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_iommu.h>
23 #include <linux/of_irq.h>
24 #include <linux/of_platform.h>
25 #include <linux/platform_device.h>
27 const struct of_device_id of_default_bus_match_table
[] = {
28 { .compatible
= "simple-bus", },
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 * Returns platform_device pointer, or NULL if not found
46 struct platform_device
*of_find_device_by_node(struct device_node
*np
)
50 dev
= bus_find_device(&platform_bus_type
, NULL
, np
, of_dev_node_match
);
51 return dev
? to_platform_device(dev
) : NULL
;
53 EXPORT_SYMBOL(of_find_device_by_node
);
55 #ifdef CONFIG_OF_ADDRESS
57 * The following routines scan a subtree and registers a device for
58 * each applicable node.
60 * Note: sparc doesn't use these routines because it has a different
61 * mechanism for creating devices from device tree nodes.
65 * of_device_make_bus_id - Use the device node data to assign a unique name
66 * @dev: pointer to device structure that is linked to a device tree node
68 * This routine will first try using the translated bus address to
69 * derive a unique name. If it cannot, then it will prepend names from
70 * parent nodes until a unique name can be derived.
72 void of_device_make_bus_id(struct device
*dev
)
74 struct device_node
*node
= dev
->of_node
;
78 /* Construct the name, using parent nodes if necessary to ensure uniqueness */
79 while (node
->parent
) {
81 * If the address can be translated, then that is as much
82 * uniqueness as we need. Make it the first component and return
84 reg
= of_get_property(node
, "reg", NULL
);
85 if (reg
&& (addr
= of_translate_address(node
, reg
)) != OF_BAD_ADDR
) {
86 dev_set_name(dev
, dev_name(dev
) ? "%llx.%s:%s" : "%llx.%s",
87 (unsigned long long)addr
, node
->name
,
92 /* format arguments only used if dev_name() resolves to NULL */
93 dev_set_name(dev
, dev_name(dev
) ? "%s:%s" : "%s",
94 strrchr(node
->full_name
, '/') + 1, dev_name(dev
));
100 * of_device_alloc - Allocate and initialize an of_device
101 * @np: device node to assign to device
102 * @bus_id: Name to assign to the device. May be null to use default name.
103 * @parent: Parent device.
105 struct platform_device
*of_device_alloc(struct device_node
*np
,
107 struct device
*parent
)
109 struct platform_device
*dev
;
110 int rc
, i
, num_reg
= 0, num_irq
;
111 struct resource
*res
, temp_res
;
113 dev
= platform_device_alloc("", -1);
117 /* count the io and irq resources */
118 while (of_address_to_resource(np
, num_reg
, &temp_res
) == 0)
120 num_irq
= of_irq_count(np
);
122 /* Populate the resource table */
123 if (num_irq
|| num_reg
) {
124 res
= kzalloc(sizeof(*res
) * (num_irq
+ num_reg
), GFP_KERNEL
);
126 platform_device_put(dev
);
130 dev
->num_resources
= num_reg
+ num_irq
;
132 for (i
= 0; i
< num_reg
; i
++, res
++) {
133 rc
= of_address_to_resource(np
, i
, res
);
136 if (of_irq_to_resource_table(np
, res
, num_irq
) != num_irq
)
137 pr_debug("not all legacy IRQ resources mapped for %s\n",
141 dev
->dev
.of_node
= of_node_get(np
);
142 dev
->dev
.parent
= parent
? : &platform_bus
;
145 dev_set_name(&dev
->dev
, "%s", bus_id
);
147 of_device_make_bus_id(&dev
->dev
);
151 EXPORT_SYMBOL(of_device_alloc
);
154 * of_dma_configure - Setup DMA configuration
155 * @dev: Device to apply DMA configuration
157 * Try to get devices's DMA configuration from DT and update it
160 * In case if platform code need to use own special DMA configuration,it
161 * can use Platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE event
162 * to fix up DMA configuration.
164 static void of_dma_configure(struct device
*dev
)
166 u64 dma_addr
, paddr
, size
;
169 unsigned long offset
;
170 struct iommu_ops
*iommu
;
173 * Set default dma-mask to 32 bit. Drivers are expected to setup
174 * the correct supported dma_mask.
176 dev
->coherent_dma_mask
= DMA_BIT_MASK(32);
179 * Set it to coherent_dma_mask by default if the architecture
180 * code has not set it.
