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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 
 15 #define pr_fmt(fmt)     "OF: " fmt
 16 
 17 #include <linux/errno.h>
 18 #include <linux/module.h>
 19 #include <linux/amba/bus.h>
 20 #include <linux/device.h>
 21 #include <linux/dma-mapping.h>
 22 #include <linux/slab.h>
 23 #include <linux/of_address.h>
 24 #include <linux/of_device.h>
 25 #include <linux/of_irq.h>
 26 #include <linux/of_platform.h>
 27 #include <linux/platform_device.h>
 28 
 29 const struct of_device_id of_default_bus_match_table[] = {
 30         { .compatible = "simple-bus", },
 31         { .compatible = "simple-mfd", },
 32 #ifdef CONFIG_ARM_AMBA
 33         { .compatible = "arm,amba-bus", },
 34 #endif /* CONFIG_ARM_AMBA */
 35         {} /* Empty terminated list */
 36 };
 37 
 38 static int of_dev_node_match(struct device *dev, void *data)
 39 {
 40         return dev->of_node == data;
 41 }
 42 
 43 /**
 44  * of_find_device_by_node - Find the platform_device associated with a node
 45  * @np: Pointer to device tree node
 46  *
 47  * Returns platform_device pointer, or NULL if not found
 48  */
 49 struct platform_device *of_find_device_by_node(struct device_node *np)
 50 {
 51         struct device *dev;
 52 
 53         dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
 54         return dev ? to_platform_device(dev) : NULL;
 55 }
 56 EXPORT_SYMBOL(of_find_device_by_node);
 57 
 58 #ifdef CONFIG_OF_ADDRESS
 59 /*
 60  * The following routines scan a subtree and registers a device for
 61  * each applicable node.
 62  *
 63  * Note: sparc doesn't use these routines because it has a different
 64  * mechanism for creating devices from device tree nodes.
 65  */
 66 
 67 /**
 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
 70  *
 71  * This routine will first try using the translated bus address to
 72  * derive a unique name. If it cannot, then it will prepend names from
 73  * parent nodes until a unique name can be derived.
 74  */
 75 void of_device_make_bus_id(struct device *dev)
 76 {
 77         struct device_node *node = dev->of_node;
 78         const __be32 *reg;
 79         u64 addr;
 80 
 81         /* Construct the name, using parent nodes if necessary to ensure uniqueness */
 82         while (node->parent) {
 83                 /*
 84                  * If the address can be translated, then that is as much
 85                  * uniqueness as we need. Make it the first component and return
 86                  */
 87                 reg = of_get_property(node, "reg", NULL);
 88                 if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
 89                         dev_set_name(dev, dev_name(dev) ? "%llx.%s:%s" : "%llx.%s",
 90                                      (unsigned long long)addr, node->name,
 91                                      dev_name(dev));
 92                         return;
 93                 }
 94 
 95                 /* format arguments only used if dev_name() resolves to NULL */
 96                 dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
 97                              strrchr(node->full_name, '/') + 1, dev_name(dev));
 98                 node = node->parent;
 99         }
100 }
101 
102 /**
103  * of_device_alloc - Allocate and initialize an of_device
104  * @np: device node to assign to device
105  * @bus_id: Name to assign to the device.  May be null to use default name.
106  * @parent: Parent device.
