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  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/sh/maple/
1/*
2 * Core maple bus functionality
3 *
4 *  Copyright (C) 2007 - 2009 Adrian McMenamin
5 *  Copyright (C) 2001 - 2008 Paul Mundt
6 *  Copyright (C) 2000 - 2001 YAEGASHI Takeshi
7 *  Copyright (C) 2001 M. R. Brown
8 *
9 * This file is subject to the terms and conditions of the GNU General Public
10 * License.  See the file "COPYING" in the main directory of this archive
11 * for more details.
12 */
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/device.h>
16#include <linux/interrupt.h>
17#include <linux/list.h>
18#include <linux/io.h>
19#include <linux/slab.h>
20#include <linux/maple.h>
21#include <linux/dma-mapping.h>
22#include <linux/delay.h>
23#include <asm/cacheflush.h>
24#include <asm/dma.h>
25#include <asm/io.h>
26#include <mach/dma.h>
27#include <mach/sysasic.h>
28
29MODULE_AUTHOR("Adrian McMenamin <adrian@mcmen.demon.co.uk>");
30MODULE_DESCRIPTION("Maple bus driver for Dreamcast");
31MODULE_LICENSE("GPL v2");
32MODULE_SUPPORTED_DEVICE("{{SEGA, Dreamcast/Maple}}");
33
34static void maple_dma_handler(struct work_struct *work);
35static void maple_vblank_handler(struct work_struct *work);
36
37static DECLARE_WORK(maple_dma_process, maple_dma_handler);
38static DECLARE_WORK(maple_vblank_process, maple_vblank_handler);
39
40static LIST_HEAD(maple_waitq);
41static LIST_HEAD(maple_sentq);
42
43/* mutex to protect queue of waiting packets */
44static DEFINE_MUTEX(maple_wlist_lock);
45
46static struct maple_driver maple_unsupported_device;
47static struct device maple_bus;
48static int subdevice_map[MAPLE_PORTS];
49static unsigned long *maple_sendbuf, *maple_sendptr, *maple_lastptr;
50static unsigned long maple_pnp_time;
51static int started, scanning, fullscan;
52static struct kmem_cache *maple_queue_cache;
53
54struct maple_device_specify {
55	int port;
56	int unit;
57};
58
59static bool checked[MAPLE_PORTS];
60static bool empty[MAPLE_PORTS];
61static struct maple_device *baseunits[MAPLE_PORTS];
62
63/**
64 * maple_driver_register - register a maple driver
65 * @drv: maple driver to be registered.
66 *
67 * Registers the passed in @drv, while updating the bus type.
68 * Devices with matching function IDs will be automatically probed.
69 */
70int maple_driver_register(struct maple_driver *drv)
71{
72	if (!drv)
73		return -EINVAL;
74
75	drv->drv.bus = &maple_bus_type;
76
77	return driver_register(&drv->drv);
78}
79EXPORT_SYMBOL_GPL(maple_driver_register);
80
81/**
82 * maple_driver_unregister - unregister a maple driver.
83 * @drv: maple driver to unregister.
84 *
85 * Cleans up after maple_driver_register(). To be invoked in the exit
86 * path of any module drivers.
