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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#include <linux/of_irq.h>
23#include <linux/of_device.h>
24#include <linux/acpi.h>
25#include <linux/iommu.h>
26#include <linux/dma-map-ops.h>
27
28#define to_amba_driver(d) container_of(d, struct amba_driver, drv)
29
30/* called on periphid match and class 0x9 coresight device. */
31static int
32amba_cs_uci_id_match(const struct amba_id *table, struct amba_device *dev)
33{
34 int ret = 0;
35 struct amba_cs_uci_id *uci;
36
37 uci = table->data;
38
39 /* no table data or zero mask - return match on periphid */
40 if (!uci || (uci->devarch_mask == 0))
41 return 1;
42
43 /* test against read devtype and masked devarch value */
44 ret = (dev->uci.devtype == uci->devtype) &&
45 ((dev->uci.devarch & uci->devarch_mask) == uci->devarch);
46 return ret;
47}
48
49static const struct amba_id *
50amba_lookup(const struct amba_id *table, struct amba_device *dev)
51{
52 while (table->mask) {
53 if (((dev->periphid & table->mask) == table->id) &&
54 ((dev->cid != CORESIGHT_CID) ||
55 (amba_cs_uci_id_match(table, dev))))
56 return table;
57 table++;
58 }
59 return NULL;
60}
61
62static int amba_get_enable_pclk(struct amba_device *pcdev)
63{
64 int ret;
65
66 pcdev->pclk = clk_get(&pcdev->dev, "apb_pclk");
67 if (IS_ERR(pcdev->pclk))
68 return PTR_ERR(pcdev->pclk);
69
70 ret = clk_prepare_enable(pcdev->pclk);
71 if (ret)
72 clk_put(pcdev->pclk);
73
74 return ret;
75}
76
77static void amba_put_disable_pclk(struct amba_device *pcdev)
78{
79 clk_disable_unprepare(pcdev->pclk);
80 clk_put(pcdev->pclk);
81}
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 int ret;
102
103 ret = driver_set_override(_dev, &dev->driver_override, buf, count);
104 if (ret)
105 return ret;
106
107 return count;
108}
109static DEVICE_ATTR_RW(driver_override);
110
111#define amba_attr_func(name,fmt,arg...) \
112static ssize_t name##_show(struct device *_dev, \
113 struct device_attribute *attr, char *buf) \
114{ \
115 struct amba_device *dev = to_amba_device(_dev); \
116 return sprintf(buf, fmt, arg); \
117} \
118static DEVICE_ATTR_RO(name)
119
120amba_attr_func(id, "%08x\n", dev->periphid);
121amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
122 (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
123 dev->res.flags);
124
125static struct attribute *amba_dev_attrs[] = {
126 &dev_attr_id.attr,
127 &dev_attr_resource.attr,
128 &dev_attr_driver_override.attr,
129 NULL,
130};
131ATTRIBUTE_GROUPS(amba_dev);
132
133static int amba_read_periphid(struct amba_device *dev)
134{
135 struct reset_control *rstc;
136 u32 size, pid, cid;
137 void __iomem *tmp;
138 int i, ret;
139
140 ret = dev_pm_domain_attach(&dev->dev, true);
141 if (ret) {
142 dev_dbg(&dev->dev, "can't get PM domain: %d\n", ret);
143 goto err_out;
144 }
145
146 ret = amba_get_enable_pclk(dev);
147 if (ret) {
148 dev_dbg(&dev->dev, "can't get pclk: %d\n", ret);
149 goto err_pm;
150 }
151
152 /*
153 * Find reset control(s) of the amba bus and de-assert them.
154 */
155 rstc = of_reset_control_array_get_optional_shared(dev->dev.of_node);
156 if (IS_ERR(rstc)) {
157 ret = PTR_ERR(rstc);
158 if (ret != -EPROBE_DEFER)
159 dev_err(&dev->dev, "can't get reset: %d\n", ret);
160 goto err_clk;
161 }
162 reset_control_deassert(rstc);
163 reset_control_put(rstc);
164
165 size = resource_size(&dev->res);
166 tmp = ioremap(dev->res.start, size);
167 if (!tmp) {
168 ret = -ENOMEM;
169 goto err_clk;
170 }
171
172 /*
173 * Read pid and cid based on size of resource
174 * they are located at end of region
175 */
176 for (pid = 0, i = 0; i < 4; i++)
177 pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) << (i * 8);
178 for (cid = 0, i = 0; i < 4; i++)
179 cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) << (i * 8);
180
181 if (cid == CORESIGHT_CID) {
182 /* set the base to the start of the last 4k block */
183 void __iomem *csbase = tmp + size - 4096;
184
185 dev->uci.devarch = readl(csbase + UCI_REG_DEVARCH_OFFSET);
186 dev->uci.devtype = readl(csbase + UCI_REG_DEVTYPE_OFFSET) & 0xff;
187 }
188
189 if (cid == AMBA_CID || cid == CORESIGHT_CID) {
190 dev->periphid = pid;
191 dev->cid = cid;
192 }
193
194 if (!dev->periphid)
195 ret = -ENODEV;
196
197 iounmap(tmp);
198
199err_clk:
200 amba_put_disable_pclk(dev);
201err_pm:
202 dev_pm_domain_detach(&dev->dev, true);
203err_out:
204 return ret;
205}
206
207static int amba_match(struct device *dev, struct device_driver *drv)
208{
209 struct amba_device *pcdev = to_amba_device(dev);
210 struct amba_driver *pcdrv = to_amba_driver(drv);
211
212 mutex_lock(&pcdev->periphid_lock);
213 if (!pcdev->periphid) {
214 int ret = amba_read_periphid(pcdev);
215
216 /*
217 * Returning any error other than -EPROBE_DEFER from bus match
218 * can cause driver registration failure. So, if there's a
219 * permanent failure in reading pid and cid, simply map it to
220 * -EPROBE_DEFER.
