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Linux/drivers/of/platform.c

  1 /*
  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
  7  *
  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.
 12  *
 13  */
 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>
 25 
 26 const struct of_device_id of_default_bus_match_table[] = {
 27         { .compatible = "simple-bus", },
 28         { .compatible = "simple-mfd", },
 29 #ifdef CONFIG_ARM_AMBA
 30         { .compatible = "arm,amba-bus", },
 31 #endif /* CONFIG_ARM_AMBA */
 32         {} /* Empty terminated list */
 33 };
 34 EXPORT_SYMBOL(of_default_bus_match_table);
 35 
 36 static int of_dev_node_match(struct device *dev, void *data)
 37 {
 38         return dev->of_node == data;
 39 }
 40 
 41 /**
 42  * of_find_device_by_node - Find the platform_device associated with a node
 43  * @np: Pointer to device tree node
 44  *
 45  * Returns platform_device pointer, or NULL if not found
 46  */
 47 struct platform_device *of_find_device_by_node(struct device_node *np)
 48 {
 49         struct device *dev;
 50 
 51         dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
 52         return dev ? to_platform_device(dev) : NULL;
 53 }
 54 EXPORT_SYMBOL(of_find_device_by_node);
 55 
 56 #ifdef CONFIG_OF_ADDRESS
 57 /*
 58  * The following routines scan a subtree and registers a device for
 59  * each applicable node.
 60  *
 61  * Note: sparc doesn't use these routines because it has a different
 62  * mechanism for creating devices from device tree nodes.
 63  */
 64 
 65 /**
 66  * of_device_make_bus_id - Use the device node data to assign a unique name
 67  * @dev: pointer to device structure that is linked to a device tree node
 68  *
 69  * This routine will first try using the translated bus address to
 70  * derive a unique name. If it cannot, then it will prepend names from
 71  * parent nodes until a unique name can be derived.
 72  */
 73 void of_device_make_bus_id(struct device *dev)
 74 {
 75         struct device_node *node = dev->of_node;
 76         const __be32 *reg;
 77         u64 addr;
 78 
 79         /* Construct the name, using parent nodes if necessary to ensure uniqueness */
 80         while (node->parent) {
 81                 /*
 82                  * If the address can be translated, then that is as much
 83                  * uniqueness as we need. Make it the first component and return
 84                  */
 85                 reg = of_get_property(node, "reg", NULL);
 86                 if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
 87                         dev_set_name(dev, dev_name(dev) ? "%llx.%s:%s" : "%llx.%s",
 88                                      (unsigned long long)addr, node->name,
 89                                      dev_name(dev));
 90                         return;
 91                 }
 92 
 93                 /* format arguments only used if dev_name() resolves to NULL */
 94                 dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
 95                              strrchr(node->full_name, '/') + 1, dev_name(dev));
 96                 node = node->parent;
 97         }
 98 }
 99 
100 /**
101  * of_device_alloc - Allocate and initialize an of_device
102  * @np: device node to assign to device
103  * @bus_id: Name to assign to the device.  May be null to use default name.
104  * @parent: Parent device.
