1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
4 * <benh@kernel.crashing.org>
5 * and Arnd Bergmann, IBM Corp.
6 * Merged from powerpc/kernel/of_platform.c and
7 * sparc{,64}/kernel/of_device.c by Stephen Rothwell
10 #define pr_fmt(fmt) "OF: " fmt
12 #include <linux/errno.h>
13 #include <linux/module.h>
14 #include <linux/amba/bus.h>
15 #include <linux/device.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/slab.h>
18 #include <linux/of_address.h>
19 #include <linux/of_device.h>
20 #include <linux/of_iommu.h>
21 #include <linux/of_irq.h>
22 #include <linux/of_platform.h>
23 #include <linux/platform_device.h>
25 const struct of_device_id of_default_bus_match_table
[] = {
26 { .compatible
= "simple-bus", },
27 { .compatible
= "simple-mfd", },
28 { .compatible
= "isa", },
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 * Takes a reference to the embedded struct device which needs to be dropped
47 * Returns platform_device pointer, or NULL if not found
49 struct platform_device
*of_find_device_by_node(struct device_node
*np
)
53 dev
= bus_find_device(&platform_bus_type
, NULL
, np
, of_dev_node_match
);
54 return dev
? to_platform_device(dev
) : NULL
;
56 EXPORT_SYMBOL(of_find_device_by_node
);
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 the translated bus address to
72 * derive a unique name. If it cannot, then it will prepend names from
73 * parent nodes until a unique name can be derived.
75 static void of_device_make_bus_id(struct device
*dev
)
77 struct device_node
*node
= dev
->of_node
;
81 /* Construct the name, using parent nodes if necessary to ensure uniqueness */
82 while (node
->parent
) {
84 * If the address can be translated, then that is as much
85 * uniqueness as we need. Make it the first component and return
87 reg
= of_get_property(node
, "reg", NULL
);
88 if (reg
&& (addr
= of_translate_address(node
, reg
)) != OF_BAD_ADDR
) {
89 dev_set_name(dev
, dev_name(dev
) ? "%llx.%s:%s" : "%llx.%s",
90 (unsigned long long)addr
, node
->name
,
95 /* format arguments only used if dev_name() resolves to NULL */
96 dev_set_name(dev
, dev_name(dev
) ? "%s:%s" : "%s",
97 kbasename(node
->full_name
), dev_name(dev
));
103 * of_device_alloc - Allocate and initialize an of_device
104 * @np: device node to assign to device
105 * @bus_id: Name to assign to the device. May be null to use default name.
106 * @parent: Parent device.
108 struct platform_device
*of_device_alloc(struct device_node
*np
,
110 struct device
*parent
)
112 struct platform_device
*dev
;
113 int rc
, i
, num_reg
= 0, num_irq
;
114 struct resource
*res
, temp_res
;
116 dev
= platform_device_alloc("", PLATFORM_DEVID_NONE
);
120 /* count the io and irq resources */
121 while (of_address_to_resource(np
, num_reg
, &temp_res
) == 0)
123 num_irq
= of_irq_count(np
);
125 /* Populate the resource table */
126 if (num_irq
|| num_reg
) {
127 res
= kzalloc(sizeof(*res
) * (num_irq
+ num_reg
), GFP_KERNEL
);
129 platform_device_put(dev
);
133 dev
->num_resources
= num_reg
+ num_irq
;
135 for (i
= 0; i
< num_reg
; i
++, res
++) {
136 rc
= of_address_to_resource(np
, i
, res
);
139 if (of_irq_to_resource_table(np
, res
, num_irq
) != num_irq
)
140 pr_debug("not all legacy IRQ resources mapped for %s\n",
144 dev
->dev
.of_node
= of_node_get(np
);
145 dev
->dev
.fwnode
= &np
->fwnode
;
146 dev
->dev
.parent
= parent
? : &platform_bus
;
149 dev_set_name(&dev
->dev
, "%s", bus_id
);
151 of_device_make_bus_id(&dev
->dev
);
155 EXPORT_SYMBOL(of_device_alloc
);
158 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
159 * @np: pointer to node to create device for
160 * @bus_id: name to assign device
161 * @platform_data: pointer to populate platform_data pointer with
162 * @parent: Linux device model parent device.
