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10#include <linux/module.h>
11#include <linux/init.h>
12#include <linux/device.h>
13#include <linux/string.h>
14#include <linux/slab.h>
15#include <linux/io.h>
16#include <linux/pm.h>
17#include <linux/pm_runtime.h>
18#include <linux/pm_domain.h>
19#include <linux/amba/bus.h>
20#include <linux/sizes.h>
21#include <linux/limits.h>
22#include <linux/clk/clk-conf.h>
23
24#include <asm/irq.h>
25
26#define to_amba_driver(d) container_of(d, struct amba_driver, drv)
27
28static const struct amba_id *
29amba_lookup(const struct amba_id *table, struct amba_device *dev)
30{
31 int ret = 0;
32
33 while (table->mask) {
34 ret = (dev->periphid & table->mask) == table->id;
35 if (ret)
36 break;
37 table++;
38 }
39
40 return ret ? table : NULL;
41}
42
43static int amba_match(struct device *dev, struct device_driver *drv)
44{
45 struct amba_device *pcdev = to_amba_device(dev);
46 struct amba_driver *pcdrv = to_amba_driver(drv);
47
48
49 if (pcdev->driver_override)
50 return !strcmp(pcdev->driver_override, drv->name);
51
52 return amba_lookup(pcdrv->id_table, pcdev) != NULL;
53}
54
55static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
56{
57 struct amba_device *pcdev = to_amba_device(dev);
58 int retval = 0;
59
60 retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
61 if (retval)
62 return retval;
63
64 retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid);
65 return retval;
66}
67
68static ssize_t driver_override_show(struct device *_dev,
69 struct device_attribute *attr, char *buf)
70{
71 struct amba_device *dev = to_amba_device(_dev);
72 ssize_t len;
73
74 device_lock(_dev);
75 len = sprintf(buf, "%s\n", dev->driver_override);
76 device_unlock(_dev);
77 return len;
78}
79
80static ssize_t driver_override_store(struct device *_dev,
81 struct device_attribute *attr,
82 const char *buf, size_t count)
83{
84 struct amba_device *dev = to_amba_device(_dev);
85 char *driver_override, *old, *cp;
86
87
88 if (count >= (PAGE_SIZE - 1))
89 return -EINVAL;
90
91 driver_override = kstrndup(buf, count, GFP_KERNEL);
92 if (!driver_override)
93 return -ENOMEM;
94
95 cp = strchr(driver_override, '\n');
96 if (cp)
97 *cp = '\0';
98
99 device_lock(_dev);
100 old = dev->driver_override;
101 if (strlen(driver_override)) {
102 dev->driver_override = driver_override;
103 } else {
104 kfree(driver_override);
105 dev->driver_override = NULL;
106 }
107 device_unlock(_dev);
108
109 kfree(old);
110
111 return count;
112}
113static DEVICE_ATTR_RW(driver_override);
114
115#define amba_attr_func(name,fmt,arg...) \
116static ssize_t name##_show(struct device *_dev, \
117 struct device_attribute *attr, char *buf) \
118{ \
119 struct amba_device *dev = to_amba_device(_dev); \
120 return sprintf(buf, fmt, arg); \
121} \
122static DEVICE_ATTR_RO(name)
123
124amba_attr_func(id, "%08x\n", dev->periphid);
125amba_attr_func(irq0, "%u\n", dev->irq[0]);
126amba_attr_func(irq1, "%u\n", dev->irq[1]);
127amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
128 (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
129 dev->res.flags);
130
131static struct attribute *amba_dev_attrs[] = {
132 &dev_attr_id.attr,
133 &dev_attr_resource.attr,
134 &dev_attr_driver_override.attr,
135 NULL,
136};
137ATTRIBUTE_GROUPS(amba_dev);
