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 #if defined(CONFIG_PPC_DCR)
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 either the dcr-reg or the reg property
72 * value to derive a unique name. As a last resort it will use the node
73 * name followed by a unique number.
75 void of_device_make_bus_id(struct device *dev)
77 static atomic_t bus_no_reg_magic;
78 struct device_node *node = dev->of_node;
86 * If it's a DCR based device, use 'd' for native DCRs
87 * and 'D' for MMIO DCRs.
89 reg = of_get_property(node, "dcr-reg", NULL);
91 #ifdef CONFIG_PPC_DCR_NATIVE
92 dev_set_name(dev, "d%x.%s", *reg, node->name);
93 #else /* CONFIG_PPC_DCR_NATIVE */
94 u64 addr = of_translate_dcr_address(node, *reg, NULL);
95 if (addr != OF_BAD_ADDR) {
96 dev_set_name(dev, "D%llx.%s",
97 (unsigned long long)addr, node->name);
100 #endif /* !CONFIG_PPC_DCR_NATIVE */
102 #endif /* CONFIG_PPC_DCR */
105 * For MMIO, get the physical address
107 reg = of_get_property(node, "reg", NULL);
109 if (of_can_translate_address(node)) {
110 addr = of_translate_address(node, reg);
112 addrp = of_get_address(node, 0, NULL, NULL);
114 addr = of_read_number(addrp, 1);
118 if (addr != OF_BAD_ADDR) {
119 dev_set_name(dev, "%llx.%s",
120 (unsigned long long)addr, node->name);
126 * No BusID, use the node name and add a globally incremented
127 * counter (and pray...)
129 magic = atomic_add_return(1, &bus_no_reg_magic);
130 dev_set_name(dev, "%s.%d", node->name, magic - 1);
134 * of_device_alloc - Allocate and initialize an of_device
135 * @np: device node to assign to device
136 * @bus_id: Name to assign to the device. May be null to use default name.
137 * @parent: Parent device.
139 struct platform_device *of_device_alloc(struct device_node *np,
141 struct device *parent)
143 struct platform_device *dev;
144 int rc, i, num_reg = 0, num_irq;
145 struct resource *res, temp_res;
147 dev = platform_device_alloc("", -1);
151 /* count the io and irq resources */
152 if (of_can_translate_address(np))
153 while (of_address_to_resource(np, num_reg, &temp_res) == 0)
155 num_irq = of_irq_count(np);
157 /* Populate the resource table */
158 if (num_irq || num_reg) {
159 res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
161 platform_device_put(dev);
165 dev->num_resources = num_reg + num_irq;
167 for (i = 0; i < num_reg; i++, res++) {
168 rc = of_address_to_resource(np, i, res);
171 if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
172 pr_debug("not all legacy IRQ resources mapped for %s\n",
176 dev->dev.of_node = of_node_get(np);
177 #if defined(CONFIG_MICROBLAZE)
178 dev->dev.dma_mask = &dev->archdata.dma_mask;
180 dev->dev.parent = parent;
183 dev_set_name(&dev->dev, "%s", bus_id);
185 of_device_make_bus_id(&dev->dev);
189 EXPORT_SYMBOL(of_device_alloc);
192 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
193 * @np: pointer to node to create device for
194 * @bus_id: name to assign device
195 * @platform_data: pointer to populate platform_data pointer with
196 * @parent: Linux device model parent device.
198 * Returns pointer to created platform device, or NULL if a device was not
199 * registered. Unavailable devices will not get registered.
201 static struct platform_device *of_platform_device_create_pdata(
202 struct device_node *np,
205 struct device *parent)
207 struct platform_device *dev;
209 if (!of_device_is_available(np) ||
210 of_node_test_and_set_flag(np, OF_POPULATED))
213 dev = of_device_alloc(np, bus_id, parent);
217 #if defined(CONFIG_MICROBLAZE)
218 dev->archdata.dma_mask = 0xffffffffUL;
220 dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
221 if (!dev->dev.dma_mask)
222 dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
223 dev->dev.bus = &platform_bus_type;
224 dev->dev.platform_data = platform_data;
226 /* We do not fill the DMA ops for platform devices by default.
