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.
15 #define pr_fmt(fmt) "OF: " fmt
17 #include <linux/errno.h>
18 #include <linux/module.h>
19 #include <linux/amba/bus.h>
20 #include <linux/device.h>
21 #include <linux/dma-mapping.h>
22 #include <linux/slab.h>
23 #include <linux/of_address.h>
24 #include <linux/of_device.h>
25 #include <linux/of_irq.h>
26 #include <linux/of_platform.h>
27 #include <linux/platform_device.h>
29 const struct of_device_id of_default_bus_match_table
[] = {
30 { .compatible
= "simple-bus", },
31 { .compatible
= "simple-mfd", },
32 { .compatible
= "isa", },
33 #ifdef CONFIG_ARM_AMBA
34 { .compatible
= "arm,amba-bus", },
35 #endif /* CONFIG_ARM_AMBA */
36 {} /* Empty terminated list */
39 static int of_dev_node_match(struct device
*dev
, void *data
)
41 return dev
->of_node
== data
;
45 * of_find_device_by_node - Find the platform_device associated with a node
46 * @np: Pointer to device tree node
48 * Takes a reference to the embedded struct device which needs to be dropped
51 * Returns platform_device pointer, or NULL if not found
53 struct platform_device
*of_find_device_by_node(struct device_node
*np
)
57 dev
= bus_find_device(&platform_bus_type
, NULL
, np
, of_dev_node_match
);
58 return dev
? to_platform_device(dev
) : NULL
;
60 EXPORT_SYMBOL(of_find_device_by_node
);
62 #ifdef CONFIG_OF_ADDRESS
64 * The following routines scan a subtree and registers a device for
65 * each applicable node.
67 * Note: sparc doesn't use these routines because it has a different
68 * mechanism for creating devices from device tree nodes.
72 * of_device_make_bus_id - Use the device node data to assign a unique name
73 * @dev: pointer to device structure that is linked to a device tree node
75 * This routine will first try using the translated bus address to
76 * derive a unique name. If it cannot, then it will prepend names from
77 * parent nodes until a unique name can be derived.
79 void of_device_make_bus_id(struct device
*dev
)
81 struct device_node
*node
= dev
->of_node
;
85 /* Construct the name, using parent nodes if necessary to ensure uniqueness */
86 while (node
->parent
) {
88 * If the address can be translated, then that is as much
89 * uniqueness as we need. Make it the first component and return
91 reg
= of_get_property(node
, "reg", NULL
);
92 if (reg
&& (addr
= of_translate_address(node
, reg
)) != OF_BAD_ADDR
) {
93 dev_set_name(dev
, dev_name(dev
) ? "%llx.%s:%s" : "%llx.%s",
94 (unsigned long long)addr
, node
->name
,
99 /* format arguments only used if dev_name() resolves to NULL */
100 dev_set_name(dev
, dev_name(dev
) ? "%s:%s" : "%s",
101 strrchr(node
->full_name
, '/') + 1, dev_name(dev
));
107 * of_device_alloc - Allocate and initialize an of_device
108 * @np: device node to assign to device
109 * @bus_id: Name to assign to the device. May be null to use default name.
110 * @parent: Parent device.
112 struct platform_device
*of_device_alloc(struct device_node
*np
,
114 struct device
*parent
)
116 struct platform_device
*dev
;
117 int rc
, i
, num_reg
= 0, num_irq
;
118 struct resource
*res
, temp_res
;
120 dev
= platform_device_alloc("", -1);
124 /* count the io and irq resources */
125 while (of_address_to_resource(np
, num_reg
, &temp_res
) == 0)
127 num_irq
= of_irq_count(np
);
129 /* Populate the resource table */
130 if (num_irq
|| num_reg
) {
131 res
= kzalloc(sizeof(*res
) * (num_irq
+ num_reg
), GFP_KERNEL
);
133 platform_device_put(dev
);
137 dev
->num_resources
= num_reg
+ num_irq
;
139 for (i
= 0; i
< num_reg
; i
++, res
++) {
140 rc
= of_address_to_resource(np
, i
, res
);
143 if (of_irq_to_resource_table(np
, res
, num_irq
) != num_irq
)
144 pr_debug("not all legacy IRQ resources mapped for %s\n",
148 dev
->dev
.of_node
= of_node_get(np
);
149 dev
->dev
.fwnode
= &np
->fwnode
;
150 dev
->dev
.parent
= parent
? : &platform_bus
;
153 dev_set_name(&dev
->dev
, "%s", bus_id
);
155 of_device_make_bus_id(&dev
->dev
);
159 EXPORT_SYMBOL(of_device_alloc
);
161 static void of_dma_deconfigure(struct device
*dev
)
163 arch_teardown_dma_ops(dev
);
167 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
168 * @np: pointer to node to create device for
169 * @bus_id: name to assign device
170 * @platform_data: pointer to populate platform_data pointer with
171 * @parent: Linux device model parent device.
