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/amba/bus.h>
19
20#include <asm/irq.h>
21#include <asm/sizes.h>
22
23#define to_amba_driver(d)	container_of(d, struct amba_driver, drv)
24
25static const struct amba_id *
26amba_lookup(const struct amba_id *table, struct amba_device *dev)
27{
28	int ret = 0;
29
30	while (table->mask) {
31		ret = (dev->periphid & table->mask) == table->id;
32		if (ret)
33			break;
34		table++;
35	}
36
37	return ret ? table : NULL;
38}
39
40static int amba_match(struct device *dev, struct device_driver *drv)
41{
42	struct amba_device *pcdev = to_amba_device(dev);
43	struct amba_driver *pcdrv = to_amba_driver(drv);
44
45	return amba_lookup(pcdrv->id_table, pcdev) != NULL;
46}
47
48#ifdef CONFIG_HOTPLUG
49static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
50{
51	struct amba_device *pcdev = to_amba_device(dev);
52	int retval = 0;
53
54	retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
55	if (retval)
56		return retval;
57
58	retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid);
59	return retval;
60}
61#else
62#define amba_uevent NULL
63#endif
64
65#define amba_attr_func(name,fmt,arg...)					\
66static ssize_t name##_show(struct device *_dev,				\
67			   struct device_attribute *attr, char *buf)	\
68{									\
69	struct amba_device *dev = to_amba_device(_dev);			\
70	return sprintf(buf, fmt, arg);					\
71}
72
73#define amba_attr(name,fmt,arg...)	\
74amba_attr_func(name,fmt,arg)		\
75static DEVICE_ATTR(name, S_IRUGO, name##_show, NULL)
76
77amba_attr_func(id, "%08x\n", dev->periphid);
78amba_attr(irq0, "%u\n", dev->irq[0]);
79amba_attr(irq1, "%u\n", dev->irq[1]);
80amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
81	 (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
82	 dev->res.flags);
83
84static struct device_attribute amba_dev_attrs[] = {
85	__ATTR_RO(id),
86	__ATTR_RO(resource),
87	__ATTR_NULL,
88};
89
90#ifdef CONFIG_PM_SLEEP
91
92static int amba_legacy_suspend(struct device *dev, pm_message_t mesg)
93{
94	struct amba_driver *adrv = to_amba_driver(dev->driver);
95	struct amba_device *adev = to_amba_device(dev);
96	int ret = 0;
97
98	if (dev->driver && adrv->suspend)
99		ret = adrv->suspend(adev, mesg);
100
101	return ret;
102}
103
104static int amba_legacy_resume(struct device *dev)
105{
106	struct amba_driver *adrv = to_amba_driver(dev->driver);
107	struct amba_device *adev = to_amba_device(dev);
108	int ret = 0;
109
110	if (dev->driver && adrv->resume)
111		ret = adrv->resume(adev);
112
113	return ret;
114}
115
116#endif /* CONFIG_PM_SLEEP */
117
118#ifdef CONFIG_SUSPEND
119
120static int amba_pm_suspend(struct device *dev)
121{
122	struct device_driver *drv = dev->driver;
123	int ret = 0;
124
125	if (!drv)
126		return 0;
127
128	if (drv->pm) {
129		if (drv->pm->suspend)
130			ret = drv->pm->suspend(dev);
131	} else {
132		ret = amba_legacy_suspend(dev, PMSG_SUSPEND);
133	}
134
135	return ret;
136}
137
138static int amba_pm_resume(struct device *dev)
139{
140	struct device_driver *drv = dev->driver;
141	int ret = 0;
142
143	if (!drv)
144		return 0;
145
146	if (drv->pm) {
147		if (drv->pm->resume)
148			ret = drv->pm->resume(dev);
149	} else {
150		ret = amba_legacy_resume(dev);
