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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/arch/arm/common/amba.c
4 *
5 * Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved.
6 */
7 #include <linux/module.h>
8 #include <linux/init.h>
9 #include <linux/device.h>
10 #include <linux/string.h>
11 #include <linux/slab.h>
12 #include <linux/io.h>
13 #include <linux/pm.h>
14 #include <linux/pm_runtime.h>
15 #include <linux/pm_domain.h>
16 #include <linux/amba/bus.h>
17 #include <linux/sizes.h>
18 #include <linux/limits.h>
19 #include <linux/clk/clk-conf.h>
20 #include <linux/platform_device.h>
21 #include <linux/reset.h>
22
23 #include <asm/irq.h>
24
25 #define to_amba_driver(d) container_of(d, struct amba_driver, drv)
26
27 /* called on periphid match and class 0x9 coresight device. */
28 static int
29 amba_cs_uci_id_match(const struct amba_id *table, struct amba_device *dev)
30 {
31 int ret = 0;
32 struct amba_cs_uci_id *uci;
33
34 uci = table->data;
35
36 /* no table data or zero mask - return match on periphid */
37 if (!uci || (uci->devarch_mask == 0))
38 return 1;
39
40 /* test against read devtype and masked devarch value */
41 ret = (dev->uci.devtype == uci->devtype) &&
42 ((dev->uci.devarch & uci->devarch_mask) == uci->devarch);
43 return ret;
44 }
45
46 static const struct amba_id *
47 amba_lookup(const struct amba_id *table, struct amba_device *dev)
48 {
49 while (table->mask) {
50 if (((dev->periphid & table->mask) == table->id) &&
51 ((dev->cid != CORESIGHT_CID) ||
52 (amba_cs_uci_id_match(table, dev))))
53 return table;
54 table++;
55 }
56 return NULL;
57 }
58
59 static int amba_get_enable_pclk(struct amba_device *pcdev)
60 {
61 int ret;
62
63 pcdev->pclk = clk_get(&pcdev->dev, "apb_pclk");
64 if (IS_ERR(pcdev->pclk))
65 return PTR_ERR(pcdev->pclk);
66
67 ret = clk_prepare_enable(pcdev->pclk);
68 if (ret)
69 clk_put(pcdev->pclk);
70
71 return ret;
72 }
73
74 static void amba_put_disable_pclk(struct amba_device *pcdev)
75 {
76 clk_disable_unprepare(pcdev->pclk);
77 clk_put(pcdev->pclk);
78 }
79
80
81 static ssize_t driver_override_show(struct device *_dev,
82 struct device_attribute *attr, char *buf)
83 {
84 struct amba_device *dev = to_amba_device(_dev);
85 ssize_t len;
86
87 device_lock(_dev);
88 len = sprintf(buf, "%s\n", dev->driver_override);
89 device_unlock(_dev);
90 return len;
91 }
92
93 static ssize_t driver_override_store(struct device *_dev,
94 struct device_attribute *attr,
95 const char *buf, size_t count)
96 {
97 struct amba_device *dev = to_amba_device(_dev);
98 char *driver_override, *old, *cp;
99
100 /* We need to keep extra room for a newline */
101 if (count >= (PAGE_SIZE - 1))
102 return -EINVAL;
103
104 driver_override = kstrndup(buf, count, GFP_KERNEL);
105 if (!driver_override)
106 return -ENOMEM;
107
108 cp = strchr(driver_override, '\n');
109 if (cp)
110 *cp = '\0';
111
112 device_lock(_dev);
113 old = dev->driver_override;
114 if (strlen(driver_override)) {
115 dev->driver_override = driver_override;
116 } else {
117 kfree(driver_override);
118 dev->driver_override = NULL;
119 }
120 device_unlock(_dev);
121
122 kfree(old);
123
124 return count;
125 }
126 static DEVICE_ATTR_RW(driver_override);
127
128 #define amba_attr_func(name,fmt,arg...) \
129 static ssize_t name##_show(struct device *_dev, \
130 struct device_attribute *attr, char *buf) \
131 { \
132 struct amba_device *dev = to_amba_device(_dev); \
133 return sprintf(buf, fmt, arg); \
134 } \
135 static DEVICE_ATTR_RO(name)
136
137 amba_attr_func(id, "%08x\n", dev->periphid);
138 amba_attr_func(irq0, "%u\n", dev->irq[0]);
139 amba_attr_func(irq1, "%u\n", dev->irq[1]);
140 amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
141 (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
142 dev->res.flags);
143
144 static struct attribute *amba_dev_attrs[] = {
145 &dev_attr_id.attr,
146 &dev_attr_resource.attr,
147 &dev_attr_driver_override.attr,
148 NULL,
149 };
150 ATTRIBUTE_GROUPS(amba_dev);
151
152 static int amba_match(struct device *dev, struct device_driver *drv)
153 {
154 struct amba_device *pcdev = to_amba_device(dev);
155 struct amba_driver *pcdrv = to_amba_driver(drv);
156
157 /* When driver_override is set, only bind to the matching driver */
158 if (pcdev->driver_override)
159 return !strcmp(pcdev->driver_override, drv->name);
160
161 return amba_lookup(pcdrv->id_table, pcdev) != NULL;
162 }
163
164 static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
165 {
166 struct amba_device *pcdev = to_amba_device(dev);
167 int retval = 0;
168
169 retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
170 if (retval)
171 return retval;
172
173 retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid);
174 return retval;
175 }
176
177 /*
178 * These are the device model conversion veneers; they convert the
179 * device model structures to our more specific structures.
