summaryrefslogtreecommitdiffstats
path: root/drivers/of/platform.c
blob: 6c48d73a7fd7c0f60d6a5a1d82c65b3045d1d3a5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
/*
 *    Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
 *			 <benh@kernel.crashing.org>
 *    and		 Arnd Bergmann, IBM Corp.
 *    Merged from powerpc/kernel/of_platform.c and
 *    sparc{,64}/kernel/of_device.c by Stephen Rothwell
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 *
 */
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/amba/bus.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>

const struct of_device_id of_default_bus_match_table[] = {
	{ .compatible = "simple-bus", },
#ifdef CONFIG_ARM_AMBA
	{ .compatible = "arm,amba-bus", },
#endif /* CONFIG_ARM_AMBA */
	{} /* Empty terminated list */
};

static int of_dev_node_match(struct device *dev, void *data)
{
	return dev->of_node == data;
}

/**
 * of_find_device_by_node - Find the platform_device associated with a node
 * @np: Pointer to device tree node
 *
 * Returns platform_device pointer, or NULL if not found
 */
struct platform_device *of_find_device_by_node(struct device_node *np)
{
	struct device *dev;

	dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
	return dev ? to_platform_device(dev) : NULL;
}
EXPORT_SYMBOL(of_find_device_by_node);

#ifdef CONFIG_OF_ADDRESS
/*
 * The following routines scan a subtree and registers a device for
 * each applicable node.
 *
 * Note: sparc doesn't use these routines because it has a different
 * mechanism for creating devices from device tree nodes.
 */

/**
 * of_device_make_bus_id - Use the device node data to assign a unique name
 * @dev: pointer to device structure that is linked to a device tree node
 *
 * This routine will first try using the translated bus address to
 * derive a unique name. If it cannot, then it will prepend names from
 * parent nodes until a unique name can be derived.
 */
void of_device_make_bus_id(struct device *dev)
{
	struct device_node *node = dev->of_node;
	const __be32 *reg;
	u64 addr;

	/* Construct the name, using parent nodes if necessary to ensure uniqueness */
	while (node->parent) {
		/*
		 * If the address can be translated, then that is as much
		 * uniqueness as we need. Make it the first component and return
		 */
		reg = of_get_property(node, "reg", NULL);
		if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
			dev_set_name(dev, dev_name(dev) ? "%llx.%s:%s" : "%llx.%s",
				     (unsigned long long)addr, node->name,
				     dev_name(dev));
			return;
		}

		/* format arguments only used if dev_name() resolves to NULL */
		dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
			     strrchr(node->full_name, '/') + 1, dev_name(dev));
		node = node->parent;
	}
}

/**
 * of_device_alloc - Allocate and initialize an of_device
 * @np: device node to assign to device
 * @bus_id: Name to assign to the device.  May be null to use default name.
 * @parent: Parent device.
 */
struct platform_device *of_device_alloc(struct device_node *np,
				  const char *bus_id,
				  struct device *parent)
{
	struct platform_device *dev;
	int rc, i, num_reg = 0, num_irq;
	struct resource *res, temp_res;

	dev = platform_device_alloc("", -1);
	if (!dev)
		return NULL;

	/* count the io and irq resources */
	while (of_address_to_resource(np, num_reg, &temp_res) == 0)
		num_reg++;
	num_irq = of_irq_count(np);

	/* Populate the resource table */
	if (num_irq || num_reg) {
		res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
		if (!res) {
			platform_device_put(dev);
			return NULL;
		}

		dev->num_resources = num_reg + num_irq;
		dev->resource = res;
		for (i = 0; i < num_reg; i++, res++) {
			rc = of_address_to_resource(np, i, res);
			WARN_ON(rc);
		}
		if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
			pr_debug("not all legacy IRQ resources mapped for %s\n",
				 np->name);
	}

	dev->dev.of_node = of_node_get(np);
	dev->dev.parent = parent;

	if (bus_id)
		dev_set_name(&dev->dev, "%s", bus_id);
	else
		of_device_make_bus_id(&dev->dev);

	return dev;
}
EXPORT_SYMBOL(of_device_alloc);

