Version:  2.0.40 2.2.26 2.4.37 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19

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_iommu.h>
 23 #include <linux/of_irq.h>
 24 #include <linux/of_platform.h>
 25 #include <linux/platform_device.h>
 26 
 27 const struct of_device_id of_default_bus_match_table[] = {
 28         { .compatible = "simple-bus", },
 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 /**
154  * of_dma_configure - Setup DMA configuration
155  * @dev:        Device to apply DMA configuration
156  *
157  * Try to get devices's DMA configuration from DT and update it
158  * accordingly.
159  *
160  * In case if platform code need to use own special DMA configuration,it
161  * can use Platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE event
162  * to fix up DMA configuration.
163  */
164 static void of_dma_configure(struct device *dev)
165 {
166         u64 dma_addr, paddr, size;
167         int ret;
168         bool coherent;
169         unsigned long offset;
170         struct iommu_ops *iommu;
171 
172         /*
173          * Set default dma-mask to 32 bit. Drivers are expected to setup
174          * the correct supported dma_mask.
175          */
176         dev->coherent_dma_mask = DMA_BIT_MASK(32);
177 
178         /*
179          * Set it to coherent_dma_mask by default if the architecture
180          * code has not set it.
181          */
182         if (!dev->dma_mask)
183                 dev->dma_mask = &dev->coherent_dma_mask;
184 
185         ret = of_dma_get_range(dev->of_node, &dma_addr, &paddr, &size);
186         if (ret < 0) {
187                 dma_addr = offset = 0;
188                 size = dev->coherent_dma_mask;
189         } else {
190                 offset = PFN_DOWN(paddr - dma_addr);
191                 dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
192         }
193         dev->dma_pfn_offset = offset;
194 
195         coherent = of_dma_is_coherent(dev->of_node);
196         dev_dbg(dev, "device is%sdma coherent\n",
197                 coherent ? " " : " not ");
198 
199         iommu = of_iommu_configure(dev);
200         dev_dbg(dev, "device is%sbehind an iommu\n",
201                 iommu ? " " : " not ");
202 
203         arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
204 }
205 
206 static void of_dma_deconfigure(struct device *dev)
207 {
208         arch_teardown_dma_ops(dev);
209 }
210 
211 /**
212  * of_platform_device_create_pdata - Alloc, initialize and register an of_device
213  * @np: pointer to node to create device for
214  * @bus_id: name to assign device
215  * @platform_data: pointer to populate platform_data pointer with
216  * @parent: Linux device model parent device.
217  *
218  * Returns pointer to created platform device, or NULL if a device was not
219  * registered.  Unavailable devices will not get registered.
220  */
221 static struct platform_device *of_platform_device_create_pdata(
222                                         struct device_node *np,
223                                         const char *bus_id,
224                                         void *platform_data,
225                                         struct device *parent)
226 {
227         struct platform_device *dev;
228 
229         if (!of_device_is_available(np) ||
230             of_node_test_and_set_flag(np, OF_POPULATED))
231                 return NULL;
232 
233         dev = of_device_alloc(np, bus_id, parent);
234         if (!dev)
235                 goto err_clear_flag;
236 
237         dev->dev.bus = &platform_bus_type;
238         dev->dev.platform_data = platform_data;
239         of_dma_configure(&dev->dev);
240 
241         if (of_device_add(dev) != 0) {
242                 of_dma_deconfigure(&dev->dev);
243                 platform_device_put(dev);
244                 goto err_clear_flag;
245         }
246 
247         return dev;
248 
249 err_clear_flag:
250         of_node_clear_flag(np, OF_POPULATED);
251         return NULL;
252 }
253 
254 /**
255  * of_platform_device_create - Alloc, initialize and register an of_device
256  * @np: pointer to node to create device for
257  * @bus_id: name to assign device
258  * @parent: Linux device model parent device.
259  *
260  * Returns pointer to created platform device, or NULL if a device was not
261  * registered.  Unavailable devices will not get registered.
