2 * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
3 * <benh@kernel.crashing.org>
4 * and Arnd Bergmann, IBM Corp.
5 * Merged from powerpc/kernel/of_platform.c and
6 * sparc{,64}/kernel/of_device.c by Stephen Rothwell
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
14 #include <linux/errno.h>
15 #include <linux/module.h>
16 #include <linux/amba/bus.h>
17 #include <linux/device.h>
18 #include <linux/dma-mapping.h>
19 #include <linux/slab.h>
20 #include <linux/of_address.h>
21 #include <linux/of_device.h>
22 #include <linux/of_irq.h>
23 #include <linux/of_platform.h>
24 #include <linux/platform_device.h>
26 const struct of_device_id of_default_bus_match_table[] = {
27 { .compatible = "simple-bus", },
28 { .compatible = "simple-mfd", },
29 #ifdef CONFIG_ARM_AMBA
30 { .compatible = "arm,amba-bus", },
31 #endif /* CONFIG_ARM_AMBA */
32 {} /* Empty terminated list */
35 static int of_dev_node_match(struct device *dev, void *data)
37 return dev->of_node == data;
41 * of_find_device_by_node - Find the platform_device associated with a node
42 * @np: Pointer to device tree node
44 * Returns 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(&platform_bus_type, NULL, np, of_dev_node_match);
51 return dev ? to_platform_device(dev) : NULL;
53 EXPORT_SYMBOL(of_find_device_by_node);
55 #ifdef CONFIG_OF_ADDRESS
57 * The following routines scan a subtree and registers a device for
58 * each applicable node.
60 * Note: sparc doesn't use these routines because it has a different
61 * mechanism for creating devices from device tree nodes.
65 * of_device_make_bus_id - Use the device node data to assign a unique name
66 * @dev: pointer to device structure that is linked to a device tree node
68 * This routine will first try using the translated bus address to
69 * derive a unique name. If it cannot, then it will prepend names from
70 * parent nodes until a unique name can be derived.
72 void of_device_make_bus_id(struct device *dev)
74 struct device_node *node = dev->of_node;
78 /* Construct the name, using parent nodes if necessary to ensure uniqueness */
79 while (node->parent) {
81 * If the address can be translated, then that is as much
82 * uniqueness as we need. Make it the first component and return
84 reg = of_get_property(node, "reg", NULL);
85 if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
86 dev_set_name(dev, dev_name(dev) ? "%llx.%s:%s" : "%llx.%s",
87 (unsigned long long)addr, node->name,
92 /* format arguments only used if dev_name() resolves to NULL */
93 dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
94 strrchr(node->full_name, '/') + 1, dev_name(dev));
100 * of_device_alloc - Allocate and initialize an of_device
101 * @np: device node to assign to device
102 * @bus_id: Name to assign to the device. May be null to use default name.
103 * @parent: Parent device.
105 struct platform_device *of_device_alloc(struct device_node *np,
107 struct device *parent)
109 struct platform_device *dev;
110 int rc, i, num_reg = 0, num_irq;
111 struct resource *res, temp_res;
113 dev = platform_device_alloc("", -1);
117 /* count the io and irq resources */
118 while (of_address_to_resource(np, num_reg, &temp_res) == 0)
120 num_irq = of_irq_count(np);
122 /* Populate the resource table */
123 if (num_irq || num_reg) {
124 res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
126 platform_device_put(dev);
130 dev->num_resources = num_reg + num_irq;
132 for (i = 0; i < num_reg; i++, res++) {
133 rc = of_address_to_resource(np, i, res);
136 if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
137 pr_debug("not all legacy IRQ resources mapped for %s\n",
141 dev->dev.of_node = of_node_get(np);
142 dev->dev.parent = parent ? : &platform_bus;
145 dev_set_name(&dev->dev, "%s", bus_id);
147 of_device_make_bus_id(&dev->dev);
151 EXPORT_SYMBOL(of_device_alloc);
153 static void of_dma_deconfigure(struct device *dev)
155 arch_teardown_dma_ops(dev);
159 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
160 * @np: pointer to node to create device for
161 * @bus_id: name to assign device
162 * @platform_data: pointer to populate platform_data pointer with
163 * @parent: Linux device model parent device.
165 * Returns pointer to created platform device, or NULL if a device was not
166 * registered. Unavailable devices will not get registered.
