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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         { .compatible = "isa", },
 33 #ifdef CONFIG_ARM_AMBA
 34         { .compatible = "arm,amba-bus", },
 35 #endif /* CONFIG_ARM_AMBA */
 36         {} /* Empty terminated list */
 37 };
 38 
 39 static int of_dev_node_match(struct device *dev, void *data)
 40 {
 41         return dev->of_node == data;
 42 }
 43 
 44 /**
 45  * of_find_device_by_node - Find the platform_device associated with a node
 46  * @np: Pointer to device tree node
 47  *
 48  * Returns platform_device pointer, or NULL if not found
 49  */
 50 struct platform_device *of_find_device_by_node(struct device_node *np)
 51 {
 52         struct device *dev;
 53 
 54         dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
 55         return dev ? to_platform_device(dev) : NULL;
 56 }
 57 EXPORT_SYMBOL(of_find_device_by_node);
 58 
 59 #ifdef CONFIG_OF_ADDRESS
 60 /*
 61  * The following routines scan a subtree and registers a device for
 62  * each applicable node.
 63  *
 64  * Note: sparc doesn't use these routines because it has a different
 65  * mechanism for creating devices from device tree nodes.
 66  */
 67 
 68 /**
 69  * of_device_make_bus_id - Use the device node data to assign a unique name
 70  * @dev: pointer to device structure that is linked to a device tree node
 71  *
 72  * This routine will first try using the translated bus address to
 73  * derive a unique name. If it cannot, then it will prepend names from
 74  * parent nodes until a unique name can be derived.
 75  */
 76 void of_device_make_bus_id(struct device *dev)
 77 {
 78         struct device_node *node = dev->of_node;
 79         const __be32 *reg;
 80         u64 addr;
 81 
 82         /* Construct the name, using parent nodes if necessary to ensure uniqueness */
 83         while (node->parent) {
 84                 /*
 85                  * If the address can be translated, then that is as much
 86                  * uniqueness as we need. Make it the first component and return
 87                  */
 88                 reg = of_get_property(node, "reg", NULL);
 89                 if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
 90                         dev_set_name(dev, dev_name(dev) ? "%llx.%s:%s" : "%llx.%s",
 91                                      (unsigned long long)addr, node->name,
 92                                      dev_name(dev));
 93                         return;
 94                 }
 95 
 96                 /* format arguments only used if dev_name() resolves to NULL */
 97                 dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
 98                              strrchr(node->full_name, '/') + 1, dev_name(dev));
 99                 node = node->parent;
100         }
101 }
102 
103 /**
104  * of_device_alloc - Allocate and initialize an of_device
105  * @np: device node to assign to device
106  * @bus_id: Name to assign to the device.  May be null to use default name.
107  * @parent: Parent device.
108  */
109 struct platform_device *of_device_alloc(struct device_node *np,
110                                   const char *bus_id,
111                                   struct device *parent)
112 {
113         struct platform_device *dev;
114         int rc, i, num_reg = 0, num_irq;
115         struct resource *res, temp_res;
116 
117         dev = platform_device_alloc("", -1);
118         if (!dev)
119                 return NULL;
120 
121         /* count the io and irq resources */
122         while (of_address_to_resource(np, num_reg, &temp_res) == 0)
123                 num_reg++;
124         num_irq = of_irq_count(np);
125 
126         /* Populate the resource table */
127         if (num_irq || num_reg) {
128                 res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
129                 if (!res) {
130                         platform_device_put(dev);
131                         return NULL;
132                 }
133 
134                 dev->num_resources = num_reg + num_irq;
135                 dev->resource = res;
136                 for (i = 0; i < num_reg; i++, res++) {
137                         rc = of_address_to_resource(np, i, res);
138                         WARN_ON(rc);
139                 }
140                 if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
141                         pr_debug("not all legacy IRQ resources mapped for %s\n",
142                                  np->name);
143         }
144 
145         dev->dev.of_node = of_node_get(np);
146         dev->dev.fwnode = &np->fwnode;
147         dev->dev.parent = parent ? : &platform_bus;
148 
149         if (bus_id)
150                 dev_set_name(&dev->dev, "%s", bus_id);
151         else
152                 of_device_make_bus_id(&dev->dev);
153 
154         return dev;
155 }
156 EXPORT_SYMBOL(of_device_alloc);
157 
158 static void of_dma_deconfigure(struct device *dev)
159 {
160         arch_teardown_dma_ops(dev);
161 }
162 
163 /**
164  * of_platform_device_create_pdata - Alloc, initialize and register an of_device
165  * @np: pointer to node to create device for
166  * @bus_id: name to assign device
167  * @platform_data: pointer to populate platform_data pointer with
168  * @parent: Linux device model parent device.