227 * This is currently the responsibility of the platform code
228 * to do such, possibly using a device notifier
231 if (of_device_add(dev) != 0) {
232 platform_device_put(dev);
239 of_node_clear_flag(np, OF_POPULATED);
244 * of_platform_device_create - Alloc, initialize and register an of_device
245 * @np: pointer to node to create device for
246 * @bus_id: name to assign device
247 * @parent: Linux device model parent device.
249 * Returns pointer to created platform device, or NULL if a device was not
250 * registered. Unavailable devices will not get registered.
252 struct platform_device *of_platform_device_create(struct device_node *np,
254 struct device *parent)
256 return of_platform_device_create_pdata(np, bus_id, NULL, parent);
258 EXPORT_SYMBOL(of_platform_device_create);
260 #ifdef CONFIG_ARM_AMBA
261 static struct amba_device *of_amba_device_create(struct device_node *node,
264 struct device *parent)
266 struct amba_device *dev;
270 pr_debug("Creating amba device %s\n", node->full_name);
272 if (!of_device_is_available(node) ||
273 of_node_test_and_set_flag(node, OF_POPULATED))
276 dev = amba_device_alloc(NULL, 0, 0);
278 pr_err("%s(): amba_device_alloc() failed for %s\n",
279 __func__, node->full_name);
283 /* setup generic device info */
284 dev->dev.coherent_dma_mask = ~0;
285 dev->dev.of_node = of_node_get(node);
286 dev->dev.parent = parent;
287 dev->dev.platform_data = platform_data;
289 dev_set_name(&dev->dev, "%s", bus_id);
291 of_device_make_bus_id(&dev->dev);
293 /* Allow the HW Peripheral ID to be overridden */
294 prop = of_get_property(node, "arm,primecell-periphid", NULL);
296 dev->periphid = of_read_ulong(prop, 1);
298 /* Decode the IRQs and address ranges */
299 for (i = 0; i < AMBA_NR_IRQS; i++)
300 dev->irq[i] = irq_of_parse_and_map(node, i);
302 ret = of_address_to_resource(node, 0, &dev->res);
304 pr_err("%s(): of_address_to_resource() failed (%d) for %s\n",
305 __func__, ret, node->full_name);
309 ret = amba_device_add(dev, &iomem_resource);
311 pr_err("%s(): amba_device_add() failed (%d) for %s\n",
312 __func__, ret, node->full_name);
319 amba_device_put(dev);
321 of_node_clear_flag(node, OF_POPULATED);
324 #else /* CONFIG_ARM_AMBA */
325 static struct amba_device *of_amba_device_create(struct device_node *node,
328 struct device *parent)
332 #endif /* CONFIG_ARM_AMBA */
335 * of_devname_lookup() - Given a device node, lookup the preferred Linux name
337 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
338 struct device_node *np)
345 for(; lookup->compatible != NULL; lookup++) {
346 if (!of_device_is_compatible(np, lookup->compatible))
348 if (!of_address_to_resource(np, 0, &res))
349 if (res.start != lookup->phys_addr)
351 pr_debug("%s: devname=%s\n", np->full_name, lookup->name);
359 * of_platform_bus_create() - Create a device for a node and its children.
360 * @bus: device node of the bus to instantiate
361 * @matches: match table for bus nodes
362 * @lookup: auxdata table for matching id and platform_data with device nodes
363 * @parent: parent for new device, or NULL for top level.
364 * @strict: require compatible property
366 * Creates a platform_device for the provided device_node, and optionally
367 * recursively create devices for all the child nodes.
