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_iommu.h>
23 #include <linux/of_irq.h>
24 #include <linux/of_platform.h>
25 #include <linux/platform_device.h>
27 const struct of_device_id of_default_bus_match_table[] = {
28 { .compatible = "simple-bus", },
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);
154 * of_dma_configure - Setup DMA configuration
155 * @dev: Device to apply DMA configuration
157 * Try to get devices's DMA configuration from DT and update it
160 * In case if platform code need to use own special DMA configuration,it
161 * can use Platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE event
162 * to fix up DMA configuration.
164 static void of_dma_configure(struct device *dev)
166 u64 dma_addr, paddr, size;
169 unsigned long offset;
170 struct iommu_ops *iommu;
173 * Set default dma-mask to 32 bit. Drivers are expected to setup
174 * the correct supported dma_mask.
176 dev->coherent_dma_mask = DMA_BIT_MASK(32);
179 * Set it to coherent_dma_mask by default if the architecture
180 * code has not set it.
183 dev->dma_mask = &dev->coherent_dma_mask;
185 ret = of_dma_get_range(dev->of_node, &dma_addr, &paddr, &size);
187 dma_addr = offset = 0;
188 size = dev->coherent_dma_mask;
190 offset = PFN_DOWN(paddr - dma_addr);
191 dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
193 dev->dma_pfn_offset = offset;
195 coherent = of_dma_is_coherent(dev->of_node);
196 dev_dbg(dev, "device is%sdma coherent\n",
197 coherent ? " " : " not ");
199 iommu = of_iommu_configure(dev);
200 dev_dbg(dev, "device is%sbehind an iommu\n",
201 iommu ? " " : " not ");
203 arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
206 static void of_dma_deconfigure(struct device *dev)
208 arch_teardown_dma_ops(dev);
212 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
213 * @np: pointer to node to create device for
214 * @bus_id: name to assign device
215 * @platform_data: pointer to populate platform_data pointer with
216 * @parent: Linux device model parent device.
218 * Returns pointer to created platform device, or NULL if a device was not
219 * registered. Unavailable devices will not get registered.
221 static struct platform_device *of_platform_device_create_pdata(
222 struct device_node *np,
225 struct device *parent)
227 struct platform_device *dev;
229 if (!of_device_is_available(np) ||
230 of_node_test_and_set_flag(np, OF_POPULATED))
233 dev = of_device_alloc(np, bus_id, parent);
237 dev->dev.bus = &platform_bus_type;
238 dev->dev.platform_data = platform_data;
239 of_dma_configure(&dev->dev);
241 if (of_device_add(dev) != 0) {
242 of_dma_deconfigure(&dev->dev);
243 platform_device_put(dev);
250 of_node_clear_flag(np, OF_POPULATED);
255 * of_platform_device_create - Alloc, initialize and register an of_device
256 * @np: pointer to node to create device for
257 * @bus_id: name to assign device
258 * @parent: Linux device model parent device.
260 * Returns pointer to created platform device, or NULL if a device was not
261 * registered. Unavailable devices will not get registered.