221 */
222 if (ret) {
223 mutex_unlock(&pcdev->periphid_lock);
224 return -EPROBE_DEFER;
225 }
226 dev_set_uevent_suppress(dev, false);
227 kobject_uevent(&dev->kobj, KOBJ_ADD);
228 }
229 mutex_unlock(&pcdev->periphid_lock);
230
231 /* When driver_override is set, only bind to the matching driver */
232 if (pcdev->driver_override)
233 return !strcmp(pcdev->driver_override, drv->name);
234
235 return amba_lookup(pcdrv->id_table, pcdev) != NULL;
236}
237
238static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
239{
240 struct amba_device *pcdev = to_amba_device(dev);
241 int retval = 0;
242
243 retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
244 if (retval)
245 return retval;
246
247 retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid);
248 return retval;
249}
250
251static int of_amba_device_decode_irq(struct amba_device *dev)
252{
253 struct device_node *node = dev->dev.of_node;
254 int i, irq = 0;
255
256 if (IS_ENABLED(CONFIG_OF_IRQ) && node) {
257 /* Decode the IRQs and address ranges */
258 for (i = 0; i < AMBA_NR_IRQS; i++) {
259 irq = of_irq_get(node, i);
260 if (irq < 0) {
261 if (irq == -EPROBE_DEFER)
262 return irq;
263 irq = 0;
264 }
265
266 dev->irq[i] = irq;
267 }
268 }
269
270 return 0;
271}
272
273/*
274 * These are the device model conversion veneers; they convert the
275 * device model structures to our more specific structures.
276 */
277static int amba_probe(struct device *dev)
278{
279 struct amba_device *pcdev = to_amba_device(dev);
280 struct amba_driver *pcdrv = to_amba_driver(dev->driver);
281 const struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev);
282 int ret;
283
284 do {
285 ret = of_amba_device_decode_irq(pcdev);
286 if (ret)
287 break;
288
289 ret = of_clk_set_defaults(dev->of_node, false);
290 if (ret < 0)
291 break;
292
293 ret = dev_pm_domain_attach(dev, true);
294 if (ret)
295 break;
296
297 ret = amba_get_enable_pclk(pcdev);
298 if (ret) {
299 dev_pm_domain_detach(dev, true);
300 break;
301 }
302
303 pm_runtime_get_noresume(dev);
304 pm_runtime_set_active(dev);
305 pm_runtime_enable(dev);
306
307 ret = pcdrv->probe(pcdev, id);
308 if (ret == 0)
309 break;
310
311 pm_runtime_disable(dev);
312 pm_runtime_set_suspended(dev);
313 pm_runtime_put_noidle(dev);
314
315 amba_put_disable_pclk(pcdev);
316 dev_pm_domain_detach(dev, true);
317 } while (0);
318
319 return ret;
320}
321
322static void amba_remove(struct device *dev)
323{
324 struct amba_device *pcdev = to_amba_device(dev);
325 struct amba_driver *drv = to_amba_driver(dev->driver);
326
327 pm_runtime_get_sync(dev);
328 if (drv->remove)
329 drv->remove(pcdev);
330 pm_runtime_put_noidle(dev);
331
332 /* Undo the runtime PM settings in amba_probe() */
333 pm_runtime_disable(dev);
334 pm_runtime_set_suspended(dev);
335 pm_runtime_put_noidle(dev);
336
337 amba_put_disable_pclk(pcdev);
338 dev_pm_domain_detach(dev, true);
339}
340
341static void amba_shutdown(struct device *dev)
342{
343 struct amba_driver *drv;
344
345 if (!dev->driver)
346 return;
347
348 drv = to_amba_driver(dev->driver);
349 if (drv->shutdown)
350 drv->shutdown(to_amba_device(dev));
351}
352
353static int amba_dma_configure(struct device *dev)
354{
355 struct amba_driver *drv = to_amba_driver(dev->driver);
356 enum dev_dma_attr attr;
357 int ret = 0;
358
359 if (dev->of_node) {
360 ret = of_dma_configure(dev, dev->of_node, true);
361 } else if (has_acpi_companion(dev)) {
362 attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode));
363 ret = acpi_dma_configure(dev, attr);
364 }
365
366 if (!ret && !drv->driver_managed_dma) {
367 ret = iommu_device_use_default_domain(dev);
368 if (ret)
369 arch_teardown_dma_ops(dev);
370 }
371
372 return ret;
373}
374
375static void amba_dma_cleanup(struct device *dev)
376{
377 struct amba_driver *drv = to_amba_driver(dev->driver);
378
379 if (!drv->driver_managed_dma)
380 iommu_device_unuse_default_domain(dev);
381}
382
383#ifdef CONFIG_PM
384/*
385 * Hooks to provide runtime PM of the pclk (bus clock). It is safe to
386 * enable/disable the bus clock at runtime PM suspend/resume as this
387 * does not result in loss of context.