107  */
108 struct platform_device *of_device_alloc(struct device_node *np,
109                                   const char *bus_id,
110                                   struct device *parent)
111 {
112         struct platform_device *dev;
113         int rc, i, num_reg = 0, num_irq;
114         struct resource *res, temp_res;
115 
116         dev = platform_device_alloc("", -1);
117         if (!dev)
118                 return NULL;
119 
120         /* count the io and irq resources */
121         while (of_address_to_resource(np, num_reg, &temp_res) == 0)
122                 num_reg++;
123         num_irq = of_irq_count(np);
124 
125         /* Populate the resource table */
126         if (num_irq || num_reg) {
127                 res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
128                 if (!res) {
129                         platform_device_put(dev);
130                         return NULL;
131                 }
132 
133                 dev->num_resources = num_reg + num_irq;
134                 dev->resource = res;
135                 for (i = 0; i < num_reg; i++, res++) {
136                         rc = of_address_to_resource(np, i, res);
137                         WARN_ON(rc);
138                 }
139                 if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
140                         pr_debug("not all legacy IRQ resources mapped for %s\n",
141                                  np->name);
142         }
143 
144         dev->dev.of_node = of_node_get(np);
145         dev->dev.parent = parent ? : &platform_bus;
146 
147         if (bus_id)
148                 dev_set_name(&dev->dev, "%s", bus_id);
149         else
150                 of_device_make_bus_id(&dev->dev);
151 
152         return dev;
153 }
154 EXPORT_SYMBOL(of_device_alloc);
155 
156 static void of_dma_deconfigure(struct device *dev)
157 {
158         arch_teardown_dma_ops(dev);
159 }
160 
161 /**
162  * of_platform_device_create_pdata - Alloc, initialize and register an of_device
163  * @np: pointer to node to create device for
164  * @bus_id: name to assign device
165  * @platform_data: pointer to populate platform_data pointer with
166  * @parent: Linux device model parent device.
167  *
168  * Returns pointer to created platform device, or NULL if a device was not
169  * registered.  Unavailable devices will not get registered.
170  */
171 static struct platform_device *of_platform_device_create_pdata(
172                                         struct device_node *np,
173                                         const char *bus_id,
174                                         void *platform_data,
175                                         struct device *parent)
176 {
177         struct platform_device *dev;
178 
179         if (!of_device_is_available(np) ||
180             of_node_test_and_set_flag(np, OF_POPULATED))
181                 return NULL;
182 
183         dev = of_device_alloc(np, bus_id, parent);
184         if (!dev)
185                 goto err_clear_flag;
186 
187         dev->dev.bus = &platform_bus_type;
188         dev->dev.platform_data = platform_data;
189         of_dma_configure(&dev->dev, dev->dev.of_node);
190         of_msi_configure(&dev->dev, dev->dev.of_node);
191 
192         if (of_device_add(dev) != 0) {
193                 of_dma_deconfigure(&dev->dev);
194                 platform_device_put(dev);
195                 goto err_clear_flag;
196         }
197 
198         return dev;
199 
200 err_clear_flag:
201         of_node_clear_flag(np, OF_POPULATED);
202         return NULL;
203 }
204 
205 /**
206  * of_platform_device_create - Alloc, initialize and register an of_device
207  * @np: pointer to node to create device for
208  * @bus_id: name to assign device
209  * @parent: Linux device model parent device.
210  *
211  * Returns pointer to created platform device, or NULL if a device was not
212  * registered.  Unavailable devices will not get registered.