138
139#ifdef CONFIG_PM
140
141
142
143
144
145static int amba_pm_runtime_suspend(struct device *dev)
146{
147 struct amba_device *pcdev = to_amba_device(dev);
148 int ret = pm_generic_runtime_suspend(dev);
149
150 if (ret == 0 && dev->driver) {
151 if (pm_runtime_is_irq_safe(dev))
152 clk_disable(pcdev->pclk);
153 else
154 clk_disable_unprepare(pcdev->pclk);
155 }
156
157 return ret;
158}
159
160static int amba_pm_runtime_resume(struct device *dev)
161{
162 struct amba_device *pcdev = to_amba_device(dev);
163 int ret;
164
165 if (dev->driver) {
166 if (pm_runtime_is_irq_safe(dev))
167 ret = clk_enable(pcdev->pclk);
168 else
169 ret = clk_prepare_enable(pcdev->pclk);
170
171 if (ret)
172 return ret;
173 }
174
175 return pm_generic_runtime_resume(dev);
176}
177#endif
178
179static const struct dev_pm_ops amba_pm = {
180 .suspend = pm_generic_suspend,
181 .resume = pm_generic_resume,
182 .freeze = pm_generic_freeze,
183 .thaw = pm_generic_thaw,
184 .poweroff = pm_generic_poweroff,
185 .restore = pm_generic_restore,
186 SET_RUNTIME_PM_OPS(
187 amba_pm_runtime_suspend,
188 amba_pm_runtime_resume,
189 NULL
190 )
191};
192
193
194
195
196
197struct bus_type amba_bustype = {
198 .name = "amba",
199 .dev_groups = amba_dev_groups,
200 .match = amba_match,
201 .uevent = amba_uevent,
202 .pm = &amba_pm,
203 .force_dma = true,
204};
205
206static int __init amba_init(void)
207{
208 return bus_register(&amba_bustype);
209}
210
211postcore_initcall(amba_init);
212
213static int amba_get_enable_pclk(struct amba_device *pcdev)
214{
215 int ret;
216
217 pcdev->pclk = clk_get(&pcdev->dev, "apb_pclk");
218 if (IS_ERR(pcdev->pclk))
219 return PTR_ERR(pcdev->pclk);
220
221 ret = clk_prepare_enable(pcdev->pclk);
222 if (ret)
223 clk_put(pcdev->pclk);
224
225 return ret;
226}
227
228static void amba_put_disable_pclk(struct amba_device *pcdev)
229{
230 clk_disable_unprepare(pcdev->pclk);
231 clk_put(pcdev->pclk);
232}
233
234
235
236
237
238static int amba_probe(struct device *dev)
239{
240 struct amba_device *pcdev = to_amba_device(dev);
241 struct amba_driver *pcdrv = to_amba_driver(dev->driver);
242 const struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev);
243 int ret;
244
245 do {
246 ret = of_clk_set_defaults(dev->of_node, false);
247 if (ret < 0)
248 break;
249
250 ret = dev_pm_domain_attach(dev, true);
251 if (ret == -EPROBE_DEFER)
252 break;
253
254 ret = amba_get_enable_pclk(pcdev);
255 if (ret) {
256 dev_pm_domain_detach(dev, true);
257 break;
258 }
259
260 pm_runtime_get_noresume(dev);
261 pm_runtime_set_active(dev);
262 pm_runtime_enable(dev);
263
264 ret = pcdrv->probe(pcdev, id);
265 if (ret == 0)
266 break;
267
268 pm_runtime_disable(dev);
269 pm_runtime_set_suspended(dev);
270 pm_runtime_put_noidle(dev);
271
272 amba_put_disable_pclk(pcdev);
273 dev_pm_domain_detach(dev, true);
274 } while (0);
275
276 return ret;
277}
278
279static int amba_remove(struct device *dev)
280{
281 struct amba_device *pcdev = to_amba_device(dev);
282 struct amba_driver *drv = to_amba_driver(dev->driver);
283 int ret;
284
285 pm_runtime_get_sync(dev);
286 ret = drv->remove(pcdev);
287 pm_runtime_put_noidle(dev);
288
289
290 pm_runtime_disable(dev);
291 pm_runtime_set_suspended(dev);
292 pm_runtime_put_noidle(dev);
293
294 amba_put_disable_pclk(pcdev);