180 */
181 static int amba_probe(struct device *dev)
182 {
183 struct amba_device *pcdev = to_amba_device(dev);
184 struct amba_driver *pcdrv = to_amba_driver(dev->driver);
185 const struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev);
186 int ret;
187
188 do {
189 ret = of_clk_set_defaults(dev->of_node, false);
190 if (ret < 0)
191 break;
192
193 ret = dev_pm_domain_attach(dev, true);
194 if (ret)
195 break;
196
197 ret = amba_get_enable_pclk(pcdev);
198 if (ret) {
199 dev_pm_domain_detach(dev, true);
200 break;
201 }
202
203 pm_runtime_get_noresume(dev);
204 pm_runtime_set_active(dev);
205 pm_runtime_enable(dev);
206
207 ret = pcdrv->probe(pcdev, id);
208 if (ret == 0)
209 break;
210
211 pm_runtime_disable(dev);
212 pm_runtime_set_suspended(dev);
213 pm_runtime_put_noidle(dev);
214
215 amba_put_disable_pclk(pcdev);
216 dev_pm_domain_detach(dev, true);
217 } while (0);
218
219 return ret;
220 }
221
222 static void amba_remove(struct device *dev)
223 {
224 struct amba_device *pcdev = to_amba_device(dev);
225 struct amba_driver *drv = to_amba_driver(dev->driver);
226
227 pm_runtime_get_sync(dev);
228 if (drv->remove)
229 drv->remove(pcdev);
230 pm_runtime_put_noidle(dev);
231
232 /* Undo the runtime PM settings in amba_probe() */
233 pm_runtime_disable(dev);
234 pm_runtime_set_suspended(dev);
235 pm_runtime_put_noidle(dev);
236
237 amba_put_disable_pclk(pcdev);
238 dev_pm_domain_detach(dev, true);
239 }
240
241 static void amba_shutdown(struct device *dev)
242 {
243 struct amba_driver *drv;
244
245 if (!dev->driver)
246 return;
247
248 drv = to_amba_driver(dev->driver);
249 if (drv->shutdown)
250 drv->shutdown(to_amba_device(dev));
251 }
252
253 #ifdef CONFIG_PM
254 /*
255 * Hooks to provide runtime PM of the pclk (bus clock). It is safe to
256 * enable/disable the bus clock at runtime PM suspend/resume as this
257 * does not result in loss of context.