168 static struct platform_device *of_platform_device_create_pdata(
169 struct device_node *np,
172 struct device *parent)
174 struct platform_device *dev;
176 if (!of_device_is_available(np) ||
177 of_node_test_and_set_flag(np, OF_POPULATED))
180 dev = of_device_alloc(np, bus_id, parent);
184 dev->dev.bus = &platform_bus_type;
185 dev->dev.platform_data = platform_data;
186 of_dma_configure(&dev->dev, dev->dev.of_node);
187 of_msi_configure(&dev->dev, dev->dev.of_node);
189 if (of_device_add(dev) != 0) {
190 of_dma_deconfigure(&dev->dev);
191 platform_device_put(dev);
198 of_node_clear_flag(np, OF_POPULATED);
203 * of_platform_device_create - Alloc, initialize and register an of_device
204 * @np: pointer to node to create device for
205 * @bus_id: name to assign device
206 * @parent: Linux device model parent device.
208 * Returns pointer to created platform device, or NULL if a device was not
209 * registered. Unavailable devices will not get registered.
211 struct platform_device *of_platform_device_create(struct device_node *np,
213 struct device *parent)
215 return of_platform_device_create_pdata(np, bus_id, NULL, parent);
217 EXPORT_SYMBOL(of_platform_device_create);
219 #ifdef CONFIG_ARM_AMBA
220 static struct amba_device *of_amba_device_create(struct device_node *node,
223 struct device *parent)
225 struct amba_device *dev;
229 pr_debug("Creating amba device %s\n", node->full_name);
231 if (!of_device_is_available(node) ||
232 of_node_test_and_set_flag(node, OF_POPULATED))
235 dev = amba_device_alloc(NULL, 0, 0);
237 pr_err("%s(): amba_device_alloc() failed for %s\n",
238 __func__, node->full_name);
242 /* setup generic device info */
243 dev->dev.of_node = of_node_get(node);
244 dev->dev.parent = parent ? : &platform_bus;
245 dev->dev.platform_data = platform_data;
247 dev_set_name(&dev->dev, "%s", bus_id);
249 of_device_make_bus_id(&dev->dev);
250 of_dma_configure(&dev->dev, dev->dev.of_node);
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("%s(): of_address_to_resource() failed (%d) for %s\n",
264 __func__, ret, node->full_name);
268 ret = amba_device_add(dev, &iomem_resource);
270 pr_err("%s(): amba_device_add() failed (%d) for %s\n",
271 __func__, ret, node->full_name);
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_devname_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("%s: devname=%s\n", np->full_name, 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("%s: compatible match\n", np->full_name);
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 %s, no compatible prop\n",
361 __func__, bus->full_name);
365 if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
366 pr_debug("%s() - skipping %s, already populated\n",
367 __func__, bus->full_name);
371 auxdata = of_dev_lookup(lookup, bus);
373 bus_id = auxdata->name;
374 platform_data = auxdata->platform_data;
377 if (of_device_is_compatible(bus, "arm,primecell")) {
379 * Don't return an error here to keep compatibility with older
382 of_amba_device_create(bus, bus_id, platform_data, parent);
386 dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
387 if (!dev || !of_match_node(matches, bus))
390 for_each_child_of_node(bus, child) {
391 pr_debug(" create child: %s\n", child->full_name);
392 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
398 of_node_set_flag(bus, OF_POPULATED_BUS);
403 * of_platform_bus_probe() - Probe the device-tree for platform buses
404 * @root: parent of the first level to probe or NULL for the root of the tree
405 * @matches: match table for bus nodes
406 * @parent: parent to hook devices from, NULL for toplevel
408 * Note that children of the provided root are not instantiated as devices
409 * unless the specified root itself matches the bus list and is not NULL.
411 int of_platform_bus_probe(struct device_node *root,
412 const struct of_device_id *matches,
413 struct device *parent)
415 struct device_node *child;
418 root = root ? of_node_get(root) : of_find_node_by_path("/");
422 pr_debug("%s()\n", __func__);
423 pr_debug(" starting at: %s\n", root->full_name);
425 /* Do a self check of bus type, if there's a match, create children */
426 if (of_match_node(matches, root)) {
427 rc = of_platform_bus_create(root, matches, NULL, parent, false);
428 } else for_each_child_of_node(root, child) {
429 if (!of_match_node(matches, child))
431 rc = of_platform_bus_create(child, matches, NULL, parent, false);
441 EXPORT_SYMBOL(of_platform_bus_probe);
444 * of_platform_populate() - Populate platform_devices from device tree data
445 * @root: parent of the first level to probe or NULL for the root of the tree
446 * @matches: match table, NULL to use the default
447 * @lookup: auxdata table for matching id and platform_data with device nodes
448 * @parent: parent to hook devices from, NULL for toplevel
450 * Similar to of_platform_bus_probe(), this function walks the device tree
451 * and creates devices from nodes. It differs in that it follows the modern
452 * convention of requiring all device nodes to have a 'compatible' property,
453 * and it is suitable for creating devices which are children of the root
454 * node (of_platform_bus_probe will only create children of the root which
455 * are selected by the @matches argument).
