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 #ifdef CONFIG_ARM_AMBA
29 { .compatible
= "arm,amba-bus", },
30 #endif /* CONFIG_ARM_AMBA */
31 {} /* Empty terminated list */
34 static int of_dev_node_match(struct device
*dev
, void *data
)
36 return dev
->of_node
== data
;
40 * of_find_device_by_node - Find the platform_device associated with a node
41 * @np: Pointer to device tree node
43 * Returns platform_device pointer, or NULL if not found
45 struct platform_device
*of_find_device_by_node(struct device_node
*np
)
49 dev
= bus_find_device(&platform_bus_type
, NULL
, np
, of_dev_node_match
);
50 return dev
? to_platform_device(dev
) : NULL
;
52 EXPORT_SYMBOL(of_find_device_by_node
);
54 #ifdef CONFIG_OF_ADDRESS
56 * The following routines scan a subtree and registers a device for
57 * each applicable node.
59 * Note: sparc doesn't use these routines because it has a different
60 * mechanism for creating devices from device tree nodes.
64 * of_device_make_bus_id - Use the device node data to assign a unique name
65 * @dev: pointer to device structure that is linked to a device tree node
67 * This routine will first try using the translated bus address to
68 * derive a unique name. If it cannot, then it will prepend names from
69 * parent nodes until a unique name can be derived.
71 void of_device_make_bus_id(struct device
*dev
)
73 struct device_node
*node
= dev
->of_node
;
77 /* Construct the name, using parent nodes if necessary to ensure uniqueness */
78 while (node
->parent
) {
80 * If the address can be translated, then that is as much
81 * uniqueness as we need. Make it the first component and return
83 reg
= of_get_property(node
, "reg", NULL
);
84 if (reg
&& (addr
= of_translate_address(node
, reg
)) != OF_BAD_ADDR
) {
85 dev_set_name(dev
, dev_name(dev
) ? "%llx.%s:%s" : "%llx.%s",
86 (unsigned long long)addr
, node
->name
,
91 /* format arguments only used if dev_name() resolves to NULL */
92 dev_set_name(dev
, dev_name(dev
) ? "%s:%s" : "%s",
93 strrchr(node
->full_name
, '/') + 1, dev_name(dev
));
99 * of_device_alloc - Allocate and initialize an of_device
100 * @np: device node to assign to device
101 * @bus_id: Name to assign to the device. May be null to use default name.
102 * @parent: Parent device.
104 struct platform_device
*of_device_alloc(struct device_node
*np
,
106 struct device
*parent
)
108 struct platform_device
*dev
;
109 int rc
, i
, num_reg
= 0, num_irq
;
110 struct resource
*res
, temp_res
;
112 dev
= platform_device_alloc("", -1);
116 /* count the io and irq resources */
117 while (of_address_to_resource(np
, num_reg
, &temp_res
) == 0)
119 num_irq
= of_irq_count(np
);
121 /* Populate the resource table */
122 if (num_irq
|| num_reg
) {
123 res
= kzalloc(sizeof(*res
) * (num_irq
+ num_reg
), GFP_KERNEL
);
125 platform_device_put(dev
);
129 dev
->num_resources
= num_reg
+ num_irq
;
131 for (i
= 0; i
< num_reg
; i
++, res
++) {
132 rc
= of_address_to_resource(np
, i
, res
);
135 if (of_irq_to_resource_table(np
, res
, num_irq
) != num_irq
)
136 pr_debug("not all legacy IRQ resources mapped for %s\n",
140 dev
->dev
.of_node
= of_node_get(np
);
141 dev
->dev
.parent
= parent
? : &platform_bus
;
144 dev_set_name(&dev
->dev
, "%s", bus_id
);
146 of_device_make_bus_id(&dev
->dev
);
150 EXPORT_SYMBOL(of_device_alloc
);
152 static void of_dma_deconfigure(struct device
*dev
)
154 arch_teardown_dma_ops(dev
);
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_dma_configure(&dev
->dev
, dev
->dev
.of_node
);
187 if (of_device_add(dev
) != 0) {
188 of_dma_deconfigure(&dev
->dev
);
189 platform_device_put(dev
);
196 of_node_clear_flag(np
, OF_POPULATED
);
201 * of_platform_device_create - Alloc, initialize and register an of_device
202 * @np: pointer to node to create device for
203 * @bus_id: name to assign device
204 * @parent: Linux device model parent device.