164 * Returns pointer to created platform device, or NULL if a device was not
165 * registered. Unavailable devices will not get registered.
167 static struct platform_device
*of_platform_device_create_pdata(
168 struct device_node
*np
,
171 struct device
*parent
)
173 struct platform_device
*dev
;
175 if (!of_device_is_available(np
) ||
176 of_node_test_and_set_flag(np
, OF_POPULATED
))
179 dev
= of_device_alloc(np
, bus_id
, parent
);
183 dev
->dev
.bus
= &platform_bus_type
;
184 dev
->dev
.platform_data
= platform_data
;
185 of_msi_configure(&dev
->dev
, dev
->dev
.of_node
);
187 if (of_device_add(dev
) != 0) {
188 platform_device_put(dev
);
195 of_node_clear_flag(np
, OF_POPULATED
);
200 * of_platform_device_create - Alloc, initialize and register an of_device
201 * @np: pointer to node to create device for
202 * @bus_id: name to assign device
203 * @parent: Linux device model parent device.
205 * Returns pointer to created platform device, or NULL if a device was not
206 * registered. Unavailable devices will not get registered.
208 struct platform_device
*of_platform_device_create(struct device_node
*np
,
210 struct device
*parent
)
212 return of_platform_device_create_pdata(np
, bus_id
, NULL
, parent
);
214 EXPORT_SYMBOL(of_platform_device_create
);
216 #ifdef CONFIG_ARM_AMBA
217 static struct amba_device
*of_amba_device_create(struct device_node
*node
,
220 struct device
*parent
)
222 struct amba_device
*dev
;
226 pr_debug("Creating amba device %pOF\n", node
);
228 if (!of_device_is_available(node
) ||
229 of_node_test_and_set_flag(node
, OF_POPULATED
))
232 dev
= amba_device_alloc(NULL
, 0, 0);
236 /* setup generic device info */
237 dev
->dev
.of_node
= of_node_get(node
);
238 dev
->dev
.fwnode
= &node
->fwnode
;
239 dev
->dev
.parent
= parent
? : &platform_bus
;
240 dev
->dev
.platform_data
= platform_data
;
242 dev_set_name(&dev
->dev
, "%s", bus_id
);
244 of_device_make_bus_id(&dev
->dev
);
246 /* Allow the HW Peripheral ID to be overridden */
247 prop
= of_get_property(node
, "arm,primecell-periphid", NULL
);
249 dev
->periphid
= of_read_ulong(prop
, 1);
251 /* Decode the IRQs and address ranges */
252 for (i
= 0; i
< AMBA_NR_IRQS
; i
++)
253 dev
->irq
[i
] = irq_of_parse_and_map(node
, i
);
255 ret
= of_address_to_resource(node
, 0, &dev
->res
);
257 pr_err("amba: of_address_to_resource() failed (%d) for %pOF\n",
262 ret
= amba_device_add(dev
, &iomem_resource
);
264 pr_err("amba_device_add() failed (%d) for %pOF\n",
272 amba_device_put(dev
);
274 of_node_clear_flag(node
, OF_POPULATED
);
277 #else /* CONFIG_ARM_AMBA */
278 static struct amba_device
*of_amba_device_create(struct device_node
*node
,
281 struct device
*parent
)
285 #endif /* CONFIG_ARM_AMBA */
288 * of_devname_lookup() - Given a device node, lookup the preferred Linux name
290 static const struct of_dev_auxdata
*of_dev_lookup(const struct of_dev_auxdata
*lookup
,
291 struct device_node
*np
)
293 const struct of_dev_auxdata
*auxdata
;
301 for (; auxdata
->compatible
; auxdata
++) {
302 if (!of_device_is_compatible(np
, auxdata
->compatible
))
305 if (!of_address_to_resource(np
, 0, &res
))
306 if (res
.start
!= auxdata
->phys_addr
)
308 pr_debug("%pOF: devname=%s\n", np
, auxdata
->name
);
315 /* Try compatible match if no phys_addr and name are specified */
317 for (; auxdata
->compatible
; auxdata
++) {
318 if (!of_device_is_compatible(np
, auxdata
->compatible
))
320 if (!auxdata
->phys_addr
&& !auxdata
->name
) {
321 pr_debug("%pOF: compatible match\n", np
);
330 * of_platform_bus_create() - Create a device for a node and its children.
