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 */
34 EXPORT_SYMBOL(of_default_bus_match_table);
36 static int of_dev_node_match(struct device *dev, void *data)
38 return dev->of_node == data;
42 * of_find_device_by_node - Find the platform_device associated with a node
43 * @np: Pointer to device tree node
45 * Returns platform_device pointer, or NULL if not found
47 struct platform_device *of_find_device_by_node(struct device_node *np)
51 dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
52 return dev ? to_platform_device(dev) : NULL;
54 EXPORT_SYMBOL(of_find_device_by_node);
56 #ifdef CONFIG_OF_ADDRESS
58 * The following routines scan a subtree and registers a device for
59 * each applicable node.
61 * Note: sparc doesn't use these routines because it has a different
62 * mechanism for creating devices from device tree nodes.
66 * of_device_make_bus_id - Use the device node data to assign a unique name
67 * @dev: pointer to device structure that is linked to a device tree node
69 * This routine will first try using the translated bus address to
70 * derive a unique name. If it cannot, then it will prepend names from
71 * parent nodes until a unique name can be derived.
73 void of_device_make_bus_id(struct device *dev)
75 struct device_node *node = dev->of_node;
79 /* Construct the name, using parent nodes if necessary to ensure uniqueness */
80 while (node->parent) {
82 * If the address can be translated, then that is as much
83 * uniqueness as we need. Make it the first component and return
85 reg = of_get_property(node, "reg", NULL);
86 if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
87 dev_set_name(dev, dev_name(dev) ? "%llx.%s:%s" : "%llx.%s",
88 (unsigned long long)addr, node->name,
93 /* format arguments only used if dev_name() resolves to NULL */
94 dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
95 strrchr(node->full_name, '/') + 1, dev_name(dev));
101 * of_device_alloc - Allocate and initialize an of_device
102 * @np: device node to assign to device
103 * @bus_id: Name to assign to the device. May be null to use default name.
104 * @parent: Parent device.
106 struct platform_device *of_device_alloc(struct device_node *np,
108 struct device *parent)
110 struct platform_device *dev;
111 int rc, i, num_reg = 0, num_irq;
112 struct resource *res, temp_res;
114 dev = platform_device_alloc("", -1);
118 /* count the io and irq resources */
119 while (of_address_to_resource(np, num_reg, &temp_res) == 0)
121 num_irq = of_irq_count(np);
123 /* Populate the resource table */
124 if (num_irq || num_reg) {
125 res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
127 platform_device_put(dev);
131 dev->num_resources = num_reg + num_irq;
133 for (i = 0; i < num_reg; i++, res++) {
134 rc = of_address_to_resource(np, i, res);
137 if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
138 pr_debug("not all legacy IRQ resources mapped for %s\n",
142 dev->dev.of_node = of_node_get(np);
143 dev->dev.parent = parent ? : &platform_bus;
146 dev_set_name(&dev->dev, "%s", bus_id);
148 of_device_make_bus_id(&dev->dev);
152 EXPORT_SYMBOL(of_device_alloc);
154 static void of_dma_deconfigure(struct device *dev)
156 arch_teardown_dma_ops(dev);
160 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
161 * @np: pointer to node to create device for
162 * @bus_id: name to assign device
163 * @platform_data: pointer to populate platform_data pointer with
164 * @parent: Linux device model parent device.
166 * Returns pointer to created platform device, or NULL if a device was not
167 * registered. Unavailable devices will not get registered.
169 static struct platform_device *of_platform_device_create_pdata(
170 struct device_node *np,
173 struct device *parent)
175 struct platform_device *dev;
177 if (!of_device_is_available(np) ||
178 of_node_test_and_set_flag(np, OF_POPULATED))
181 dev = of_device_alloc(np, bus_id, parent);
185 dev->dev.bus = &platform_bus_type;
186 dev->dev.platform_data = platform_data;
187 of_dma_configure(&dev->dev, dev->dev.of_node);
188 of_msi_configure(&dev->dev, dev->dev.of_node);
190 if (of_device_add(dev) != 0) {
191 of_dma_deconfigure(&dev->dev);
192 platform_device_put(dev);
199 of_node_clear_flag(np, OF_POPULATED);
204 * of_platform_device_create - Alloc, initialize and register an of_device
205 * @np: pointer to node to create device for
206 * @bus_id: name to assign device
207 * @parent: Linux device model parent device.
209 * Returns pointer to created platform device, or NULL if a device was not
210 * registered. Unavailable devices will not get registered.