369 static int of_platform_bus_create(struct device_node *bus,
370 const struct of_device_id *matches,
371 const struct of_dev_auxdata *lookup,
372 struct device *parent, bool strict)
374 const struct of_dev_auxdata *auxdata;
375 struct device_node *child;
376 struct platform_device *dev;
377 const char *bus_id = NULL;
378 void *platform_data = NULL;
381 /* Make sure it has a compatible property */
382 if (strict && (!of_get_property(bus, "compatible", NULL))) {
383 pr_debug("%s() - skipping %s, no compatible prop\n",
384 __func__, bus->full_name);
388 auxdata = of_dev_lookup(lookup, bus);
390 bus_id = auxdata->name;
391 platform_data = auxdata->platform_data;
394 if (of_device_is_compatible(bus, "arm,primecell")) {
396 * Don't return an error here to keep compatibility with older
399 of_amba_device_create(bus, bus_id, platform_data, parent);
403 dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
404 if (!dev || !of_match_node(matches, bus))
407 for_each_child_of_node(bus, child) {
408 pr_debug(" create child: %s\n", child->full_name);
409 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
419 * of_platform_bus_probe() - Probe the device-tree for platform buses
420 * @root: parent of the first level to probe or NULL for the root of the tree
421 * @matches: match table for bus nodes
422 * @parent: parent to hook devices from, NULL for toplevel
424 * Note that children of the provided root are not instantiated as devices
425 * unless the specified root itself matches the bus list and is not NULL.
427 int of_platform_bus_probe(struct device_node *root,
428 const struct of_device_id *matches,
429 struct device *parent)
431 struct device_node *child;
434 root = root ? of_node_get(root) : of_find_node_by_path("/");
438 pr_debug("of_platform_bus_probe()\n");
439 pr_debug(" starting at: %s\n", root->full_name);
441 /* Do a self check of bus type, if there's a match, create children */
442 if (of_match_node(matches, root)) {
443 rc = of_platform_bus_create(root, matches, NULL, parent, false);
444 } else for_each_child_of_node(root, child) {
445 if (!of_match_node(matches, child))
447 rc = of_platform_bus_create(child, matches, NULL, parent, false);
455 EXPORT_SYMBOL(of_platform_bus_probe);
458 * of_platform_populate() - Populate platform_devices from device tree data
459 * @root: parent of the first level to probe or NULL for the root of the tree
460 * @matches: match table, NULL to use the default
461 * @lookup: auxdata table for matching id and platform_data with device nodes
462 * @parent: parent to hook devices from, NULL for toplevel
464 * Similar to of_platform_bus_probe(), this function walks the device tree
465 * and creates devices from nodes. It differs in that it follows the modern
466 * convention of requiring all device nodes to have a 'compatible' property,
467 * and it is suitable for creating devices which are children of the root
468 * node (of_platform_bus_probe will only create children of the root which
469 * are selected by the @matches argument).
471 * New board support should be using this function instead of
472 * of_platform_bus_probe().
474 * Returns 0 on success, < 0 on failure.
476 int of_platform_populate(struct device_node *root,
477 const struct of_device_id *matches,
478 const struct of_dev_auxdata *lookup,
479 struct device *parent)
481 struct device_node *child;
484 root = root ? of_node_get(root) : of_find_node_by_path("/");
488 for_each_child_of_node(root, child) {
489 rc = of_platform_bus_create(child, matches, lookup, parent, true);
497 EXPORT_SYMBOL_GPL(of_platform_populate);
499 static int of_platform_device_destroy(struct device *dev, void *data)
501 bool *children_left = data;
503 /* Do not touch devices not populated from the device tree */
504 if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED)) {
505 *children_left = true;
509 /* Recurse, but don't touch this device if it has any children left */
510 if (of_platform_depopulate(dev) != 0) {
511 *children_left = true;
515 if (dev->bus == &platform_bus_type)
516 platform_device_unregister(to_platform_device(dev));
517 #ifdef CONFIG_ARM_AMBA
518 else if (dev->bus == &amba_bustype)
519 amba_device_unregister(to_amba_device(dev));
522 *children_left = true;
526 of_node_clear_flag(dev->of_node, OF_POPULATED);
532 * of_platform_depopulate() - Remove devices populated from device tree
533 * @parent: device which childred will be removed
535 * Complementary to of_platform_populate(), this function removes children
536 * of the given device (and, recurrently, their children) that have been
537 * created from their respective device tree nodes (and only those,
538 * leaving others - eg. manually created - unharmed).
540 * Returns 0 when all children devices have been removed or
541 * -EBUSY when some children remained.
543 int of_platform_depopulate(struct device *parent)
545 bool children_left = false;
547 device_for_each_child(parent, &children_left,
548 of_platform_device_destroy);
550 return children_left ? -EBUSY : 0;
552 EXPORT_SYMBOL_GPL(of_platform_depopulate);
554 #endif /* CONFIG_OF_ADDRESS */