258 */
259 static int amba_pm_runtime_suspend(struct device *dev)
260 {
261 struct amba_device *pcdev = to_amba_device(dev);
262 int ret = pm_generic_runtime_suspend(dev);
263
264 if (ret == 0 && dev->driver) {
265 if (pm_runtime_is_irq_safe(dev))
266 clk_disable(pcdev->pclk);
267 else
268 clk_disable_unprepare(pcdev->pclk);
269 }
270
271 return ret;
272 }
273
274 static int amba_pm_runtime_resume(struct device *dev)
275 {
276 struct amba_device *pcdev = to_amba_device(dev);
277 int ret;
278
279 if (dev->driver) {
280 if (pm_runtime_is_irq_safe(dev))
281 ret = clk_enable(pcdev->pclk);
282 else
283 ret = clk_prepare_enable(pcdev->pclk);
284 /* Failure is probably fatal to the system, but... */
285 if (ret)
286 return ret;
287 }
288
289 return pm_generic_runtime_resume(dev);
290 }
291 #endif /* CONFIG_PM */
292
293 static const struct dev_pm_ops amba_pm = {
294 .suspend = pm_generic_suspend,
295 .resume = pm_generic_resume,
296 .freeze = pm_generic_freeze,
297 .thaw = pm_generic_thaw,
298 .poweroff = pm_generic_poweroff,
299 .restore = pm_generic_restore,
300 SET_RUNTIME_PM_OPS(
301 amba_pm_runtime_suspend,
302 amba_pm_runtime_resume,
303 NULL
304 )
305 };
306
307 /*
308 * Primecells are part of the Advanced Microcontroller Bus Architecture,
309 * so we call the bus "amba".
310 * DMA configuration for platform and AMBA bus is same. So here we reuse
311 * platform's DMA config routine.
312 */
313 struct bus_type amba_bustype = {
314 .name = "amba",
315 .dev_groups = amba_dev_groups,
316 .match = amba_match,
317 .uevent = amba_uevent,
318 .probe = amba_probe,
319 .remove = amba_remove,
320 .shutdown = amba_shutdown,
321 .dma_configure = platform_dma_configure,
322 .pm = &amba_pm,
323 };
324 EXPORT_SYMBOL_GPL(amba_bustype);
325
326 static int __init amba_init(void)
327 {
328 return bus_register(&amba_bustype);
329 }
330
331 postcore_initcall(amba_init);
332
333 /**
334 * amba_driver_register - register an AMBA device driver
335 * @drv: amba device driver structure
336 *
337 * Register an AMBA device driver with the Linux device model
338 * core. If devices pre-exist, the drivers probe function will
339 * be called.
340 */
341 int amba_driver_register(struct amba_driver *drv)
342 {
343 if (!drv->probe)
344 return -EINVAL;
345
346 drv->drv.bus = &amba_bustype;
347
348 return driver_register(&drv->drv);
349 }
350
351 /**
352 * amba_driver_unregister - remove an AMBA device driver
353 * @drv: AMBA device driver structure to remove
354 *
355 * Unregister an AMBA device driver from the Linux device
356 * model. The device model will call the drivers remove function
357 * for each device the device driver is currently handling.
358 */
359 void amba_driver_unregister(struct amba_driver *drv)
360 {
361 driver_unregister(&drv->drv);
362 }
363
364
365 static void amba_device_release(struct device *dev)
366 {
367 struct amba_device *d = to_amba_device(dev);
368
369 if (d->res.parent)
370 release_resource(&d->res);
371 kfree(d);
372 }
373
374 static int amba_device_try_add(struct amba_device *dev, struct resource *parent)
375 {
376 u32 size;
377 void __iomem *tmp;
378 int i, ret;
379
380 ret = request_resource(parent, &dev->res);
381 if (ret)
382 goto err_out;
383
384 /* Hard-coded primecell ID instead of plug-n-play */
385 if (dev->periphid != 0)
386 goto skip_probe;
387
388 /*
389 * Dynamically calculate the size of the resource
390 * and use this for iomap
391 */
392 size = resource_size(&dev->res);
393 tmp = ioremap(dev->res.start, size);
394 if (!tmp) {
395 ret = -ENOMEM;
396 goto err_release;
397 }
398
399 ret = dev_pm_domain_attach(&dev->dev, true);
400 if (ret) {
401 iounmap(tmp);
402 goto err_release;
403 }
404
405 ret = amba_get_enable_pclk(dev);
406 if (ret == 0) {
407 u32 pid, cid;
408 struct reset_control *rstc;
409
410 /*
411 * Find reset control(s) of the amba bus and de-assert them.
