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 #ifdef CONFIG_ARM_AMBA
29 { .compatible = "arm,amba-bus", },
30 #endif /* CONFIG_ARM_AMBA */
31 {} /* Empty terminated list */
34 static int of_dev_node_match(struct device *dev, void *data)
36 return dev->of_node == data;
40 * of_find_device_by_node - Find the platform_device associated with a node
41 * @np: Pointer to device tree node
43 * Returns platform_device pointer, or NULL if not found
45 struct platform_device *of_find_device_by_node(struct device_node *np)
49 dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
50 return dev ? to_platform_device(dev) : NULL;
52 EXPORT_SYMBOL(of_find_device_by_node);
54 #if defined(CONFIG_PPC_DCR)
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 either the dcr-reg or the reg property
72 * value to derive a unique name. As a last resort it will use the node
73 * name followed by a unique number.
75 void of_device_make_bus_id(struct device *dev)
77 static atomic_t bus_no_reg_magic;
78 struct device_node *node = dev->of_node;
86 * If it's a DCR based device, use 'd' for native DCRs
87 * and 'D' for MMIO DCRs.
89 reg = of_get_property(node, "dcr-reg", NULL);
91 #ifdef CONFIG_PPC_DCR_NATIVE
92 dev_set_name(dev, "d%x.%s", *reg, node->name);
93 #else /* CONFIG_PPC_DCR_NATIVE */
94 u64 addr = of_translate_dcr_address(node, *reg, NULL);
95 if (addr != OF_BAD_ADDR) {
96 dev_set_name(dev, "D%llx.%s",
97 (unsigned long long)addr, node->name);
100 #endif /* !CONFIG_PPC_DCR_NATIVE */
102 #endif /* CONFIG_PPC_DCR */
105 * For MMIO, get the physical address
107 reg = of_get_property(node, "reg", NULL);
109 if (of_can_translate_address(node)) {
110 addr = of_translate_address(node, reg);
112 addrp = of_get_address(node, 0, NULL, NULL);
114 addr = of_read_number(addrp, 1);
118 if (addr != OF_BAD_ADDR) {
119 dev_set_name(dev, "%llx.%s",
120 (unsigned long long)addr, node->name);
126 * No BusID, use the node name and add a globally incremented
127 * counter (and pray...)
129 magic = atomic_add_return(1, &bus_no_reg_magic);
130 dev_set_name(dev, "%s.%d", node->name, magic - 1);
134 * of_device_alloc - Allocate and initialize an of_device
135 * @np: device node to assign to device
136 * @bus_id: Name to assign to the device. May be null to use default name.
137 * @parent: Parent device.
139 struct platform_device *of_device_alloc(struct device_node *np,
141 struct device *parent)
143 struct platform_device *dev;
144 int rc, i, num_reg = 0, num_irq;
145 struct resource *res, temp_res;
147 dev = platform_device_alloc("", -1);
151 /* count the io and irq resources */
152 if (of_can_translate_address(np))
153 while (of_address_to_resource(np, num_reg, &temp_res) == 0)
155 num_irq = of_irq_count(np);
157 /* Populate the resource table */
158 if (num_irq || num_reg) {
159 res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
161 platform_device_put(dev);
165 dev->num_resources = num_reg + num_irq;
167 for (i = 0; i < num_reg; i++, res++) {
168 rc = of_address_to_resource(np, i, res);
171 WARN_ON(of_irq_to_resource_table(np, res, num_irq) != num_irq);
174 dev->dev.of_node = of_node_get(np);
175 #if defined(CONFIG_MICROBLAZE)
176 dev->dev.dma_mask = &dev->archdata.dma_mask;
178 dev->dev.parent = parent;
181 dev_set_name(&dev->dev, "%s", bus_id);
183 of_device_make_bus_id(&dev->dev);
187 EXPORT_SYMBOL(of_device_alloc);
190 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
191 * @np: pointer to node to create device for
192 * @bus_id: name to assign device
193 * @platform_data: pointer to populate platform_data pointer with
194 * @parent: Linux device model parent device.
196 * Returns pointer to created platform device, or NULL if a device was not
197 * registered. Unavailable devices will not get registered.
199 struct platform_device *of_platform_device_create_pdata(
200 struct device_node *np,
203 struct device *parent)
205 struct platform_device *dev;
207 if (!of_device_is_available(np) ||
208 of_node_test_and_set_flag(np, OF_POPULATED))
211 dev = of_device_alloc(np, bus_id, parent);
215 #if defined(CONFIG_MICROBLAZE)
216 dev->archdata.dma_mask = 0xffffffffUL;
218 dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
219 dev->dev.bus = &platform_bus_type;
220 dev->dev.platform_data = platform_data;
222 /* We do not fill the DMA ops for platform devices by default.