388 */
389static int amba_pm_runtime_suspend(struct device *dev)
390{
391 struct amba_device *pcdev = to_amba_device(dev);
392 int ret = pm_generic_runtime_suspend(dev);
393
394 if (ret == 0 && dev->driver) {
395 if (pm_runtime_is_irq_safe(dev))
396 clk_disable(pcdev->pclk);
397 else
398 clk_disable_unprepare(pcdev->pclk);
399 }
400
401 return ret;
402}
403
404static int amba_pm_runtime_resume(struct device *dev)
405{
406 struct amba_device *pcdev = to_amba_device(dev);
407 int ret;
408
409 if (dev->driver) {
410 if (pm_runtime_is_irq_safe(dev))
411 ret = clk_enable(pcdev->pclk);
412 else
413 ret = clk_prepare_enable(pcdev->pclk);
414 /* Failure is probably fatal to the system, but... */
415 if (ret)
416 return ret;
417 }
418
419 return pm_generic_runtime_resume(dev);
420}
421#endif /* CONFIG_PM */
422
423static const struct dev_pm_ops amba_pm = {
424 SET_RUNTIME_PM_OPS(
425 amba_pm_runtime_suspend,
426 amba_pm_runtime_resume,
427 NULL
428 )
429};
430
431/*
432 * Primecells are part of the Advanced Microcontroller Bus Architecture,
433 * so we call the bus "amba".
434 * DMA configuration for platform and AMBA bus is same. So here we reuse
435 * platform's DMA config routine.
436 */
437struct bus_type amba_bustype = {
438 .name = "amba",
439 .dev_groups = amba_dev_groups,
440 .match = amba_match,
441 .uevent = amba_uevent,
442 .probe = amba_probe,
443 .remove = amba_remove,
444 .shutdown = amba_shutdown,
445 .dma_configure = amba_dma_configure,
446 .dma_cleanup = amba_dma_cleanup,
447 .pm = &amba_pm,
448};
449EXPORT_SYMBOL_GPL(amba_bustype);
450
451static int __init amba_init(void)
452{
453 return bus_register(&amba_bustype);
454}
455
456postcore_initcall(amba_init);
457
458static int amba_proxy_probe(struct amba_device *adev,
459 const struct amba_id *id)
460{
461 WARN(1, "Stub driver should never match any device.\n");
462 return -ENODEV;
463}
464
465static const struct amba_id amba_stub_drv_ids[] = {
466 { 0, 0 },
467};
468
469static struct amba_driver amba_proxy_drv = {
470 .drv = {
471 .name = "amba-proxy",
472 },
473 .probe = amba_proxy_probe,
474 .id_table = amba_stub_drv_ids,
475};
476
477static int __init amba_stub_drv_init(void)
478{
479 if (!IS_ENABLED(CONFIG_MODULES))
480 return 0;
481
482 /*
483 * The amba_match() function will get called only if there is at least
484 * one amba driver registered. If all amba drivers are modules and are
485 * only loaded based on uevents, then we'll hit a chicken-and-egg
486 * situation where amba_match() is waiting on drivers and drivers are
487 * waiting on amba_match(). So, register a stub driver to make sure
488 * amba_match() is called even if no amba driver has been registered.
489 */
490 return amba_driver_register(&amba_proxy_drv);
491}
492late_initcall_sync(amba_stub_drv_init);
493
494/**
495 * amba_driver_register - register an AMBA device driver
496 * @drv: amba device driver structure
497 *
498 * Register an AMBA device driver with the Linux device model
499 * core. If devices pre-exist, the drivers probe function will
500 * be called.
501 */
502int amba_driver_register(struct amba_driver *drv)
503{
504 if (!drv->probe)
505 return -EINVAL;
506
507 drv->drv.bus = &amba_bustype;
508
509 return driver_register(&drv->drv);
510}
511EXPORT_SYMBOL(amba_driver_register);
512
513/**
514 * amba_driver_unregister - remove an AMBA device driver
515 * @drv: AMBA device driver structure to remove
516 *
517 * Unregister an AMBA device driver from the Linux device
518 * model. The device model will call the drivers remove function
519 * for each device the device driver is currently handling.
