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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 #ifdef CONFIG_ARM_AMBA
 29         { .compatible = "arm,amba-bus", },
 30 #endif /* CONFIG_ARM_AMBA */
 31         {} /* Empty terminated list */
 32 };
 33 
 34 static int of_dev_node_match(struct device *dev, void *data)
 35 {
 36         return dev->of_node == data;
 37 }
 38 
 39 /**
 40  * of_find_device_by_node - Find the platform_device associated with a node
 41  * @np: Pointer to device tree node
 42  *
 43  * Returns platform_device pointer, or NULL if not found
 44  */
 45 struct platform_device *of_find_device_by_node(struct device_node *np)
 46 {
 47         struct device *dev;
 48 
 49         dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
 50         return dev ? to_platform_device(dev) : NULL;
 51 }
 52 EXPORT_SYMBOL(of_find_device_by_node);
 53 
 54 #if defined(CONFIG_PPC_DCR)
 55 #include <asm/dcr.h>
 56 #endif
 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 either the dcr-reg or the reg property
 72  * value to derive a unique name.  As a last resort it will use the node
 73  * name followed by a unique number.
 74  */
 75 void of_device_make_bus_id(struct device *dev)
 76 {
 77         static atomic_t bus_no_reg_magic;
 78         struct device_node *node = dev->of_node;
 79         const __be32 *reg;
 80         u64 addr;
 81         const __be32 *addrp;
 82         int magic;
 83 
 84 #ifdef CONFIG_PPC_DCR
 85         /*
 86          * If it's a DCR based device, use 'd' for native DCRs
 87          * and 'D' for MMIO DCRs.
 88          */
 89         reg = of_get_property(node, "dcr-reg", NULL);
 90         if (reg) {
 91 #ifdef CONFIG_PPC_DCR_NATIVE
 92                 dev_set_name(dev, "d%x.%s", *reg, node->name);
 93 #else /* CONFIG_PPC_DCR_NATIVE */
 94                 u64 addr = of_translate_dcr_address(node, *reg, NULL);
 95                 if (addr != OF_BAD_ADDR) {
 96                         dev_set_name(dev, "D%llx.%s",
 97                                      (unsigned long long)addr, node->name);
 98                         return;
 99                 }
100 #endif /* !CONFIG_PPC_DCR_NATIVE */
101         }
102 #endif /* CONFIG_PPC_DCR */
103 
104         /*
105          * For MMIO, get the physical address
106          */
107         reg = of_get_property(node, "reg", NULL);
108         if (reg) {
109                 if (of_can_translate_address(node)) {
110                         addr = of_translate_address(node, reg);
111                 } else {
112                         addrp = of_get_address(node, 0, NULL, NULL);
113                         if (addrp)
114                                 addr = of_read_number(addrp, 1);
115                         else
116                                 addr = OF_BAD_ADDR;
117                 }
118                 if (addr != OF_BAD_ADDR) {
119                         dev_set_name(dev, "%llx.%s",
120                                      (unsigned long long)addr, node->name);
121                         return;
122                 }
123         }
124 
125         /*
126          * No BusID, use the node name and add a globally incremented
127          * counter (and pray...)
128          */
129         magic = atomic_add_return(1, &bus_no_reg_magic);
130         dev_set_name(dev, "%s.%d", node->name, magic - 1);
131 }
132 
133 /**
134  * of_device_alloc - Allocate and initialize an of_device
135  * @np: device node to assign to device
136  * @bus_id: Name to assign to the device.  May be null to use default name.
137  * @parent: Parent device.