173 * Returns pointer to created platform device, or NULL if a device was not
174 * registered. Unavailable devices will not get registered.
176 static struct platform_device
*of_platform_device_create_pdata(
177 struct device_node
*np
,
180 struct device
*parent
)
182 struct platform_device
*dev
;
184 if (!of_device_is_available(np
) ||
185 of_node_test_and_set_flag(np
, OF_POPULATED
))
188 dev
= of_device_alloc(np
, bus_id
, parent
);
192 dev
->dev
.bus
= &platform_bus_type
;
193 dev
->dev
.platform_data
= platform_data
;
194 of_dma_configure(&dev
->dev
, dev
->dev
.of_node
);
195 of_msi_configure(&dev
->dev
, dev
->dev
.of_node
);
197 if (of_device_add(dev
) != 0) {
198 of_dma_deconfigure(&dev
->dev
);
199 platform_device_put(dev
);
206 of_node_clear_flag(np
, OF_POPULATED
);
211 * of_platform_device_create - Alloc, initialize and register an of_device
212 * @np: pointer to node to create device for
213 * @bus_id: name to assign device
214 * @parent: Linux device model parent device.
216 * Returns pointer to created platform device, or NULL if a device was not
217 * registered. Unavailable devices will not get registered.
219 struct platform_device
*of_platform_device_create(struct device_node
*np
,
221 struct device
*parent
)
223 return of_platform_device_create_pdata(np
, bus_id
, NULL
, parent
);
225 EXPORT_SYMBOL(of_platform_device_create
);
227 #ifdef CONFIG_ARM_AMBA
228 static struct amba_device
*of_amba_device_create(struct device_node
*node
,
231 struct device
*parent
)
233 struct amba_device
*dev
;
237 pr_debug("Creating amba device %s\n", node
->full_name
);
239 if (!of_device_is_available(node
) ||
240 of_node_test_and_set_flag(node
, OF_POPULATED
))
243 dev
= amba_device_alloc(NULL
, 0, 0);
247 /* setup generic device info */
248 dev
->dev
.of_node
= of_node_get(node
);
249 dev
->dev
.fwnode
= &node
->fwnode
;
250 dev
->dev
.parent
= parent
? : &platform_bus
;
251 dev
->dev
.platform_data
= platform_data
;
253 dev_set_name(&dev
->dev
, "%s", bus_id
);
255 of_device_make_bus_id(&dev
->dev
);
256 of_dma_configure(&dev
->dev
, dev
->dev
.of_node
);
258 /* Allow the HW Peripheral ID to be overridden */
259 prop
= of_get_property(node
, "arm,primecell-periphid", NULL
);
261 dev
->periphid
= of_read_ulong(prop
, 1);
263 /* Decode the IRQs and address ranges */
264 for (i
= 0; i
< AMBA_NR_IRQS
; i
++)
265 dev
->irq
[i
] = irq_of_parse_and_map(node
, i
);
267 ret
= of_address_to_resource(node
, 0, &dev
->res
);
269 pr_err("amba: of_address_to_resource() failed (%d) for %s\n",
270 ret
, node
->full_name
);
274 ret
= amba_device_add(dev
, &iomem_resource
);
276 pr_err("amba_device_add() failed (%d) for %s\n",
277 ret
, node
->full_name
);
284 amba_device_put(dev
);
286 of_node_clear_flag(node
, OF_POPULATED
);
289 #else /* CONFIG_ARM_AMBA */
290 static struct amba_device
*of_amba_device_create(struct device_node
*node
,
293 struct device
*parent
)
297 #endif /* CONFIG_ARM_AMBA */
300 * of_devname_lookup() - Given a device node, lookup the preferred Linux name
302 static const struct of_dev_auxdata
*of_dev_lookup(const struct of_dev_auxdata
*lookup
,
303 struct device_node
*np
)
305 const struct of_dev_auxdata
*auxdata
;
313 for (; auxdata
->compatible
; auxdata
++) {
314 if (!of_device_is_compatible(np
, auxdata
->compatible
))
317 if (!of_address_to_resource(np
, 0, &res
))
318 if (res
.start
!= auxdata
->phys_addr
)
320 pr_debug("%s: devname=%s\n", np
->full_name
, auxdata
->name
);
327 /* Try compatible match if no phys_addr and name are specified */
329 for (; auxdata
->compatible
; auxdata
++) {
330 if (!of_device_is_compatible(np
, auxdata
->compatible
))
332 if (!auxdata
->phys_addr
&& !auxdata
->name
) {
333 pr_debug("%s: compatible match\n", np
->full_name
);
342 * of_platform_bus_create() - Create a device for a node and its children.