/**
 * of_dma_configure - Setup DMA configuration
 * @dev:	Device to apply DMA configuration
 *
 * Try to get devices's DMA configuration from DT and update it
 * accordingly.
 *
 * In case if platform code need to use own special DMA configuration,it
 * can use Platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE event
 * to fix up DMA configuration.
 */
static void of_dma_configure(struct platform_device *pdev)
{
	u64 dma_addr, paddr, size;
	int ret;
	struct device *dev = &pdev->dev;

#if defined(CONFIG_MICROBLAZE)
	pdev->archdata.dma_mask = 0xffffffffUL;
#endif

	/*
	 * Set default dma-mask to 32 bit. Drivers are expected to setup
	 * the correct supported dma_mask.
	 */
	dev->coherent_dma_mask = DMA_BIT_MASK(32);

	/*
	 * Set it to coherent_dma_mask by default if the architecture
	 * code has not set it.
	 */
	if (!dev->dma_mask)
		dev->dma_mask = &dev->coherent_dma_mask;

	/*
	 * if dma-coherent property exist, call arch hook to setup
	 * dma coherent operations.
	 */
	if (of_dma_is_coherent(dev->of_node)) {
		set_arch_dma_coherent_ops(dev);
		dev_dbg(dev, "device is dma coherent\n");
	}

	/*
	 * if dma-ranges property doesn't exist - just return else
	 * setup the dma offset
	 */
	ret = of_dma_get_range(dev->of_node, &dma_addr, &paddr, &size);
	if (ret < 0) {
		dev_dbg(dev, "no dma range information to setup\n");
		return;
	}

	/* DMA ranges found. Calculate and set dma_pfn_offset */
	dev->dma_pfn_offset = PFN_DOWN(paddr - dma_addr);
	dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", dev->dma_pfn_offset);
}

/**
 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
 * @np: pointer to node to create device for
 * @bus_id: name to assign device
 * @platform_data: pointer to populate platform_data pointer with
 * @parent: Linux device model parent device.
 *
 * Returns pointer to created platform device, or NULL if a device was not
 * registered.  Unavailable devices will not get registered.
 */
static struct platform_device *of_platform_device_create_pdata(
					struct device_node *np,
					const char *bus_id,
					void *platform_data,
					struct device *parent)
{
	struct platform_device *dev;

	if (!of_device_is_available(np) ||
	    of_node_test_and_set_flag(np, OF_POPULATED))
		return NULL;

	dev = of_device_alloc(np, bus_id, parent);
	if (!dev)
		goto err_clear_flag;

	of_dma_configure(dev);
	dev->dev.bus = &platform_bus_type;
	dev->dev.platform_data = platform_data;

	/* We do not fill the DMA ops for platform devices by default.
	 * This is currently the responsibility of the platform code
	 * to do such, possibly using a device notifier
	 */

	if (of_device_add(dev) != 0) {
		platform_device_put(dev);
		goto err_clear_flag;
	}

	return dev;

err_clear_flag:
	of_node_clear_flag(np, OF_POPULATED);
	return NULL;
}

/**
 * of_platform_device_create - Alloc, initialize and register an of_device
 * @np: pointer to node to create device for
 * @bus_id: name to assign device
 * @parent: Linux device model parent device.
 *
 * Returns pointer to created platform device, or NULL if a device was not
 * registered.  Unavailable devices will not get registered.
 */
struct platform_device *of_platform_device_create(struct device_node *np,
					    const char *bus_id,
					    struct device *parent)
{
	return of_platform_device_create_pdata(np, bus_id, NULL, parent);
}
EXPORT_SYMBOL(of_platform_device_create);

#ifdef CONFIG_ARM_AMBA
static struct amba_device *of_amba_device_create(struct device_node *node,
						 const char *bus_id,
						 void *platform_data,
						 struct device *parent)
{
	struct amba_device *dev;
	const void *prop;
	int i, ret;

	pr_debug("Creating amba device %s\n", node->full_name);

	if (!of_device_is_available(node) ||
	    of_node_test_and_set_flag(node, OF_POPULATED))
		return NULL;

	dev = amba_device_alloc(NULL, 0, 0);
	if (!dev) {
		pr_err("%s(): amba_device_alloc() failed for %s\n",
		       __func__, node->full_name);
		goto err_clear_flag;
	}