87 */
88void maple_driver_unregister(struct maple_driver *drv)
89{
90	driver_unregister(&drv->drv);
91}
92EXPORT_SYMBOL_GPL(maple_driver_unregister);
93
94/* set hardware registers to enable next round of dma */
95static void maple_dma_reset(void)
96{
97	ctrl_outl(MAPLE_MAGIC, MAPLE_RESET);
98	/* set trig type to 0 for software trigger, 1 for hardware (VBLANK) */
99	ctrl_outl(1, MAPLE_TRIGTYPE);
100	/*
101	* Maple system register
102	* bits 31 - 16	timeout in units of 20nsec
103	* bit 12	hard trigger - set 0 to keep responding to VBLANK
104	* bits 9 - 8	set 00 for 2 Mbps, 01 for 1 Mbps
105	* bits 3 - 0	delay (in 1.3ms) between VBLANK and start of DMA
106	* max delay is 11
107	*/
108	ctrl_outl(MAPLE_2MBPS | MAPLE_TIMEOUT(0xFFFF), MAPLE_SPEED);
109	ctrl_outl(virt_to_phys(maple_sendbuf), MAPLE_DMAADDR);
110	ctrl_outl(1, MAPLE_ENABLE);
111}
112
113/**
114 * maple_getcond_callback - setup handling MAPLE_COMMAND_GETCOND
115 * @dev: device responding
116 * @callback: handler callback
117 * @interval: interval in jiffies between callbacks
118 * @function: the function code for the device
119 */
120void maple_getcond_callback(struct maple_device *dev,
121			void (*callback) (struct mapleq *mq),
122			unsigned long interval, unsigned long function)
123{
124	dev->callback = callback;
125	dev->interval = interval;
126	dev->function = cpu_to_be32(function);
127	dev->when = jiffies;
128}
129EXPORT_SYMBOL_GPL(maple_getcond_callback);
130
131static int maple_dma_done(void)
132{
133	return (ctrl_inl(MAPLE_STATE) & 1) == 0;
134}
135
136static void maple_release_device(struct device *dev)
137{
138	struct maple_device *mdev;
139	struct mapleq *mq;
140
141	mdev = to_maple_dev(dev);
142	mq = mdev->mq;
143	kmem_cache_free(maple_queue_cache, mq->recvbuf);
144	kfree(mq);
145	kfree(mdev);
146}
147
148/**
149 * maple_add_packet - add a single instruction to the maple bus queue
150 * @mdev: maple device
151 * @function: function on device being queried
152 * @command: maple command to add
153 * @length: length of command string (in 32 bit words)
154 * @data: remainder of command string
155 */
156int maple_add_packet(struct maple_device *mdev, u32 function, u32 command,
157	size_t length, void *data)
158{
159	int ret = 0;
160	void *sendbuf = NULL;
161
162	if (length) {
163		sendbuf = kzalloc(length * 4, GFP_KERNEL);
164		if (!sendbuf) {
165			ret = -ENOMEM;
166			goto out;
167		}
168		((__be32 *)sendbuf)[0] = cpu_to_be32(function);
169	}
170
171	mdev->mq->command = command;
172	mdev->mq->length = length;
173	if (length > 1)
174		memcpy(sendbuf + 4, data, (length - 1) * 4);
175	mdev->mq->sendbuf = sendbuf;
176
177	mutex_lock(&maple_wlist_lock);
178	list_add_tail(&mdev->mq->list, &maple_waitq);
179	mutex_unlock(&maple_wlist_lock);
180out:
181	return ret;
182}
183EXPORT_SYMBOL_GPL(maple_add_packet);
184
185static struct mapleq *maple_allocq(struct maple_device *mdev)
186{
187	struct mapleq *mq;
188
189	mq = kzalloc(sizeof(*mq), GFP_KERNEL);
190	if (!mq)
191		goto failed_nomem;
192
193	INIT_LIST_HEAD(&mq->list);
194	mq->dev = mdev;
195	mq->recvbuf = kmem_cache_zalloc(maple_queue_cache, GFP_KERNEL);
196	if (!mq->recvbuf)
197		goto failed_p2;
198	mq->recvbuf->buf = &((mq->recvbuf->bufx)[0]);
199
200	return mq;
201
202failed_p2:
203	kfree(mq);
204failed_nomem:
205	dev_err(&mdev->dev, "could not allocate memory for device (%d, %d)\n",
206		mdev->port, mdev->unit);
207	return NULL;
208}
209
210static struct maple_device *maple_alloc_dev(int port, int unit)
211{
212	struct maple_device *mdev;
213
214	/* zero this out to avoid kobj subsystem
215	* thinking it has already been registered */
216
217	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