343 * @bus: device node of the bus to instantiate
344 * @matches: match table for bus nodes
345 * @lookup: auxdata table for matching id and platform_data with device nodes
346 * @parent: parent for new device, or NULL for top level.
347 * @strict: require compatible property
349 * Creates a platform_device for the provided device_node, and optionally
350 * recursively create devices for all the child nodes.
352 static int of_platform_bus_create(struct device_node
*bus
,
353 const struct of_device_id
*matches
,
354 const struct of_dev_auxdata
*lookup
,
355 struct device
*parent
, bool strict
)
357 const struct of_dev_auxdata
*auxdata
;
358 struct device_node
*child
;
359 struct platform_device
*dev
;
360 const char *bus_id
= NULL
;
361 void *platform_data
= NULL
;
364 /* Make sure it has a compatible property */
365 if (strict
&& (!of_get_property(bus
, "compatible", NULL
))) {
366 pr_debug("%s() - skipping %s, no compatible prop\n",
367 __func__
, bus
->full_name
);
371 if (of_node_check_flag(bus
, OF_POPULATED_BUS
)) {
372 pr_debug("%s() - skipping %s, already populated\n",
373 __func__
, bus
->full_name
);
377 auxdata
= of_dev_lookup(lookup
, bus
);
379 bus_id
= auxdata
->name
;
380 platform_data
= auxdata
->platform_data
;
383 if (of_device_is_compatible(bus
, "arm,primecell")) {
385 * Don't return an error here to keep compatibility with older
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("%s()\n", __func__
);
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);
447 EXPORT_SYMBOL(of_platform_bus_probe
);
450 * of_platform_populate() - Populate platform_devices from device tree data
451 * @root: parent of the first level to probe or NULL for the root of the tree
452 * @matches: match table, NULL to use the default
453 * @lookup: auxdata table for matching id and platform_data with device nodes
454 * @parent: parent to hook devices from, NULL for toplevel
456 * Similar to of_platform_bus_probe(), this function walks the device tree
457 * and creates devices from nodes. It differs in that it follows the modern
458 * convention of requiring all device nodes to have a 'compatible' property,
459 * and it is suitable for creating devices which are children of the root
460 * node (of_platform_bus_probe will only create children of the root which
461 * are selected by the @matches argument).
463 * New board support should be using this function instead of
464 * of_platform_bus_probe().
466 * Returns 0 on success, < 0 on failure.
468 int of_platform_populate(struct device_node
*root
,
469 const struct of_device_id
*matches
,
470 const struct of_dev_auxdata
*lookup
,
471 struct device
*parent
)
473 struct device_node
*child
;
476 root
= root
? of_node_get(root
) : of_find_node_by_path("/");
480 pr_debug("%s()\n", __func__
);
481 pr_debug(" starting at: %s\n", root
->full_name
);
483 for_each_child_of_node(root
, child
) {
484 rc
= of_platform_bus_create(child
, matches
, lookup
, parent
, true);
490 of_node_set_flag(root
, OF_POPULATED_BUS
);
495 EXPORT_SYMBOL_GPL(of_platform_populate
);
497 int of_platform_default_populate(struct device_node
*root
,
498 const struct of_dev_auxdata
*lookup
,
499 struct device
*parent
)
501 return of_platform_populate(root
, of_default_bus_match_table
, lookup
,
504 EXPORT_SYMBOL_GPL(of_platform_default_populate
);
507 static int __init
of_platform_default_populate_init(void)
509 struct device_node
*node
;
511 if (!of_have_populated_dt())
515 * Handle ramoops explicitly, since it is inside /reserved-memory,
516 * which lacks a "compatible" property.