457 * New board support should be using this function instead of
458 * of_platform_bus_probe().
460 * Returns 0 on success, < 0 on failure.
462 int of_platform_populate(struct device_node *root,
463 const struct of_device_id *matches,
464 const struct of_dev_auxdata *lookup,
465 struct device *parent)
467 struct device_node *child;
470 root = root ? of_node_get(root) : of_find_node_by_path("/");
474 pr_debug("%s()\n", __func__);
475 pr_debug(" starting at: %s\n", root->full_name);
477 for_each_child_of_node(root, child) {
478 rc = of_platform_bus_create(child, matches, lookup, parent, true);
484 of_node_set_flag(root, OF_POPULATED_BUS);
489 EXPORT_SYMBOL_GPL(of_platform_populate);
491 int of_platform_default_populate(struct device_node *root,
492 const struct of_dev_auxdata *lookup,
493 struct device *parent)
495 return of_platform_populate(root, of_default_bus_match_table, lookup,
498 EXPORT_SYMBOL_GPL(of_platform_default_populate);
500 static int __init of_platform_default_populate_init(void)
502 if (of_have_populated_dt())
503 of_platform_default_populate(NULL, NULL, NULL);
507 arch_initcall_sync(of_platform_default_populate_init);
509 static int of_platform_device_destroy(struct device *dev, void *data)
511 /* Do not touch devices not populated from the device tree */
512 if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
515 /* Recurse for any nodes that were treated as busses */
516 if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
517 device_for_each_child(dev, NULL, of_platform_device_destroy);
519 if (dev->bus == &platform_bus_type)
520 platform_device_unregister(to_platform_device(dev));
521 #ifdef CONFIG_ARM_AMBA
522 else if (dev->bus == &amba_bustype)
523 amba_device_unregister(to_amba_device(dev));
526 of_dma_deconfigure(dev);
527 of_node_clear_flag(dev->of_node, OF_POPULATED);
528 of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
533 * of_platform_depopulate() - Remove devices populated from device tree
534 * @parent: device which children will be removed
536 * Complementary to of_platform_populate(), this function removes children
537 * of the given device (and, recurrently, their children) that have been
538 * created from their respective device tree nodes (and only those,
539 * leaving others - eg. manually created - unharmed).
541 * Returns 0 when all children devices have been removed or
542 * -EBUSY when some children remained.
544 void of_platform_depopulate(struct device *parent)
546 if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
547 device_for_each_child(parent, NULL, of_platform_device_destroy);
548 of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
551 EXPORT_SYMBOL_GPL(of_platform_depopulate);
553 #ifdef CONFIG_OF_DYNAMIC
554 static int of_platform_notify(struct notifier_block *nb,
555 unsigned long action, void *arg)
557 struct of_reconfig_data *rd = arg;
558 struct platform_device *pdev_parent, *pdev;
561 switch (of_reconfig_get_state_change(action, rd)) {
562 case OF_RECONFIG_CHANGE_ADD:
563 /* verify that the parent is a bus */
564 if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
565 return NOTIFY_OK; /* not for us */
567 /* already populated? (driver using of_populate manually) */
568 if (of_node_check_flag(rd->dn, OF_POPULATED))
571 /* pdev_parent may be NULL when no bus platform device */
572 pdev_parent = of_find_device_by_node(rd->dn->parent);
573 pdev = of_platform_device_create(rd->dn, NULL,
574 pdev_parent ? &pdev_parent->dev : NULL);
575 of_dev_put(pdev_parent);
578 pr_err("%s: failed to create for '%s'\n",
579 __func__, rd->dn->full_name);
580 /* of_platform_device_create tosses the error code */
581 return notifier_from_errno(-EINVAL);
585 case OF_RECONFIG_CHANGE_REMOVE:
587 /* already depopulated? */
588 if (!of_node_check_flag(rd->dn, OF_POPULATED))
591 /* find our device by node */
592 pdev = of_find_device_by_node(rd->dn);
594 return NOTIFY_OK; /* no? not meant for us */
596 /* unregister takes one ref away */
597 of_platform_device_destroy(&pdev->dev, &children_left);
599 /* and put the reference of the find */
607 static struct notifier_block platform_of_notifier = {
608 .notifier_call = of_platform_notify,
611 void of_platform_register_reconfig_notifier(void)
613 WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
615 #endif /* CONFIG_OF_DYNAMIC */
617 #endif /* CONFIG_OF_ADDRESS */