169  *
170  * Returns pointer to created platform device, or NULL if a device was not
171  * registered.  Unavailable devices will not get registered.
172  */
173 static struct platform_device *of_platform_device_create_pdata(
174                                         struct device_node *np,
175                                         const char *bus_id,
176                                         void *platform_data,
177                                         struct device *parent)
178 {
179         struct platform_device *dev;
180 
181         if (!of_device_is_available(np) ||
182             of_node_test_and_set_flag(np, OF_POPULATED))
183                 return NULL;
184 
185         dev = of_device_alloc(np, bus_id, parent);
186         if (!dev)
187                 goto err_clear_flag;
188 
189         dev->dev.bus = &platform_bus_type;
190         dev->dev.platform_data = platform_data;
191         of_dma_configure(&dev->dev, dev->dev.of_node);
192         of_msi_configure(&dev->dev, dev->dev.of_node);
193 
194         if (of_device_add(dev) != 0) {
195                 of_dma_deconfigure(&dev->dev);
196                 platform_device_put(dev);
197                 goto err_clear_flag;
198         }
199 
200         return dev;
201 
202 err_clear_flag:
203         of_node_clear_flag(np, OF_POPULATED);
204         return NULL;
205 }
206 
207 /**
208  * of_platform_device_create - Alloc, initialize and register an of_device
209  * @np: pointer to node to create device for
210  * @bus_id: name to assign device
211  * @parent: Linux device model parent device.
212  *
213  * Returns pointer to created platform device, or NULL if a device was not
214  * registered.  Unavailable devices will not get registered.
215  */
216 struct platform_device *of_platform_device_create(struct device_node *np,
217                                             const char *bus_id,
218                                             struct device *parent)
219 {
220         return of_platform_device_create_pdata(np, bus_id, NULL, parent);
221 }
222 EXPORT_SYMBOL(of_platform_device_create);
223 
224 #ifdef CONFIG_ARM_AMBA
225 static struct amba_device *of_amba_device_create(struct device_node *node,
226                                                  const char *bus_id,
227                                                  void *platform_data,
228                                                  struct device *parent)
229 {
230         struct amba_device *dev;
231         const void *prop;
232         int i, ret;
233 
234         pr_debug("Creating amba device %s\n", node->full_name);
235 
236         if (!of_device_is_available(node) ||
237             of_node_test_and_set_flag(node, OF_POPULATED))
238                 return NULL;
239 
240         dev = amba_device_alloc(NULL, 0, 0);
241         if (!dev)
242                 goto err_clear_flag;
243 
244         /* setup generic device info */
245         dev->dev.of_node = of_node_get(node);
246         dev->dev.fwnode = &node->fwnode;
247         dev->dev.parent = parent ? : &platform_bus;
248         dev->dev.platform_data = platform_data;
249         if (bus_id)
250                 dev_set_name(&dev->dev, "%s", bus_id);
251         else
252                 of_device_make_bus_id(&dev->dev);
253         of_dma_configure(&dev->dev, dev->dev.of_node);
254 
255         /* Allow the HW Peripheral ID to be overridden */
256         prop = of_get_property(node, "arm,primecell-periphid", NULL);
257         if (prop)
258                 dev->periphid = of_read_ulong(prop, 1);
259 
260         /* Decode the IRQs and address ranges */
261         for (i = 0; i < AMBA_NR_IRQS; i++)
262                 dev->irq[i] = irq_of_parse_and_map(node, i);
263 
264         ret = of_address_to_resource(node, 0, &dev->res);
265         if (ret) {
266                 pr_err("amba: of_address_to_resource() failed (%d) for %s\n",
267                        ret, node->full_name);
268                 goto err_free;
269         }
270 
271         ret = amba_device_add(dev, &iomem_resource);
272         if (ret) {
273                 pr_err("amba_device_add() failed (%d) for %s\n",
274                        ret, node->full_name);
