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 const struct of_device_id of_skipped_node_table
[] = {
36 { .compatible
= "operating-points-v2", },
37 {} /* Empty terminated list */
40 static int of_dev_node_match(struct device
*dev
, void *data
)
42 return dev
->of_node
== data
;
46 * of_find_device_by_node - Find the platform_device associated with a node
47 * @np: Pointer to device tree node
49 * Takes a reference to the embedded struct device which needs to be dropped
52 * Returns platform_device pointer, or NULL if not found
54 struct platform_device
*of_find_device_by_node(struct device_node
*np
)
58 dev
= bus_find_device(&platform_bus_type
, NULL
, np
, of_dev_node_match
);
59 return dev
? to_platform_device(dev
) : NULL
;
61 EXPORT_SYMBOL(of_find_device_by_node
);
63 #ifdef CONFIG_OF_ADDRESS
65 * The following routines scan a subtree and registers a device for
66 * each applicable node.
68 * Note: sparc doesn't use these routines because it has a different
69 * mechanism for creating devices from device tree nodes.
73 * of_device_make_bus_id - Use the device node data to assign a unique name
74 * @dev: pointer to device structure that is linked to a device tree node
76 * This routine will first try using the translated bus address to
77 * derive a unique name. If it cannot, then it will prepend names from
78 * parent nodes until a unique name can be derived.
80 static void of_device_make_bus_id(struct device
*dev
)
82 struct device_node
*node
= dev
->of_node
;
86 /* Construct the name, using parent nodes if necessary to ensure uniqueness */
87 while (node
->parent
) {
89 * If the address can be translated, then that is as much
90 * uniqueness as we need. Make it the first component and return
92 reg
= of_get_property(node
, "reg", NULL
);
93 if (reg
&& (addr
= of_translate_address(node
, reg
)) != OF_BAD_ADDR
) {
94 dev_set_name(dev
, dev_name(dev
) ? "%llx.%s:%s" : "%llx.%s",
95 (unsigned long long)addr
, node
->name
,
100 /* format arguments only used if dev_name() resolves to NULL */
101 dev_set_name(dev
, dev_name(dev
) ? "%s:%s" : "%s",
102 kbasename(node
->full_name
), dev_name(dev
));
108 * of_device_alloc - Allocate and initialize an of_device
109 * @np: device node to assign to device
110 * @bus_id: Name to assign to the device. May be null to use default name.
111 * @parent: Parent device.
113 struct platform_device
*of_device_alloc(struct device_node
*np
,
115 struct device
*parent
)
117 struct platform_device
*dev
;
118 int rc
, i
, num_reg
= 0, num_irq
;
119 struct resource
*res
, temp_res
;
121 dev
= platform_device_alloc("", PLATFORM_DEVID_NONE
);
125 /* count the io and irq resources */
126 while (of_address_to_resource(np
, num_reg
, &temp_res
) == 0)
128 num_irq
= of_irq_count(np
);
130 /* Populate the resource table */
131 if (num_irq
|| num_reg
) {
132 res
= kcalloc(num_irq
+ num_reg
, sizeof(*res
), GFP_KERNEL
);
134 platform_device_put(dev
);
138 dev
->num_resources
= num_reg
+ num_irq
;
140 for (i
= 0; i
< num_reg
; i
++, res
++) {
141 rc
= of_address_to_resource(np
, i
, res
);
144 if (of_irq_to_resource_table(np
, res
, num_irq
) != num_irq
)
145 pr_debug("not all legacy IRQ resources mapped for %s\n",
149 dev
->dev
.of_node
= of_node_get(np
);
150 dev
->dev
.fwnode
= &np
->fwnode
;
151 dev
->dev
.parent
= parent
? : &platform_bus
;
154 dev_set_name(&dev
->dev
, "%s", bus_id
);
156 of_device_make_bus_id(&dev
->dev
);
160 EXPORT_SYMBOL(of_device_alloc
);
163 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
164 * @np: pointer to node to create device for
165 * @bus_id: name to assign device
166 * @platform_data: pointer to populate platform_data pointer with
167 * @parent: Linux device model parent device.
169 * Returns pointer to created platform device, or NULL if a device was not
170 * registered. Unavailable devices will not get registered.