412 */
413 rstc = of_reset_control_array_get_optional_shared(dev->dev.of_node);
414 if (IS_ERR(rstc)) {
415 ret = PTR_ERR(rstc);
416 if (ret != -EPROBE_DEFER)
417 dev_err(&dev->dev, "can't get reset: %d\n",
418 ret);
419 goto err_reset;
420 }
421 reset_control_deassert(rstc);
422 reset_control_put(rstc);
423
424 /*
425 * Read pid and cid based on size of resource
426 * they are located at end of region
427 */
428 for (pid = 0, i = 0; i < 4; i++)
429 pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) <<
430 (i * 8);
431 for (cid = 0, i = 0; i < 4; i++)
432 cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) <<
433 (i * 8);
434
435 if (cid == CORESIGHT_CID) {
436 /* set the base to the start of the last 4k block */
437 void __iomem *csbase = tmp + size - 4096;
438
439 dev->uci.devarch =
440 readl(csbase + UCI_REG_DEVARCH_OFFSET);
441 dev->uci.devtype =
442 readl(csbase + UCI_REG_DEVTYPE_OFFSET) & 0xff;
443 }
444
445 amba_put_disable_pclk(dev);
446
447 if (cid == AMBA_CID || cid == CORESIGHT_CID) {
448 dev->periphid = pid;
449 dev->cid = cid;
450 }
451
452 if (!dev->periphid)
453 ret = -ENODEV;
454 }
455
456 iounmap(tmp);
457 dev_pm_domain_detach(&dev->dev, true);
458
459 if (ret)
460 goto err_release;
461
462 skip_probe:
463 ret = device_add(&dev->dev);
464 if (ret)
465 goto err_release;
466
467 if (dev->irq[0])
468 ret = device_create_file(&dev->dev, &dev_attr_irq0);
469 if (ret == 0 && dev->irq[1])
470 ret = device_create_file(&dev->dev, &dev_attr_irq1);
471 if (ret == 0)
472 return ret;
473
474 device_unregister(&dev->dev);
475
476 err_release:
477 release_resource(&dev->res);
478 err_out:
479 return ret;
480
481 err_reset:
482 amba_put_disable_pclk(dev);
483 iounmap(tmp);
484 dev_pm_domain_detach(&dev->dev, true);
485 goto err_release;
486 }
487
488 /*
489 * Registration of AMBA device require reading its pid and cid registers.
490 * To do this, the device must be turned on (if it is a part of power domain)
491 * and have clocks enabled. However in some cases those resources might not be
492 * yet available. Returning EPROBE_DEFER is not a solution in such case,
493 * because callers don't handle this special error code. Instead such devices
494 * are added to the special list and their registration is retried from
495 * periodic worker, until all resources are available and registration succeeds.
496 */
497 struct deferred_device {
498 struct amba_device *dev;
499 struct resource *parent;
500 struct list_head node;
501 };
502
503 static LIST_HEAD(deferred_devices);
504 static DEFINE_MUTEX(deferred_devices_lock);
505
506 static void amba_deferred_retry_func(struct work_struct *dummy);
507 static DECLARE_DELAYED_WORK(deferred_retry_work, amba_deferred_retry_func);
508
509 #define DEFERRED_DEVICE_TIMEOUT (msecs_to_jiffies(5 * 1000))
510
511 static int amba_deferred_retry(void)
512 {
513 struct deferred_device *ddev, *tmp;
514
515 mutex_lock(&deferred_devices_lock);
516
517 list_for_each_entry_safe(ddev, tmp, &deferred_devices, node) {
518 int ret = amba_device_try_add(ddev->dev, ddev->parent);
519
520 if (ret == -EPROBE_DEFER)
521 continue;
522
523 list_del_init(&ddev->node);
524 kfree(ddev);
525 }
526
527 mutex_unlock(&deferred_devices_lock);
528
529 return 0;
530 }
531 late_initcall(amba_deferred_retry);
532
533 static void amba_deferred_retry_func(struct work_struct *dummy)
534 {
535 amba_deferred_retry();
536
537 if (!list_empty(&deferred_devices))
538 schedule_delayed_work(&deferred_retry_work,
539 DEFERRED_DEVICE_TIMEOUT);
540 }
541
542 /**
543 * amba_device_add - add a previously allocated AMBA device structure
544 * @dev: AMBA device allocated by amba_device_alloc
545 * @parent: resource parent for this devices resources
546 *
547 * Claim the resource, and read the device cell ID if not already
548 * initialized. Register the AMBA device with the Linux device
549 * manager.
