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 */