206 * Returns pointer to created platform device, or NULL if a device was not
207 * registered. Unavailable devices will not get registered.
209 struct platform_device
*of_platform_device_create(struct device_node
*np
,
211 struct device
*parent
)
213 return of_platform_device_create_pdata(np
, bus_id
, NULL
, parent
);
215 EXPORT_SYMBOL(of_platform_device_create
);
217 #ifdef CONFIG_ARM_AMBA
218 static struct amba_device
*of_amba_device_create(struct device_node
*node
,
221 struct device
*parent
)
223 struct amba_device
*dev
;
227 pr_debug("Creating amba device %s\n", node
->full_name
);
229 if (!of_device_is_available(node
) ||
230 of_node_test_and_set_flag(node
, OF_POPULATED
))
233 dev
= amba_device_alloc(NULL
, 0, 0);
235 pr_err("%s(): amba_device_alloc() failed for %s\n",
236 __func__
, node
->full_name
);
240 /* setup generic device info */
241 dev
->dev
.of_node
= of_node_get(node
);
242 dev
->dev
.parent
= parent
? : &platform_bus
;
243 dev
->dev
.platform_data
= platform_data
;
245 dev_set_name(&dev
->dev
, "%s", bus_id
);
247 of_device_make_bus_id(&dev
->dev
);
248 of_dma_configure(&dev
->dev
, dev
->dev
.of_node
);
250 /* Allow the HW Peripheral ID to be overridden */
251 prop
= of_get_property(node
, "arm,primecell-periphid", NULL
);
253 dev
->periphid
= of_read_ulong(prop
, 1);
255 /* Decode the IRQs and address ranges */
256 for (i
= 0; i
< AMBA_NR_IRQS
; i
++)
257 dev
->irq
[i
] = irq_of_parse_and_map(node
, i
);
259 ret
= of_address_to_resource(node
, 0, &dev
->res
);
261 pr_err("%s(): of_address_to_resource() failed (%d) for %s\n",
262 __func__
, ret
, node
->full_name
);
266 ret
= amba_device_add(dev
, &iomem_resource
);
268 pr_err("%s(): amba_device_add() failed (%d) for %s\n",
269 __func__
, ret
, node
->full_name
);
276 amba_device_put(dev
);
278 of_node_clear_flag(node
, OF_POPULATED
);
281 #else /* CONFIG_ARM_AMBA */
282 static struct amba_device
*of_amba_device_create(struct device_node
*node
,
285 struct device
*parent
)
289 #endif /* CONFIG_ARM_AMBA */
292 * of_devname_lookup() - Given a device node, lookup the preferred Linux name
294 static const struct of_dev_auxdata
*of_dev_lookup(const struct of_dev_auxdata
*lookup
,
295 struct device_node
*np
)
302 for(; lookup
->compatible
!= NULL
; lookup
++) {
303 if (!of_device_is_compatible(np
, lookup
->compatible
))
305 if (!of_address_to_resource(np
, 0, &res
))
306 if (res
.start
!= lookup
->phys_addr
)
308 pr_debug("%s: devname=%s\n", np
->full_name
, lookup
->name
);
316 * of_platform_bus_create() - Create a device for a node and its children.
317 * @bus: device node of the bus to instantiate
318 * @matches: match table for bus nodes
319 * @lookup: auxdata table for matching id and platform_data with device nodes
320 * @parent: parent for new device, or NULL for top level.
321 * @strict: require compatible property
323 * Creates a platform_device for the provided device_node, and optionally
324 * recursively create devices for all the child nodes.