105  */
106 struct platform_device *of_device_alloc(struct device_node *np,
107                                   const char *bus_id,
108                                   struct device *parent)
109 {
110         struct platform_device *dev;
111         int rc, i, num_reg = 0, num_irq;
112         struct resource *res, temp_res;
113 
114         dev = platform_device_alloc("", -1);
115         if (!dev)
116                 return NULL;
117 
118         /* count the io and irq resources */
119         while (of_address_to_resource(np, num_reg, &temp_res) == 0)
120                 num_reg++;
121         num_irq = of_irq_count(np);
122 
123         /* Populate the resource table */
124         if (num_irq || num_reg) {
125                 res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
126                 if (!res) {
127                         platform_device_put(dev);
128                         return NULL;
129                 }
130 
131                 dev->num_resources = num_reg + num_irq;
132                 dev->resource = res;
133                 for (i = 0; i < num_reg; i++, res++) {
134                         rc = of_address_to_resource(np, i, res);
135                         WARN_ON(rc);
136                 }
137                 if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
138                         pr_debug("not all legacy IRQ resources mapped for %s\n",
139                                  np->name);
140         }
141 
142         dev->dev.of_node = of_node_get(np);
143         dev->dev.parent = parent ? : &platform_bus;
144 
145         if (bus_id)
146                 dev_set_name(&dev->dev, "%s", bus_id);
147         else
148                 of_device_make_bus_id(&dev->dev);
149 
150         return dev;
151 }
152 EXPORT_SYMBOL(of_device_alloc);
153 
154 static void of_dma_deconfigure(struct device *dev)
155 {
156         arch_teardown_dma_ops(dev);
157 }
158 
159 /**
160  * of_platform_device_create_pdata - Alloc, initialize and register an of_device
161  * @np: pointer to node to create device for
162  * @bus_id: name to assign device
163  * @platform_data: pointer to populate platform_data pointer with
164  * @parent: Linux device model parent device.
165  *
166  * Returns pointer to created platform device, or NULL if a device was not
167  * registered.  Unavailable devices will not get registered.
168  */
169 static struct platform_device *of_platform_device_create_pdata(
170                                         struct device_node *np,
171                                         const char *bus_id,
172                                         void *platform_data,
173                                         struct device *parent)
174 {
175         struct platform_device *dev;
176 
177         if (!of_device_is_available(np) ||
178             of_node_test_and_set_flag(np, OF_POPULATED))
179                 return NULL;
180 
181         dev = of_device_alloc(np, bus_id, parent);
182         if (!dev)
183                 goto err_clear_flag;
184 
185         dev->dev.bus = &platform_bus_type;
186         dev->dev.platform_data = platform_data;
187         of_dma_configure(&dev->dev, dev->dev.of_node);
188         of_msi_configure(&dev->dev, dev->dev.of_node);
189 
190         if (of_device_add(dev) != 0) {
191                 of_dma_deconfigure(&dev->dev);
192                 platform_device_put(dev);
193                 goto err_clear_flag;
194         }
195 
196         return dev;
197 
198 err_clear_flag:
199         of_node_clear_flag(np, OF_POPULATED);
200         return NULL;
201 }
202 
203 /**
204  * of_platform_device_create - Alloc, initialize and register an of_device
205  * @np: pointer to node to create device for
206  * @bus_id: name to assign device
207  * @parent: Linux device model parent device.
208  *
209  * Returns pointer to created platform device, or NULL if a device was not
210  * registered.  Unavailable devices will not get registered.
211  */
212 struct platform_device *of_platform_device_create(struct device_node *np,
213                                             const char *bus_id,
214                                             struct device *parent)
215 {
216         return of_platform_device_create_pdata(np, bus_id, NULL, parent);
217 }
218 EXPORT_SYMBOL(of_platform_device_create);
219 
220 #ifdef CONFIG_ARM_AMBA
221 static struct amba_device *of_amba_device_create(struct device_node *node,
222                                                  const char *bus_id,
223                                                  void *platform_data,
224                                                  struct device *parent)
225 {
226         struct amba_device *dev;
227         const void *prop;
228         int i, ret;
229 
230         pr_debug("Creating amba device %s\n", node->full_name);
231 
232         if (!of_device_is_available(node) ||