218	if (!mdev)
219		return NULL;
220
221	mdev->port = port;
222	mdev->unit = unit;
223
224	mdev->mq = maple_allocq(mdev);
225
226	if (!mdev->mq) {
227		kfree(mdev);
228		return NULL;
229	}
230	mdev->dev.bus = &maple_bus_type;
231	mdev->dev.parent = &maple_bus;
232	init_waitqueue_head(&mdev->maple_wait);
233	return mdev;
234}
235
236static void maple_free_dev(struct maple_device *mdev)
237{
238	kmem_cache_free(maple_queue_cache, mdev->mq->recvbuf);
239	kfree(mdev->mq);
240	kfree(mdev);
241}
242
243/* process the command queue into a maple command block
244 * terminating command has bit 32 of first long set to 0
245 */
246static void maple_build_block(struct mapleq *mq)
247{
248	int port, unit, from, to, len;
249	unsigned long *lsendbuf = mq->sendbuf;
250
251	port = mq->dev->port & 3;
252	unit = mq->dev->unit;
253	len = mq->length;
254	from = port << 6;
255	to = (port << 6) | (unit > 0 ? (1 << (unit - 1)) & 0x1f : 0x20);
256
257	*maple_lastptr &= 0x7fffffff;
258	maple_lastptr = maple_sendptr;
259
260	*maple_sendptr++ = (port << 16) | len | 0x80000000;
261	*maple_sendptr++ = virt_to_phys(mq->recvbuf->buf);
262	*maple_sendptr++ =
263	    mq->command | (to << 8) | (from << 16) | (len << 24);
264	while (len-- > 0)
265		*maple_sendptr++ = *lsendbuf++;
266}
267
268/* build up command queue */
269static void maple_send(void)
270{
271	int i, maple_packets = 0;
272	struct mapleq *mq, *nmq;
273
274	if (!maple_dma_done())
275		return;
276
277	/* disable DMA */
278	ctrl_outl(0, MAPLE_ENABLE);
279
280	if (!list_empty(&maple_sentq))
281		goto finish;
282
283	mutex_lock(&maple_wlist_lock);
284	if (list_empty(&maple_waitq)) {
285		mutex_unlock(&maple_wlist_lock);
286		goto finish;
287	}
288
289	maple_lastptr = maple_sendbuf;
290	maple_sendptr = maple_sendbuf;
291
292	list_for_each_entry_safe(mq, nmq, &maple_waitq, list) {
293		maple_build_block(mq);
294		list_del_init(&mq->list);
295		list_add_tail(&mq->list, &maple_sentq);
296		if (maple_packets++ > MAPLE_MAXPACKETS)
297			break;
298	}
299	mutex_unlock(&maple_wlist_lock);
300	if (maple_packets > 0) {
301		for (i = 0; i < (1 << MAPLE_DMA_PAGES); i++)
302			dma_cache_sync(0, maple_sendbuf + i * PAGE_SIZE,
303				       PAGE_SIZE, DMA_BIDIRECTIONAL);
304	}
305
306finish:
307	maple_dma_reset();
308}
309
310/* check if there is a driver registered likely to match this device */
311static int maple_check_matching_driver(struct device_driver *driver,
312					void *devptr)
313{
314	struct maple_driver *maple_drv;
315	struct maple_device *mdev;
316
317	mdev = devptr;
318	maple_drv = to_maple_driver(driver);
319	if (mdev->devinfo.function & cpu_to_be32(maple_drv->function))
320		return 1;
321	return 0;
322}
323
324static void maple_detach_driver(struct maple_device *mdev)
325{
326	device_unregister(&mdev->dev);
327}
328
329/* process initial MAPLE_COMMAND_DEVINFO for each device or port */
330static void maple_attach_driver(struct maple_device *mdev)
331{
332	char *p, *recvbuf;
333	unsigned long function;
334	int matched, error;
335
336	recvbuf = mdev->mq->recvbuf->buf;
337	/* copy the data as individual elements in
338	* case of memory optimisation */
339	memcpy(&mdev->devinfo.function, recvbuf + 4, 4);
340	memcpy(&mdev->devinfo.function_data[0], recvbuf + 8, 12);
341	memcpy(&mdev->devinfo.area_code, recvbuf + 20, 1);
342	memcpy(&mdev->devinfo.connector_direction, recvbuf + 21, 1);
343	memcpy(&mdev->devinfo.product_name[0], recvbuf + 22, 30);
344	memcpy(&mdev->devinfo.standby_power, recvbuf + 112, 2);
345	memcpy(&mdev->devinfo.max_power, recvbuf + 114, 2);
346	memcpy(mdev->product_name, mdev->devinfo.product_name, 30);
347	mdev->product_name[30] = '\0';