213  */
214 struct platform_device *of_platform_device_create(struct device_node *np,
215                                             const char *bus_id,
216                                             struct device *parent)
217 {
218         return of_platform_device_create_pdata(np, bus_id, NULL, parent);
219 }
220 EXPORT_SYMBOL(of_platform_device_create);
221 
222 #ifdef CONFIG_ARM_AMBA
223 static struct amba_device *of_amba_device_create(struct device_node *node,
224                                                  const char *bus_id,
225                                                  void *platform_data,
226                                                  struct device *parent)
227 {
228         struct amba_device *dev;
229         const void *prop;
230         int i, ret;
231 
232         pr_debug("Creating amba device %s\n", node->full_name);
233 
234         if (!of_device_is_available(node) ||
235             of_node_test_and_set_flag(node, OF_POPULATED))
236                 return NULL;
237 
238         dev = amba_device_alloc(NULL, 0, 0);
239         if (!dev)
240                 goto err_clear_flag;
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("amba: of_address_to_resource() failed (%d) for %s\n",
264                        ret, node->full_name);
265                 goto err_free;
266         }
267 
268         ret = amba_device_add(dev, &iomem_resource);
269         if (ret) {
270                 pr_err("amba_device_add() failed (%d) for %s\n",
271                        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         const struct of_dev_auxdata *auxdata;
300         struct resource res;
301         int compatible = 0;
302 
303         if (!lookup)
304                 return NULL;
305 
306         auxdata = lookup;
307         for (; auxdata->compatible; auxdata++) {
308                 if (!of_device_is_compatible(np, auxdata->compatible))
309                         continue;
310                 compatible++;
311                 if (!of_address_to_resource(np, 0, &res))
312                         if (res.start != auxdata->phys_addr)
313                                 continue;
314                 pr_debug("%s: devname=%s\n", np->full_name, auxdata->name);
315                 return auxdata;
316         }
317 
318         if (!compatible)
319                 return NULL;
320 
321         /* Try compatible match if no phys_addr and name are specified */
322         auxdata = lookup;
323         for (; auxdata->compatible; auxdata++) {
324                 if (!of_device_is_compatible(np, auxdata->compatible))
325                         continue;
326                 if (!auxdata->phys_addr && !auxdata->name) {
327                         pr_debug("%s: compatible match\n", np->full_name);
328                         return auxdata;
329                 }
330         }
331 
332         return NULL;
333 }
334 
335 /**
336  * of_platform_bus_create() - Create a device for a node and its children.
337  * @bus: device node of the bus to instantiate
338  * @matches: match table for bus nodes
339  * @lookup: auxdata table for matching id and platform_data with device nodes
340  * @parent: parent for new device, or NULL for top level.
341  * @strict: require compatible property
342  *
343  * Creates a platform_device for the provided device_node, and optionally
344  * recursively create devices for all the child nodes.
345  */
346 static int of_platform_bus_create(struct device_node *bus,
347                                   const struct of_device_id *matches,
348                                   const struct of_dev_auxdata *lookup,
349                                   struct device *parent, bool strict)
350 {
351         const struct of_dev_auxdata *auxdata;
352         struct device_node *child;
353         struct platform_device *dev;
354         const char *bus_id = NULL;
355         void *platform_data = NULL;
356         int rc = 0;
357 
358         /* Make sure it has a compatible property */
359         if (strict && (!of_get_property(bus, "compatible", NULL))) {
360                 pr_debug("%s() - skipping %s, no compatible prop\n",
361                          __func__, bus->full_name);
362                 return 0;
363         }
364 
365         if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
366                 pr_debug("%s() - skipping %s, already populated\n",
367                         __func__, bus->full_name);
368                 return 0;
369         }
370 
371         auxdata = of_dev_lookup(lookup, bus);
372         if (auxdata) {
373                 bus_id = auxdata->name;
374                 platform_data = auxdata->platform_data;
375         }
376 
377         if (of_device_is_compatible(bus, "arm,primecell")) {
378                 /*
379                  * Don't return an error here to keep compatibility with older
380                  * device tree files.
381                  */
382                 of_amba_device_create(bus, bus_id, platform_data, parent);
383                 return 0;
384         }
385 
386         dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
387         if (!dev || !of_match_node(matches, bus))
388                 return 0;
389 
390         for_each_child_of_node(bus, child) {
391                 pr_debug("   create child: %s\n", child->full_name);
392                 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
393                 if (rc) {
394                         of_node_put(child);
395                         break;
396                 }
397         }
398         of_node_set_flag(bus, OF_POPULATED_BUS);
399         return rc;
400 }
401 
402 /**
403  * of_platform_bus_probe() - Probe the device-tree for platform buses
404  * @root: parent of the first level to probe or NULL for the root of the tree
405  * @matches: match table for bus nodes
406  * @parent: parent to hook devices from, NULL for toplevel
407  *
408  * Note that children of the provided root are not instantiated as devices
409  * unless the specified root itself matches the bus list and is not NULL.