138  */
139 struct platform_device *of_device_alloc(struct device_node *np,
140                                   const char *bus_id,
141                                   struct device *parent)
142 {
143         struct platform_device *dev;
144         int rc, i, num_reg = 0, num_irq;
145         struct resource *res, temp_res;
146 
147         dev = platform_device_alloc("", -1);
148         if (!dev)
149                 return NULL;
150 
151         /* count the io and irq resources */
152         if (of_can_translate_address(np))
153                 while (of_address_to_resource(np, num_reg, &temp_res) == 0)
154                         num_reg++;
155         num_irq = of_irq_count(np);
156 
157         /* Populate the resource table */
158         if (num_irq || num_reg) {
159                 res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
160                 if (!res) {
161                         platform_device_put(dev);
162                         return NULL;
163                 }
164 
165                 dev->num_resources = num_reg + num_irq;
166                 dev->resource = res;
167                 for (i = 0; i < num_reg; i++, res++) {
168                         rc = of_address_to_resource(np, i, res);
169                         WARN_ON(rc);
170                 }
171                 if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
172                         pr_debug("not all legacy IRQ resources mapped for %s\n",
173                                  np->name);
174         }
175 
176         dev->dev.of_node = of_node_get(np);
177 #if defined(CONFIG_MICROBLAZE)
178         dev->dev.dma_mask = &dev->archdata.dma_mask;
179 #endif
180         dev->dev.parent = parent;
181 
182         if (bus_id)
183                 dev_set_name(&dev->dev, "%s", bus_id);
184         else
185                 of_device_make_bus_id(&dev->dev);
186 
187         return dev;
188 }
189 EXPORT_SYMBOL(of_device_alloc);
190 
191 /**
192  * of_platform_device_create_pdata - Alloc, initialize and register an of_device
193  * @np: pointer to node to create device for
194  * @bus_id: name to assign device
195  * @platform_data: pointer to populate platform_data pointer with
196  * @parent: Linux device model parent device.
197  *
198  * Returns pointer to created platform device, or NULL if a device was not
199  * registered.  Unavailable devices will not get registered.
200  */
201 static struct platform_device *of_platform_device_create_pdata(
202                                         struct device_node *np,
203                                         const char *bus_id,
204                                         void *platform_data,
205                                         struct device *parent)
206 {
207         struct platform_device *dev;
208 
209         if (!of_device_is_available(np))
210                 return NULL;
211 
212         dev = of_device_alloc(np, bus_id, parent);
213         if (!dev)
214                 return NULL;
215 
216 #if defined(CONFIG_MICROBLAZE)
217         dev->archdata.dma_mask = 0xffffffffUL;
218 #endif
219         dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
220         if (!dev->dev.dma_mask)
221                 dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
222         dev->dev.bus = &platform_bus_type;
223         dev->dev.platform_data = platform_data;
224 
225         /* We do not fill the DMA ops for platform devices by default.
226          * This is currently the responsibility of the platform code
227          * to do such, possibly using a device notifier
228          */
229 
230         if (of_device_add(dev) != 0) {
231                 platform_device_put(dev);
232                 return NULL;
233         }
234 
235         return dev;
236 }
237 
238 /**
239  * of_platform_device_create - Alloc, initialize and register an of_device
240  * @np: pointer to node to create device for
241  * @bus_id: name to assign device
242  * @parent: Linux device model parent device.
243  *
244  * Returns pointer to created platform device, or NULL if a device was not
245  * registered.  Unavailable devices will not get registered.