263 struct platform_device *of_platform_device_create(struct device_node *np,
265 struct device *parent)
267 return of_platform_device_create_pdata(np, bus_id, NULL, parent);
269 EXPORT_SYMBOL(of_platform_device_create);
271 #ifdef CONFIG_ARM_AMBA
272 static struct amba_device *of_amba_device_create(struct device_node *node,
275 struct device *parent)
277 struct amba_device *dev;
281 pr_debug("Creating amba device %s\n", node->full_name);
283 if (!of_device_is_available(node) ||
284 of_node_test_and_set_flag(node, OF_POPULATED))
287 dev = amba_device_alloc(NULL, 0, 0);
289 pr_err("%s(): amba_device_alloc() failed for %s\n",
290 __func__, node->full_name);
294 /* setup generic device info */
295 dev->dev.of_node = of_node_get(node);
296 dev->dev.parent = parent ? : &platform_bus;
297 dev->dev.platform_data = platform_data;
299 dev_set_name(&dev->dev, "%s", bus_id);
301 of_device_make_bus_id(&dev->dev);
302 of_dma_configure(&dev->dev);
304 /* Allow the HW Peripheral ID to be overridden */
305 prop = of_get_property(node, "arm,primecell-periphid", NULL);
307 dev->periphid = of_read_ulong(prop, 1);
309 /* Decode the IRQs and address ranges */
310 for (i = 0; i < AMBA_NR_IRQS; i++)
311 dev->irq[i] = irq_of_parse_and_map(node, i);
313 ret = of_address_to_resource(node, 0, &dev->res);
315 pr_err("%s(): of_address_to_resource() failed (%d) for %s\n",
316 __func__, ret, node->full_name);
320 ret = amba_device_add(dev, &iomem_resource);
322 pr_err("%s(): amba_device_add() failed (%d) for %s\n",
323 __func__, ret, node->full_name);
330 amba_device_put(dev);
332 of_node_clear_flag(node, OF_POPULATED);
335 #else /* CONFIG_ARM_AMBA */
336 static struct amba_device *of_amba_device_create(struct device_node *node,
339 struct device *parent)
343 #endif /* CONFIG_ARM_AMBA */
346 * of_devname_lookup() - Given a device node, lookup the preferred Linux name
348 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
349 struct device_node *np)
356 for(; lookup->compatible != NULL; lookup++) {
357 if (!of_device_is_compatible(np, lookup->compatible))
359 if (!of_address_to_resource(np, 0, &res))
360 if (res.start != lookup->phys_addr)
362 pr_debug("%s: devname=%s\n", np->full_name, lookup->name);
370 * of_platform_bus_create() - Create a device for a node and its children.
371 * @bus: device node of the bus to instantiate
372 * @matches: match table for bus nodes
373 * @lookup: auxdata table for matching id and platform_data with device nodes
374 * @parent: parent for new device, or NULL for top level.
375 * @strict: require compatible property
377 * Creates a platform_device for the provided device_node, and optionally
378 * recursively create devices for all the child nodes.
380 static int of_platform_bus_create(struct device_node *bus,
381 const struct of_device_id *matches,
382 const struct of_dev_auxdata *lookup,
383 struct device *parent, bool strict)
385 const struct of_dev_auxdata *auxdata;
386 struct device_node *child;
387 struct platform_device *dev;
388 const char *bus_id = NULL;
389 void *platform_data = NULL;
392 /* Make sure it has a compatible property */
393 if (strict && (!of_get_property(bus, "compatible", NULL))) {
394 pr_debug("%s() - skipping %s, no compatible prop\n",
395 __func__, bus->full_name);
399 auxdata = of_dev_lookup(lookup, bus);
401 bus_id = auxdata->name;
402 platform_data = auxdata->platform_data;
405 if (of_device_is_compatible(bus, "arm,primecell")) {
407 * Don't return an error here to keep compatibility with older
410 of_amba_device_create(bus, bus_id, platform_data, parent);
414 dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
415 if (!dev || !of_match_node(matches, bus))
418 for_each_child_of_node(bus, child) {
419 pr_debug(" create child: %s\n", child->full_name);
420 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
426 of_node_set_flag(bus, OF_POPULATED_BUS);
431 * of_platform_bus_probe() - Probe the device-tree for platform buses
432 * @root: parent of the first level to probe or NULL for the root of the tree
433 * @matches: match table for bus nodes
434 * @parent: parent to hook devices from, NULL for toplevel
436 * Note that children of the provided root are not instantiated as devices
437 * unless the specified root itself matches the bus list and is not NULL.
439 int of_platform_bus_probe(struct device_node *root,
440 const struct of_device_id *matches,
441 struct device *parent)
443 struct device_node *child;
446 root = root ? of_node_get(root) : of_find_node_by_path("/");
450 pr_debug("of_platform_bus_probe()\n");
451 pr_debug(" starting at: %s\n", root->full_name);
453 /* Do a self check of bus type, if there's a match, create children */
454 if (of_match_node(matches, root)) {
455 rc = of_platform_bus_create(root, matches, NULL, parent, false);
456 } else for_each_child_of_node(root, child) {
457 if (!of_match_node(matches, child))
459 rc = of_platform_bus_create(child, matches, NULL, parent, false);
467 EXPORT_SYMBOL(of_platform_bus_probe);
470 * of_platform_populate() - Populate platform_devices from device tree data
471 * @root: parent of the first level to probe or NULL for the root of the tree
472 * @matches: match table, NULL to use the default
473 * @lookup: auxdata table for matching id and platform_data with device nodes
474 * @parent: parent to hook devices from, NULL for toplevel
476 * Similar to of_platform_bus_probe(), this function walks the device tree
477 * and creates devices from nodes. It differs in that it follows the modern
478 * convention of requiring all device nodes to have a 'compatible' property,
479 * and it is suitable for creating devices which are children of the root
480 * node (of_platform_bus_probe will only create children of the root which
481 * are selected by the @matches argument).