520 */
521void amba_driver_unregister(struct amba_driver *drv)
522{
523 driver_unregister(&drv->drv);
524}
525EXPORT_SYMBOL(amba_driver_unregister);
526
527static void amba_device_release(struct device *dev)
528{
529 struct amba_device *d = to_amba_device(dev);
530
531 if (d->res.parent)
532 release_resource(&d->res);
533 mutex_destroy(&d->periphid_lock);
534 kfree(d);
535}
536
537/**
538 * amba_device_add - add a previously allocated AMBA device structure
539 * @dev: AMBA device allocated by amba_device_alloc
540 * @parent: resource parent for this devices resources
541 *
542 * Claim the resource, and read the device cell ID if not already
543 * initialized. Register the AMBA device with the Linux device
544 * manager.
545 */
546int amba_device_add(struct amba_device *dev, struct resource *parent)
547{
548 int ret;
549
550 ret = request_resource(parent, &dev->res);
551 if (ret)
552 return ret;
553
554 /* If primecell ID isn't hard-coded, figure it out */
555 if (!dev->periphid) {
556 /*
557 * AMBA device uevents require reading its pid and cid
558 * registers. To do this, the device must be on, clocked and
559 * out of reset. However in some cases those resources might
560 * not yet be available. If that's the case, we suppress the
561 * generation of uevents until we can read the pid and cid
562 * registers. See also amba_match().
563 */
564 if (amba_read_periphid(dev))
565 dev_set_uevent_suppress(&dev->dev, true);
566 }
567
568 ret = device_add(&dev->dev);
569 if (ret)
570 release_resource(&dev->res);
571
572 return ret;
573}
574EXPORT_SYMBOL_GPL(amba_device_add);
575
576static void amba_device_initialize(struct amba_device *dev, const char *name)
577{
578 device_initialize(&dev->dev);
579 if (name)
580 dev_set_name(&dev->dev, "%s", name);
581 dev->dev.release = amba_device_release;
582 dev->dev.bus = &amba_bustype;
583 dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
584 dev->dev.dma_parms = &dev->dma_parms;
585 dev->res.name = dev_name(&dev->dev);
586 mutex_init(&dev->periphid_lock);
587}
588
589/**
590 * amba_device_alloc - allocate an AMBA device
591 * @name: sysfs name of the AMBA device
592 * @base: base of AMBA device
593 * @size: size of AMBA device
594 *
595 * Allocate and initialize an AMBA device structure. Returns %NULL
596 * on failure.
597 */
598struct amba_device *amba_device_alloc(const char *name, resource_size_t base,
599 size_t size)
600{
601 struct amba_device *dev;
602
603 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
604 if (dev) {
605 amba_device_initialize(dev, name);
606 dev->res.start = base;
607 dev->res.end = base + size - 1;
608 dev->res.flags = IORESOURCE_MEM;
609 }
610
611 return dev;
612}
613EXPORT_SYMBOL_GPL(amba_device_alloc);
614
615/**
616 * amba_device_register - register an AMBA device
617 * @dev: AMBA device to register
618 * @parent: parent memory resource
619 *
620 * Setup the AMBA device, reading the cell ID if present.
621 * Claim the resource, and register the AMBA device with
622 * the Linux device manager.
623 */
624int amba_device_register(struct amba_device *dev, struct resource *parent)
625{
626 amba_device_initialize(dev, dev->dev.init_name);
627 dev->dev.init_name = NULL;
628
629 return amba_device_add(dev, parent);
630}
631EXPORT_SYMBOL(amba_device_register);
632
633/**
634 * amba_device_put - put an AMBA device
635 * @dev: AMBA device to put
636 */
637void amba_device_put(struct amba_device *dev)
638{
639 put_device(&dev->dev);
640}
641EXPORT_SYMBOL_GPL(amba_device_put);
642
643/**
644 * amba_device_unregister - unregister an AMBA device
645 * @dev: AMBA device to remove
646 *
647 * Remove the specified AMBA device from the Linux device
648 * manager. All files associated with this object will be
649 * destroyed, and device drivers notified that the device has
650 * been removed. The AMBA device's resources including
651 * the amba_device structure will be freed once all
652 * references to it have been dropped.
653 */
654void amba_device_unregister(struct amba_device *dev)
655{
656 device_unregister(&dev->dev);
657}
658EXPORT_SYMBOL(amba_device_unregister);
659
660/**
661 * amba_request_regions - request all mem regions associated with device
662 * @dev: amba_device structure for device
663 * @name: name, or NULL to use driver name
664 */
665int amba_request_regions(struct amba_device *dev, const char *name)
666{
667 int ret = 0;
668 u32 size;
669
670 if (!name)
671 name = dev->dev.driver->name;
672
673 size = resource_size(&dev->res);
674
675 if (!request_mem_region(dev->res.start, size, name))
676 ret = -EBUSY;
677
678 return ret;
679}
680EXPORT_SYMBOL(amba_request_regions);
681
682/**
683 * amba_release_regions - release mem regions associated with device
684 * @dev: amba_device structure for device
685 *
686 * Release regions claimed by a successful call to amba_request_regions.
