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

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