233             of_node_test_and_set_flag(node, OF_POPULATED))
234                 return NULL;
235 
236         dev = amba_device_alloc(NULL, 0, 0);
237         if (!dev) {
238                 pr_err("%s(): amba_device_alloc() failed for %s\n",
239                        __func__, node->full_name);
240                 goto err_clear_flag;
241         }
242 
243         /* setup generic device info */
244         dev->dev.of_node = of_node_get(node);
245         dev->dev.parent = parent ? : &platform_bus;
246         dev->dev.platform_data = platform_data;
247         if (bus_id)
248                 dev_set_name(&dev->dev, "%s", bus_id);
249         else
250                 of_device_make_bus_id(&dev->dev);
251         of_dma_configure(&dev->dev, dev->dev.of_node);
252 
253         /* Allow the HW Peripheral ID to be overridden */
254         prop = of_get_property(node, "arm,primecell-periphid", NULL);
255         if (prop)
256                 dev->periphid = of_read_ulong(prop, 1);
257 
258         /* Decode the IRQs and address ranges */
259         for (i = 0; i < AMBA_NR_IRQS; i++)
260                 dev->irq[i] = irq_of_parse_and_map(node, i);
261 
262         ret = of_address_to_resource(node, 0, &dev->res);
263         if (ret) {
264                 pr_err("%s(): of_address_to_resource() failed (%d) for %s\n",
265                        __func__, ret, node->full_name);
266                 goto err_free;
267         }
268 
269         ret = amba_device_add(dev, &iomem_resource);
270         if (ret) {
271                 pr_err("%s(): amba_device_add() failed (%d) for %s\n",
272                        __func__, ret, node->full_name);
273                 goto err_free;
274         }
275 
276         return dev;
277 
278 err_free:
279         amba_device_put(dev);
280 err_clear_flag:
281         of_node_clear_flag(node, OF_POPULATED);
282         return NULL;
283 }
284 #else /* CONFIG_ARM_AMBA */
285 static struct amba_device *of_amba_device_create(struct device_node *node,
286                                                  const char *bus_id,
287                                                  void *platform_data,
288                                                  struct device *parent)
289 {
290         return NULL;
291 }
292 #endif /* CONFIG_ARM_AMBA */
293 
294 /**
295  * of_devname_lookup() - Given a device node, lookup the preferred Linux name
296  */
297 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
298                                  struct device_node *np)
299 {
300         struct resource res;
301 
302         if (!lookup)
303                 return NULL;
304 
305         for(; lookup->compatible != NULL; lookup++) {
306                 if (!of_device_is_compatible(np, lookup->compatible))
307                         continue;
308                 if (!of_address_to_resource(np, 0, &res))
309                         if (res.start != lookup->phys_addr)
310                                 continue;
311                 pr_debug("%s: devname=%s\n", np->full_name, lookup->name);
312                 return lookup;
313         }
314 
315         return NULL;
316 }
317 
318 /**
319  * of_platform_bus_create() - Create a device for a node and its children.
320  * @bus: device node of the bus to instantiate
321  * @matches: match table for bus nodes
322  * @lookup: auxdata table for matching id and platform_data with device nodes
323  * @parent: parent for new device, or NULL for top level.
324  * @strict: require compatible property
325  *
326  * Creates a platform_device for the provided device_node, and optionally
327  * recursively create devices for all the child nodes.
328  */
329 static int of_platform_bus_create(struct device_node *bus,
330                                   const struct of_device_id *matches,
331                                   const struct of_dev_auxdata *lookup,
332                                   struct device *parent, bool strict)
333 {
334         const struct of_dev_auxdata *auxdata;
335         struct device_node *child;
336         struct platform_device *dev;
337         const char *bus_id = NULL;
338         void *platform_data = NULL;
339         int rc = 0;
340 
341         /* Make sure it has a compatible property */
342         if (strict && (!of_get_property(bus, "compatible", NULL))) {
343                 pr_debug("%s() - skipping %s, no compatible prop\n",
344                          __func__, bus->full_name);
345                 return 0;
346         }
347 
348         auxdata = of_dev_lookup(lookup, bus);
349         if (auxdata) {
350                 bus_id = auxdata->name;
351                 platform_data = auxdata->platform_data;
352         }
353 
354         if (of_device_is_compatible(bus, "arm,primecell")) {
355                 /*
356                  * Don't return an error here to keep compatibility with older
357                  * device tree files.