223 * This is currently the responsibility of the platform code
224 * to do such, possibly using a device notifier
227 if (of_device_add(dev) != 0) {
228 platform_device_put(dev);
235 of_node_clear_flag(np, OF_POPULATED);
240 * of_platform_device_create - Alloc, initialize and register an of_device
241 * @np: pointer to node to create device for
242 * @bus_id: name to assign device
243 * @parent: Linux device model parent device.
245 * Returns pointer to created platform device, or NULL if a device was not
246 * registered. Unavailable devices will not get registered.
248 struct platform_device *of_platform_device_create(struct device_node *np,
250 struct device *parent)
252 return of_platform_device_create_pdata(np, bus_id, NULL, parent);
254 EXPORT_SYMBOL(of_platform_device_create);
256 #ifdef CONFIG_ARM_AMBA
257 static struct amba_device *of_amba_device_create(struct device_node *node,
260 struct device *parent)
262 struct amba_device *dev;
266 pr_debug("Creating amba device %s\n", node->full_name);
268 if (!of_device_is_available(node) ||
269 of_node_test_and_set_flag(node, OF_POPULATED))
272 dev = amba_device_alloc(NULL, 0, 0);
274 pr_err("%s(): amba_device_alloc() failed for %s\n",
275 __func__, node->full_name);
279 /* setup generic device info */
280 dev->dev.coherent_dma_mask = ~0;
281 dev->dev.of_node = of_node_get(node);
282 dev->dev.parent = parent;
283 dev->dev.platform_data = platform_data;
285 dev_set_name(&dev->dev, "%s", bus_id);
287 of_device_make_bus_id(&dev->dev);
289 /* setup amba-specific device info */
292 /* Allow the HW Peripheral ID to be overridden */
293 prop = of_get_property(node, "arm,primecell-periphid", NULL);
295 dev->periphid = of_read_ulong(prop, 1);
297 /* Decode the IRQs and address ranges */
298 for (i = 0; i < AMBA_NR_IRQS; i++)
299 dev->irq[i] = irq_of_parse_and_map(node, i);
301 ret = of_address_to_resource(node, 0, &dev->res);
305 ret = amba_device_add(dev, &iomem_resource);
312 amba_device_put(dev);
314 of_node_clear_flag(node, OF_POPULATED);
317 #else /* CONFIG_ARM_AMBA */
318 static struct amba_device *of_amba_device_create(struct device_node *node,
321 struct device *parent)
325 #endif /* CONFIG_ARM_AMBA */
328 * of_devname_lookup() - Given a device node, lookup the preferred Linux name
330 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
331 struct device_node *np)
338 for(; lookup->compatible != NULL; lookup++) {
339 if (!of_device_is_compatible(np, lookup->compatible))
341 if (!of_address_to_resource(np, 0, &res))
342 if (res.start != lookup->phys_addr)
344 pr_debug("%s: devname=%s\n", np->full_name, lookup->name);
352 * of_platform_bus_create() - Create a device for a node and its children.
353 * @bus: device node of the bus to instantiate
354 * @matches: match table for bus nodes
355 * @lookup: auxdata table for matching id and platform_data with device nodes
356 * @parent: parent for new device, or NULL for top level.
357 * @strict: require compatible property
359 * Creates a platform_device for the provided device_node, and optionally
360 * recursively create devices for all the child nodes.
362 static int of_platform_bus_create(struct device_node *bus,
363 const struct of_device_id *matches,
364 const struct of_dev_auxdata *lookup,
365 struct device *parent, bool strict)
367 const struct of_dev_auxdata *auxdata;
368 struct device_node *child;
369 struct platform_device *dev;
370 const char *bus_id = NULL;
371 void *platform_data = NULL;
374 /* Make sure it has a compatible property */
375 if (strict && (!of_get_property(bus, "compatible", NULL))) {
376 pr_debug("%s() - skipping %s, no compatible prop\n",
377 __func__, bus->full_name);
381 auxdata = of_dev_lookup(lookup, bus);
383 bus_id = auxdata->name;
384 platform_data = auxdata->platform_data;
387 if (of_device_is_compatible(bus, "arm,primecell")) {
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: %s\n", child->full_name);
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("of_platform_bus_probe()\n");
429 pr_debug(" starting at: %s\n", root->full_name);
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);
445 EXPORT_SYMBOL(of_platform_bus_probe);
448 * of_platform_populate() - Populate platform_devices from device tree data
449 * @root: parent of the first level to probe or NULL for the root of the tree
450 * @matches: match table, NULL to use the default
451 * @lookup: auxdata table for matching id and platform_data with device nodes
452 * @parent: parent to hook devices from, NULL for toplevel
454 * Similar to of_platform_bus_probe(), this function walks the device tree
455 * and creates devices from nodes. It differs in that it follows the modern
456 * convention of requiring all device nodes to have a 'compatible' property,
457 * and it is suitable for creating devices which are children of the root
458 * node (of_platform_bus_probe will only create children of the root which
459 * are selected by the @matches argument).