	/* setup generic device info */
	dev->dev.coherent_dma_mask = ~0;
	dev->dev.of_node = of_node_get(node);
	dev->dev.parent = parent;
	dev->dev.platform_data = platform_data;
	if (bus_id)
		dev_set_name(&dev->dev, "%s", bus_id);
	else
		of_device_make_bus_id(&dev->dev);

	/* Allow the HW Peripheral ID to be overridden */
	prop = of_get_property(node, "arm,primecell-periphid", NULL);
	if (prop)
		dev->periphid = of_read_ulong(prop, 1);

	/* Decode the IRQs and address ranges */
	for (i = 0; i < AMBA_NR_IRQS; i++)
		dev->irq[i] = irq_of_parse_and_map(node, i);

	ret = of_address_to_resource(node, 0, &dev->res);
	if (ret) {
		pr_err("%s(): of_address_to_resource() failed (%d) for %s\n",
		       __func__, ret, node->full_name);
		goto err_free;
	}

	ret = amba_device_add(dev, &iomem_resource);
	if (ret) {
		pr_err("%s(): amba_device_add() failed (%d) for %s\n",
		       __func__, ret, node->full_name);
		goto err_free;
	}

	return dev;

err_free:
	amba_device_put(dev);
err_clear_flag:
	of_node_clear_flag(node, OF_POPULATED);
	return NULL;
}
#else /* CONFIG_ARM_AMBA */
static struct amba_device *of_amba_device_create(struct device_node *node,
						 const char *bus_id,
						 void *platform_data,
						 struct device *parent)
{
	return NULL;
}
#endif /* CONFIG_ARM_AMBA */

/**
 * of_devname_lookup() - Given a device node, lookup the preferred Linux name
 */
static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
				 struct device_node *np)
{
	struct resource res;

	if (!lookup)
		return NULL;

	for(; lookup->compatible != NULL; lookup++) {
		if (!of_device_is_compatible(np, lookup->compatible))
			continue;
		if (!of_address_to_resource(np, 0, &res))
			if (res.start != lookup->phys_addr)
				continue;
		pr_debug("%s: devname=%s\n", np->full_name, lookup->name);
		return lookup;
	}

	return NULL;
}

/**
 * of_platform_bus_create() - Create a device for a node and its children.
 * @bus: device node of the bus to instantiate
 * @matches: match table for bus nodes
 * @lookup: auxdata table for matching id and platform_data with device nodes
 * @parent: parent for new device, or NULL for top level.
 * @strict: require compatible property
 *
 * Creates a platform_device for the provided device_node, and optionally
 * recursively create devices for all the child nodes.
 */
static int of_platform_bus_create(struct device_node *bus,
				  const struct of_device_id *matches,
				  const struct of_dev_auxdata *lookup,
				  struct device *parent, bool strict)
{
	const struct of_dev_auxdata *auxdata;
	struct device_node *child;
	struct platform_device *dev;
	const char *bus_id = NULL;
	void *platform_data = NULL;
	int rc = 0;

	/* Make sure it has a compatible property */
	if (strict && (!of_get_property(bus, "compatible", NULL))) {
		pr_debug("%s() - skipping %s, no compatible prop\n",
			 __func__, bus->full_name);
		return 0;
	}

	auxdata = of_dev_lookup(lookup, bus);
	if (auxdata) {
		bus_id = auxdata->name;
		platform_data = auxdata->platform_data;
	}

	if (of_device_is_compatible(bus, "arm,primecell")) {
		/*
		 * Don't return an error here to keep compatibility with older
		 * device tree files.
		 */
		of_amba_device_create(bus, bus_id, platform_data, parent);
		return 0;
	}

	dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
	if (!dev || !of_match_node(matches, bus))
		return 0;

	for_each_child_of_node(bus, child) {
		pr_debug("   create child: %s\n", child->full_name);
		rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
		if (rc) {
			of_node_put(child);
			break;
		}
	}
	return rc;
}