262  */
263 struct platform_device *of_platform_device_create(struct device_node *np,
264                                             const char *bus_id,
265                                             struct device *parent)
266 {
267         return of_platform_device_create_pdata(np, bus_id, NULL, parent);
268 }
269 EXPORT_SYMBOL(of_platform_device_create);
270 
271 #ifdef CONFIG_ARM_AMBA
272 static struct amba_device *of_amba_device_create(struct device_node *node,
273                                                  const char *bus_id,
274                                                  void *platform_data,
275                                                  struct device *parent)
276 {
277         struct amba_device *dev;
278         const void *prop;
279         int i, ret;
280 
281         pr_debug("Creating amba device %s\n", node->full_name);
282 
283         if (!of_device_is_available(node) ||
284             of_node_test_and_set_flag(node, OF_POPULATED))
285                 return NULL;
286 
287         dev = amba_device_alloc(NULL, 0, 0);
288         if (!dev) {
289                 pr_err("%s(): amba_device_alloc() failed for %s\n",
290                        __func__, node->full_name);
291                 goto err_clear_flag;
292         }
293 
294         /* setup generic device info */
295         dev->dev.of_node = of_node_get(node);
296         dev->dev.parent = parent ? : &platform_bus;
297         dev->dev.platform_data = platform_data;
298         if (bus_id)
299                 dev_set_name(&dev->dev, "%s", bus_id);
300         else
301                 of_device_make_bus_id(&dev->dev);
302         of_dma_configure(&dev->dev);
303 
304         /* Allow the HW Peripheral ID to be overridden */
305         prop = of_get_property(node, "arm,primecell-periphid", NULL);
306         if (prop)
307                 dev->periphid = of_read_ulong(prop, 1);
308 
309         /* Decode the IRQs and address ranges */
310         for (i = 0; i < AMBA_NR_IRQS; i++)
311                 dev->irq[i] = irq_of_parse_and_map(node, i);
312 
313         ret = of_address_to_resource(node, 0, &dev->res);
314         if (ret) {
315                 pr_err("%s(): of_address_to_resource() failed (%d) for %s\n",
316                        __func__, ret, node->full_name);
317                 goto err_free;
318         }
319 
320         ret = amba_device_add(dev, &iomem_resource);
321         if (ret) {
322                 pr_err("%s(): amba_device_add() failed (%d) for %s\n",
323                        __func__, ret, node->full_name);
324                 goto err_free;
325         }
326 
327         return dev;
328 
329 err_free:
330         amba_device_put(dev);
331 err_clear_flag:
332         of_node_clear_flag(node, OF_POPULATED);
333         return NULL;
334 }
335 #else /* CONFIG_ARM_AMBA */
336 static struct amba_device *of_amba_device_create(struct device_node *node,
337                                                  const char *bus_id,
338                                                  void *platform_data,
339                                                  struct device *parent)
340 {
341         return NULL;
342 }
343 #endif /* CONFIG_ARM_AMBA */
344 
345 /**
346  * of_devname_lookup() - Given a device node, lookup the preferred Linux name
347  */
348 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
349                                  struct device_node *np)
350 {
351         struct resource res;
352 
353         if (!lookup)
354                 return NULL;
355 
356         for(; lookup->compatible != NULL; lookup++) {
357                 if (!of_device_is_compatible(np, lookup->compatible))
358                         continue;
359                 if (!of_address_to_resource(np, 0, &res))
360                         if (res.start != lookup->phys_addr)
361                                 continue;
362                 pr_debug("%s: devname=%s\n", np->full_name, lookup->name);
363                 return lookup;
364         }
365 
366         return NULL;
367 }
368 
369 /**
370  * of_platform_bus_create() - Create a device for a node and its children.
371  * @bus: device node of the bus to instantiate
372  * @matches: match table for bus nodes
373  * @lookup: auxdata table for matching id and platform_data with device nodes
374  * @parent: parent for new device, or NULL for top level.
375  * @strict: require compatible property
376  *
377  * Creates a platform_device for the provided device_node, and optionally
378  * recursively create devices for all the child nodes.