151	}
152
153	return ret;
154}
155
156#else /* !CONFIG_SUSPEND */
157
158#define amba_pm_suspend		NULL
159#define amba_pm_resume		NULL
160
161#endif /* !CONFIG_SUSPEND */
162
163#ifdef CONFIG_HIBERNATE_CALLBACKS
164
165static int amba_pm_freeze(struct device *dev)
166{
167	struct device_driver *drv = dev->driver;
168	int ret = 0;
169
170	if (!drv)
171		return 0;
172
173	if (drv->pm) {
174		if (drv->pm->freeze)
175			ret = drv->pm->freeze(dev);
176	} else {
177		ret = amba_legacy_suspend(dev, PMSG_FREEZE);
178	}
179
180	return ret;
181}
182
183static int amba_pm_thaw(struct device *dev)
184{
185	struct device_driver *drv = dev->driver;
186	int ret = 0;
187
188	if (!drv)
189		return 0;
190
191	if (drv->pm) {
192		if (drv->pm->thaw)
193			ret = drv->pm->thaw(dev);
194	} else {
195		ret = amba_legacy_resume(dev);
196	}
197
198	return ret;
199}
200
201static int amba_pm_poweroff(struct device *dev)
202{
203	struct device_driver *drv = dev->driver;
204	int ret = 0;
205
206	if (!drv)
207		return 0;
208
209	if (drv->pm) {
210		if (drv->pm->poweroff)
211			ret = drv->pm->poweroff(dev);
212	} else {
213		ret = amba_legacy_suspend(dev, PMSG_HIBERNATE);
214	}
215
216	return ret;
217}
218
219static int amba_pm_restore(struct device *dev)
220{
221	struct device_driver *drv = dev->driver;
222	int ret = 0;
223
224	if (!drv)
225		return 0;
226
227	if (drv->pm) {
228		if (drv->pm->restore)
229			ret = drv->pm->restore(dev);
230	} else {
231		ret = amba_legacy_resume(dev);
232	}
233
234	return ret;
235}
236
237#else /* !CONFIG_HIBERNATE_CALLBACKS */
238
239#define amba_pm_freeze		NULL
240#define amba_pm_thaw		NULL
241#define amba_pm_poweroff		NULL
242#define amba_pm_restore		NULL
243
244#endif /* !CONFIG_HIBERNATE_CALLBACKS */
245
246#ifdef CONFIG_PM_RUNTIME
247/*
248 * Hooks to provide runtime PM of the pclk (bus clock).  It is safe to
249 * enable/disable the bus clock at runtime PM suspend/resume as this
250 * does not result in loss of context.
251 */
252static int amba_pm_runtime_suspend(struct device *dev)
253{
254	struct amba_device *pcdev = to_amba_device(dev);
255	int ret = pm_generic_runtime_suspend(dev);
256
257	if (ret == 0 && dev->driver)
258		clk_disable(pcdev->pclk);
259
260	return ret;
261}
262
263static int amba_pm_runtime_resume(struct device *dev)
264{
265	struct amba_device *pcdev = to_amba_device(dev);
266	int ret;
267
268	if (dev->driver) {
269		ret = clk_enable(pcdev->pclk);
270		/* Failure is probably fatal to the system, but... */
271		if (ret)
272			return ret;
273	}
274
275	return pm_generic_runtime_resume(dev);
276}
277#endif
278
279#ifdef CONFIG_PM
280
281static const struct dev_pm_ops amba_pm = {
282	.suspend	= amba_pm_suspend,
283	.resume		= amba_pm_resume,
284	.freeze		= amba_pm_freeze,
285	.thaw		= amba_pm_thaw,
286	.poweroff	= amba_pm_poweroff,
287	.restore	= amba_pm_restore,
288	SET_RUNTIME_PM_OPS(
289		amba_pm_runtime_suspend,
290		amba_pm_runtime_resume,
291		pm_generic_runtime_idle
292	)
293};
294
295#define AMBA_PM (&amba_pm)
296
297#else /* !CONFIG_PM */
298
299#define AMBA_PM	NULL
300
301#endif /* !CONFIG_PM */
302
303/*
304 * Primecells are part of the Advanced Microcontroller Bus Architecture,
305 * so we call the bus "amba".