410  */
411 int of_platform_bus_probe(struct device_node *root,
412                           const struct of_device_id *matches,
413                           struct device *parent)
414 {
415         struct device_node *child;
416         int rc = 0;
417 
418         root = root ? of_node_get(root) : of_find_node_by_path("/");
419         if (!root)
420                 return -EINVAL;
421 
422         pr_debug("%s()\n", __func__);
423         pr_debug(" starting at: %s\n", root->full_name);
424 
425         /* Do a self check of bus type, if there's a match, create children */
426         if (of_match_node(matches, root)) {
427                 rc = of_platform_bus_create(root, matches, NULL, parent, false);
428         } else for_each_child_of_node(root, child) {
429                 if (!of_match_node(matches, child))
430                         continue;
431                 rc = of_platform_bus_create(child, matches, NULL, parent, false);
432                 if (rc) {
433                         of_node_put(child);
434                         break;
435                 }
436         }
437 
438         of_node_put(root);
439         return rc;
440 }
441 EXPORT_SYMBOL(of_platform_bus_probe);
442 
443 /**
444  * of_platform_populate() - Populate platform_devices from device tree data
445  * @root: parent of the first level to probe or NULL for the root of the tree
446  * @matches: match table, NULL to use the default
447  * @lookup: auxdata table for matching id and platform_data with device nodes
448  * @parent: parent to hook devices from, NULL for toplevel
449  *
450  * Similar to of_platform_bus_probe(), this function walks the device tree
451  * and creates devices from nodes.  It differs in that it follows the modern
452  * convention of requiring all device nodes to have a 'compatible' property,
453  * and it is suitable for creating devices which are children of the root
454  * node (of_platform_bus_probe will only create children of the root which
455  * are selected by the @matches argument).
456  *
457  * New board support should be using this function instead of
458  * of_platform_bus_probe().
459  *
460  * Returns 0 on success, < 0 on failure.
461  */
462 int of_platform_populate(struct device_node *root,
463                         const struct of_device_id *matches,
464                         const struct of_dev_auxdata *lookup,
465                         struct device *parent)
466 {
467         struct device_node *child;
468         int rc = 0;
469 
470         root = root ? of_node_get(root) : of_find_node_by_path("/");
471         if (!root)
472                 return -EINVAL;
473 
474         pr_debug("%s()\n", __func__);
475         pr_debug(" starting at: %s\n", root->full_name);
476 
477         for_each_child_of_node(root, child) {
478                 rc = of_platform_bus_create(child, matches, lookup, parent, true);
479                 if (rc) {
480                         of_node_put(child);
481                         break;
482                 }
483         }
484         of_node_set_flag(root, OF_POPULATED_BUS);
485 
486         of_node_put(root);
487         return rc;
488 }
489 EXPORT_SYMBOL_GPL(of_platform_populate);
490 
491 int of_platform_default_populate(struct device_node *root,
492                                  const struct of_dev_auxdata *lookup,
493                                  struct device *parent)
494 {
495         return of_platform_populate(root, of_default_bus_match_table, lookup,
496                                     parent);
497 }
498 EXPORT_SYMBOL_GPL(of_platform_default_populate);
499 
500 #ifndef CONFIG_PPC
501 static int __init of_platform_default_populate_init(void)
502 {
503         struct device_node *node;
504 
505         if (!of_have_populated_dt())
506                 return -ENODEV;
507 
508         /*
509          * Handle ramoops explicitly, since it is inside /reserved-memory,
510          * which lacks a "compatible" property.