379  */
380 static int of_platform_bus_create(struct device_node *bus,
381                                   const struct of_device_id *matches,
382                                   const struct of_dev_auxdata *lookup,
383                                   struct device *parent, bool strict)
384 {
385         const struct of_dev_auxdata *auxdata;
386         struct device_node *child;
387         struct platform_device *dev;
388         const char *bus_id = NULL;
389         void *platform_data = NULL;
390         int rc = 0;
391 
392         /* Make sure it has a compatible property */
393         if (strict && (!of_get_property(bus, "compatible", NULL))) {
394                 pr_debug("%s() - skipping %s, no compatible prop\n",
395                          __func__, bus->full_name);
396                 return 0;
397         }
398 
399         auxdata = of_dev_lookup(lookup, bus);
400         if (auxdata) {
401                 bus_id = auxdata->name;
402                 platform_data = auxdata->platform_data;
403         }
404 
405         if (of_device_is_compatible(bus, "arm,primecell")) {
406                 /*
407                  * Don't return an error here to keep compatibility with older
408                  * device tree files.
409                  */
410                 of_amba_device_create(bus, bus_id, platform_data, parent);
411                 return 0;
412         }
413 
414         dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
415         if (!dev || !of_match_node(matches, bus))
416                 return 0;
417 
418         for_each_child_of_node(bus, child) {
419                 pr_debug("   create child: %s\n", child->full_name);
420                 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
421                 if (rc) {
422                         of_node_put(child);
423                         break;
424                 }
425         }
426         of_node_set_flag(bus, OF_POPULATED_BUS);
427         return rc;
428 }
429 
430 /**
431  * of_platform_bus_probe() - Probe the device-tree for platform buses
432  * @root: parent of the first level to probe or NULL for the root of the tree
433  * @matches: match table for bus nodes
434  * @parent: parent to hook devices from, NULL for toplevel
435  *
436  * Note that children of the provided root are not instantiated as devices
437  * unless the specified root itself matches the bus list and is not NULL.
438  */
439 int of_platform_bus_probe(struct device_node *root,
440                           const struct of_device_id *matches,
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         pr_debug("of_platform_bus_probe()\n");
451         pr_debug(" starting at: %s\n", root->full_name);
452 
453         /* Do a self check of bus type, if there's a match, create children */
454         if (of_match_node(matches, root)) {
455                 rc = of_platform_bus_create(root, matches, NULL, parent, false);
456         } else for_each_child_of_node(root, child) {
457                 if (!of_match_node(matches, child))
458                         continue;
459                 rc = of_platform_bus_create(child, matches, NULL, parent, false);
460                 if (rc)
461                         break;
462         }
463 
464         of_node_put(root);
465         return rc;
466 }
467 EXPORT_SYMBOL(of_platform_bus_probe);
468 
469 /**
470  * of_platform_populate() - Populate platform_devices from device tree data
471  * @root: parent of the first level to probe or NULL for the root of the tree
472  * @matches: match table, NULL to use the default
473  * @lookup: auxdata table for matching id and platform_data with device nodes
474  * @parent: parent to hook devices from, NULL for toplevel
475  *
476  * Similar to of_platform_bus_probe(), this function walks the device tree
477  * and creates devices from nodes.  It differs in that it follows the modern
478  * convention of requiring all device nodes to have a 'compatible' property,
479  * and it is suitable for creating devices which are children of the root
480  * node (of_platform_bus_probe will only create children of the root which
481  * are selected by the @matches argument).
482  *
483  * New board support should be using this function instead of
484  * of_platform_bus_probe().
485  *
486  * Returns 0 on success, < 0 on failure.