246  */
247 struct platform_device *of_platform_device_create(struct device_node *np,
248                                             const char *bus_id,
249                                             struct device *parent)
250 {
251         return of_platform_device_create_pdata(np, bus_id, NULL, parent);
252 }
253 EXPORT_SYMBOL(of_platform_device_create);
254 
255 #ifdef CONFIG_ARM_AMBA
256 static struct amba_device *of_amba_device_create(struct device_node *node,
257                                                  const char *bus_id,
258                                                  void *platform_data,
259                                                  struct device *parent)
260 {
261         struct amba_device *dev;
262         const void *prop;
263         int i, ret;
264 
265         pr_debug("Creating amba device %s\n", node->full_name);
266 
267         if (!of_device_is_available(node))
268                 return NULL;
269 
270         dev = amba_device_alloc(NULL, 0, 0);
271         if (!dev) {
272                 pr_err("%s(): amba_device_alloc() failed for %s\n",
273                        __func__, node->full_name);
274                 return NULL;
275         }
276 
277         /* setup generic device info */
278         dev->dev.coherent_dma_mask = ~0;
279         dev->dev.of_node = of_node_get(node);
280         dev->dev.parent = parent;
281         dev->dev.platform_data = platform_data;
282         if (bus_id)
283                 dev_set_name(&dev->dev, "%s", bus_id);
284         else
285                 of_device_make_bus_id(&dev->dev);
286 
287         /* Allow the HW Peripheral ID to be overridden */
288         prop = of_get_property(node, "arm,primecell-periphid", NULL);
289         if (prop)
290                 dev->periphid = of_read_ulong(prop, 1);
291 
292         /* Decode the IRQs and address ranges */
293         for (i = 0; i < AMBA_NR_IRQS; i++)
294                 dev->irq[i] = irq_of_parse_and_map(node, i);
295 
296         ret = of_address_to_resource(node, 0, &dev->res);
297         if (ret) {
298                 pr_err("%s(): of_address_to_resource() failed (%d) for %s\n",
299                        __func__, ret, node->full_name);
300                 goto err_free;
301         }
302 
303         ret = amba_device_add(dev, &iomem_resource);
304         if (ret) {
305                 pr_err("%s(): amba_device_add() failed (%d) for %s\n",
306                        __func__, ret, node->full_name);
307                 goto err_free;
308         }
309 
310         return dev;
311 
312 err_free:
313         amba_device_put(dev);
314         return NULL;
315 }
316 #else /* CONFIG_ARM_AMBA */
317 static struct amba_device *of_amba_device_create(struct device_node *node,
318                                                  const char *bus_id,
319                                                  void *platform_data,
320                                                  struct device *parent)
321 {
322         return NULL;
323 }
324 #endif /* CONFIG_ARM_AMBA */
325 
326 /**
327  * of_devname_lookup() - Given a device node, lookup the preferred Linux name
328  */
329 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
330                                  struct device_node *np)
331 {
332         struct resource res;
333 
334         if (!lookup)
335                 return NULL;
336 
337         for(; lookup->compatible != NULL; lookup++) {
338                 if (!of_device_is_compatible(np, lookup->compatible))
339                         continue;
340                 if (!of_address_to_resource(np, 0, &res))
341                         if (res.start != lookup->phys_addr)
342                                 continue;
343                 pr_debug("%s: devname=%s\n", np->full_name, lookup->name);
344                 return lookup;
345         }
346 
347         return NULL;
348 }
349 
350 /**
351  * of_platform_bus_create() - Create a device for a node and its children.
352  * @bus: device node of the bus to instantiate
353  * @matches: match table for bus nodes
354  * @lookup: auxdata table for matching id and platform_data with device nodes
355  * @parent: parent for new device, or NULL for top level.
356  * @strict: require compatible property
357  *
358  * Creates a platform_device for the provided device_node, and optionally
359  * recursively create devices for all the child nodes.
360  */
361 static int of_platform_bus_create(struct device_node *bus,
362                                   const struct of_device_id *matches,
363                                   const struct of_dev_auxdata *lookup,
364                                   struct device *parent, bool strict)
365 {
366         const struct of_dev_auxdata *auxdata;
367         struct device_node *child;
368         struct platform_device *dev;
369         const char *bus_id = NULL;
370         void *platform_data = NULL;
371         int rc = 0;
372 
373         /* Make sure it has a compatible property */
374         if (strict && (!of_get_property(bus, "compatible", NULL))) {
375                 pr_debug("%s() - skipping %s, no compatible prop\n",
376                          __func__, bus->full_name);
377                 return 0;
378         }
379 
380         auxdata = of_dev_lookup(lookup, bus);
381         if (auxdata) {
382                 bus_id = auxdata->name;
383                 platform_data = auxdata->platform_data;
384         }
385 
386         if (of_device_is_compatible(bus, "arm,primecell")) {
387                 /*
388                  * Don't return an error here to keep compatibility with older
389                  * device tree files.