275                 goto err_free;
276         }
277 
278         return dev;
279 
280 err_free:
281         amba_device_put(dev);
282 err_clear_flag:
283         of_node_clear_flag(node, OF_POPULATED);
284         return NULL;
285 }
286 #else /* CONFIG_ARM_AMBA */
287 static struct amba_device *of_amba_device_create(struct device_node *node,
288                                                  const char *bus_id,
289                                                  void *platform_data,
290                                                  struct device *parent)
291 {
292         return NULL;
293 }
294 #endif /* CONFIG_ARM_AMBA */
295 
296 /**
297  * of_devname_lookup() - Given a device node, lookup the preferred Linux name
298  */
299 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
300                                  struct device_node *np)
301 {
302         const struct of_dev_auxdata *auxdata;
303         struct resource res;
304         int compatible = 0;
305 
306         if (!lookup)
307                 return NULL;
308 
309         auxdata = lookup;
310         for (; auxdata->compatible; auxdata++) {
311                 if (!of_device_is_compatible(np, auxdata->compatible))
312                         continue;
313                 compatible++;
314                 if (!of_address_to_resource(np, 0, &res))
315                         if (res.start != auxdata->phys_addr)
316                                 continue;
317                 pr_debug("%s: devname=%s\n", np->full_name, auxdata->name);
318                 return auxdata;
319         }
320 
321         if (!compatible)
322                 return NULL;
323 
324         /* Try compatible match if no phys_addr and name are specified */
325         auxdata = lookup;
326         for (; auxdata->compatible; auxdata++) {
327                 if (!of_device_is_compatible(np, auxdata->compatible))
328                         continue;
329                 if (!auxdata->phys_addr && !auxdata->name) {
330                         pr_debug("%s: compatible match\n", np->full_name);
331                         return auxdata;
332                 }
333         }
334 
335         return NULL;
336 }
337 
338 /**
339  * of_platform_bus_create() - Create a device for a node and its children.
340  * @bus: device node of the bus to instantiate
341  * @matches: match table for bus nodes
342  * @lookup: auxdata table for matching id and platform_data with device nodes
343  * @parent: parent for new device, or NULL for top level.
344  * @strict: require compatible property
345  *
346  * Creates a platform_device for the provided device_node, and optionally
347  * recursively create devices for all the child nodes.
348  */
349 static int of_platform_bus_create(struct device_node *bus,
350                                   const struct of_device_id *matches,
351                                   const struct of_dev_auxdata *lookup,
352                                   struct device *parent, bool strict)
353 {
354         const struct of_dev_auxdata *auxdata;
355         struct device_node *child;
356         struct platform_device *dev;
357         const char *bus_id = NULL;
358         void *platform_data = NULL;
359         int rc = 0;
360 
361         /* Make sure it has a compatible property */
362         if (strict && (!of_get_property(bus, "compatible", NULL))) {
363                 pr_debug("%s() - skipping %s, no compatible prop\n",
364                          __func__, bus->full_name);
365                 return 0;
366         }
367 
368         if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
369                 pr_debug("%s() - skipping %s, already populated\n",
370                         __func__, bus->full_name);
371                 return 0;
372         }
373 
374         auxdata = of_dev_lookup(lookup, bus);
375         if (auxdata) {
376                 bus_id = auxdata->name;
377                 platform_data = auxdata->platform_data;
378         }
379 
380         if (of_device_is_compatible(bus, "arm,primecell")) {
381                 /*
382                  * Don't return an error here to keep compatibility with older
383                  * device tree files.