212 struct platform_device *of_platform_device_create(struct device_node *np,
214 struct device *parent)
216 return of_platform_device_create_pdata(np, bus_id, NULL, parent);
218 EXPORT_SYMBOL(of_platform_device_create);
220 #ifdef CONFIG_ARM_AMBA
221 static struct amba_device *of_amba_device_create(struct device_node *node,
224 struct device *parent)
226 struct amba_device *dev;
230 pr_debug("Creating amba device %s\n", node->full_name);
232 if (!of_device_is_available(node) ||
233 of_node_test_and_set_flag(node, OF_POPULATED))
236 dev = amba_device_alloc(NULL, 0, 0);
238 pr_err("%s(): amba_device_alloc() failed for %s\n",
239 __func__, node->full_name);
243 /* setup generic device info */
244 dev->dev.of_node = of_node_get(node);
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);
251 of_dma_configure(&dev->dev, dev->dev.of_node);
253 /* Allow the HW Peripheral ID to be overridden */
254 prop = of_get_property(node, "arm,primecell-periphid", NULL);
256 dev->periphid = of_read_ulong(prop, 1);
258 /* Decode the IRQs and address ranges */
259 for (i = 0; i < AMBA_NR_IRQS; i++)
260 dev->irq[i] = irq_of_parse_and_map(node, i);
262 ret = of_address_to_resource(node, 0, &dev->res);
264 pr_err("%s(): of_address_to_resource() failed (%d) for %s\n",
265 __func__, ret, node->full_name);
269 ret = amba_device_add(dev, &iomem_resource);
271 pr_err("%s(): amba_device_add() failed (%d) for %s\n",
272 __func__, ret, node->full_name);
279 amba_device_put(dev);
281 of_node_clear_flag(node, OF_POPULATED);
284 #else /* CONFIG_ARM_AMBA */
285 static struct amba_device *of_amba_device_create(struct device_node *node,
288 struct device *parent)
292 #endif /* CONFIG_ARM_AMBA */
295 * of_devname_lookup() - Given a device node, lookup the preferred Linux name
297 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
298 struct device_node *np)
300 const struct of_dev_auxdata *auxdata;
308 for (; auxdata->compatible; auxdata++) {
309 if (!of_device_is_compatible(np, auxdata->compatible))
312 if (!of_address_to_resource(np, 0, &res))
313 if (res.start != auxdata->phys_addr)
315 pr_debug("%s: devname=%s\n", np->full_name, auxdata->name);
322 /* Try compatible match if no phys_addr and name are specified */
324 for (; auxdata->compatible; auxdata++) {
325 if (!of_device_is_compatible(np, auxdata->compatible))
327 if (!auxdata->phys_addr && !auxdata->name) {
328 pr_debug("%s: compatible match\n", np->full_name);
337 * of_platform_bus_create() - Create a device for a node and its children.
338 * @bus: device node of the bus to instantiate
339 * @matches: match table for bus nodes
340 * @lookup: auxdata table for matching id and platform_data with device nodes
341 * @parent: parent for new device, or NULL for top level.
342 * @strict: require compatible property
344 * Creates a platform_device for the provided device_node, and optionally
345 * recursively create devices for all the child nodes.
347 static int of_platform_bus_create(struct device_node *bus,
348 const struct of_device_id *matches,
349 const struct of_dev_auxdata *lookup,
350 struct device *parent, bool strict)
352 const struct of_dev_auxdata *auxdata;
353 struct device_node *child;
354 struct platform_device *dev;
355 const char *bus_id = NULL;
356 void *platform_data = NULL;
359 /* Make sure it has a compatible property */
360 if (strict && (!of_get_property(bus, "compatible", NULL))) {
361 pr_debug("%s() - skipping %s, no compatible prop\n",
362 __func__, bus->full_name);
366 auxdata = of_dev_lookup(lookup, bus);
368 bus_id = auxdata->name;
369 platform_data = auxdata->platform_data;
372 if (of_device_is_compatible(bus, "arm,primecell")) {
374 * Don't return an error here to keep compatibility with older
377 of_amba_device_create(bus, bus_id, platform_data, parent);
381 dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
382 if (!dev || !of_match_node(matches, bus))
385 for_each_child_of_node(bus, child) {
386 pr_debug(" create child: %s\n", child->full_name);
387 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
393 of_node_set_flag(bus, OF_POPULATED_BUS);
398 * of_platform_bus_probe() - Probe the device-tree for platform buses
399 * @root: parent of the first level to probe or NULL for the root of the tree
400 * @matches: match table for bus nodes
401 * @parent: parent to hook devices from, NULL for toplevel
403 * Note that children of the provided root are not instantiated as devices
404 * unless the specified root itself matches the bus list and is not NULL.