487  */
488 int of_platform_populate(struct device_node *root,
489                         const struct of_device_id *matches,
490                         const struct of_dev_auxdata *lookup,
491                         struct device *parent)
492 {
493         struct device_node *child;
494         int rc = 0;
495 
496         root = root ? of_node_get(root) : of_find_node_by_path("/");
497         if (!root)
498                 return -EINVAL;
499 
500         for_each_child_of_node(root, child) {
501                 rc = of_platform_bus_create(child, matches, lookup, parent, true);
502                 if (rc)
503                         break;
504         }
505         of_node_set_flag(root, OF_POPULATED_BUS);
506 
507         of_node_put(root);
508         return rc;
509 }
510 EXPORT_SYMBOL_GPL(of_platform_populate);
511 
512 static int of_platform_device_destroy(struct device *dev, void *data)
513 {
514         /* Do not touch devices not populated from the device tree */
515         if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
516                 return 0;
517 
518         /* Recurse for any nodes that were treated as busses */
519         if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
520                 device_for_each_child(dev, NULL, of_platform_device_destroy);
521 
522         if (dev->bus == &platform_bus_type)
523                 platform_device_unregister(to_platform_device(dev));
524 #ifdef CONFIG_ARM_AMBA
525         else if (dev->bus == &amba_bustype)
526                 amba_device_unregister(to_amba_device(dev));
527 #endif
528 
529         of_node_clear_flag(dev->of_node, OF_POPULATED);
530         of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
531         return 0;
532 }
533 
534 /**
535  * of_platform_depopulate() - Remove devices populated from device tree
536  * @parent: device which children will be removed
537  *
538  * Complementary to of_platform_populate(), this function removes children
539  * of the given device (and, recurrently, their children) that have been
540  * created from their respective device tree nodes (and only those,
541  * leaving others - eg. manually created - unharmed).
542  *
543  * Returns 0 when all children devices have been removed or
544  * -EBUSY when some children remained.
545  */
546 void of_platform_depopulate(struct device *parent)
547 {
548         if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
549                 device_for_each_child(parent, NULL, of_platform_device_destroy);
550                 of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
551         }
552 }
553 EXPORT_SYMBOL_GPL(of_platform_depopulate);
554 
555 #ifdef CONFIG_OF_DYNAMIC
556 static int of_platform_notify(struct notifier_block *nb,
557                                 unsigned long action, void *arg)
558 {
559         struct of_reconfig_data *rd = arg;
560         struct platform_device *pdev_parent, *pdev;
561         bool children_left;
562 
563         switch (of_reconfig_get_state_change(action, rd)) {
564         case OF_RECONFIG_CHANGE_ADD:
565                 /* verify that the parent is a bus */
566                 if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
567                         return NOTIFY_OK;       /* not for us */
568 
569                 /* already populated? (driver using of_populate manually) */
570                 if (of_node_check_flag(rd->dn, OF_POPULATED))
571                         return NOTIFY_OK;
572 
573                 /* pdev_parent may be NULL when no bus platform device */
574                 pdev_parent = of_find_device_by_node(rd->dn->parent);
575                 pdev = of_platform_device_create(rd->dn, NULL,
576                                 pdev_parent ? &pdev_parent->dev : NULL);
577                 of_dev_put(pdev_parent);
578 
579                 if (pdev == NULL) {
580                         pr_err("%s: failed to create for '%s'\n",
581                                         __func__, rd->dn->full_name);
582                         /* of_platform_device_create tosses the error code */
583                         return notifier_from_errno(-EINVAL);
584                 }
585                 break;
586 
587         case OF_RECONFIG_CHANGE_REMOVE:
588 
589                 /* already depopulated? */
590                 if (!of_node_check_flag(rd->dn, OF_POPULATED))
591                         return NOTIFY_OK;
592 
593                 /* find our device by node */
594                 pdev = of_find_device_by_node(rd->dn);
595                 if (pdev == NULL)
596                         return NOTIFY_OK;       /* no? not meant for us */
597 
598                 /* unregister takes one ref away */
599                 of_platform_device_destroy(&pdev->dev, &children_left);
600 
601                 /* and put the reference of the find */
602                 of_dev_put(pdev);
603                 break;
604         }
605 
606         return NOTIFY_OK;
607 }
608 
609 static struct notifier_block platform_of_notifier = {
610         .notifier_call = of_platform_notify,
611 };
612 
613 void of_platform_register_reconfig_notifier(void)
614 {
615         WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
616 }
617 #endif /* CONFIG_OF_DYNAMIC */
618 
619 #endif /* CONFIG_OF_ADDRESS */
620 

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