295 dev_pm_domain_detach(dev, true);
296
297 return ret;
298}
299
300static void amba_shutdown(struct device *dev)
301{
302 struct amba_driver *drv = to_amba_driver(dev->driver);
303 drv->shutdown(to_amba_device(dev));
304}
305
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311
312
313
314int amba_driver_register(struct amba_driver *drv)
315{
316 drv->drv.bus = &amba_bustype;
317
318#define SETFN(fn) if (drv->fn) drv->drv.fn = amba_##fn
319 SETFN(probe);
320 SETFN(remove);
321 SETFN(shutdown);
322
323 return driver_register(&drv->drv);
324}
325
326
327
328
329
330
331
332
333
334void amba_driver_unregister(struct amba_driver *drv)
335{
336 driver_unregister(&drv->drv);
337}
338
339
340static void amba_device_release(struct device *dev)
341{
342 struct amba_device *d = to_amba_device(dev);
343
344 if (d->res.parent)
345 release_resource(&d->res);
346 kfree(d);
347}
348
349static int amba_device_try_add(struct amba_device *dev, struct resource *parent)
350{
351 u32 size;
352 void __iomem *tmp;
353 int i, ret;
354
355 WARN_ON(dev->irq[0] == (unsigned int)-1);
356 WARN_ON(dev->irq[1] == (unsigned int)-1);
357
358 ret = request_resource(parent, &dev->res);
359 if (ret)
360 goto err_out;
361
362
363 if (dev->periphid != 0)
364 goto skip_probe;
365
366
367
368
369
370 size = resource_size(&dev->res);
371 tmp = ioremap(dev->res.start, size);
372 if (!tmp) {
373 ret = -ENOMEM;
374 goto err_release;
375 }
376
377 ret = dev_pm_domain_attach(&dev->dev, true);
378 if (ret == -EPROBE_DEFER) {
379 iounmap(tmp);
380 goto err_release;
381 }
382
383 ret = amba_get_enable_pclk(dev);
384 if (ret == 0) {
385 u32 pid, cid;
386
387
388
389
390
391 for (pid = 0, i = 0; i < 4; i++)
392 pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) <<
393 (i * 8);
394 for (cid = 0, i = 0; i < 4; i++)
395 cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) <<
396 (i * 8);
397
398 amba_put_disable_pclk(dev);
399
400 if (cid == AMBA_CID || cid == CORESIGHT_CID)
401 dev->periphid = pid;
402
403 if (!dev->periphid)
404 ret = -ENODEV;
405 }
406
407 iounmap(tmp);
408 dev_pm_domain_detach(&dev->dev, true);
409
410 if (ret)
411 goto err_release;
412
413 skip_probe:
414 ret = device_add(&dev->dev);
415 if (ret)
416 goto err_release;
417
418 if (dev->irq[0])
419 ret = device_create_file(&dev->dev, &dev_attr_irq0);
420 if (ret == 0 && dev->irq[1])
421 ret = device_create_file(&dev->dev, &dev_attr_irq1);
422 if (ret == 0)
423 return ret;
424
425 device_unregister(&dev->dev);
426
427 err_release:
428 release_resource(&dev->res);
429 err_out:
430 return ret;
431}
432
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439
440
441
442struct deferred_device {
443 struct amba_device *dev;
444 struct resource *parent;
445 struct list_head node;
446};
447
448static LIST_HEAD(deferred_devices);
449static DEFINE_MUTEX(deferred_devices_lock);
450
451static void amba_deferred_retry_func(struct work_struct *dummy);
452static DECLARE_DELAYED_WORK(deferred_retry_work, amba_deferred_retry_func);
453
454#define DEFERRED_DEVICE_TIMEOUT (msecs_to_jiffies(5 * 1000))
455
456static void amba_deferred_retry_func(struct work_struct *dummy)
457{
458 struct deferred_device *ddev, *tmp;
459
460 mutex_lock(&deferred_devices_lock);
461
462 list_for_each_entry_safe(ddev, tmp, &deferred_devices, node) {
