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;
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",
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);
371 if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
372 pr_debug("%s() - skipping %pOF, already populated\n",
377 auxdata = of_dev_lookup(lookup, bus);
379 bus_id = auxdata->name;
380 platform_data = auxdata->platform_data;
383 if (of_device_is_compatible(bus, "arm,primecell")) {
385 * Don't return an error here to keep compatibility with older
388 of_amba_device_create(bus, bus_id, platform_data, parent);
392 dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
393 if (!dev || !of_match_node(matches, bus))
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);
404 of_node_set_flag(bus, OF_POPULATED_BUS);
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
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.
417 int of_platform_bus_probe(struct device_node *root,
418 const struct of_device_id *matches,
419 struct device *parent)
421 struct device_node *child;
424 root = root ? of_node_get(root) : of_find_node_by_path("/");
428 pr_debug("%s()\n", __func__);
429 pr_debug(" starting at: %pOF\n", root);
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))
437 rc = of_platform_bus_create(child, matches, NULL, parent, false);
447 EXPORT_SYMBOL(of_platform_bus_probe);
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
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).
463 * New board support should be using this function instead of
464 * of_platform_bus_probe().
466 * Returns 0 on success, < 0 on failure.
468 int 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)
473 struct device_node *child;
476 root = root ? of_node_get(root) : of_find_node_by_path("/");
480 pr_debug("%s()\n", __func__);
481 pr_debug(" starting at: %pOF\n", root);
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);
491 device_links_supplier_sync_state_resume();
493 of_node_set_flag(root, OF_POPULATED_BUS);
498 EXPORT_SYMBOL_GPL(of_platform_populate);
500 int of_platform_default_populate(struct device_node *root,
501 const struct of_dev_auxdata *lookup,
502 struct device *parent)
504 return of_platform_populate(root, of_default_bus_match_table, lookup,
507 EXPORT_SYMBOL_GPL(of_platform_default_populate);
510 static const struct of_device_id reserved_mem_matches[] = {
511 { .compatible = "qcom,rmtfs-mem" },
512 { .compatible = "qcom,cmd-db" },
513 { .compatible = "ramoops" },
514 { .compatible = "nvmem-rmem" },
518 static int __init of_platform_default_populate_init(void)
520 struct device_node *node;
522 device_links_supplier_sync_state_pause();
524 if (!of_have_populated_dt())
528 * Handle certain compatibles explicitly, since we don't want to create
529 * platform_devices for every node in /reserved-memory with a
532 for_each_matching_node(node, reserved_mem_matches)
533 of_platform_device_create(node, NULL, NULL);
535 node = of_find_node_by_path("/firmware");
537 of_platform_populate(node, NULL, NULL, NULL);
541 /* Populate everything else. */
542 of_platform_default_populate(NULL, NULL, NULL);
546 arch_initcall_sync(of_platform_default_populate_init);
548 static int __init of_platform_sync_state_init(void)
550 device_links_supplier_sync_state_resume();
553 late_initcall_sync(of_platform_sync_state_init);
556 int of_platform_device_destroy(struct device *dev, void *data)
558 /* Do not touch devices not populated from the device tree */
559 if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
562 /* Recurse for any nodes that were treated as busses */
563 if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
564 device_for_each_child(dev, NULL, of_platform_device_destroy);
566 of_node_clear_flag(dev->of_node, OF_POPULATED);
567 of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
569 if (dev->bus == &platform_bus_type)
570 platform_device_unregister(to_platform_device(dev));
571 #ifdef CONFIG_ARM_AMBA
572 else if (dev->bus == &amba_bustype)
573 amba_device_unregister(to_amba_device(dev));
578 EXPORT_SYMBOL_GPL(of_platform_device_destroy);
581 * of_platform_depopulate() - Remove devices populated from device tree
582 * @parent: device which children will be removed
584 * Complementary to of_platform_populate(), this function removes children
585 * of the given device (and, recurrently, their children) that have been
586 * created from their respective device tree nodes (and only those,
587 * leaving others - eg. manually created - unharmed).
589 void of_platform_depopulate(struct device *parent)
591 if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
592 device_for_each_child_reverse(parent, NULL, of_platform_device_destroy);
593 of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
596 EXPORT_SYMBOL_GPL(of_platform_depopulate);
598 static void devm_of_platform_populate_release(struct device *dev, void *res)
600 of_platform_depopulate(*(struct device **)res);
604 * devm_of_platform_populate() - Populate platform_devices from device tree data
605 * @dev: device that requested to populate from device tree data
607 * Similar to of_platform_populate(), but will automatically call
608 * of_platform_depopulate() when the device is unbound from the bus.
610 * Returns 0 on success, < 0 on failure.
612 int devm_of_platform_populate(struct device *dev)
620 ptr = devres_alloc(devm_of_platform_populate_release,
621 sizeof(*ptr), GFP_KERNEL);
625 ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
630 devres_add(dev, ptr);
635 EXPORT_SYMBOL_GPL(devm_of_platform_populate);
637 static int devm_of_platform_match(struct device *dev, void *res, void *data)
639 struct device **ptr = res;
650 * devm_of_platform_depopulate() - Remove devices populated from device tree
651 * @dev: device that requested to depopulate from device tree data
653 * Complementary to devm_of_platform_populate(), this function removes children
654 * of the given device (and, recurrently, their children) that have been
655 * created from their respective device tree nodes (and only those,
656 * leaving others - eg. manually created - unharmed).
658 void devm_of_platform_depopulate(struct device *dev)
662 ret = devres_release(dev, devm_of_platform_populate_release,
663 devm_of_platform_match, dev);
667 EXPORT_SYMBOL_GPL(devm_of_platform_depopulate);
669 #ifdef CONFIG_OF_DYNAMIC
670 static int of_platform_notify(struct notifier_block *nb,
671 unsigned long action, void *arg)
673 struct of_reconfig_data *rd = arg;
674 struct platform_device *pdev_parent, *pdev;
677 switch (of_reconfig_get_state_change(action, rd)) {
678 case OF_RECONFIG_CHANGE_ADD:
679 /* verify that the parent is a bus */
680 if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
681 return NOTIFY_OK; /* not for us */
683 /* already populated? (driver using of_populate manually) */
684 if (of_node_check_flag(rd->dn, OF_POPULATED))
687 /* pdev_parent may be NULL when no bus platform device */
688 pdev_parent = of_find_device_by_node(rd->dn->parent);
689 pdev = of_platform_device_create(rd->dn, NULL,
690 pdev_parent ? &pdev_parent->dev : NULL);
691 platform_device_put(pdev_parent);
694 pr_err("%s: failed to create for '%pOF'\n",
696 /* of_platform_device_create tosses the error code */
697 return notifier_from_errno(-EINVAL);
701 case OF_RECONFIG_CHANGE_REMOVE:
703 /* already depopulated? */
704 if (!of_node_check_flag(rd->dn, OF_POPULATED))
707 /* find our device by node */
708 pdev = of_find_device_by_node(rd->dn);
710 return NOTIFY_OK; /* no? not meant for us */
712 /* unregister takes one ref away */
713 of_platform_device_destroy(&pdev->dev, &children_left);
715 /* and put the reference of the find */
716 platform_device_put(pdev);
723 static struct notifier_block platform_of_notifier = {
724 .notifier_call = of_platform_notify,
727 void of_platform_register_reconfig_notifier(void)
729 WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
731 #endif /* CONFIG_OF_DYNAMIC */
733 #endif /* CONFIG_OF_ADDRESS */