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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                 WARN_ON(of_irq_to_resource_table(np, res, num_irq) != num_irq);
172         }
173 
174         dev->dev.of_node = of_node_get(np);
175 #if defined(CONFIG_MICROBLAZE)
176         dev->dev.dma_mask = &dev->archdata.dma_mask;
177 #endif
178         dev->dev.parent = parent;
179 
180         if (bus_id)
181                 dev_set_name(&dev->dev, "%s", bus_id);
182         else
183                 of_device_make_bus_id(&dev->dev);
184 
185         return dev;
186 }
187 EXPORT_SYMBOL(of_device_alloc);
188 
189 /**
190  * of_platform_device_create_pdata - Alloc, initialize and register an of_device
191  * @np: pointer to node to create device for
192  * @bus_id: name to assign device
193  * @platform_data: pointer to populate platform_data pointer with
194  * @parent: Linux device model parent device.
195  *
196  * Returns pointer to created platform device, or NULL if a device was not
197  * registered.  Unavailable devices will not get registered.
198  */
199 static struct platform_device *of_platform_device_create_pdata(
200                                         struct device_node *np,
201                                         const char *bus_id,
202                                         void *platform_data,
203                                         struct device *parent)
204 {
205         struct platform_device *dev;
206 
207         if (!of_device_is_available(np))
208                 return NULL;
209 
210         dev = of_device_alloc(np, bus_id, parent);
211         if (!dev)
212                 return NULL;
213 
214 #if defined(CONFIG_MICROBLAZE)
215         dev->archdata.dma_mask = 0xffffffffUL;
216 #endif
217         dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
218         if (!dev->dev.dma_mask)
219                 dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
220         dev->dev.bus = &platform_bus_type;
221         dev->dev.platform_data = platform_data;
222 
223         /* We do not fill the DMA ops for platform devices by default.
224          * This is currently the responsibility of the platform code
225          * to do such, possibly using a device notifier
226          */
227 
228         if (of_device_add(dev) != 0) {
229                 platform_device_put(dev);
230                 return NULL;
231         }
232 
233         return dev;
234 }
235 
236 /**
237  * of_platform_device_create - Alloc, initialize and register an of_device
238  * @np: pointer to node to create device for
239  * @bus_id: name to assign device
240  * @parent: Linux device model parent device.
241  *
242  * Returns pointer to created platform device, or NULL if a device was not
243  * registered.  Unavailable devices will not get registered.
244  */
245 struct platform_device *of_platform_device_create(struct device_node *np,
246                                             const char *bus_id,
247                                             struct device *parent)
248 {
249         return of_platform_device_create_pdata(np, bus_id, NULL, parent);
250 }
251 EXPORT_SYMBOL(of_platform_device_create);
252 
253 #ifdef CONFIG_ARM_AMBA
254 static struct amba_device *of_amba_device_create(struct device_node *node,
255                                                  const char *bus_id,
256                                                  void *platform_data,
257                                                  struct device *parent)
258 {
259         struct amba_device *dev;
260         const void *prop;
261         int i, ret;
262 
263         pr_debug("Creating amba device %s\n", node->full_name);
264 
265         if (!of_device_is_available(node))
266                 return NULL;
267 
268         dev = amba_device_alloc(NULL, 0, 0);
269         if (!dev) {
270                 pr_err("%s(): amba_device_alloc() failed for %s\n",
271                        __func__, node->full_name);
272                 return NULL;
273         }
274 
275         /* setup generic device info */
276         dev->dev.coherent_dma_mask = ~0;
277         dev->dev.of_node = of_node_get(node);
278         dev->dev.parent = parent;
279         dev->dev.platform_data = platform_data;
280         if (bus_id)
281                 dev_set_name(&dev->dev, "%s", bus_id);
282         else
283                 of_device_make_bus_id(&dev->dev);
284 
285         /* Allow the HW Peripheral ID to be overridden */
286         prop = of_get_property(node, "arm,primecell-periphid", NULL);
287         if (prop)
288                 dev->periphid = of_read_ulong(prop, 1);
289 
290         /* Decode the IRQs and address ranges */
291         for (i = 0; i < AMBA_NR_IRQS; i++)
292                 dev->irq[i] = irq_of_parse_and_map(node, i);
293 
294         ret = of_address_to_resource(node, 0, &dev->res);
295         if (ret) {
296                 pr_err("%s(): of_address_to_resource() failed (%d) for %s\n",
297                        __func__, ret, node->full_name);
298                 goto err_free;
299         }
300 
301         ret = amba_device_add(dev, &iomem_resource);
302         if (ret) {
303                 pr_err("%s(): amba_device_add() failed (%d) for %s\n",
304                        __func__, ret, node->full_name);
305                 goto err_free;
306         }
307 
308         return dev;
309 
310 err_free:
311         amba_device_put(dev);
312         return NULL;
313 }
314 #else /* CONFIG_ARM_AMBA */
315 static struct amba_device *of_amba_device_create(struct device_node *node,
316                                                  const char *bus_id,
317                                                  void *platform_data,
318                                                  struct device *parent)
319 {
320         return NULL;
321 }
322 #endif /* CONFIG_ARM_AMBA */
323 
324 /**
325  * of_devname_lookup() - Given a device node, lookup the preferred Linux name
326  */
327 static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
328                                  struct device_node *np)
329 {
330         struct resource res;
331 
332         if (!lookup)
333                 return NULL;
334 
335         for(; lookup->compatible != NULL; lookup++) {
336                 if (!of_device_is_compatible(np, lookup->compatible))
337                         continue;
338                 if (!of_address_to_resource(np, 0, &res))
339                         if (res.start != lookup->phys_addr)
340                                 continue;
341                 pr_debug("%s: devname=%s\n", np->full_name, lookup->name);
342                 return lookup;
343         }
344 
345         return NULL;
346 }
347 
348 /**
349  * of_platform_bus_create() - Create a device for a node and its children.