687 */
688void amba_release_regions(struct amba_device *dev)
689{
690 u32 size;
691
692 size = resource_size(&dev->res);
693 release_mem_region(dev->res.start, size);
694}
695EXPORT_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
23#include <asm/irq.h>
24
25#define to_amba_driver(d) container_of(d, struct amba_driver, drv)
26
27static const struct amba_id *
28amba_lookup(const struct amba_id *table, struct amba_device *dev)
29{
30 int ret = 0;
31
32 while (table->mask) {
33 ret = (dev->periphid & table->mask) == table->id;
34 if (ret)
35 break;
36 table++;
37 }
38
39 return ret ? table : NULL;
40}
41
42static int amba_match(struct device *dev, struct device_driver *drv)
43{
44 struct amba_device *pcdev = to_amba_device(dev);
45 struct amba_driver *pcdrv = to_amba_driver(drv);
46
47 /* When driver_override is set, only bind to the matching driver */
48 if (pcdev->driver_override)
49 return !strcmp(pcdev->driver_override, drv->name);
50
51 return amba_lookup(pcdrv->id_table, pcdev) != NULL;
52}
53
54static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
55{
56 struct amba_device *pcdev = to_amba_device(dev);
57 int retval = 0;
58
59 retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
60 if (retval)
61 return retval;
62
63 retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid);
64 return retval;
65}
66
67static ssize_t driver_override_show(struct device *_dev,
68 struct device_attribute *attr, char *buf)
69{
70 struct amba_device *dev = to_amba_device(_dev);
71
72 if (!dev->driver_override)
73 return 0;
74
75 return sprintf(buf, "%s\n", dev->driver_override);
76}
77
78static ssize_t driver_override_store(struct device *_dev,
79 struct device_attribute *attr,
80 const char *buf, size_t count)
81{
82 struct amba_device *dev = to_amba_device(_dev);
83 char *driver_override, *old = dev->driver_override, *cp;
84
85 if (count > PATH_MAX)
86 return -EINVAL;
87
88 driver_override = kstrndup(buf, count, GFP_KERNEL);
89 if (!driver_override)
90 return -ENOMEM;
91
92 cp = strchr(driver_override, '\n');
93 if (cp)
94 *cp = '\0';
95
96 if (strlen(driver_override)) {
97 dev->driver_override = driver_override;
98 } else {
99 kfree(driver_override);
100 dev->driver_override = NULL;
101 }
102
103 kfree(old);
104
105 return count;
106}
107
108#define amba_attr_func(name,fmt,arg...) \
109static ssize_t name##_show(struct device *_dev, \
110 struct device_attribute *attr, char *buf) \
111{ \
112 struct amba_device *dev = to_amba_device(_dev); \
113 return sprintf(buf, fmt, arg); \
114}
115
116#define amba_attr(name,fmt,arg...) \
117amba_attr_func(name,fmt,arg) \
118static DEVICE_ATTR(name, S_IRUGO, name##_show, NULL)
119
120amba_attr_func(id, "%08x\n", dev->periphid);
121amba_attr(irq0, "%u\n", dev->irq[0]);
122amba_attr(irq1, "%u\n", dev->irq[1]);
123amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
124 (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
125 dev->res.flags);
126
127static struct device_attribute amba_dev_attrs[] = {
128 __ATTR_RO(id),
129 __ATTR_RO(resource),
130 __ATTR_RW(driver_override),
131 __ATTR_NULL,
132};
133
134#ifdef CONFIG_PM
135/*
136 * Hooks to provide runtime PM of the pclk (bus clock). It is safe to
137 * enable/disable the bus clock at runtime PM suspend/resume as this
138 * does not result in loss of context.
139 */
140static int amba_pm_runtime_suspend(struct device *dev)
141{
142 struct amba_device *pcdev = to_amba_device(dev);
143 int ret = pm_generic_runtime_suspend(dev);
144
145 if (ret == 0 && dev->driver) {
146 if (pm_runtime_is_irq_safe(dev))
147 clk_disable(pcdev->pclk);
148 else
149 clk_disable_unprepare(pcdev->pclk);
150 }
151
152 return ret;
153}
154
155static int amba_pm_runtime_resume(struct device *dev)
156{
157 struct amba_device *pcdev = to_amba_device(dev);
158 int ret;
159
160 if (dev->driver) {
161 if (pm_runtime_is_irq_safe(dev))
162 ret = clk_enable(pcdev->pclk);
163 else
164 ret = clk_prepare_enable(pcdev->pclk);
165 /* Failure is probably fatal to the system, but... */
166 if (ret)
167 return ret;
168 }
169
170 return pm_generic_runtime_resume(dev);
171}
172#endif /* CONFIG_PM */
173
174static const struct dev_pm_ops amba_pm = {
175 .suspend = pm_generic_suspend,
176 .resume = pm_generic_resume,
177 .freeze = pm_generic_freeze,
178 .thaw = pm_generic_thaw,
179 .poweroff = pm_generic_poweroff,
180 .restore = pm_generic_restore,
181 SET_RUNTIME_PM_OPS(
182 amba_pm_runtime_suspend,
183 amba_pm_runtime_resume,
184 NULL
185 )
186};
187
188/*
189 * Primecells are part of the Advanced Microcontroller Bus Architecture,
190 * so we call the bus "amba".