550 */
551 int amba_device_add(struct amba_device *dev, struct resource *parent)
552 {
553 int ret = amba_device_try_add(dev, parent);
554
555 if (ret == -EPROBE_DEFER) {
556 struct deferred_device *ddev;
557
558 ddev = kmalloc(sizeof(*ddev), GFP_KERNEL);
559 if (!ddev)
560 return -ENOMEM;
561
562 ddev->dev = dev;
563 ddev->parent = parent;
564 ret = 0;
565
566 mutex_lock(&deferred_devices_lock);
567
568 if (list_empty(&deferred_devices))
569 schedule_delayed_work(&deferred_retry_work,
570 DEFERRED_DEVICE_TIMEOUT);
571 list_add_tail(&ddev->node, &deferred_devices);
572
573 mutex_unlock(&deferred_devices_lock);
574 }
575 return ret;
576 }
577 EXPORT_SYMBOL_GPL(amba_device_add);
578
579 static struct amba_device *
580 amba_aphb_device_add(struct device *parent, const char *name,
581 resource_size_t base, size_t size, int irq1, int irq2,
582 void *pdata, unsigned int periphid, u64 dma_mask,
583 struct resource *resbase)
584 {
585 struct amba_device *dev;
586 int ret;
587
588 dev = amba_device_alloc(name, base, size);
589 if (!dev)
590 return ERR_PTR(-ENOMEM);
591
592 dev->dev.coherent_dma_mask = dma_mask;
593 dev->irq[0] = irq1;
594 dev->irq[1] = irq2;
595 dev->periphid = periphid;
596 dev->dev.platform_data = pdata;
597 dev->dev.parent = parent;
598
599 ret = amba_device_add(dev, resbase);
600 if (ret) {
601 amba_device_put(dev);
602 return ERR_PTR(ret);
603 }
604
605 return dev;
606 }
607
608 struct amba_device *
609 amba_apb_device_add(struct device *parent, const char *name,
610 resource_size_t base, size_t size, int irq1, int irq2,
611 void *pdata, unsigned int periphid)
612 {
613 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
614 periphid, 0, &iomem_resource);
615 }
616 EXPORT_SYMBOL_GPL(amba_apb_device_add);
617
618 struct amba_device *
619 amba_ahb_device_add(struct device *parent, const char *name,
620 resource_size_t base, size_t size, int irq1, int irq2,
621 void *pdata, unsigned int periphid)
622 {
623 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
624 periphid, ~0ULL, &iomem_resource);
625 }
626 EXPORT_SYMBOL_GPL(amba_ahb_device_add);
627
628 struct amba_device *
629 amba_apb_device_add_res(struct device *parent, const char *name,
630 resource_size_t base, size_t size, int irq1,
631 int irq2, void *pdata, unsigned int periphid,
632 struct resource *resbase)
633 {
634 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
635 periphid, 0, resbase);
636 }
637 EXPORT_SYMBOL_GPL(amba_apb_device_add_res);
638
639 struct amba_device *
640 amba_ahb_device_add_res(struct device *parent, const char *name,
641 resource_size_t base, size_t size, int irq1,
642 int irq2, void *pdata, unsigned int periphid,
643 struct resource *resbase)
644 {
645 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
646 periphid, ~0ULL, resbase);
647 }
648 EXPORT_SYMBOL_GPL(amba_ahb_device_add_res);
649
650
651 static void amba_device_initialize(struct amba_device *dev, const char *name)
652 {
653 device_initialize(&dev->dev);
654 if (name)
655 dev_set_name(&dev->dev, "%s", name);
656 dev->dev.release = amba_device_release;
657 dev->dev.bus = &amba_bustype;
658 dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
659 dev->dev.dma_parms = &dev->dma_parms;
660 dev->res.name = dev_name(&dev->dev);
661 }
662
663 /**
664 * amba_device_alloc - allocate an AMBA device
665 * @name: sysfs name of the AMBA device
666 * @base: base of AMBA device
667 * @size: size of AMBA device
668 *
669 * Allocate and initialize an AMBA device structure. Returns %NULL
670 * on failure.
671 */
672 struct amba_device *amba_device_alloc(const char *name, resource_size_t base,
673 size_t size)
674 {
675 struct amba_device *dev;
676
677 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
678 if (dev) {
679 amba_device_initialize(dev, name);
680 dev->res.start = base;
681 dev->res.end = base + size - 1;
682 dev->res.flags = IORESOURCE_MEM;
683 }
684
685 return dev;
686 }
687 EXPORT_SYMBOL_GPL(amba_device_alloc);
688
689 /**
690 * amba_device_register - register an AMBA device
691 * @dev: AMBA device to register
692 * @parent: parent memory resource
693 *
694 * Setup the AMBA device, reading the cell ID if present.