384                  */
385                 of_amba_device_create(bus, bus_id, platform_data, parent);
386                 return 0;
387         }
388 
389         dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
390         if (!dev || !of_match_node(matches, bus))
391                 return 0;
392 
393         for_each_child_of_node(bus, child) {
394                 pr_debug("   create child: %s\n", child->full_name);
395                 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
396                 if (rc) {
397                         of_node_put(child);
398                         break;
399                 }
400         }
401         of_node_set_flag(bus, OF_POPULATED_BUS);
402         return rc;
403 }
404 
405 /**
406  * of_platform_bus_probe() - Probe the device-tree for platform buses
407  * @root: parent of the first level to probe or NULL for the root of the tree
408  * @matches: match table for bus nodes
409  * @parent: parent to hook devices from, NULL for toplevel
410  *
411  * Note that children of the provided root are not instantiated as devices
412  * unless the specified root itself matches the bus list and is not NULL.
413  */
414 int of_platform_bus_probe(struct device_node *root,
415                           const struct of_device_id *matches,
416                           struct device *parent)
417 {
418         struct device_node *child;
419         int rc = 0;
420 
421         root = root ? of_node_get(root) : of_find_node_by_path("/");
422         if (!root)
423                 return -EINVAL;
424 
425         pr_debug("%s()\n", __func__);
426         pr_debug(" starting at: %s\n", root->full_name);
427 
428         /* Do a self check of bus type, if there's a match, create children */
429         if (of_match_node(matches, root)) {
430                 rc = of_platform_bus_create(root, matches, NULL, parent, false);
431         } else for_each_child_of_node(root, child) {
432                 if (!of_match_node(matches, child))
433                         continue;
434                 rc = of_platform_bus_create(child, matches, NULL, parent, false);
435                 if (rc) {
436                         of_node_put(child);
437                         break;
438                 }
439         }
440 
441         of_node_put(root);
442         return rc;
443 }
444 EXPORT_SYMBOL(of_platform_bus_probe);
445 
446 /**
447  * of_platform_populate() - Populate platform_devices from device tree data
448  * @root: parent of the first level to probe or NULL for the root of the tree
449  * @matches: match table, NULL to use the default
450  * @lookup: auxdata table for matching id and platform_data with device nodes
451  * @parent: parent to hook devices from, NULL for toplevel
452  *
453  * Similar to of_platform_bus_probe(), this function walks the device tree
454  * and creates devices from nodes.  It differs in that it follows the modern
455  * convention of requiring all device nodes to have a 'compatible' property,
456  * and it is suitable for creating devices which are children of the root
457  * node (of_platform_bus_probe will only create children of the root which
458  * are selected by the @matches argument).
459  *
460  * New board support should be using this function instead of
461  * of_platform_bus_probe().
462  *
463  * Returns 0 on success, < 0 on failure.
464  */
465 int of_platform_populate(struct device_node *root,
466                         const struct of_device_id *matches,
467                         const struct of_dev_auxdata *lookup,
468                         struct device *parent)
469 {
470         struct device_node *child;
471         int rc = 0;
472 
473         root = root ? of_node_get(root) : of_find_node_by_path("/");
474         if (!root)
475                 return -EINVAL;
476 
477         pr_debug("%s()\n", __func__);
478         pr_debug(" starting at: %s\n", root->full_name);
479 
480         for_each_child_of_node(root, child) {
481                 rc = of_platform_bus_create(child, matches, lookup, parent, true);
482                 if (rc) {
483                         of_node_put(child);
484                         break;
485                 }
486         }
487         of_node_set_flag(root, OF_POPULATED_BUS);
488 
489         of_node_put(root);
490         return rc;
491 }
492 EXPORT_SYMBOL_GPL(of_platform_populate);
493 
494 int of_platform_default_populate(struct device_node *root,
495                                  const struct of_dev_auxdata *lookup,
496                                  struct device *parent)
497 {
498         return of_platform_populate(root, of_default_bus_match_table, lookup,
499                                     parent);
500 }
501 EXPORT_SYMBOL_GPL(of_platform_default_populate);
502 
503 #ifndef CONFIG_PPC
504 static int __init of_platform_default_populate_init(void)
505 {
506         struct device_node *node;
507 
508         if (!of_have_populated_dt())
509                 return -ENODEV;
510 
511         /*
512          * Handle ramoops explicitly, since it is inside /reserved-memory,
513          * which lacks a "compatible" property.