483 * New board support should be using this function instead of
484 * of_platform_bus_probe().
486 * Returns 0 on success, < 0 on failure.
488 int of_platform_populate(struct device_node *root,
489 const struct of_device_id *matches,
490 const struct of_dev_auxdata *lookup,
491 struct device *parent)
493 struct device_node *child;
496 root = root ? of_node_get(root) : of_find_node_by_path("/");
500 for_each_child_of_node(root, child) {
501 rc = of_platform_bus_create(child, matches, lookup, parent, true);
505 of_node_set_flag(root, OF_POPULATED_BUS);
510 EXPORT_SYMBOL_GPL(of_platform_populate);
512 static int of_platform_device_destroy(struct device *dev, void *data)
514 /* Do not touch devices not populated from the device tree */
515 if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
518 /* Recurse for any nodes that were treated as busses */
519 if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
520 device_for_each_child(dev, NULL, of_platform_device_destroy);
522 if (dev->bus == &platform_bus_type)
523 platform_device_unregister(to_platform_device(dev));
524 #ifdef CONFIG_ARM_AMBA
525 else if (dev->bus == &amba_bustype)
526 amba_device_unregister(to_amba_device(dev));
529 of_node_clear_flag(dev->of_node, OF_POPULATED);
530 of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
535 * of_platform_depopulate() - Remove devices populated from device tree
536 * @parent: device which children will be removed
538 * Complementary to of_platform_populate(), this function removes children
539 * of the given device (and, recurrently, their children) that have been
540 * created from their respective device tree nodes (and only those,
541 * leaving others - eg. manually created - unharmed).
543 * Returns 0 when all children devices have been removed or
544 * -EBUSY when some children remained.
546 void of_platform_depopulate(struct device *parent)
548 if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
549 device_for_each_child(parent, NULL, of_platform_device_destroy);
550 of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
553 EXPORT_SYMBOL_GPL(of_platform_depopulate);
555 #ifdef CONFIG_OF_DYNAMIC
556 static int of_platform_notify(struct notifier_block *nb,
557 unsigned long action, void *arg)
559 struct of_reconfig_data *rd = arg;
560 struct platform_device *pdev_parent, *pdev;
563 switch (of_reconfig_get_state_change(action, rd)) {
564 case OF_RECONFIG_CHANGE_ADD:
565 /* verify that the parent is a bus */
566 if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
567 return NOTIFY_OK; /* not for us */
569 /* already populated? (driver using of_populate manually) */
570 if (of_node_check_flag(rd->dn, OF_POPULATED))
573 /* pdev_parent may be NULL when no bus platform device */
574 pdev_parent = of_find_device_by_node(rd->dn->parent);
575 pdev = of_platform_device_create(rd->dn, NULL,
576 pdev_parent ? &pdev_parent->dev : NULL);
577 of_dev_put(pdev_parent);
580 pr_err("%s: failed to create for '%s'\n",
581 __func__, rd->dn->full_name);
582 /* of_platform_device_create tosses the error code */
583 return notifier_from_errno(-EINVAL);
587 case OF_RECONFIG_CHANGE_REMOVE:
589 /* already depopulated? */
590 if (!of_node_check_flag(rd->dn, OF_POPULATED))
593 /* find our device by node */
594 pdev = of_find_device_by_node(rd->dn);
596 return NOTIFY_OK; /* no? not meant for us */
598 /* unregister takes one ref away */
599 of_platform_device_destroy(&pdev->dev, &children_left);
601 /* and put the reference of the find */
609 static struct notifier_block platform_of_notifier = {
610 .notifier_call = of_platform_notify,
613 void of_platform_register_reconfig_notifier(void)
615 WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
617 #endif /* CONFIG_OF_DYNAMIC */
619 #endif /* CONFIG_OF_ADDRESS */