511          */
512         node = of_find_node_by_path("/reserved-memory");
513         if (node) {
514                 node = of_find_compatible_node(node, NULL, "ramoops");
515                 if (node)
516                         of_platform_device_create(node, NULL, NULL);
517         }
518 
519         /* Populate everything else. */
520         of_platform_default_populate(NULL, NULL, NULL);
521 
522         return 0;
523 }
524 arch_initcall_sync(of_platform_default_populate_init);
525 #endif
526 
527 static int of_platform_device_destroy(struct device *dev, void *data)
528 {
529         /* Do not touch devices not populated from the device tree */
530         if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
531                 return 0;
532 
533         /* Recurse for any nodes that were treated as busses */
534         if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
535                 device_for_each_child(dev, NULL, of_platform_device_destroy);
536 
537         if (dev->bus == &platform_bus_type)
538                 platform_device_unregister(to_platform_device(dev));
539 #ifdef CONFIG_ARM_AMBA
540         else if (dev->bus == &amba_bustype)
541                 amba_device_unregister(to_amba_device(dev));
542 #endif
543 
544         of_dma_deconfigure(dev);
545         of_node_clear_flag(dev->of_node, OF_POPULATED);
546         of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
547         return 0;
548 }
549 
550 /**
551  * of_platform_depopulate() - Remove devices populated from device tree
552  * @parent: device which children will be removed
553  *
554  * Complementary to of_platform_populate(), this function removes children
555  * of the given device (and, recurrently, their children) that have been
556  * created from their respective device tree nodes (and only those,
557  * leaving others - eg. manually created - unharmed).
558  *
559  * Returns 0 when all children devices have been removed or
560  * -EBUSY when some children remained.
561  */
562 void of_platform_depopulate(struct device *parent)
563 {
564         if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
565                 device_for_each_child(parent, NULL, of_platform_device_destroy);
566                 of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
567         }
568 }
569 EXPORT_SYMBOL_GPL(of_platform_depopulate);
570 
571 #ifdef CONFIG_OF_DYNAMIC
572 static int of_platform_notify(struct notifier_block *nb,
573                                 unsigned long action, void *arg)
574 {
575         struct of_reconfig_data *rd = arg;
576         struct platform_device *pdev_parent, *pdev;
577         bool children_left;
578 
579         switch (of_reconfig_get_state_change(action, rd)) {
580         case OF_RECONFIG_CHANGE_ADD:
581                 /* verify that the parent is a bus */
582                 if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
583                         return NOTIFY_OK;       /* not for us */
584 
585                 /* already populated? (driver using of_populate manually) */
586                 if (of_node_check_flag(rd->dn, OF_POPULATED))
587                         return NOTIFY_OK;
588 
589                 /* pdev_parent may be NULL when no bus platform device */
590                 pdev_parent = of_find_device_by_node(rd->dn->parent);
591                 pdev = of_platform_device_create(rd->dn, NULL,
592                                 pdev_parent ? &pdev_parent->dev : NULL);
593                 of_dev_put(pdev_parent);
594 
595                 if (pdev == NULL) {
596                         pr_err("%s: failed to create for '%s'\n",
597                                         __func__, rd->dn->full_name);
598                         /* of_platform_device_create tosses the error code */
599                         return notifier_from_errno(-EINVAL);
600                 }
601                 break;
602 
603         case OF_RECONFIG_CHANGE_REMOVE:
604 
605                 /* already depopulated? */
606                 if (!of_node_check_flag(rd->dn, OF_POPULATED))
607                         return NOTIFY_OK;
608 
609                 /* find our device by node */
610                 pdev = of_find_device_by_node(rd->dn);
611                 if (pdev == NULL)
612                         return NOTIFY_OK;       /* no? not meant for us */
613 
614                 /* unregister takes one ref away */
615                 of_platform_device_destroy(&pdev->dev, &children_left);
616 
617                 /* and put the reference of the find */
618                 of_dev_put(pdev);
619                 break;
620         }
621 
622         return NOTIFY_OK;
623 }
624 
625 static struct notifier_block platform_of_notifier = {
626         .notifier_call = of_platform_notify,
627 };
628 
629 void of_platform_register_reconfig_notifier(void)
630 {
631         WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
632 }
633 #endif /* CONFIG_OF_DYNAMIC */
634 
635 #endif /* CONFIG_OF_ADDRESS */
636 

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