406 int of_platform_bus_probe(struct device_node *root,
407 const struct of_device_id *matches,
408 struct device *parent)
410 struct device_node *child;
413 root = root ? of_node_get(root) : of_find_node_by_path("/");
417 pr_debug("of_platform_bus_probe()\n");
418 pr_debug(" starting at: %s\n", root->full_name);
420 /* Do a self check of bus type, if there's a match, create children */
421 if (of_match_node(matches, root)) {
422 rc = of_platform_bus_create(root, matches, NULL, parent, false);
423 } else for_each_child_of_node(root, child) {
424 if (!of_match_node(matches, child))
426 rc = of_platform_bus_create(child, matches, NULL, parent, false);
436 EXPORT_SYMBOL(of_platform_bus_probe);
439 * of_platform_populate() - Populate platform_devices from device tree data
440 * @root: parent of the first level to probe or NULL for the root of the tree
441 * @matches: match table, NULL to use the default
442 * @lookup: auxdata table for matching id and platform_data with device nodes
443 * @parent: parent to hook devices from, NULL for toplevel
445 * Similar to of_platform_bus_probe(), this function walks the device tree
446 * and creates devices from nodes. It differs in that it follows the modern
447 * convention of requiring all device nodes to have a 'compatible' property,
448 * and it is suitable for creating devices which are children of the root
449 * node (of_platform_bus_probe will only create children of the root which
450 * are selected by the @matches argument).
452 * New board support should be using this function instead of
453 * of_platform_bus_probe().
455 * Returns 0 on success, < 0 on failure.
457 int of_platform_populate(struct device_node *root,
458 const struct of_device_id *matches,
459 const struct of_dev_auxdata *lookup,
460 struct device *parent)
462 struct device_node *child;
465 root = root ? of_node_get(root) : of_find_node_by_path("/");
469 for_each_child_of_node(root, child) {
470 rc = of_platform_bus_create(child, matches, lookup, parent, true);
476 of_node_set_flag(root, OF_POPULATED_BUS);
481 EXPORT_SYMBOL_GPL(of_platform_populate);
483 int of_platform_default_populate(struct device_node *root,
484 const struct of_dev_auxdata *lookup,
485 struct device *parent)
487 return of_platform_populate(root, of_default_bus_match_table, lookup,
490 EXPORT_SYMBOL_GPL(of_platform_default_populate);
492 static int of_platform_device_destroy(struct device *dev, void *data)
494 /* Do not touch devices not populated from the device tree */
495 if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
498 /* Recurse for any nodes that were treated as busses */
499 if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
500 device_for_each_child(dev, NULL, of_platform_device_destroy);
502 if (dev->bus == &platform_bus_type)
503 platform_device_unregister(to_platform_device(dev));
504 #ifdef CONFIG_ARM_AMBA
505 else if (dev->bus == &amba_bustype)
506 amba_device_unregister(to_amba_device(dev));
509 of_dma_deconfigure(dev);
510 of_node_clear_flag(dev->of_node, OF_POPULATED);
511 of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
516 * of_platform_depopulate() - Remove devices populated from device tree
517 * @parent: device which children will be removed
519 * Complementary to of_platform_populate(), this function removes children
520 * of the given device (and, recurrently, their children) that have been
521 * created from their respective device tree nodes (and only those,
522 * leaving others - eg. manually created - unharmed).
524 * Returns 0 when all children devices have been removed or
525 * -EBUSY when some children remained.
527 void of_platform_depopulate(struct device *parent)
529 if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
530 device_for_each_child(parent, NULL, of_platform_device_destroy);
531 of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
534 EXPORT_SYMBOL_GPL(of_platform_depopulate);
536 #ifdef CONFIG_OF_DYNAMIC
537 static int of_platform_notify(struct notifier_block *nb,
538 unsigned long action, void *arg)
540 struct of_reconfig_data *rd = arg;
541 struct platform_device *pdev_parent, *pdev;
544 switch (of_reconfig_get_state_change(action, rd)) {
545 case OF_RECONFIG_CHANGE_ADD:
546 /* verify that the parent is a bus */
547 if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
548 return NOTIFY_OK; /* not for us */
550 /* already populated? (driver using of_populate manually) */
551 if (of_node_check_flag(rd->dn, OF_POPULATED))
554 /* pdev_parent may be NULL when no bus platform device */
555 pdev_parent = of_find_device_by_node(rd->dn->parent);
556 pdev = of_platform_device_create(rd->dn, NULL,
557 pdev_parent ? &pdev_parent->dev : NULL);
558 of_dev_put(pdev_parent);
561 pr_err("%s: failed to create for '%s'\n",
562 __func__, rd->dn->full_name);
563 /* of_platform_device_create tosses the error code */
564 return notifier_from_errno(-EINVAL);
568 case OF_RECONFIG_CHANGE_REMOVE:
570 /* already depopulated? */
571 if (!of_node_check_flag(rd->dn, OF_POPULATED))
574 /* find our device by node */
575 pdev = of_find_device_by_node(rd->dn);
577 return NOTIFY_OK; /* no? not meant for us */
579 /* unregister takes one ref away */
580 of_platform_device_destroy(&pdev->dev, &children_left);
582 /* and put the reference of the find */
590 static struct notifier_block platform_of_notifier = {
591 .notifier_call = of_platform_notify,
594 void of_platform_register_reconfig_notifier(void)
596 WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
598 #endif /* CONFIG_OF_DYNAMIC */
600 #endif /* CONFIG_OF_ADDRESS */