172 static struct platform_device
*of_platform_device_create_pdata(
173 struct device_node
*np
,
176 struct device
*parent
)
178 struct platform_device
*dev
;
180 if (!of_device_is_available(np
) ||
181 of_node_test_and_set_flag(np
, OF_POPULATED
))
184 dev
= of_device_alloc(np
, bus_id
, parent
);
188 dev
->dev
.coherent_dma_mask
= DMA_BIT_MASK(32);
189 if (!dev
->dev
.dma_mask
)
190 dev
->dev
.dma_mask
= &dev
->dev
.coherent_dma_mask
;
191 dev
->dev
.bus
= &platform_bus_type
;
192 dev
->dev
.platform_data
= platform_data
;
193 of_msi_configure(&dev
->dev
, dev
->dev
.of_node
);
195 if (of_device_add(dev
) != 0) {
196 platform_device_put(dev
);
203 of_node_clear_flag(np
, OF_POPULATED
);
208 * of_platform_device_create - Alloc, initialize and register an of_device
209 * @np: pointer to node to create device for
210 * @bus_id: name to assign device
211 * @parent: Linux device model parent device.
213 * Returns pointer to created platform device, or NULL if a device was not
214 * registered. Unavailable devices will not get registered.
216 struct platform_device
*of_platform_device_create(struct device_node
*np
,
218 struct device
*parent
)
220 return of_platform_device_create_pdata(np
, bus_id
, NULL
, parent
);
222 EXPORT_SYMBOL(of_platform_device_create
);
224 #ifdef CONFIG_ARM_AMBA
225 static struct amba_device
*of_amba_device_create(struct device_node
*node
,
228 struct device
*parent
)
230 struct amba_device
*dev
;
234 pr_debug("Creating amba device %pOF\n", node
);
236 if (!of_device_is_available(node
) ||
237 of_node_test_and_set_flag(node
, OF_POPULATED
))
240 dev
= amba_device_alloc(NULL
, 0, 0);
244 /* AMBA devices only support a single DMA mask */
245 dev
->dev
.coherent_dma_mask
= DMA_BIT_MASK(32);
246 dev
->dev
.dma_mask
= &dev
->dev
.coherent_dma_mask
;
248 /* setup generic device info */
249 dev
->dev
.of_node
= of_node_get(node
);
250 dev
->dev
.fwnode
= &node
->fwnode
;
251 dev
->dev
.parent
= parent
? : &platform_bus
;
252 dev
->dev
.platform_data
= platform_data
;
254 dev_set_name(&dev
->dev
, "%s", bus_id
);
256 of_device_make_bus_id(&dev
->dev
);
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 %pOF\n",
274 ret
= amba_device_add(dev
, &iomem_resource
);
276 pr_err("amba_device_add() failed (%d) for %pOF\n",
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("%pOF: devname=%s\n", np
, 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("%pOF: compatible match\n", np
);
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 %pOF, no compatible prop\n",
371 /* Skip nodes for which we don't want to create devices */
372 if (unlikely(of_match_node(of_skipped_node_table
, bus
))) {
373 pr_debug("%s() - skipping %pOF node\n", __func__
, bus
);
377 if (of_node_check_flag(bus
, OF_POPULATED_BUS
)) {
378 pr_debug("%s() - skipping %pOF, already populated\n",
383 auxdata
= of_dev_lookup(lookup
, bus
);
385 bus_id
= auxdata
->name
;
386 platform_data
= auxdata
->platform_data
;
389 if (of_device_is_compatible(bus
, "arm,primecell")) {
391 * Don't return an error here to keep compatibility with older
394 of_amba_device_create(bus
, bus_id
, platform_data
, parent
);
398 dev
= of_platform_device_create_pdata(bus
, bus_id
, platform_data
, parent
);
399 if (!dev
|| !of_match_node(matches
, bus
))
402 for_each_child_of_node(bus
, child
) {
403 pr_debug(" create child: %pOF\n", child
);
404 rc
= of_platform_bus_create(child
, matches
, lookup
, &dev
->dev
, strict
);
410 of_node_set_flag(bus
, OF_POPULATED_BUS
);
415 * of_platform_bus_probe() - Probe the device-tree for platform buses
416 * @root: parent of the first level to probe or NULL for the root of the tree
417 * @matches: match table for bus nodes
418 * @parent: parent to hook devices from, NULL for toplevel
420 * Note that children of the provided root are not instantiated as devices
421 * unless the specified root itself matches the bus list and is not NULL.