191 */
192struct bus_type amba_bustype = {
193 .name = "amba",
194 .dev_attrs = amba_dev_attrs,
195 .match = amba_match,
196 .uevent = amba_uevent,
197 .pm = &amba_pm,
198};
199
200static int __init amba_init(void)
201{
202 return bus_register(&amba_bustype);
203}
204
205postcore_initcall(amba_init);
206
207static int amba_get_enable_pclk(struct amba_device *pcdev)
208{
209 int ret;
210
211 pcdev->pclk = clk_get(&pcdev->dev, "apb_pclk");
212 if (IS_ERR(pcdev->pclk))
213 return PTR_ERR(pcdev->pclk);
214
215 ret = clk_prepare_enable(pcdev->pclk);
216 if (ret)
217 clk_put(pcdev->pclk);
218
219 return ret;
220}
221
222static void amba_put_disable_pclk(struct amba_device *pcdev)
223{
224 clk_disable_unprepare(pcdev->pclk);
225 clk_put(pcdev->pclk);
226}
227
228/*
229 * These are the device model conversion veneers; they convert the
230 * device model structures to our more specific structures.
231 */
232static int amba_probe(struct device *dev)
233{
234 struct amba_device *pcdev = to_amba_device(dev);
235 struct amba_driver *pcdrv = to_amba_driver(dev->driver);
236 const struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev);
237 int ret;
238
239 do {
240 ret = dev_pm_domain_attach(dev, true);
241 if (ret == -EPROBE_DEFER)
242 break;
243
244 ret = amba_get_enable_pclk(pcdev);
245 if (ret) {
246 dev_pm_domain_detach(dev, true);
247 break;
248 }
249
250 pm_runtime_get_noresume(dev);
251 pm_runtime_set_active(dev);
252 pm_runtime_enable(dev);
253
254 ret = pcdrv->probe(pcdev, id);
255 if (ret == 0)
256 break;
257
258 pm_runtime_disable(dev);
259 pm_runtime_set_suspended(dev);
260 pm_runtime_put_noidle(dev);
261
262 amba_put_disable_pclk(pcdev);
263 dev_pm_domain_detach(dev, true);
264 } while (0);
265
266 return ret;
267}
268
269static int amba_remove(struct device *dev)
270{
271 struct amba_device *pcdev = to_amba_device(dev);
272 struct amba_driver *drv = to_amba_driver(dev->driver);
273 int ret;
274
275 pm_runtime_get_sync(dev);
276 ret = drv->remove(pcdev);
277 pm_runtime_put_noidle(dev);
278
279 /* Undo the runtime PM settings in amba_probe() */
280 pm_runtime_disable(dev);
281 pm_runtime_set_suspended(dev);
282 pm_runtime_put_noidle(dev);
283
284 amba_put_disable_pclk(pcdev);
285 dev_pm_domain_detach(dev, true);
286
287 return ret;
288}
289
290static void amba_shutdown(struct device *dev)
291{
292 struct amba_driver *drv = to_amba_driver(dev->driver);
293 drv->shutdown(to_amba_device(dev));
294}
295
296/**
297 * amba_driver_register - register an AMBA device driver
298 * @drv: amba device driver structure
299 *
300 * Register an AMBA device driver with the Linux device model
301 * core. If devices pre-exist, the drivers probe function will
302 * be called.
303 */
304int amba_driver_register(struct amba_driver *drv)
305{
306 drv->drv.bus = &amba_bustype;
307
308#define SETFN(fn) if (drv->fn) drv->drv.fn = amba_##fn
309 SETFN(probe);
310 SETFN(remove);
311 SETFN(shutdown);
312
313 return driver_register(&drv->drv);
314}
315
316/**
317 * amba_driver_unregister - remove an AMBA device driver
318 * @drv: AMBA device driver structure to remove
319 *
320 * Unregister an AMBA device driver from the Linux device
321 * model. The device model will call the drivers remove function
322 * for each device the device driver is currently handling.
323 */
324void amba_driver_unregister(struct amba_driver *drv)
325{
326 driver_unregister(&drv->drv);
327}
328
329
330static void amba_device_release(struct device *dev)
331{
332 struct amba_device *d = to_amba_device(dev);
333
334 if (d->res.parent)
335 release_resource(&d->res);
336 kfree(d);
337}
338
339/**
340 * amba_device_add - add a previously allocated AMBA device structure
341 * @dev: AMBA device allocated by amba_device_alloc
342 * @parent: resource parent for this devices resources
343 *
344 * Claim the resource, and read the device cell ID if not already
345 * initialized. Register the AMBA device with the Linux device
346 * manager.