358                  */
359                 of_amba_device_create(bus, bus_id, platform_data, parent);
360                 return 0;
361         }
362 
363         dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
364         if (!dev || !of_match_node(matches, bus))
365                 return 0;
366 
367         for_each_child_of_node(bus, child) {
368                 pr_debug("   create child: %s\n", child->full_name);
369                 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
370                 if (rc) {
371                         of_node_put(child);
372                         break;
373                 }
374         }
375         of_node_set_flag(bus, OF_POPULATED_BUS);
376         return rc;
377 }
378 
379 /**
380  * of_platform_bus_probe() - Probe the device-tree for platform buses
381  * @root: parent of the first level to probe or NULL for the root of the tree
382  * @matches: match table for bus nodes
383  * @parent: parent to hook devices from, NULL for toplevel
384  *
385  * Note that children of the provided root are not instantiated as devices
386  * unless the specified root itself matches the bus list and is not NULL.
387  */
388 int of_platform_bus_probe(struct device_node *root,
389                           const struct of_device_id *matches,
390                           struct device *parent)
391 {
392         struct device_node *child;
393         int rc = 0;
394 
395         root = root ? of_node_get(root) : of_find_node_by_path("/");
396         if (!root)
397                 return -EINVAL;
398 
399         pr_debug("of_platform_bus_probe()\n");
400         pr_debug(" starting at: %s\n", root->full_name);
401 
402         /* Do a self check of bus type, if there's a match, create children */
403         if (of_match_node(matches, root)) {
404                 rc = of_platform_bus_create(root, matches, NULL, parent, false);
405         } else for_each_child_of_node(root, child) {
406                 if (!of_match_node(matches, child))
407                         continue;
408                 rc = of_platform_bus_create(child, matches, NULL, parent, false);
409                 if (rc) {
410                         of_node_put(child);
411                         break;
412                 }
413         }
414 
415         of_node_put(root);
416         return rc;
417 }
418 EXPORT_SYMBOL(of_platform_bus_probe);
419 
420 /**
421  * of_platform_populate() - Populate platform_devices from device tree data
422  * @root: parent of the first level to probe or NULL for the root of the tree
423  * @matches: match table, NULL to use the default
424  * @lookup: auxdata table for matching id and platform_data with device nodes
425  * @parent: parent to hook devices from, NULL for toplevel
426  *
427  * Similar to of_platform_bus_probe(), this function walks the device tree
428  * and creates devices from nodes.  It differs in that it follows the modern
429  * convention of requiring all device nodes to have a 'compatible' property,
430  * and it is suitable for creating devices which are children of the root
431  * node (of_platform_bus_probe will only create children of the root which
432  * are selected by the @matches argument).
433  *
434  * New board support should be using this function instead of
435  * of_platform_bus_probe().
436  *
437  * Returns 0 on success, < 0 on failure.