514          */
515         node = of_find_node_by_path("/reserved-memory");
516         if (node) {
517                 node = of_find_compatible_node(node, NULL, "ramoops");
518                 if (node)
519                         of_platform_device_create(node, NULL, NULL);
520         }
521 
522         /* Populate everything else. */
523         of_platform_default_populate(NULL, NULL, NULL);
524 
525         return 0;
526 }
527 arch_initcall_sync(of_platform_default_populate_init);
528 #endif
529 
530 static int of_platform_device_destroy(struct device *dev, void *data)
531 {
532         /* Do not touch devices not populated from the device tree */
533         if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
534                 return 0;
535 
536         /* Recurse for any nodes that were treated as busses */
537         if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
538                 device_for_each_child(dev, NULL, of_platform_device_destroy);
539 
540         if (dev->bus == &platform_bus_type)
541                 platform_device_unregister(to_platform_device(dev));
542 #ifdef CONFIG_ARM_AMBA
543         else if (dev->bus == &amba_bustype)
544                 amba_device_unregister(to_amba_device(dev));
545 #endif
546 
547         of_dma_deconfigure(dev);
548         of_node_clear_flag(dev->of_node, OF_POPULATED);
549         of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
550         return 0;
551 }
552 
553 /**
554  * of_platform_depopulate() - Remove devices populated from device tree
555  * @parent: device which children will be removed
556  *
557  * Complementary to of_platform_populate(), this function removes children
558  * of the given device (and, recurrently, their children) that have been
559  * created from their respective device tree nodes (and only those,
560  * leaving others - eg. manually created - unharmed).
561  *
562  * Returns 0 when all children devices have been removed or
563  * -EBUSY when some children remained.
564  */
565 void of_platform_depopulate(struct device *parent)
566 {
567         if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
568                 device_for_each_child(parent, NULL, of_platform_device_destroy);
569                 of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
570         }
571 }
572 EXPORT_SYMBOL_GPL(of_platform_depopulate);
573 
574 #ifdef CONFIG_OF_DYNAMIC
575 static int of_platform_notify(struct notifier_block *nb,
576                                 unsigned long action, void *arg)
577 {
578         struct of_reconfig_data *rd = arg;
579         struct platform_device *pdev_parent, *pdev;
580         bool children_left;
581 
582         switch (of_reconfig_get_state_change(action, rd)) {
583         case OF_RECONFIG_CHANGE_ADD:
584                 /* verify that the parent is a bus */
585                 if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
586                         return NOTIFY_OK;       /* not for us */
587 
588                 /* already populated? (driver using of_populate manually) */
589                 if (of_node_check_flag(rd->dn, OF_POPULATED))
590                         return NOTIFY_OK;
591 
592                 /* pdev_parent may be NULL when no bus platform device */
593                 pdev_parent = of_find_device_by_node(rd->dn->parent);
594                 pdev = of_platform_device_create(rd->dn, NULL,
595                                 pdev_parent ? &pdev_parent->dev : NULL);
596                 of_dev_put(pdev_parent);
597 
598                 if (pdev == NULL) {
599                         pr_err("%s: failed to create for '%s'\n",
600                                         __func__, rd->dn->full_name);
601                         /* of_platform_device_create tosses the error code */
602                         return notifier_from_errno(-EINVAL);
603                 }
604                 break;
605 
606         case OF_RECONFIG_CHANGE_REMOVE:
607 
608                 /* already depopulated? */
609                 if (!of_node_check_flag(rd->dn, OF_POPULATED))
610                         return NOTIFY_OK;
611 
612                 /* find our device by node */
613                 pdev = of_find_device_by_node(rd->dn);
614                 if (pdev == NULL)
615                         return NOTIFY_OK;       /* no? not meant for us */
616 
617                 /* unregister takes one ref away */
618                 of_platform_device_destroy(&pdev->dev, &children_left);
619 
620                 /* and put the reference of the find */
621                 of_dev_put(pdev);
622                 break;
623         }
624 
625         return NOTIFY_OK;
626 }
627 
628 static struct notifier_block platform_of_notifier = {
629         .notifier_call = of_platform_notify,
630 };
631 
632 void of_platform_register_reconfig_notifier(void)
633 {
634         WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
635 }
636 #endif /* CONFIG_OF_DYNAMIC */
637 
638 #endif /* CONFIG_OF_ADDRESS */
639 

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