183 dev
->dma_mask
= &dev
->coherent_dma_mask
;
185 ret
= of_dma_get_range(dev
->of_node
, &dma_addr
, &paddr
, &size
);
187 dma_addr
= offset
= 0;
188 size
= dev
->coherent_dma_mask
;
190 offset
= PFN_DOWN(paddr
- dma_addr
);
191 dev_dbg(dev
, "dma_pfn_offset(%#08lx)\n", offset
);
193 dev
->dma_pfn_offset
= offset
;
195 coherent
= of_dma_is_coherent(dev
->of_node
);
196 dev_dbg(dev
, "device is%sdma coherent\n",
197 coherent
? " " : " not ");
199 iommu
= of_iommu_configure(dev
);
200 dev_dbg(dev
, "device is%sbehind an iommu\n",
201 iommu
? " " : " not ");
203 arch_setup_dma_ops(dev
, dma_addr
, size
, iommu
, coherent
);
206 static void of_dma_deconfigure(struct device
*dev
)
208 arch_teardown_dma_ops(dev
);
212 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
213 * @np: pointer to node to create device for
214 * @bus_id: name to assign device
215 * @platform_data: pointer to populate platform_data pointer with
216 * @parent: Linux device model parent device.
218 * Returns pointer to created platform device, or NULL if a device was not
219 * registered. Unavailable devices will not get registered.
221 static struct platform_device
*of_platform_device_create_pdata(
222 struct device_node
*np
,
225 struct device
*parent
)
227 struct platform_device
*dev
;
229 if (!of_device_is_available(np
) ||
230 of_node_test_and_set_flag(np
, OF_POPULATED
))
233 dev
= of_device_alloc(np
, bus_id
, parent
);
237 dev
->dev
.bus
= &platform_bus_type
;
238 dev
->dev
.platform_data
= platform_data
;
239 of_dma_configure(&dev
->dev
);
241 if (of_device_add(dev
) != 0) {
242 of_dma_deconfigure(&dev
->dev
);
243 platform_device_put(dev
);
250 of_node_clear_flag(np
, OF_POPULATED
);
255 * of_platform_device_create - Alloc, initialize and register an of_device
256 * @np: pointer to node to create device for
257 * @bus_id: name to assign device
258 * @parent: Linux device model parent device.
260 * Returns pointer to created platform device, or NULL if a device was not
261 * registered. Unavailable devices will not get registered.
263 struct platform_device
*of_platform_device_create(struct device_node
*np
,
265 struct device
*parent
)
267 return of_platform_device_create_pdata(np
, bus_id
, NULL
, parent
);
269 EXPORT_SYMBOL(of_platform_device_create
);
271 #ifdef CONFIG_ARM_AMBA
272 static struct amba_device
*of_amba_device_create(struct device_node
*node
,
275 struct device
*parent
)
277 struct amba_device
*dev
;
281 pr_debug("Creating amba device %s\n", node
->full_name
);
283 if (!of_device_is_available(node
) ||
284 of_node_test_and_set_flag(node
, OF_POPULATED
))
287 dev
= amba_device_alloc(NULL
, 0, 0);
289 pr_err("%s(): amba_device_alloc() failed for %s\n",
290 __func__
, node
->full_name
);
294 /* setup generic device info */
295 dev
->dev
.of_node
= of_node_get(node
);
296 dev
->dev
.parent
= parent
? : &platform_bus
;
297 dev
->dev
.platform_data
= platform_data
;
299 dev_set_name(&dev
->dev
, "%s", bus_id
);
301 of_device_make_bus_id(&dev
->dev
);
302 of_dma_configure(&dev
->dev
);
304 /* Allow the HW Peripheral ID to be overridden */
305 prop
= of_get_property(node
, "arm,primecell-periphid", NULL
);
307 dev
->periphid
= of_read_ulong(prop
, 1);
309 /* Decode the IRQs and address ranges */
310 for (i
= 0; i
< AMBA_NR_IRQS
; i
++)
311 dev
->irq
[i
] = irq_of_parse_and_map(node
, i
);
313 ret
= of_address_to_resource(node
, 0, &dev
->res
);
315 pr_err("%s(): of_address_to_resource() failed (%d) for %s\n",
316 __func__
, ret
, node
->full_name
);
320 ret
= amba_device_add(dev
, &iomem_resource
);
322 pr_err("%s(): amba_device_add() failed (%d) for %s\n",
323 __func__
, ret
, node
->full_name
);
330 amba_device_put(dev
);
332 of_node_clear_flag(node
, OF_POPULATED
);
335 #else /* CONFIG_ARM_AMBA */
336 static struct amba_device
*of_amba_device_create(struct device_node
*node
,
339 struct device
*parent
)
343 #endif /* CONFIG_ARM_AMBA */
346 * of_devname_lookup() - Given a device node, lookup the preferred Linux name
348 static const struct of_dev_auxdata
*of_dev_lookup(const struct of_dev_auxdata
*lookup
,
349 struct device_node
*np
)
356 for(; lookup
->compatible
!= NULL
; lookup
++) {
357 if (!of_device_is_compatible(np
, lookup
->compatible
))
359 if (!of_address_to_resource(np
, 0, &res
))
360 if (res
.start
!= lookup
->phys_addr
)
362 pr_debug("%s: devname=%s\n", np
->full_name
, lookup
->name
);
370 * of_platform_bus_create() - Create a device for a node and its children.