331 * @bus: device node of the bus to instantiate
332 * @matches: match table for bus nodes
333 * @lookup: auxdata table for matching id and platform_data with device nodes
334 * @parent: parent for new device, or NULL for top level.
335 * @strict: require compatible property
337 * Creates a platform_device for the provided device_node, and optionally
338 * recursively create devices for all the child nodes.
340 static int of_platform_bus_create(struct device_node
*bus
,
341 const struct of_device_id
*matches
,
342 const struct of_dev_auxdata
*lookup
,
343 struct device
*parent
, bool strict
)
345 const struct of_dev_auxdata
*auxdata
;
346 struct device_node
*child
;
347 struct platform_device
*dev
;
348 const char *bus_id
= NULL
;
349 void *platform_data
= NULL
;
352 /* Make sure it has a compatible property */
353 if (strict
&& (!of_get_property(bus
, "compatible", NULL
))) {
354 pr_debug("%s() - skipping %pOF, no compatible prop\n",
359 if (of_node_check_flag(bus
, OF_POPULATED_BUS
)) {
360 pr_debug("%s() - skipping %pOF, already populated\n",
365 auxdata
= of_dev_lookup(lookup
, bus
);
367 bus_id
= auxdata
->name
;
368 platform_data
= auxdata
->platform_data
;
371 if (of_device_is_compatible(bus
, "arm,primecell")) {
373 * Don't return an error here to keep compatibility with older
376 of_amba_device_create(bus
, bus_id
, platform_data
, parent
);
380 dev
= of_platform_device_create_pdata(bus
, bus_id
, platform_data
, parent
);
381 if (!dev
|| !of_match_node(matches
, bus
))
384 for_each_child_of_node(bus
, child
) {
385 pr_debug(" create child: %pOF\n", child
);
386 rc
= of_platform_bus_create(child
, matches
, lookup
, &dev
->dev
, strict
);
392 of_node_set_flag(bus
, OF_POPULATED_BUS
);
397 * of_platform_bus_probe() - Probe the device-tree for platform buses
398 * @root: parent of the first level to probe or NULL for the root of the tree
399 * @matches: match table for bus nodes
400 * @parent: parent to hook devices from, NULL for toplevel
402 * Note that children of the provided root are not instantiated as devices
403 * unless the specified root itself matches the bus list and is not NULL.
405 int of_platform_bus_probe(struct device_node
*root
,
406 const struct of_device_id
*matches
,
407 struct device
*parent
)
409 struct device_node
*child
;
412 root
= root
? of_node_get(root
) : of_find_node_by_path("/");
416 pr_debug("%s()\n", __func__
);
417 pr_debug(" starting at: %pOF\n", root
);
419 /* Do a self check of bus type, if there's a match, create children */
420 if (of_match_node(matches
, root
)) {
421 rc
= of_platform_bus_create(root
, matches
, NULL
, parent
, false);
422 } else for_each_child_of_node(root
, child
) {
423 if (!of_match_node(matches
, child
))
425 rc
= of_platform_bus_create(child
, matches
, NULL
, parent
, false);
435 EXPORT_SYMBOL(of_platform_bus_probe
);
438 * of_platform_populate() - Populate platform_devices from device tree data
439 * @root: parent of the first level to probe or NULL for the root of the tree
440 * @matches: match table, NULL to use the default
441 * @lookup: auxdata table for matching id and platform_data with device nodes
442 * @parent: parent to hook devices from, NULL for toplevel
444 * Similar to of_platform_bus_probe(), this function walks the device tree
445 * and creates devices from nodes. It differs in that it follows the modern
446 * convention of requiring all device nodes to have a 'compatible' property,
447 * and it is suitable for creating devices which are children of the root
448 * node (of_platform_bus_probe will only create children of the root which
449 * are selected by the @matches argument).