350  * @bus: device node of the bus to instantiate
351  * @matches: match table for bus nodes
352  * @lookup: auxdata table for matching id and platform_data with device nodes
353  * @parent: parent for new device, or NULL for top level.
354  * @strict: require compatible property
355  *
356  * Creates a platform_device for the provided device_node, and optionally
357  * recursively create devices for all the child nodes.
358  */
359 static int of_platform_bus_create(struct device_node *bus,
360                                   const struct of_device_id *matches,
361                                   const struct of_dev_auxdata *lookup,
362                                   struct device *parent, bool strict)
363 {
364         const struct of_dev_auxdata *auxdata;
365         struct device_node *child;
366         struct platform_device *dev;
367         const char *bus_id = NULL;
368         void *platform_data = NULL;
369         int rc = 0;
370 
371         /* Make sure it has a compatible property */
372         if (strict && (!of_get_property(bus, "compatible", NULL))) {
373                 pr_debug("%s() - skipping %s, no compatible prop\n",
374                          __func__, bus->full_name);
375                 return 0;
376         }
377 
378         auxdata = of_dev_lookup(lookup, bus);
379         if (auxdata) {
380                 bus_id = auxdata->name;
381                 platform_data = auxdata->platform_data;
382         }
383 
384         if (of_device_is_compatible(bus, "arm,primecell")) {
385                 /*
386                  * Don't return an error here to keep compatibility with older
387                  * device tree files.
388                  */
389                 of_amba_device_create(bus, bus_id, platform_data, parent);
390                 return 0;
391         }
392 
393         dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
394         if (!dev || !of_match_node(matches, bus))
395                 return 0;
396 
397         for_each_child_of_node(bus, child) {
398                 pr_debug("   create child: %s\n", child->full_name);
399                 rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
400                 if (rc) {
401                         of_node_put(child);
402                         break;
403                 }
404         }
405         return rc;
406 }
407 
408 /**
409  * of_platform_bus_probe() - Probe the device-tree for platform buses
410  * @root: parent of the first level to probe or NULL for the root of the tree
411  * @matches: match table for bus nodes
412  * @parent: parent to hook devices from, NULL for toplevel
413  *
414  * Note that children of the provided root are not instantiated as devices
415  * unless the specified root itself matches the bus list and is not NULL.
416  */
417 int of_platform_bus_probe(struct device_node *root,
418                           const struct of_device_id *matches,
419                           struct device *parent)
420 {
421         struct device_node *child;
422         int rc = 0;
423 
424         root = root ? of_node_get(root) : of_find_node_by_path("/");
425         if (!root)
426                 return -EINVAL;
427 
428         pr_debug("of_platform_bus_probe()\n");
429         pr_debug(" starting at: %s\n", root->full_name);
430 
431         /* Do a self check of bus type, if there's a match, create children */
432         if (of_match_node(matches, root)) {
433                 rc = of_platform_bus_create(root, matches, NULL, parent, false);
434         } else for_each_child_of_node(root, child) {
435                 if (!of_match_node(matches, child))
436                         continue;
437                 rc = of_platform_bus_create(child, matches, NULL, parent, false);
438                 if (rc)
439                         break;
440         }
441 
442         of_node_put(root);
443         return rc;
444 }
445 EXPORT_SYMBOL(of_platform_bus_probe);
446 
447 /**
448  * of_platform_populate() - Populate platform_devices from device tree data
449  * @root: parent of the first level to probe or NULL for the root of the tree
450  * @matches: match table, NULL to use the default
451  * @lookup: auxdata table for matching id and platform_data with device nodes
452  * @parent: parent to hook devices from, NULL for toplevel
453  *
454  * Similar to of_platform_bus_probe(), this function walks the device tree
455  * and creates devices from nodes.  It differs in that it follows the modern
456  * convention of requiring all device nodes to have a 'compatible' property,
457  * and it is suitable for creating devices which are children of the root
458  * node (of_platform_bus_probe will only create children of the root which
459  * are selected by the @matches argument).
460  *
461  * New board support should be using this function instead of
462  * of_platform_bus_probe().
463  *
464  * Returns 0 on success, < 0 on failure.
465  */
466 int of_platform_populate(struct device_node *root,
467                         const struct of_device_id *matches,
468                         const struct of_dev_auxdata *lookup,
469                         struct device *parent)
470 {
471         struct device_node *child;
472         int rc = 0;
473 
474         root = root ? of_node_get(root) : of_find_node_by_path("/");
475         if (!root)
476                 return -EINVAL;
477 
478         for_each_child_of_node(root, child) {
479                 rc = of_platform_bus_create(child, matches, lookup, parent, true);
480                 if (rc)
481                         break;
482         }
483 
484         of_node_put(root);
485         return rc;
486 }
487 EXPORT_SYMBOL_GPL(of_platform_populate);
488 #endif /* CONFIG_OF_ADDRESS */
489 

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