306 */
307struct bus_type amba_bustype = {
308	.name		= "amba",
309	.dev_attrs	= amba_dev_attrs,
310	.match		= amba_match,
311	.uevent		= amba_uevent,
312	.pm		= AMBA_PM,
313};
314
315static int __init amba_init(void)
316{
317	return bus_register(&amba_bustype);
318}
319
320postcore_initcall(amba_init);
321
322static int amba_get_enable_pclk(struct amba_device *pcdev)
323{
324	struct clk *pclk = clk_get(&pcdev->dev, "apb_pclk");
325	int ret;
326
327	pcdev->pclk = pclk;
328
329	if (IS_ERR(pclk))
330		return PTR_ERR(pclk);
331
332	ret = clk_prepare(pclk);
333	if (ret) {
334		clk_put(pclk);
335		return ret;
336	}
337
338	ret = clk_enable(pclk);
339	if (ret) {
340		clk_unprepare(pclk);
341		clk_put(pclk);
342	}
343
344	return ret;
345}
346
347static void amba_put_disable_pclk(struct amba_device *pcdev)
348{
349	struct clk *pclk = pcdev->pclk;
350
351	clk_disable(pclk);
352	clk_unprepare(pclk);
353	clk_put(pclk);
354}
355
356/*
357 * These are the device model conversion veneers; they convert the
358 * device model structures to our more specific structures.
359 */
360static int amba_probe(struct device *dev)
361{
362	struct amba_device *pcdev = to_amba_device(dev);
363	struct amba_driver *pcdrv = to_amba_driver(dev->driver);
364	const struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev);
365	int ret;
366
367	do {
368		ret = amba_get_enable_pclk(pcdev);
369		if (ret)
370			break;
371
372		pm_runtime_get_noresume(dev);
373		pm_runtime_set_active(dev);
374		pm_runtime_enable(dev);
375
376		ret = pcdrv->probe(pcdev, id);
377		if (ret == 0)
378			break;
379
380		pm_runtime_disable(dev);
381		pm_runtime_set_suspended(dev);
382		pm_runtime_put_noidle(dev);
383
384		amba_put_disable_pclk(pcdev);
385	} while (0);
386
387	return ret;
388}
389
390static int amba_remove(struct device *dev)
391{
392	struct amba_device *pcdev = to_amba_device(dev);
393	struct amba_driver *drv = to_amba_driver(dev->driver);
394	int ret;
395
396	pm_runtime_get_sync(dev);
397	ret = drv->remove(pcdev);
398	pm_runtime_put_noidle(dev);
399
400	/* Undo the runtime PM settings in amba_probe() */
401	pm_runtime_disable(dev);
402	pm_runtime_set_suspended(dev);
403	pm_runtime_put_noidle(dev);
404
405	amba_put_disable_pclk(pcdev);
406
407	return ret;
408}
409
410static void amba_shutdown(struct device *dev)
411{
412	struct amba_driver *drv = to_amba_driver(dev->driver);
413	drv->shutdown(to_amba_device(dev));
414}
415
416/**
417 *	amba_driver_register - register an AMBA device driver
418 *	@drv: amba device driver structure
419 *
420 *	Register an AMBA device driver with the Linux device model
421 *	core.  If devices pre-exist, the drivers probe function will
422 *	be called.
423 */
424int amba_driver_register(struct amba_driver *drv)
425{
426	drv->drv.bus = &amba_bustype;
427
428#define SETFN(fn)	if (drv->fn) drv->drv.fn = amba_##fn
429	SETFN(probe);
430	SETFN(remove);
431	SETFN(shutdown);
432
433	return driver_register(&drv->drv);
434}
435
436/**
437 *	amba_driver_unregister - remove an AMBA device driver
438 *	@drv: AMBA device driver structure to remove
439 *
440 *	Unregister an AMBA device driver from the Linux device
441 *	model.  The device model will call the drivers remove function
442 *	for each device the device driver is currently handling.
443 */
444void amba_driver_unregister(struct amba_driver *drv)
445{
446	driver_unregister(&drv->drv);
447}
448
449
450static void amba_device_release(struct device *dev)
451{
452	struct amba_device *d = to_amba_device(dev);
453
454	if (d->res.parent)
455		release_resource(&d->res);
456	kfree(d);
457}
458
459/**
460 *	amba_device_add - add a previously allocated AMBA device structure
461 *	@dev: AMBA device allocated by amba_device_alloc
462 *	@parent: resource parent for this devices resources
463 *
464 *	Claim the resource, and read the device cell ID if not already
465 *	initialized.  Register the AMBA device with the Linux device
466 *	manager.
