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