371 * @bus: device node of the bus to instantiate
372 * @matches: match table for bus nodes
373 * @lookup: auxdata table for matching id and platform_data with device nodes
374 * @parent: parent for new device, or NULL for top level.
375 * @strict: require compatible property
377 * Creates a platform_device for the provided device_node, and optionally
378 * recursively create devices for all the child nodes.
380 static int of_platform_bus_create(struct device_node
*bus
,
381 const struct of_device_id
*matches
,
382 const struct of_dev_auxdata
*lookup
,
383 struct device
*parent
, bool strict
)
385 const struct of_dev_auxdata
*auxdata
;
386 struct device_node
*child
;
387 struct platform_device
*dev
;
388 const char *bus_id
= NULL
;
389 void *platform_data
= NULL
;
392 /* Make sure it has a compatible property */
393 if (strict
&& (!of_get_property(bus
, "compatible", NULL
))) {
394 pr_debug("%s() - skipping %s, no compatible prop\n",
395 __func__
, bus
->full_name
);
399 auxdata
= of_dev_lookup(lookup
, bus
);
401 bus_id
= auxdata
->name
;
402 platform_data
= auxdata
->platform_data
;
405 if (of_device_is_compatible(bus
, "arm,primecell")) {
407 * Don't return an error here to keep compatibility with older
410 of_amba_device_create(bus
, bus_id
, platform_data
, parent
);
414 dev
= of_platform_device_create_pdata(bus
, bus_id
, platform_data
, parent
);
415 if (!dev
|| !of_match_node(matches
, bus
))
418 for_each_child_of_node(bus
, child
) {
419 pr_debug(" create child: %s\n", child
->full_name
);
420 rc
= of_platform_bus_create(child
, matches
, lookup
, &dev
->dev
, strict
);
426 of_node_set_flag(bus
, OF_POPULATED_BUS
);
431 * of_platform_bus_probe() - Probe the device-tree for platform buses
432 * @root: parent of the first level to probe or NULL for the root of the tree
433 * @matches: match table for bus nodes
434 * @parent: parent to hook devices from, NULL for toplevel
436 * Note that children of the provided root are not instantiated as devices
437 * unless the specified root itself matches the bus list and is not NULL.
439 int of_platform_bus_probe(struct device_node
*root
,
440 const struct of_device_id
*matches
,
441 struct device
*parent
)
443 struct device_node
*child
;
446 root
= root
? of_node_get(root
) : of_find_node_by_path("/");
450 pr_debug("of_platform_bus_probe()\n");
451 pr_debug(" starting at: %s\n", root
->full_name
);
453 /* Do a self check of bus type, if there's a match, create children */
454 if (of_match_node(matches
, root
)) {
455 rc
= of_platform_bus_create(root
, matches
, NULL
, parent
, false);
456 } else for_each_child_of_node(root
, child
) {
457 if (!of_match_node(matches
, child
))
459 rc
= of_platform_bus_create(child
, matches
, NULL
, parent
, false);
467 EXPORT_SYMBOL(of_platform_bus_probe
);
470 * of_platform_populate() - Populate platform_devices from device tree data
471 * @root: parent of the first level to probe or NULL for the root of the tree
472 * @matches: match table, NULL to use the default
473 * @lookup: auxdata table for matching id and platform_data with device nodes
474 * @parent: parent to hook devices from, NULL for toplevel
476 * Similar to of_platform_bus_probe(), this function walks the device tree
477 * and creates devices from nodes. It differs in that it follows the modern
478 * convention of requiring all device nodes to have a 'compatible' property,
479 * and it is suitable for creating devices which are children of the root
480 * node (of_platform_bus_probe will only create children of the root which
481 * are selected by the @matches argument).
483 * New board support should be using this function instead of
484 * of_platform_bus_probe().
486 * Returns 0 on success, < 0 on failure.