695 * Claim the resource, and register the AMBA device with
696 * the Linux device manager.
697 */
698 int amba_device_register(struct amba_device *dev, struct resource *parent)
699 {
700 amba_device_initialize(dev, dev->dev.init_name);
701 dev->dev.init_name = NULL;
702
703 return amba_device_add(dev, parent);
704 }
705
706 /**
707 * amba_device_put - put an AMBA device
708 * @dev: AMBA device to put
709 */
710 void amba_device_put(struct amba_device *dev)
711 {
712 put_device(&dev->dev);
713 }
714 EXPORT_SYMBOL_GPL(amba_device_put);
715
716 /**
717 * amba_device_unregister - unregister an AMBA device
718 * @dev: AMBA device to remove
719 *
720 * Remove the specified AMBA device from the Linux device
721 * manager. All files associated with this object will be
722 * destroyed, and device drivers notified that the device has
723 * been removed. The AMBA device's resources including
724 * the amba_device structure will be freed once all
725 * references to it have been dropped.
726 */
727 void amba_device_unregister(struct amba_device *dev)
728 {
729 device_unregister(&dev->dev);
730 }
731
732
733 struct find_data {
734 struct amba_device *dev;
735 struct device *parent;
736 const char *busid;
737 unsigned int id;
738 unsigned int mask;
739 };
740
741 static int amba_find_match(struct device *dev, void *data)
742 {
743 struct find_data *d = data;
744 struct amba_device *pcdev = to_amba_device(dev);
745 int r;
746
747 r = (pcdev->periphid & d->mask) == d->id;
748 if (d->parent)
749 r &= d->parent == dev->parent;
750 if (d->busid)
751 r &= strcmp(dev_name(dev), d->busid) == 0;
752
753 if (r) {
754 get_device(dev);
755 d->dev = pcdev;
756 }
757
758 return r;
759 }
760
761 /**
762 * amba_find_device - locate an AMBA device given a bus id
763 * @busid: bus id for device (or NULL)
764 * @parent: parent device (or NULL)
765 * @id: peripheral ID (or 0)
766 * @mask: peripheral ID mask (or 0)
767 *
768 * Return the AMBA device corresponding to the supplied parameters.
769 * If no device matches, returns NULL.
770 *
771 * NOTE: When a valid device is found, its refcount is
772 * incremented, and must be decremented before the returned
773 * reference.
774 */
775 struct amba_device *
776 amba_find_device(const char *busid, struct device *parent, unsigned int id,
777 unsigned int mask)
778 {
779 struct find_data data;
780
781 data.dev = NULL;
782 data.parent = parent;
783 data.busid = busid;
784 data.id = id;
785 data.mask = mask;
786
787 bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
788
789 return data.dev;
790 }
791
792 /**
793 * amba_request_regions - request all mem regions associated with device
794 * @dev: amba_device structure for device
795 * @name: name, or NULL to use driver name
796 */
797 int amba_request_regions(struct amba_device *dev, const char *name)
798 {
799 int ret = 0;
800 u32 size;
801
802 if (!name)
803 name = dev->dev.driver->name;
804
805 size = resource_size(&dev->res);
806
807 if (!request_mem_region(dev->res.start, size, name))
808 ret = -EBUSY;
809
810 return ret;
811 }
812
813 /**
814 * amba_release_regions - release mem regions associated with device
815 * @dev: amba_device structure for device
816 *
817 * Release regions claimed by a successful call to amba_request_regions.
818 */
819 void amba_release_regions(struct amba_device *dev)
820 {
821 u32 size;
822
823 size = resource_size(&dev->res);
824 release_mem_region(dev->res.start, size);
825 }
826
827 EXPORT_SYMBOL(amba_driver_register);
828 EXPORT_SYMBOL(amba_driver_unregister);
829 EXPORT_SYMBOL(amba_device_register);
830 EXPORT_SYMBOL(amba_device_unregister);
831 EXPORT_SYMBOL(amba_find_device);
832 EXPORT_SYMBOL(amba_request_regions);
833 EXPORT_SYMBOL(amba_release_regions);