326 static int of_platform_bus_create(struct device_node
*bus
,
327 const struct of_device_id
*matches
,
328 const struct of_dev_auxdata
*lookup
,
329 struct device
*parent
, bool strict
)
331 const struct of_dev_auxdata
*auxdata
;
332 struct device_node
*child
;
333 struct platform_device
*dev
;
334 const char *bus_id
= NULL
;
335 void *platform_data
= NULL
;
338 /* Make sure it has a compatible property */
339 if (strict
&& (!of_get_property(bus
, "compatible", NULL
))) {
340 pr_debug("%s() - skipping %s, no compatible prop\n",
341 __func__
, bus
->full_name
);
345 auxdata
= of_dev_lookup(lookup
, bus
);
347 bus_id
= auxdata
->name
;
348 platform_data
= auxdata
->platform_data
;
351 if (of_device_is_compatible(bus
, "arm,primecell")) {
353 * Don't return an error here to keep compatibility with older
356 of_amba_device_create(bus
, bus_id
, platform_data
, parent
);
360 dev
= of_platform_device_create_pdata(bus
, bus_id
, platform_data
, parent
);
361 if (!dev
|| !of_match_node(matches
, bus
))
364 for_each_child_of_node(bus
, child
) {
365 pr_debug(" create child: %s\n", child
->full_name
);
366 rc
= of_platform_bus_create(child
, matches
, lookup
, &dev
->dev
, strict
);
372 of_node_set_flag(bus
, OF_POPULATED_BUS
);
377 * of_platform_bus_probe() - Probe the device-tree for platform buses
378 * @root: parent of the first level to probe or NULL for the root of the tree
379 * @matches: match table for bus nodes
380 * @parent: parent to hook devices from, NULL for toplevel
382 * Note that children of the provided root are not instantiated as devices
383 * unless the specified root itself matches the bus list and is not NULL.
385 int of_platform_bus_probe(struct device_node
*root
,
386 const struct of_device_id
*matches
,
387 struct device
*parent
)
389 struct device_node
*child
;
392 root
= root
? of_node_get(root
) : of_find_node_by_path("/");
396 pr_debug("of_platform_bus_probe()\n");
397 pr_debug(" starting at: %s\n", root
->full_name
);
399 /* Do a self check of bus type, if there's a match, create children */
400 if (of_match_node(matches
, root
)) {
401 rc
= of_platform_bus_create(root
, matches
, NULL
, parent
, false);
402 } else for_each_child_of_node(root
, child
) {
403 if (!of_match_node(matches
, child
))
405 rc
= of_platform_bus_create(child
, matches
, NULL
, parent
, false);
413 EXPORT_SYMBOL(of_platform_bus_probe
);
416 * of_platform_populate() - Populate platform_devices from device tree data
417 * @root: parent of the first level to probe or NULL for the root of the tree
418 * @matches: match table, NULL to use the default
419 * @lookup: auxdata table for matching id and platform_data with device nodes
420 * @parent: parent to hook devices from, NULL for toplevel
422 * Similar to of_platform_bus_probe(), this function walks the device tree
423 * and creates devices from nodes. It differs in that it follows the modern
424 * convention of requiring all device nodes to have a 'compatible' property,
425 * and it is suitable for creating devices which are children of the root
426 * node (of_platform_bus_probe will only create children of the root which
427 * are selected by the @matches argument).
429 * New board support should be using this function instead of
430 * of_platform_bus_probe().
432 * Returns 0 on success, < 0 on failure.