423 int of_platform_bus_probe(struct device_node
*root
,
424 const struct of_device_id
*matches
,
425 struct device
*parent
)
427 struct device_node
*child
;
430 root
= root
? of_node_get(root
) : of_find_node_by_path("/");
434 pr_debug("%s()\n", __func__
);
435 pr_debug(" starting at: %pOF\n", root
);
437 /* Do a self check of bus type, if there's a match, create children */
438 if (of_match_node(matches
, root
)) {
439 rc
= of_platform_bus_create(root
, matches
, NULL
, parent
, false);
440 } else for_each_child_of_node(root
, child
) {
441 if (!of_match_node(matches
, child
))
443 rc
= of_platform_bus_create(child
, matches
, NULL
, parent
, false);
453 EXPORT_SYMBOL(of_platform_bus_probe
);
456 * of_platform_populate() - Populate platform_devices from device tree data
457 * @root: parent of the first level to probe or NULL for the root of the tree
458 * @matches: match table, NULL to use the default
459 * @lookup: auxdata table for matching id and platform_data with device nodes
460 * @parent: parent to hook devices from, NULL for toplevel
462 * Similar to of_platform_bus_probe(), this function walks the device tree
463 * and creates devices from nodes. It differs in that it follows the modern
464 * convention of requiring all device nodes to have a 'compatible' property,
465 * and it is suitable for creating devices which are children of the root
466 * node (of_platform_bus_probe will only create children of the root which
467 * are selected by the @matches argument).
469 * New board support should be using this function instead of
470 * of_platform_bus_probe().
472 * Returns 0 on success, < 0 on failure.
474 int of_platform_populate(struct device_node
*root
,
475 const struct of_device_id
*matches
,
476 const struct of_dev_auxdata
*lookup
,
477 struct device
*parent
)
479 struct device_node
*child
;
482 root
= root
? of_node_get(root
) : of_find_node_by_path("/");
486 pr_debug("%s()\n", __func__
);
487 pr_debug(" starting at: %pOF\n", root
);
489 for_each_child_of_node(root
, child
) {
490 rc
= of_platform_bus_create(child
, matches
, lookup
, parent
, true);
496 of_node_set_flag(root
, OF_POPULATED_BUS
);
501 EXPORT_SYMBOL_GPL(of_platform_populate
);
503 int of_platform_default_populate(struct device_node
*root
,
504 const struct of_dev_auxdata
*lookup
,
505 struct device
*parent
)
507 return of_platform_populate(root
, of_default_bus_match_table
, lookup
,
510 EXPORT_SYMBOL_GPL(of_platform_default_populate
);
513 static const struct of_device_id reserved_mem_matches
[] = {
514 { .compatible
= "qcom,rmtfs-mem" },
515 { .compatible
= "qcom,cmd-db" },
516 { .compatible
= "ramoops" },
520 static int __init
of_platform_default_populate_init(void)
522 struct device_node
*node
;
524 if (!of_have_populated_dt())
528 * Handle certain compatibles explicitly, since we don't want to create
529 * platform_devices for every node in /reserved-memory with a
532 for_each_matching_node(node
, reserved_mem_matches
)
533 of_platform_device_create(node
, NULL
, NULL
);
535 node
= of_find_node_by_path("/firmware");
537 of_platform_populate(node
, NULL
, NULL
, NULL
);
541 /* Populate everything else. */
542 of_platform_default_populate(NULL
, NULL
, NULL
);
546 arch_initcall_sync(of_platform_default_populate_init
);
549 int of_platform_device_destroy(struct device
*dev
, void *data
)
551 /* Do not touch devices not populated from the device tree */
552 if (!dev
->of_node
|| !of_node_check_flag(dev
->of_node
, OF_POPULATED
))
555 /* Recurse for any nodes that were treated as busses */
556 if (of_node_check_flag(dev
->of_node
, OF_POPULATED_BUS
))
557 device_for_each_child(dev
, NULL
, of_platform_device_destroy
);
559 of_node_clear_flag(dev
->of_node
, OF_POPULATED
);
560 of_node_clear_flag(dev
->of_node
, OF_POPULATED_BUS
);
562 if (dev
->bus
== &platform_bus_type
)
563 platform_device_unregister(to_platform_device(dev
));
564 #ifdef CONFIG_ARM_AMBA
565 else if (dev
->bus
== &amba_bustype
)
566 amba_device_unregister(to_amba_device(dev
));
571 EXPORT_SYMBOL_GPL(of_platform_device_destroy
);
574 * of_platform_depopulate() - Remove devices populated from device tree
575 * @parent: device which children will be removed
577 * Complementary to of_platform_populate(), this function removes children
578 * of the given device (and, recurrently, their children) that have been
579 * created from their respective device tree nodes (and only those,
580 * leaving others - eg. manually created - unharmed).