467 */
468int amba_device_add(struct amba_device *dev, struct resource *parent)
469{
470	u32 size;
471	void __iomem *tmp;
472	int i, ret;
473
474	WARN_ON(dev->irq[0] == (unsigned int)-1);
475	WARN_ON(dev->irq[1] == (unsigned int)-1);
476
477	ret = request_resource(parent, &dev->res);
478	if (ret)
479		goto err_out;
480
481	/* Hard-coded primecell ID instead of plug-n-play */
482	if (dev->periphid != 0)
483		goto skip_probe;
484
485	/*
486	 * Dynamically calculate the size of the resource
487	 * and use this for iomap
488	 */
489	size = resource_size(&dev->res);
490	tmp = ioremap(dev->res.start, size);
491	if (!tmp) {
492		ret = -ENOMEM;
493		goto err_release;
494	}
495
496	ret = amba_get_enable_pclk(dev);
497	if (ret == 0) {
498		u32 pid, cid;
499
500		/*
501		 * Read pid and cid based on size of resource
502		 * they are located at end of region
503		 */
504		for (pid = 0, i = 0; i < 4; i++)
505			pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) <<
506				(i * 8);
507		for (cid = 0, i = 0; i < 4; i++)
508			cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) <<
509				(i * 8);
510
511		amba_put_disable_pclk(dev);
512
513		if (cid == AMBA_CID)
514			dev->periphid = pid;
515
516		if (!dev->periphid)
517			ret = -ENODEV;
518	}
519
520	iounmap(tmp);
521
522	if (ret)
523		goto err_release;
524
525 skip_probe:
526	ret = device_add(&dev->dev);
527	if (ret)
528		goto err_release;
529
530	if (dev->irq[0] && dev->irq[0] != NO_IRQ)
531		ret = device_create_file(&dev->dev, &dev_attr_irq0);
532	if (ret == 0 && dev->irq[1] && dev->irq[1] != NO_IRQ)
533		ret = device_create_file(&dev->dev, &dev_attr_irq1);
534	if (ret == 0)
535		return ret;
536
537	device_unregister(&dev->dev);
538
539 err_release:
540	release_resource(&dev->res);
541 err_out:
542	return ret;
543}
544EXPORT_SYMBOL_GPL(amba_device_add);
545
546static void amba_device_initialize(struct amba_device *dev, const char *name)
547{
548	device_initialize(&dev->dev);
549	if (name)
550		dev_set_name(&dev->dev, "%s", name);
551	dev->dev.release = amba_device_release;
552	dev->dev.bus = &amba_bustype;
553	dev->dev.dma_mask = &dev->dma_mask;
554	dev->res.name = dev_name(&dev->dev);
555}
556
557/**
558 *	amba_device_alloc - allocate an AMBA device
559 *	@name: sysfs name of the AMBA device
560 *	@base: base of AMBA device
561 *	@size: size of AMBA device
562 *
563 *	Allocate and initialize an AMBA device structure.  Returns %NULL
564 *	on failure.
565 */
566struct amba_device *amba_device_alloc(const char *name, resource_size_t base,
567	size_t size)
568{
569	struct amba_device *dev;
570
571	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
572	if (dev) {
573		amba_device_initialize(dev, name);
574		dev->res.start = base;
575		dev->res.end = base + size - 1;
576		dev->res.flags = IORESOURCE_MEM;
577	}
578
579	return dev;
580}
581EXPORT_SYMBOL_GPL(amba_device_alloc);
582
583/**
584 *	amba_device_register - register an AMBA device
585 *	@dev: AMBA device to register
586 *	@parent: parent memory resource
587 *
588 *	Setup the AMBA device, reading the cell ID if present.
589 *	Claim the resource, and register the AMBA device with
590 *	the Linux device manager.