/**
 * of_platform_bus_probe() - Probe the device-tree for platform buses
 * @root: parent of the first level to probe or NULL for the root of the tree
 * @matches: match table for bus nodes
 * @parent: parent to hook devices from, NULL for toplevel
 *
 * Note that children of the provided root are not instantiated as devices
 * unless the specified root itself matches the bus list and is not NULL.
 */
int of_platform_bus_probe(struct device_node *root,
			  const struct of_device_id *matches,
			  struct device *parent)
{
	struct device_node *child;
	int rc = 0;

	root = root ? of_node_get(root) : of_find_node_by_path("/");
	if (!root)
		return -EINVAL;

	pr_debug("of_platform_bus_probe()\n");
	pr_debug(" starting at: %s\n", root->full_name);

	/* Do a self check of bus type, if there's a match, create children */
	if (of_match_node(matches, root)) {
		rc = of_platform_bus_create(root, matches, NULL, parent, false);
	} else for_each_child_of_node(root, child) {
		if (!of_match_node(matches, child))
			continue;
		rc = of_platform_bus_create(child, matches, NULL, parent, false);
		if (rc)
			break;
	}

	of_node_put(root);
	return rc;
}
EXPORT_SYMBOL(of_platform_bus_probe);

/**
 * of_platform_populate() - Populate platform_devices from device tree data
 * @root: parent of the first level to probe or NULL for the root of the tree
 * @matches: match table, NULL to use the default
 * @lookup: auxdata table for matching id and platform_data with device nodes
 * @parent: parent to hook devices from, NULL for toplevel
 *
 * Similar to of_platform_bus_probe(), this function walks the device tree
 * and creates devices from nodes.  It differs in that it follows the modern
 * convention of requiring all device nodes to have a 'compatible' property,
 * and it is suitable for creating devices which are children of the root
 * node (of_platform_bus_probe will only create children of the root which
 * are selected by the @matches argument).
 *
 * New board support should be using this function instead of
 * of_platform_bus_probe().
 *
 * Returns 0 on success, < 0 on failure.
 */
int of_platform_populate(struct device_node *root,
			const struct of_device_id *matches,
			const struct of_dev_auxdata *lookup,
			struct device *parent)
{
	struct device_node *child;
	int rc = 0;

	root = root ? of_node_get(root) : of_find_node_by_path("/");
	if (!root)
		return -EINVAL;

	for_each_child_of_node(root, child) {
		rc = of_platform_bus_create(child, matches, lookup, parent, true);
		if (rc)
			break;
	}

	of_node_put(root);
	return rc;
}
EXPORT_SYMBOL_GPL(of_platform_populate);

static int of_platform_device_destroy(struct device *dev, void *data)
{
	bool *children_left = data;

	/* Do not touch devices not populated from the device tree */
	if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED)) {
		*children_left = true;
		return 0;
	}

	/* Recurse, but don't touch this device if it has any children left */
	if (of_platform_depopulate(dev) != 0) {
		*children_left = true;
		return 0;
	}

	if (dev->bus == &platform_bus_type)
		platform_device_unregister(to_platform_device(dev));
#ifdef CONFIG_ARM_AMBA
	else if (dev->bus == &amba_bustype)
		amba_device_unregister(to_amba_device(dev));
#endif
	else {
		*children_left = true;
		return 0;
	}

	of_node_clear_flag(dev->of_node, OF_POPULATED);

	return 0;
}

/**
 * of_platform_depopulate() - Remove devices populated from device tree
 * @parent: device which childred will be removed
 *
 * Complementary to of_platform_populate(), this function removes children
 * of the given device (and, recurrently, their children) that have been
 * created from their respective device tree nodes (and only those,
 * leaving others - eg. manually created - unharmed).
 *
 * Returns 0 when all children devices have been removed or
 * -EBUSY when some children remained.
 */
int of_platform_depopulate(struct device *parent)
{
	bool children_left = false;

	device_for_each_child(parent, &children_left,
			      of_platform_device_destroy);

	return children_left ? -EBUSY : 0;
}
EXPORT_SYMBOL_GPL(of_platform_depopulate);

#endif /* CONFIG_OF_ADDRESS */
OpenPOWER on IntegriCloud