582 void of_platform_depopulate(struct device
*parent
)
584 if (parent
->of_node
&& of_node_check_flag(parent
->of_node
, OF_POPULATED_BUS
)) {
585 device_for_each_child(parent
, NULL
, of_platform_device_destroy
);
586 of_node_clear_flag(parent
->of_node
, OF_POPULATED_BUS
);
589 EXPORT_SYMBOL_GPL(of_platform_depopulate
);
591 static void devm_of_platform_populate_release(struct device
*dev
, void *res
)
593 of_platform_depopulate(*(struct device
**)res
);
597 * devm_of_platform_populate() - Populate platform_devices from device tree data
598 * @dev: device that requested to populate from device tree data
600 * Similar to of_platform_populate(), but will automatically call
601 * of_platform_depopulate() when the device is unbound from the bus.
603 * Returns 0 on success, < 0 on failure.
605 int devm_of_platform_populate(struct device
*dev
)
613 ptr
= devres_alloc(devm_of_platform_populate_release
,
614 sizeof(*ptr
), GFP_KERNEL
);
618 ret
= of_platform_populate(dev
->of_node
, NULL
, NULL
, dev
);
623 devres_add(dev
, ptr
);
628 EXPORT_SYMBOL_GPL(devm_of_platform_populate
);
630 static int devm_of_platform_match(struct device
*dev
, void *res
, void *data
)
632 struct device
**ptr
= res
;
643 * devm_of_platform_depopulate() - Remove devices populated from device tree
644 * @dev: device that requested to depopulate from device tree data
646 * Complementary to devm_of_platform_populate(), this function removes children
647 * of the given device (and, recurrently, their children) that have been
648 * created from their respective device tree nodes (and only those,
649 * leaving others - eg. manually created - unharmed).
651 void devm_of_platform_depopulate(struct device
*dev
)
655 ret
= devres_release(dev
, devm_of_platform_populate_release
,
656 devm_of_platform_match
, dev
);
660 EXPORT_SYMBOL_GPL(devm_of_platform_depopulate
);
662 #ifdef CONFIG_OF_DYNAMIC
663 static int of_platform_notify(struct notifier_block
*nb
,
664 unsigned long action
, void *arg
)
666 struct of_reconfig_data
*rd
= arg
;
667 struct platform_device
*pdev_parent
, *pdev
;
670 switch (of_reconfig_get_state_change(action
, rd
)) {
671 case OF_RECONFIG_CHANGE_ADD
:
672 /* verify that the parent is a bus */
673 if (!of_node_check_flag(rd
->dn
->parent
, OF_POPULATED_BUS
))
674 return NOTIFY_OK
; /* not for us */
676 /* already populated? (driver using of_populate manually) */
677 if (of_node_check_flag(rd
->dn
, OF_POPULATED
))
680 /* pdev_parent may be NULL when no bus platform device */
681 pdev_parent
= of_find_device_by_node(rd
->dn
->parent
);
682 pdev
= of_platform_device_create(rd
->dn
, NULL
,
683 pdev_parent
? &pdev_parent
->dev
: NULL
);
684 of_dev_put(pdev_parent
);
687 pr_err("%s: failed to create for '%pOF'\n",
689 /* of_platform_device_create tosses the error code */
690 return notifier_from_errno(-EINVAL
);
694 case OF_RECONFIG_CHANGE_REMOVE
:
696 /* already depopulated? */
697 if (!of_node_check_flag(rd
->dn
, OF_POPULATED
))
700 /* find our device by node */
701 pdev
= of_find_device_by_node(rd
->dn
);
703 return NOTIFY_OK
; /* no? not meant for us */
705 /* unregister takes one ref away */
706 of_platform_device_destroy(&pdev
->dev
, &children_left
);
708 /* and put the reference of the find */
716 static struct notifier_block platform_of_notifier
= {
717 .notifier_call
= of_platform_notify
,
720 void of_platform_register_reconfig_notifier(void)
722 WARN_ON(of_reconfig_notifier_register(&platform_of_notifier
));
724 #endif /* CONFIG_OF_DYNAMIC */
726 #endif /* CONFIG_OF_ADDRESS */