434 int of_platform_populate(struct device_node
*root
,
435 const struct of_device_id
*matches
,
436 const struct of_dev_auxdata
*lookup
,
437 struct device
*parent
)
439 struct device_node
*child
;
442 root
= root
? of_node_get(root
) : of_find_node_by_path("/");
446 for_each_child_of_node(root
, child
) {
447 rc
= of_platform_bus_create(child
, matches
, lookup
, parent
, true);
451 of_node_set_flag(root
, OF_POPULATED_BUS
);
456 EXPORT_SYMBOL_GPL(of_platform_populate
);
458 static int of_platform_device_destroy(struct device
*dev
, void *data
)
460 /* Do not touch devices not populated from the device tree */
461 if (!dev
->of_node
|| !of_node_check_flag(dev
->of_node
, OF_POPULATED
))
464 /* Recurse for any nodes that were treated as busses */
465 if (of_node_check_flag(dev
->of_node
, OF_POPULATED_BUS
))
466 device_for_each_child(dev
, NULL
, of_platform_device_destroy
);
468 if (dev
->bus
== &platform_bus_type
)
469 platform_device_unregister(to_platform_device(dev
));
470 #ifdef CONFIG_ARM_AMBA
471 else if (dev
->bus
== &amba_bustype
)
472 amba_device_unregister(to_amba_device(dev
));
475 of_dma_deconfigure(dev
);
476 of_node_clear_flag(dev
->of_node
, OF_POPULATED
);
477 of_node_clear_flag(dev
->of_node
, OF_POPULATED_BUS
);
482 * of_platform_depopulate() - Remove devices populated from device tree
483 * @parent: device which children will be removed
485 * Complementary to of_platform_populate(), this function removes children
486 * of the given device (and, recurrently, their children) that have been
487 * created from their respective device tree nodes (and only those,
488 * leaving others - eg. manually created - unharmed).
490 * Returns 0 when all children devices have been removed or
491 * -EBUSY when some children remained.
493 void of_platform_depopulate(struct device
*parent
)
495 if (parent
->of_node
&& of_node_check_flag(parent
->of_node
, OF_POPULATED_BUS
)) {
496 device_for_each_child(parent
, NULL
, of_platform_device_destroy
);
497 of_node_clear_flag(parent
->of_node
, OF_POPULATED_BUS
);
500 EXPORT_SYMBOL_GPL(of_platform_depopulate
);
502 #ifdef CONFIG_OF_DYNAMIC
503 static int of_platform_notify(struct notifier_block
*nb
,
504 unsigned long action
, void *arg
)
506 struct of_reconfig_data
*rd
= arg
;
507 struct platform_device
*pdev_parent
, *pdev
;
510 switch (of_reconfig_get_state_change(action
, rd
)) {
511 case OF_RECONFIG_CHANGE_ADD
:
512 /* verify that the parent is a bus */
513 if (!of_node_check_flag(rd
->dn
->parent
, OF_POPULATED_BUS
))
514 return NOTIFY_OK
; /* not for us */
516 /* already populated? (driver using of_populate manually) */
517 if (of_node_check_flag(rd
->dn
, OF_POPULATED
))
520 /* pdev_parent may be NULL when no bus platform device */
521 pdev_parent
= of_find_device_by_node(rd
->dn
->parent
);
522 pdev
= of_platform_device_create(rd
->dn
, NULL
,
523 pdev_parent
? &pdev_parent
->dev
: NULL
);
524 of_dev_put(pdev_parent
);
527 pr_err("%s: failed to create for '%s'\n",
528 __func__
, rd
->dn
->full_name
);
529 /* of_platform_device_create tosses the error code */
530 return notifier_from_errno(-EINVAL
);
534 case OF_RECONFIG_CHANGE_REMOVE
:
536 /* already depopulated? */
537 if (!of_node_check_flag(rd
->dn
, OF_POPULATED
))
540 /* find our device by node */
541 pdev
= of_find_device_by_node(rd
->dn
);
543 return NOTIFY_OK
; /* no? not meant for us */
545 /* unregister takes one ref away */
546 of_platform_device_destroy(&pdev
->dev
, &children_left
);
548 /* and put the reference of the find */
556 static struct notifier_block platform_of_notifier
= {
557 .notifier_call
= of_platform_notify
,
560 void of_platform_register_reconfig_notifier(void)
562 WARN_ON(of_reconfig_notifier_register(&platform_of_notifier
));
564 #endif /* CONFIG_OF_DYNAMIC */
566 #endif /* CONFIG_OF_ADDRESS */