347 */
348int amba_device_add(struct amba_device *dev, struct resource *parent)
349{
350 u32 size;
351 void __iomem *tmp;
352 int i, ret;
353
354 WARN_ON(dev->irq[0] == (unsigned int)-1);
355 WARN_ON(dev->irq[1] == (unsigned int)-1);
356
357 ret = request_resource(parent, &dev->res);
358 if (ret)
359 goto err_out;
360
361 /* Hard-coded primecell ID instead of plug-n-play */
362 if (dev->periphid != 0)
363 goto skip_probe;
364
365 /*
366 * Dynamically calculate the size of the resource
367 * and use this for iomap
368 */
369 size = resource_size(&dev->res);
370 tmp = ioremap(dev->res.start, size);
371 if (!tmp) {
372 ret = -ENOMEM;
373 goto err_release;
374 }
375
376 ret = amba_get_enable_pclk(dev);
377 if (ret == 0) {
378 u32 pid, cid;
379
380 /*
381 * Read pid and cid based on size of resource
382 * they are located at end of region
383 */
384 for (pid = 0, i = 0; i < 4; i++)
385 pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) <<
386 (i * 8);
387 for (cid = 0, i = 0; i < 4; i++)
388 cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) <<
389 (i * 8);
390
391 amba_put_disable_pclk(dev);
392
393 if (cid == AMBA_CID || cid == CORESIGHT_CID)
394 dev->periphid = pid;
395
396 if (!dev->periphid)
397 ret = -ENODEV;
398 }
399
400 iounmap(tmp);
401
402 if (ret)
403 goto err_release;
404
405 skip_probe:
406 ret = device_add(&dev->dev);
407 if (ret)
408 goto err_release;
409
410 if (dev->irq[0])
411 ret = device_create_file(&dev->dev, &dev_attr_irq0);
412 if (ret == 0 && dev->irq[1])
413 ret = device_create_file(&dev->dev, &dev_attr_irq1);
414 if (ret == 0)
415 return ret;
416
417 device_unregister(&dev->dev);
418
419 err_release:
420 release_resource(&dev->res);
421 err_out:
422 return ret;
423}
424EXPORT_SYMBOL_GPL(amba_device_add);
425
426static struct amba_device *
427amba_aphb_device_add(struct device *parent, const char *name,
428 resource_size_t base, size_t size, int irq1, int irq2,
429 void *pdata, unsigned int periphid, u64 dma_mask,
430 struct resource *resbase)
431{
432 struct amba_device *dev;
433 int ret;
434
435 dev = amba_device_alloc(name, base, size);
436 if (!dev)
437 return ERR_PTR(-ENOMEM);
438
439 dev->dev.coherent_dma_mask = dma_mask;
440 dev->irq[0] = irq1;
441 dev->irq[1] = irq2;
442 dev->periphid = periphid;
443 dev->dev.platform_data = pdata;
444 dev->dev.parent = parent;
445
446 ret = amba_device_add(dev, resbase);
447 if (ret) {
448 amba_device_put(dev);
449 return ERR_PTR(ret);
450 }
451
452 return dev;
453}
454
455struct amba_device *
456amba_apb_device_add(struct device *parent, const char *name,
457 resource_size_t base, size_t size, int irq1, int irq2,
458 void *pdata, unsigned int periphid)
459{
460 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
461 periphid, 0, &iomem_resource);
462}
463EXPORT_SYMBOL_GPL(amba_apb_device_add);
464
465struct amba_device *
466amba_ahb_device_add(struct device *parent, const char *name,
467 resource_size_t base, size_t size, int irq1, int irq2,
468 void *pdata, unsigned int periphid)
469{
470 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
471 periphid, ~0ULL, &iomem_resource);
472}
473EXPORT_SYMBOL_GPL(amba_ahb_device_add);
474
475struct amba_device *
476amba_apb_device_add_res(struct device *parent, const char *name,
477 resource_size_t base, size_t size, int irq1,
478 int irq2, void *pdata, unsigned int periphid,
479 struct resource *resbase)
480{
481 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
482 periphid, 0, resbase);
483}
484EXPORT_SYMBOL_GPL(amba_apb_device_add_res);
485
486struct amba_device *
487amba_ahb_device_add_res(struct device *parent, const char *name,
488 resource_size_t base, size_t size, int irq1,
489 int irq2, void *pdata, unsigned int periphid,
490 struct resource *resbase)
491{
492 return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
493 periphid, ~0ULL, resbase);
494}
495EXPORT_SYMBOL_GPL(amba_ahb_device_add_res);
496
497
498static void amba_device_initialize(struct amba_device *dev, const char *name)
499{
500 device_initialize(&dev->dev);
501 if (name)
502 dev_set_name(&dev->dev, "%s", name);
503 dev->dev.release = amba_device_release;
504 dev->dev.bus = &amba_bustype;
505 dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
506 dev->res.name = dev_name(&dev->dev);
507}
508
509/**
510 * amba_device_alloc - allocate an AMBA device
511 * @name: sysfs name of the AMBA device
512 * @base: base of AMBA device
513 * @size: size of AMBA device
514 *
515 * Allocate and initialize an AMBA device structure. Returns %NULL
516 * on failure.