390                  */
391                 of_amba_device_create(bus, bus_id, platform_data, parent);
392                 return 0;
393         }
394 
395         dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
396         if (!dev || !of_match_node(matches, bus))
397                 return 0;
398 
399         for_each_child_of_node(bus, child) {
400                 pr_debug("   create child: %s\n", child->full_name);
401                 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
402                 if (rc) {
403                         of_node_put(child);
404                         break;
405                 }
406         }
407         return rc;
408 }
409 
410 /**
411  * of_platform_bus_probe() - Probe the device-tree for platform buses
412  * @root: parent of the first level to probe or NULL for the root of the tree
413  * @matches: match table for bus nodes
414  * @parent: parent to hook devices from, NULL for toplevel
415  *
416  * Note that children of the provided root are not instantiated as devices
417  * unless the specified root itself matches the bus list and is not NULL.
418  */
419 int of_platform_bus_probe(struct device_node *root,
420                           const struct of_device_id *matches,
421                           struct device *parent)
422 {
423         struct device_node *child;
424         int rc = 0;
425 
426         root = root ? of_node_get(root) : of_find_node_by_path("/");
427         if (!root)
428                 return -EINVAL;
429 
430         pr_debug("of_platform_bus_probe()\n");
431         pr_debug(" starting at: %s\n", root->full_name);
432 
433         /* Do a self check of bus type, if there's a match, create children */
434         if (of_match_node(matches, root)) {
435                 rc = of_platform_bus_create(root, matches, NULL, parent, false);
436         } else for_each_child_of_node(root, child) {
437                 if (!of_match_node(matches, child))
438                         continue;
439                 rc = of_platform_bus_create(child, matches, NULL, parent, false);
440                 if (rc)
441                         break;
442         }
443 
444         of_node_put(root);
445         return rc;
446 }
447 EXPORT_SYMBOL(of_platform_bus_probe);
448 
449 /**
450  * of_platform_populate() - Populate platform_devices from device tree data
451  * @root: parent of the first level to probe or NULL for the root of the tree
452  * @matches: match table, NULL to use the default
453  * @lookup: auxdata table for matching id and platform_data with device nodes
454  * @parent: parent to hook devices from, NULL for toplevel
455  *
456  * Similar to of_platform_bus_probe(), this function walks the device tree
457  * and creates devices from nodes.  It differs in that it follows the modern
458  * convention of requiring all device nodes to have a 'compatible' property,
459  * and it is suitable for creating devices which are children of the root
460  * node (of_platform_bus_probe will only create children of the root which
461  * are selected by the @matches argument).
462  *
463  * New board support should be using this function instead of
464  * of_platform_bus_probe().
465  *
466  * Returns 0 on success, < 0 on failure.
467  */
468 int of_platform_populate(struct device_node *root,
469                         const struct of_device_id *matches,
470                         const struct of_dev_auxdata *lookup,
471                         struct device *parent)
472 {
473         struct device_node *child;
474         int rc = 0;
475 
476         root = root ? of_node_get(root) : of_find_node_by_path("/");
477         if (!root)
478                 return -EINVAL;
479 
480         for_each_child_of_node(root, child) {
481                 rc = of_platform_bus_create(child, matches, lookup, parent, true);
482                 if (rc)
483                         break;
484         }
485 
486         of_node_put(root);
487         return rc;
488 }
489 EXPORT_SYMBOL_GPL(of_platform_populate);
490 #endif /* CONFIG_OF_ADDRESS */
491 

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