451 * New board support should be using this function instead of
452 * of_platform_bus_probe().
454 * Returns 0 on success, < 0 on failure.
456 int of_platform_populate(struct device_node
*root
,
457 const struct of_device_id
*matches
,
458 const struct of_dev_auxdata
*lookup
,
459 struct device
*parent
)
461 struct device_node
*child
;
464 root
= root
? of_node_get(root
) : of_find_node_by_path("/");
468 pr_debug("%s()\n", __func__
);
469 pr_debug(" starting at: %pOF\n", root
);
471 for_each_child_of_node(root
, child
) {
472 rc
= of_platform_bus_create(child
, matches
, lookup
, parent
, true);
478 of_node_set_flag(root
, OF_POPULATED_BUS
);
483 EXPORT_SYMBOL_GPL(of_platform_populate
);
485 int of_platform_default_populate(struct device_node
*root
,
486 const struct of_dev_auxdata
*lookup
,
487 struct device
*parent
)
489 return of_platform_populate(root
, of_default_bus_match_table
, lookup
,
492 EXPORT_SYMBOL_GPL(of_platform_default_populate
);
495 static const struct of_device_id reserved_mem_matches
[] = {
496 { .compatible
= "qcom,rmtfs-mem" },
497 { .compatible
= "ramoops" },
501 static int __init
of_platform_default_populate_init(void)
503 struct device_node
*node
;
505 if (!of_have_populated_dt())
509 * Handle certain compatibles explicitly, since we don't want to create
510 * platform_devices for every node in /reserved-memory with a
513 for_each_matching_node(node
, reserved_mem_matches
)
514 of_platform_device_create(node
, NULL
, NULL
);
516 node
= of_find_node_by_path("/firmware");
518 of_platform_populate(node
, NULL
, NULL
, NULL
);
522 /* Populate everything else. */
523 of_platform_default_populate(NULL
, NULL
, NULL
);
527 arch_initcall_sync(of_platform_default_populate_init
);
530 int of_platform_device_destroy(struct device
*dev
, void *data
)
532 /* Do not touch devices not populated from the device tree */
533 if (!dev
->of_node
|| !of_node_check_flag(dev
->of_node
, OF_POPULATED
))
536 /* Recurse for any nodes that were treated as busses */
537 if (of_node_check_flag(dev
->of_node
, OF_POPULATED_BUS
))
538 device_for_each_child(dev
, NULL
, of_platform_device_destroy
);
540 if (dev
->bus
== &platform_bus_type
)
541 platform_device_unregister(to_platform_device(dev
));
542 #ifdef CONFIG_ARM_AMBA
543 else if (dev
->bus
== &amba_bustype
)
544 amba_device_unregister(to_amba_device(dev
));
547 of_node_clear_flag(dev
->of_node
, OF_POPULATED
);
548 of_node_clear_flag(dev
->of_node
, OF_POPULATED_BUS
);
551 EXPORT_SYMBOL_GPL(of_platform_device_destroy
);
554 * of_platform_depopulate() - Remove devices populated from device tree
555 * @parent: device which children will be removed
557 * Complementary to of_platform_populate(), this function removes children
558 * of the given device (and, recurrently, their children) that have been
559 * created from their respective device tree nodes (and only those,
560 * leaving others - eg. manually created - unharmed).