517 */
518struct amba_device *amba_device_alloc(const char *name, resource_size_t base,
519 size_t size)
520{
521 struct amba_device *dev;
522
523 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
524 if (dev) {
525 amba_device_initialize(dev, name);
526 dev->res.start = base;
527 dev->res.end = base + size - 1;
528 dev->res.flags = IORESOURCE_MEM;
529 }
530
531 return dev;
532}
533EXPORT_SYMBOL_GPL(amba_device_alloc);
534
535/**
536 * amba_device_register - register an AMBA device
537 * @dev: AMBA device to register
538 * @parent: parent memory resource
539 *
540 * Setup the AMBA device, reading the cell ID if present.
541 * Claim the resource, and register the AMBA device with
542 * the Linux device manager.
543 */
544int amba_device_register(struct amba_device *dev, struct resource *parent)
545{
546 amba_device_initialize(dev, dev->dev.init_name);
547 dev->dev.init_name = NULL;
548
549 return amba_device_add(dev, parent);
550}
551
552/**
553 * amba_device_put - put an AMBA device
554 * @dev: AMBA device to put
555 */
556void amba_device_put(struct amba_device *dev)
557{
558 put_device(&dev->dev);
559}
560EXPORT_SYMBOL_GPL(amba_device_put);
561
562/**
563 * amba_device_unregister - unregister an AMBA device
564 * @dev: AMBA device to remove
565 *
566 * Remove the specified AMBA device from the Linux device
567 * manager. All files associated with this object will be
568 * destroyed, and device drivers notified that the device has
569 * been removed. The AMBA device's resources including
570 * the amba_device structure will be freed once all
571 * references to it have been dropped.
572 */
573void amba_device_unregister(struct amba_device *dev)
574{
575 device_unregister(&dev->dev);
576}
577
578
579struct find_data {
580 struct amba_device *dev;
581 struct device *parent;
582 const char *busid;
583 unsigned int id;
584 unsigned int mask;
585};
586
587static int amba_find_match(struct device *dev, void *data)
588{
589 struct find_data *d = data;
590 struct amba_device *pcdev = to_amba_device(dev);
591 int r;
592
593 r = (pcdev->periphid & d->mask) == d->id;
594 if (d->parent)
595 r &= d->parent == dev->parent;
596 if (d->busid)
597 r &= strcmp(dev_name(dev), d->busid) == 0;
598
599 if (r) {
600 get_device(dev);
601 d->dev = pcdev;
602 }
603
604 return r;
605}
606
607/**
608 * amba_find_device - locate an AMBA device given a bus id
609 * @busid: bus id for device (or NULL)
610 * @parent: parent device (or NULL)
611 * @id: peripheral ID (or 0)
612 * @mask: peripheral ID mask (or 0)
613 *
614 * Return the AMBA device corresponding to the supplied parameters.
615 * If no device matches, returns NULL.
616 *
617 * NOTE: When a valid device is found, its refcount is
618 * incremented, and must be decremented before the returned
619 * reference.
620 */
621struct amba_device *
622amba_find_device(const char *busid, struct device *parent, unsigned int id,
623 unsigned int mask)
624{
625 struct find_data data;
626
627 data.dev = NULL;
628 data.parent = parent;
629 data.busid = busid;
630 data.id = id;
631 data.mask = mask;
632
633 bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
634
635 return data.dev;
636}
637
638/**
639 * amba_request_regions - request all mem regions associated with device
640 * @dev: amba_device structure for device
641 * @name: name, or NULL to use driver name
642 */
643int amba_request_regions(struct amba_device *dev, const char *name)
644{
645 int ret = 0;
646 u32 size;
647
648 if (!name)
649 name = dev->dev.driver->name;
650
651 size = resource_size(&dev->res);
652
653 if (!request_mem_region(dev->res.start, size, name))
654 ret = -EBUSY;
655
656 return ret;
657}
658
659/**
660 * amba_release_regions - release mem regions associated with device
661 * @dev: amba_device structure for device
662 *
663 * Release regions claimed by a successful call to amba_request_regions.
664 */
665void amba_release_regions(struct amba_device *dev)
666{
667 u32 size;
668
669 size = resource_size(&dev->res);
670 release_mem_region(dev->res.start, size);
671}
672
673EXPORT_SYMBOL(amba_driver_register);
674EXPORT_SYMBOL(amba_driver_unregister);
675EXPORT_SYMBOL(amba_device_register);
676EXPORT_SYMBOL(amba_device_unregister);
677EXPORT_SYMBOL(amba_find_device);
678EXPORT_SYMBOL(amba_request_regions);
679EXPORT_SYMBOL(amba_release_regions);