438  */
439 int of_platform_populate(struct device_node *root,
440                         const struct of_device_id *matches,
441                         const struct of_dev_auxdata *lookup,
442                         struct device *parent)
443 {
444         struct device_node *child;
445         int rc = 0;
446 
447         root = root ? of_node_get(root) : of_find_node_by_path("/");
448         if (!root)
449                 return -EINVAL;
450 
451         for_each_child_of_node(root, child) {
452                 rc = of_platform_bus_create(child, matches, lookup, parent, true);
453                 if (rc) {
454                         of_node_put(child);
455                         break;
456                 }
457         }
458         of_node_set_flag(root, OF_POPULATED_BUS);
459 
460         of_node_put(root);
461         return rc;
462 }
463 EXPORT_SYMBOL_GPL(of_platform_populate);
464 
465 int of_platform_default_populate(struct device_node *root,
466                                  const struct of_dev_auxdata *lookup,
467                                  struct device *parent)
468 {
469         return of_platform_populate(root, of_default_bus_match_table, lookup,
470                                     parent);
471 }
472 EXPORT_SYMBOL_GPL(of_platform_default_populate);
473 
474 static int of_platform_device_destroy(struct device *dev, void *data)
475 {
476         /* Do not touch devices not populated from the device tree */
477         if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
478                 return 0;
479 
480         /* Recurse for any nodes that were treated as busses */
481         if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
482                 device_for_each_child(dev, NULL, of_platform_device_destroy);
483 
484         if (dev->bus == &platform_bus_type)
485                 platform_device_unregister(to_platform_device(dev));
486 #ifdef CONFIG_ARM_AMBA
487         else if (dev->bus == &amba_bustype)
488                 amba_device_unregister(to_amba_device(dev));
489 #endif
490 
491         of_dma_deconfigure(dev);
492         of_node_clear_flag(dev->of_node, OF_POPULATED);
493         of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
494         return 0;
495 }
496 
497 /**
498  * of_platform_depopulate() - Remove devices populated from device tree
499  * @parent: device which children will be removed
500  *
501  * Complementary to of_platform_populate(), this function removes children
502  * of the given device (and, recurrently, their children) that have been
503  * created from their respective device tree nodes (and only those,
504  * leaving others - eg. manually created - unharmed).
505  *
506  * Returns 0 when all children devices have been removed or
507  * -EBUSY when some children remained.
508  */
509 void of_platform_depopulate(struct device *parent)
510 {
511         if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
512                 device_for_each_child(parent, NULL, of_platform_device_destroy);
513                 of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
514         }
515 }
516 EXPORT_SYMBOL_GPL(of_platform_depopulate);
517 
518 #ifdef CONFIG_OF_DYNAMIC
519 static int of_platform_notify(struct notifier_block *nb,
520                                 unsigned long action, void *arg)
521 {
522         struct of_reconfig_data *rd = arg;
523         struct platform_device *pdev_parent, *pdev;
524         bool children_left;
525 
526         switch (of_reconfig_get_state_change(action, rd)) {
527         case OF_RECONFIG_CHANGE_ADD:
528                 /* verify that the parent is a bus */
529                 if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
530                         return NOTIFY_OK;       /* not for us */
531 
532                 /* already populated? (driver using of_populate manually) */
533                 if (of_node_check_flag(rd->dn, OF_POPULATED))
534                         return NOTIFY_OK;
535 
536                 /* pdev_parent may be NULL when no bus platform device */
537                 pdev_parent = of_find_device_by_node(rd->dn->parent);
538                 pdev = of_platform_device_create(rd->dn, NULL,
539                                 pdev_parent ? &pdev_parent->dev : NULL);
540                 of_dev_put(pdev_parent);
541 
542                 if (pdev == NULL) {
543                         pr_err("%s: failed to create for '%s'\n",
544                                         __func__, rd->dn->full_name);
545                         /* of_platform_device_create tosses the error code */
546                         return notifier_from_errno(-EINVAL);
547                 }
548                 break;
549 
550         case OF_RECONFIG_CHANGE_REMOVE:
551 
552                 /* already depopulated? */
553                 if (!of_node_check_flag(rd->dn, OF_POPULATED))
554                         return NOTIFY_OK;
555 
556                 /* find our device by node */
557                 pdev = of_find_device_by_node(rd->dn);
558                 if (pdev == NULL)
559                         return NOTIFY_OK;       /* no? not meant for us */
560 
561                 /* unregister takes one ref away */
562                 of_platform_device_destroy(&pdev->dev, &children_left);
563 
564                 /* and put the reference of the find */
565                 of_dev_put(pdev);
566                 break;
567         }
568 
569         return NOTIFY_OK;
570 }
571 
572 static struct notifier_block platform_of_notifier = {
573         .notifier_call = of_platform_notify,
574 };
575 
576 void of_platform_register_reconfig_notifier(void)
577 {
578         WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
579 }
580 #endif /* CONFIG_OF_DYNAMIC */
581 
582 #endif /* CONFIG_OF_ADDRESS */
583 

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