488 int of_platform_populate(struct device_node
*root
,
489 const struct of_device_id
*matches
,
490 const struct of_dev_auxdata
*lookup
,
491 struct device
*parent
)
493 struct device_node
*child
;
496 root
= root
? of_node_get(root
) : of_find_node_by_path("/");
500 for_each_child_of_node(root
, child
) {
501 rc
= of_platform_bus_create(child
, matches
, lookup
, parent
, true);
505 of_node_set_flag(root
, OF_POPULATED_BUS
);
510 EXPORT_SYMBOL_GPL(of_platform_populate
);
512 static int of_platform_device_destroy(struct device
*dev
, void *data
)
514 /* Do not touch devices not populated from the device tree */
515 if (!dev
->of_node
|| !of_node_check_flag(dev
->of_node
, OF_POPULATED
))
518 /* Recurse for any nodes that were treated as busses */
519 if (of_node_check_flag(dev
->of_node
, OF_POPULATED_BUS
))
520 device_for_each_child(dev
, NULL
, of_platform_device_destroy
);
522 if (dev
->bus
== &platform_bus_type
)
523 platform_device_unregister(to_platform_device(dev
));
524 #ifdef CONFIG_ARM_AMBA
525 else if (dev
->bus
== &amba_bustype
)
526 amba_device_unregister(to_amba_device(dev
));
529 of_dma_deconfigure(dev
);
530 of_node_clear_flag(dev
->of_node
, OF_POPULATED
);
531 of_node_clear_flag(dev
->of_node
, OF_POPULATED_BUS
);
536 * of_platform_depopulate() - Remove devices populated from device tree
537 * @parent: device which children will be removed
539 * Complementary to of_platform_populate(), this function removes children
540 * of the given device (and, recurrently, their children) that have been
541 * created from their respective device tree nodes (and only those,
542 * leaving others - eg. manually created - unharmed).
544 * Returns 0 when all children devices have been removed or
545 * -EBUSY when some children remained.
547 void of_platform_depopulate(struct device
*parent
)
549 if (parent
->of_node
&& of_node_check_flag(parent
->of_node
, OF_POPULATED_BUS
)) {
550 device_for_each_child(parent
, NULL
, of_platform_device_destroy
);
551 of_node_clear_flag(parent
->of_node
, OF_POPULATED_BUS
);
554 EXPORT_SYMBOL_GPL(of_platform_depopulate
);
556 #ifdef CONFIG_OF_DYNAMIC
557 static int of_platform_notify(struct notifier_block
*nb
,
558 unsigned long action
, void *arg
)
560 struct of_reconfig_data
*rd
= arg
;
561 struct platform_device
*pdev_parent
, *pdev
;
564 switch (of_reconfig_get_state_change(action
, rd
)) {
565 case OF_RECONFIG_CHANGE_ADD
:
566 /* verify that the parent is a bus */
567 if (!of_node_check_flag(rd
->dn
->parent
, OF_POPULATED_BUS
))
568 return NOTIFY_OK
; /* not for us */
570 /* already populated? (driver using of_populate manually) */
571 if (of_node_check_flag(rd
->dn
, OF_POPULATED
))
574 /* pdev_parent may be NULL when no bus platform device */
575 pdev_parent
= of_find_device_by_node(rd
->dn
->parent
);
576 pdev
= of_platform_device_create(rd
->dn
, NULL
,
577 pdev_parent
? &pdev_parent
->dev
: NULL
);
578 of_dev_put(pdev_parent
);
581 pr_err("%s: failed to create for '%s'\n",
582 __func__
, rd
->dn
->full_name
);
583 /* of_platform_device_create tosses the error code */
584 return notifier_from_errno(-EINVAL
);
588 case OF_RECONFIG_CHANGE_REMOVE
:
590 /* already depopulated? */
591 if (!of_node_check_flag(rd
->dn
, OF_POPULATED
))
594 /* find our device by node */
595 pdev
= of_find_device_by_node(rd
->dn
);
597 return NOTIFY_OK
; /* no? not meant for us */
599 /* unregister takes one ref away */
600 of_platform_device_destroy(&pdev
->dev
, &children_left
);
602 /* and put the reference of the find */
610 static struct notifier_block platform_of_notifier
= {
611 .notifier_call
= of_platform_notify
,
614 void of_platform_register_reconfig_notifier(void)
616 WARN_ON(of_reconfig_notifier_register(&platform_of_notifier
));
618 #endif /* CONFIG_OF_DYNAMIC */
620 #endif /* CONFIG_OF_ADDRESS */