463 int ret = amba_device_try_add(ddev->dev, ddev->parent);
464
465 if (ret == -EPROBE_DEFER)
466 continue;
467
468 list_del_init(&ddev->node);
469 kfree(ddev);
470 }
471
472 if (!list_empty(&deferred_devices))
473 schedule_delayed_work(&deferred_retry_work,
474 DEFERRED_DEVICE_TIMEOUT);
475
476 mutex_unlock(&deferred_devices_lock);
477}
478
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486
487
488int amba_device_add(struct amba_device *dev, struct resource *parent)
489{
490 int ret = amba_device_try_add(dev, parent);
491
492 if (ret == -EPROBE_DEFER) {
493 struct deferred_device *ddev;
494
495 ddev = kmalloc(sizeof(*ddev), GFP_KERNEL);
496 if (!ddev)
497 return -ENOMEM;
498
499 ddev->dev = dev;
500 ddev->parent = parent;
501 ret = 0;
502
503 mutex_lock(&deferred_devices_lock);
504
505 if (list_empty(&deferred_devices))
506 schedule_delayed_work(&deferred_retry_work,
507 DEFERRED_DEVICE_TIMEOUT);
508 list_add_tail(&ddev->node, &deferred_devices);
509
510 mutex_unlock(&deferred_devices_lock);
511 }
512 return ret;
513}
514EXPORT_SYMBOL_GPL(amba_device_add);
515
516static struct amba_device *
517amba_aphb_device_add(struct device *parent, const char *name,
518 resource_size_t base, size_t size, int irq1, int irq2,
519 void *pdata, unsigned int periphid, u64 dma_mask,
520 struct resource *resbase)
521{
522 struct amba_device *dev;
523 int ret;
524
525 dev = amba_device_alloc(name, base, size);
526 if (!dev)
527 return ERR_PTR(-ENOMEM);
528
529 dev->dev.coherent_dma_mask = dma_mask;
530 dev->irq[0] = irq1;
531 dev->irq[1] = irq2;
532 dev->periphid = periphid;
533 dev->dev.platform_data = pdata;
534 dev->dev.parent = parent;
535
536 ret = amba_device_add(dev, resbase);
537 if (ret) {
538 amba_device_put(dev);
539 return ERR_PTR(ret);
540 }
541
542 return dev;
543}
544
545struct amba_device *
546amba_apb_device_add(struct device *parent, const char *name,
547 resource_size_t base, size_t size, int irq1, int irq2,
548 void *pdata, unsigned int periphid)
549{
550 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
551 periphid, 0, &iomem_resource);
552}
553EXPORT_SYMBOL_GPL(amba_apb_device_add);
554
555struct amba_device *
556amba_ahb_device_add(struct device *parent, const char *name,
557 resource_size_t base, size_t size, int irq1, int irq2,
558 void *pdata, unsigned int periphid)
559{
560 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
561 periphid, ~0ULL, &iomem_resource);
562}
563EXPORT_SYMBOL_GPL(amba_ahb_device_add);
564
565struct amba_device *
566amba_apb_device_add_res(struct device *parent, const char *name,
567 resource_size_t base, size_t size, int irq1,
568 int irq2, void *pdata, unsigned int periphid,
569 struct resource *resbase)
570{
571 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
572 periphid, 0, resbase);
573}
574EXPORT_SYMBOL_GPL(amba_apb_device_add_res);
575
576struct amba_device *
577amba_ahb_device_add_res(struct device *parent, const char *name,
578 resource_size_t base, size_t size, int irq1,
579 int irq2, void *pdata, unsigned int periphid,
580 struct resource *resbase)
581{
582 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
583 periphid, ~0ULL, resbase);
584}
585EXPORT_SYMBOL_GPL(amba_ahb_device_add_res);
586
587
588static void amba_device_initialize(struct amba_device *dev, const char *name)