518 node
= of_find_node_by_path("/reserved-memory");
520 node
= of_find_compatible_node(node
, NULL
, "ramoops");
522 of_platform_device_create(node
, NULL
, NULL
);
525 /* Populate everything else. */
526 of_platform_default_populate(NULL
, NULL
, NULL
);
530 arch_initcall_sync(of_platform_default_populate_init
);
533 static int of_platform_device_destroy(struct device
*dev
, void *data
)
535 /* Do not touch devices not populated from the device tree */
536 if (!dev
->of_node
|| !of_node_check_flag(dev
->of_node
, OF_POPULATED
))
539 /* Recurse for any nodes that were treated as busses */
540 if (of_node_check_flag(dev
->of_node
, OF_POPULATED_BUS
))
541 device_for_each_child(dev
, NULL
, of_platform_device_destroy
);
543 if (dev
->bus
== &platform_bus_type
)
544 platform_device_unregister(to_platform_device(dev
));
545 #ifdef CONFIG_ARM_AMBA
546 else if (dev
->bus
== &amba_bustype
)
547 amba_device_unregister(to_amba_device(dev
));
550 of_dma_deconfigure(dev
);
551 of_node_clear_flag(dev
->of_node
, OF_POPULATED
);
552 of_node_clear_flag(dev
->of_node
, OF_POPULATED_BUS
);
557 * of_platform_depopulate() - Remove devices populated from device tree
558 * @parent: device which children will be removed
560 * Complementary to of_platform_populate(), this function removes children
561 * of the given device (and, recurrently, their children) that have been
562 * created from their respective device tree nodes (and only those,
563 * leaving others - eg. manually created - unharmed).
565 void of_platform_depopulate(struct device
*parent
)
567 if (parent
->of_node
&& of_node_check_flag(parent
->of_node
, OF_POPULATED_BUS
)) {
568 device_for_each_child(parent
, NULL
, of_platform_device_destroy
);
569 of_node_clear_flag(parent
->of_node
, OF_POPULATED_BUS
);
572 EXPORT_SYMBOL_GPL(of_platform_depopulate
);
574 #ifdef CONFIG_OF_DYNAMIC
575 static int of_platform_notify(struct notifier_block
*nb
,
576 unsigned long action
, void *arg
)
578 struct of_reconfig_data
*rd
= arg
;
579 struct platform_device
*pdev_parent
, *pdev
;
582 switch (of_reconfig_get_state_change(action
, rd
)) {
583 case OF_RECONFIG_CHANGE_ADD
:
584 /* verify that the parent is a bus */
585 if (!of_node_check_flag(rd
->dn
->parent
, OF_POPULATED_BUS
))
586 return NOTIFY_OK
; /* not for us */
588 /* already populated? (driver using of_populate manually) */
589 if (of_node_check_flag(rd
->dn
, OF_POPULATED
))
592 /* pdev_parent may be NULL when no bus platform device */
593 pdev_parent
= of_find_device_by_node(rd
->dn
->parent
);
594 pdev
= of_platform_device_create(rd
->dn
, NULL
,
595 pdev_parent
? &pdev_parent
->dev
: NULL
);
596 of_dev_put(pdev_parent
);
599 pr_err("%s: failed to create for '%s'\n",
600 __func__
, rd
->dn
->full_name
);
601 /* of_platform_device_create tosses the error code */
602 return notifier_from_errno(-EINVAL
);
606 case OF_RECONFIG_CHANGE_REMOVE
:
608 /* already depopulated? */
609 if (!of_node_check_flag(rd
->dn
, OF_POPULATED
))
612 /* find our device by node */
613 pdev
= of_find_device_by_node(rd
->dn
);
615 return NOTIFY_OK
; /* no? not meant for us */
617 /* unregister takes one ref away */
618 of_platform_device_destroy(&pdev
->dev
, &children_left
);
620 /* and put the reference of the find */
628 static struct notifier_block platform_of_notifier
= {
629 .notifier_call
= of_platform_notify
,
632 void of_platform_register_reconfig_notifier(void)
634 WARN_ON(of_reconfig_notifier_register(&platform_of_notifier
));
636 #endif /* CONFIG_OF_DYNAMIC */
638 #endif /* CONFIG_OF_ADDRESS */