591 */
592int amba_device_register(struct amba_device *dev, struct resource *parent)
593{
594	amba_device_initialize(dev, dev->dev.init_name);
595	dev->dev.init_name = NULL;
596
597	if (!dev->dev.coherent_dma_mask && dev->dma_mask)
598		dev_warn(&dev->dev, "coherent dma mask is unset\n");
599
600	return amba_device_add(dev, parent);
601}
602
603/**
604 *	amba_device_put - put an AMBA device
605 *	@dev: AMBA device to put
606 */
607void amba_device_put(struct amba_device *dev)
608{
609	put_device(&dev->dev);
610}
611EXPORT_SYMBOL_GPL(amba_device_put);
612
613/**
614 *	amba_device_unregister - unregister an AMBA device
615 *	@dev: AMBA device to remove
616 *
617 *	Remove the specified AMBA device from the Linux device
618 *	manager.  All files associated with this object will be
619 *	destroyed, and device drivers notified that the device has
620 *	been removed.  The AMBA device's resources including
621 *	the amba_device structure will be freed once all
622 *	references to it have been dropped.
623 */
624void amba_device_unregister(struct amba_device *dev)
625{
626	device_unregister(&dev->dev);
627}
628
629
630struct find_data {
631	struct amba_device *dev;
632	struct device *parent;
633	const char *busid;
634	unsigned int id;
635	unsigned int mask;
636};
637
638static int amba_find_match(struct device *dev, void *data)
639{
640	struct find_data *d = data;
641	struct amba_device *pcdev = to_amba_device(dev);
642	int r;
643
644	r = (pcdev->periphid & d->mask) == d->id;
645	if (d->parent)
646		r &= d->parent == dev->parent;
647	if (d->busid)
648		r &= strcmp(dev_name(dev), d->busid) == 0;
649
650	if (r) {
651		get_device(dev);
652		d->dev = pcdev;
653	}
654
655	return r;
656}
657
658/**
659 *	amba_find_device - locate an AMBA device given a bus id
660 *	@busid: bus id for device (or NULL)
661 *	@parent: parent device (or NULL)
662 *	@id: peripheral ID (or 0)
663 *	@mask: peripheral ID mask (or 0)
664 *
665 *	Return the AMBA device corresponding to the supplied parameters.
666 *	If no device matches, returns NULL.
667 *
668 *	NOTE: When a valid device is found, its refcount is
669 *	incremented, and must be decremented before the returned
670 *	reference.
671 */
672struct amba_device *
673amba_find_device(const char *busid, struct device *parent, unsigned int id,
674		 unsigned int mask)
675{
676	struct find_data data;
677
678	data.dev = NULL;
679	data.parent = parent;
680	data.busid = busid;
681	data.id = id;
682	data.mask = mask;
683
684	bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
685
686	return data.dev;
687}
688
689/**
690 *	amba_request_regions - request all mem regions associated with device
691 *	@dev: amba_device structure for device
692 *	@name: name, or NULL to use driver name
693 */
694int amba_request_regions(struct amba_device *dev, const char *name)
695{
696	int ret = 0;
697	u32 size;
698
699	if (!name)
700		name = dev->dev.driver->name;
701
702	size = resource_size(&dev->res);
703
704	if (!request_mem_region(dev->res.start, size, name))
705		ret = -EBUSY;
706
707	return ret;
708}
709
710/**
711 *	amba_release_regions - release mem regions associated with device
712 *	@dev: amba_device structure for device
713 *
714 *	Release regions claimed by a successful call to amba_request_regions.
715 */
716void amba_release_regions(struct amba_device *dev)
717{
718	u32 size;
719
720	size = resource_size(&dev->res);
721	release_mem_region(dev->res.start, size);
722}
723
724EXPORT_SYMBOL(amba_driver_register);
725EXPORT_SYMBOL(amba_driver_unregister);
726EXPORT_SYMBOL(amba_device_register);
727EXPORT_SYMBOL(amba_device_unregister);
728EXPORT_SYMBOL(amba_find_device);
729EXPORT_SYMBOL(amba_request_regions);
730EXPORT_SYMBOL(amba_release_regions);
731