461 * New board support should be using this function instead of
462 * of_platform_bus_probe().
464 * Returns 0 on success, < 0 on failure.
466 int of_platform_populate(struct device_node *root,
467 const struct of_device_id *matches,
468 const struct of_dev_auxdata *lookup,
469 struct device *parent)
471 struct device_node *child;
474 root = root ? of_node_get(root) : of_find_node_by_path("/");
478 for_each_child_of_node(root, child) {
479 rc = of_platform_bus_create(child, matches, lookup, parent, true);
487 EXPORT_SYMBOL_GPL(of_platform_populate);
489 static int of_platform_device_destroy(struct device *dev, void *data)
491 /* Do not touch devices not populated from the device tree */
492 if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
495 /* Recurse for any nodes that were treated as busses */
496 if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
497 device_for_each_child(dev, NULL, of_platform_device_destroy);
499 if (dev->bus == &platform_bus_type)
500 platform_device_unregister(to_platform_device(dev));
501 #ifdef CONFIG_ARM_AMBA
502 else if (dev->bus == &amba_bustype)
503 amba_device_unregister(to_amba_device(dev));
506 of_node_clear_flag(dev->of_node, OF_POPULATED);
507 of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
512 * of_platform_depopulate() - Remove devices populated from device tree
513 * @parent: device which children will be removed
515 * Complementary to of_platform_populate(), this function removes children
516 * of the given device (and, recurrently, their children) that have been
517 * created from their respective device tree nodes (and only those,
518 * leaving others - eg. manually created - unharmed).
520 * Returns 0 when all children devices have been removed or
521 * -EBUSY when some children remained.
523 void of_platform_depopulate(struct device *parent)
525 device_for_each_child(parent, NULL, of_platform_device_destroy);
527 EXPORT_SYMBOL_GPL(of_platform_depopulate);
529 #ifdef CONFIG_OF_DYNAMIC
530 static int of_platform_notify(struct notifier_block *nb,
531 unsigned long action, void *arg)
533 struct of_reconfig_data *rd = arg;
534 struct platform_device *pdev_parent, *pdev;
537 switch (of_reconfig_get_state_change(action, rd)) {
538 case OF_RECONFIG_CHANGE_ADD:
539 /* verify that the parent is a bus */
540 if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
541 return NOTIFY_OK; /* not for us */
543 /* already populated? (driver using of_populate manually) */
544 if (of_node_check_flag(rd->dn, OF_POPULATED))
547 /* pdev_parent may be NULL when no bus platform device */
548 pdev_parent = of_find_device_by_node(rd->dn->parent);
549 pdev = of_platform_device_create(rd->dn, NULL,
550 pdev_parent ? &pdev_parent->dev : NULL);
551 of_dev_put(pdev_parent);
554 pr_err("%s: failed to create for '%s'\n",
555 __func__, rd->dn->full_name);
556 /* of_platform_device_create tosses the error code */
557 return notifier_from_errno(-EINVAL);
561 case OF_RECONFIG_CHANGE_REMOVE:
563 /* already depopulated? */
564 if (!of_node_check_flag(rd->dn, OF_POPULATED))
567 /* find our device by node */
568 pdev = of_find_device_by_node(rd->dn);
570 return NOTIFY_OK; /* no? not meant for us */
572 /* unregister takes one ref away */
573 of_platform_device_destroy(&pdev->dev, &children_left);
575 /* and put the reference of the find */
583 static struct notifier_block platform_of_notifier = {
584 .notifier_call = of_platform_notify,
587 void of_platform_register_reconfig_notifier(void)
589 WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
591 #endif /* CONFIG_OF_DYNAMIC */
593 #endif /* CONFIG_OF_ADDRESS */