562 void of_platform_depopulate(struct device
*parent
)
564 if (parent
->of_node
&& of_node_check_flag(parent
->of_node
, OF_POPULATED_BUS
)) {
565 device_for_each_child(parent
, NULL
, of_platform_device_destroy
);
566 of_node_clear_flag(parent
->of_node
, OF_POPULATED_BUS
);
569 EXPORT_SYMBOL_GPL(of_platform_depopulate
);
571 static void devm_of_platform_populate_release(struct device
*dev
, void *res
)
573 of_platform_depopulate(*(struct device
**)res
);
577 * devm_of_platform_populate() - Populate platform_devices from device tree data
578 * @dev: device that requested to populate from device tree data
580 * Similar to of_platform_populate(), but will automatically call
581 * of_platform_depopulate() when the device is unbound from the bus.
583 * Returns 0 on success, < 0 on failure.
585 int devm_of_platform_populate(struct device
*dev
)
593 ptr
= devres_alloc(devm_of_platform_populate_release
,
594 sizeof(*ptr
), GFP_KERNEL
);
598 ret
= of_platform_populate(dev
->of_node
, NULL
, NULL
, dev
);
603 devres_add(dev
, ptr
);
608 EXPORT_SYMBOL_GPL(devm_of_platform_populate
);
610 static int devm_of_platform_match(struct device
*dev
, void *res
, void *data
)
612 struct device
**ptr
= res
;
623 * devm_of_platform_depopulate() - Remove devices populated from device tree
624 * @dev: device that requested to depopulate from device tree data
626 * Complementary to devm_of_platform_populate(), this function removes children
627 * of the given device (and, recurrently, their children) that have been
628 * created from their respective device tree nodes (and only those,
629 * leaving others - eg. manually created - unharmed).
631 void devm_of_platform_depopulate(struct device
*dev
)
635 ret
= devres_release(dev
, devm_of_platform_populate_release
,
636 devm_of_platform_match
, dev
);
640 EXPORT_SYMBOL_GPL(devm_of_platform_depopulate
);
642 #ifdef CONFIG_OF_DYNAMIC
643 static int of_platform_notify(struct notifier_block
*nb
,
644 unsigned long action
, void *arg
)
646 struct of_reconfig_data
*rd
= arg
;
647 struct platform_device
*pdev_parent
, *pdev
;
650 switch (of_reconfig_get_state_change(action
, rd
)) {
651 case OF_RECONFIG_CHANGE_ADD
:
652 /* verify that the parent is a bus */
653 if (!of_node_check_flag(rd
->dn
->parent
, OF_POPULATED_BUS
))
654 return NOTIFY_OK
; /* not for us */
656 /* already populated? (driver using of_populate manually) */
657 if (of_node_check_flag(rd
->dn
, OF_POPULATED
))
660 /* pdev_parent may be NULL when no bus platform device */
661 pdev_parent
= of_find_device_by_node(rd
->dn
->parent
);
662 pdev
= of_platform_device_create(rd
->dn
, NULL
,
663 pdev_parent
? &pdev_parent
->dev
: NULL
);
664 of_dev_put(pdev_parent
);
667 pr_err("%s: failed to create for '%pOF'\n",
669 /* of_platform_device_create tosses the error code */
670 return notifier_from_errno(-EINVAL
);
674 case OF_RECONFIG_CHANGE_REMOVE
:
676 /* already depopulated? */
677 if (!of_node_check_flag(rd
->dn
, OF_POPULATED
))
680 /* find our device by node */
681 pdev
= of_find_device_by_node(rd
->dn
);
683 return NOTIFY_OK
; /* no? not meant for us */
685 /* unregister takes one ref away */
686 of_platform_device_destroy(&pdev
->dev
, &children_left
);
688 /* and put the reference of the find */
696 static struct notifier_block platform_of_notifier
= {
697 .notifier_call
= of_platform_notify
,
700 void of_platform_register_reconfig_notifier(void)
702 WARN_ON(of_reconfig_notifier_register(&platform_of_notifier
));
704 #endif /* CONFIG_OF_DYNAMIC */
706 #endif /* CONFIG_OF_ADDRESS */