589{
590 device_initialize(&dev->dev);
591 if (name)
592 dev_set_name(&dev->dev, "%s", name);
593 dev->dev.release = amba_device_release;
594 dev->dev.bus = &amba_bustype;
595 dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
596 dev->res.name = dev_name(&dev->dev);
597}
598
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606
607
608struct amba_device *amba_device_alloc(const char *name, resource_size_t base,
609 size_t size)
610{
611 struct amba_device *dev;
612
613 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
614 if (dev) {
615 amba_device_initialize(dev, name);
616 dev->res.start = base;
617 dev->res.end = base + size - 1;
618 dev->res.flags = IORESOURCE_MEM;
619 }
620
621 return dev;
622}
623EXPORT_SYMBOL_GPL(amba_device_alloc);
624
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631
632
633
634int amba_device_register(struct amba_device *dev, struct resource *parent)
635{
636 amba_device_initialize(dev, dev->dev.init_name);
637 dev->dev.init_name = NULL;
638
639 return amba_device_add(dev, parent);
640}
641
642
643
644
645
646void amba_device_put(struct amba_device *dev)
647{
648 put_device(&dev->dev);
649}
650EXPORT_SYMBOL_GPL(amba_device_put);
651
652
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655
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661
662
663void amba_device_unregister(struct amba_device *dev)
664{
665 device_unregister(&dev->dev);
666}
667
668
669struct find_data {
670 struct amba_device *dev;
671 struct device *parent;
672 const char *busid;
673 unsigned int id;
674 unsigned int mask;
675};
676
677static int amba_find_match(struct device *dev, void *data)
678{
679 struct find_data *d = data;
680 struct amba_device *pcdev = to_amba_device(dev);
681 int r;
682
683 r = (pcdev->periphid & d->mask) == d->id;
684 if (d->parent)
685 r &= d->parent == dev->parent;
686 if (d->busid)
687 r &= strcmp(dev_name(dev), d->busid) == 0;
688
689 if (r) {
690 get_device(dev);
691 d->dev = pcdev;
692 }
693
694 return r;
695}
696
697
698
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700
701
702
703
704
705
706
707
708
709
710
711struct amba_device *
712amba_find_device(const char *busid, struct device *parent, unsigned int id,
713 unsigned int mask)
714{
715 struct find_data data;
716
717 data.dev = NULL;
718 data.parent = parent;
719 data.busid = busid;
720 data.id = id;
721 data.mask = mask;
722
723 bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
724
725 return data.dev;
726}
727
728
729
730
731
732
733int amba_request_regions(struct amba_device *dev, const char *name)
734{
735 int ret = 0;
736 u32 size;
737
738 if (!name)
739 name = dev->dev.driver->name;
740
741 size = resource_size(&dev->res);
742
743 if (!request_mem_region(dev->res.start, size, name))
744 ret = -EBUSY;
745
746 return ret;
747}
748
749
750
751
752
753
754
755void amba_release_regions(struct amba_device *dev)
756{
757 u32 size;
758
759 size = resource_size(&dev->res);
760 release_mem_region(dev->res.start, size);
761}
762
763EXPORT_SYMBOL(amba_driver_register);
764EXPORT_SYMBOL(amba_driver_unregister);
765EXPORT_SYMBOL(amba_device_register);
766EXPORT_SYMBOL(amba_device_unregister);
767EXPORT_SYMBOL(amba_find_device);
768EXPORT_SYMBOL(amba_request_regions);
769EXPORT_SYMBOL(amba_release_regions);
770