348	memcpy(mdev->product_licence, mdev->devinfo.product_licence, 60);
349	mdev->product_licence[60] = '\0';
350
351	for (p = mdev->product_name + 29; mdev->product_name <= p; p--)
352		if (*p == ' ')
353			*p = '\0';
354		else
355			break;
356	for (p = mdev->product_licence + 59; mdev->product_licence <= p; p--)
357		if (*p == ' ')
358			*p = '\0';
359		else
360			break;
361
362	function = be32_to_cpu(mdev->devinfo.function);
363
364	dev_info(&mdev->dev, "detected %s: function 0x%lX: at (%d, %d)\n",
365		mdev->product_name, function, mdev->port, mdev->unit);
366
367	if (function > 0x200) {
368		/* Do this silently - as not a real device */
369		function = 0;
370		mdev->driver = &maple_unsupported_device;
371		dev_set_name(&mdev->dev, "%d:0.port", mdev->port);
372	} else {
373		matched =
374			bus_for_each_drv(&maple_bus_type, NULL, mdev,
375				maple_check_matching_driver);
376
377		if (matched == 0) {
378			/* Driver does not exist yet */
379			dev_info(&mdev->dev, "no driver found\n");
380			mdev->driver = &maple_unsupported_device;
381		}
382		dev_set_name(&mdev->dev, "%d:0%d.%lX", mdev->port,
383			     mdev->unit, function);
384	}
385
386	mdev->function = function;
387	mdev->dev.release = &maple_release_device;
388
389	atomic_set(&mdev->busy, 0);
390	error = device_register(&mdev->dev);
391	if (error) {
392		dev_warn(&mdev->dev, "could not register device at"
393			" (%d, %d), with error 0x%X\n", mdev->unit,
394			mdev->port, error);
395		maple_free_dev(mdev);
396		mdev = NULL;
397		return;
398	}
399}
400
401/*
402 * if device has been registered for the given
403 * port and unit then return 1 - allows identification
404 * of which devices need to be attached or detached
405 */
406static int check_maple_device(struct device *device, void *portptr)
407{
408	struct maple_device_specify *ds;
409	struct maple_device *mdev;
410
411	ds = portptr;
412	mdev = to_maple_dev(device);
413	if (mdev->port == ds->port && mdev->unit == ds->unit)
414		return 1;
415	return 0;
416}
417
418static int setup_maple_commands(struct device *device, void *ignored)
419{
420	int add;
421	struct maple_device *mdev = to_maple_dev(device);
422	if (mdev->interval > 0 && atomic_read(&mdev->busy) == 0 &&
423		time_after(jiffies, mdev->when)) {
424		/* bounce if we cannot add */
425		add = maple_add_packet(mdev,
426			be32_to_cpu(mdev->devinfo.function),
427			MAPLE_COMMAND_GETCOND, 1, NULL);
428		if (!add)
429			mdev->when = jiffies + mdev->interval;
430	} else {
431		if (time_after(jiffies, maple_pnp_time))
432			/* Ensure we don't have block reads and devinfo
433			* calls interfering with one another - so flag the
434			* device as busy */
435			if (atomic_read(&mdev->busy) == 0) {
436				atomic_set(&mdev->busy, 1);
437				maple_add_packet(mdev, 0,
438					MAPLE_COMMAND_DEVINFO, 0, NULL);
439			}
440	}
441	return 0;
442}
443
444/* VBLANK bottom half - implemented via workqueue */
445static void maple_vblank_handler(struct work_struct *work)
446{
447	int x, locking;
448	struct maple_device *mdev;
449
450	if (!maple_dma_done())
451		return;
452
453	ctrl_outl(0, MAPLE_ENABLE);
454
455	if (!list_empty(&maple_sentq))
456		goto finish;
457
458	/*
459	* Set up essential commands - to fetch data and
460	* check devices are still present
461	*/
462	bus_for_each_dev(&maple_bus_type, NULL, NULL,
463		setup_maple_commands);
464
465	if (time_after(jiffies, maple_pnp_time)) {
466		/*
467		* Scan the empty ports - bus is flakey and may have
468		* mis-reported emptyness
469		*/
470		for (x = 0; x < MAPLE_PORTS; x++) {
471			if (checked[x] && empty[x]) {
472				mdev = baseunits[x];
473				if (!mdev)
474					break;
475				atomic_set(&mdev->busy, 1);
476				locking = maple_add_packet(mdev, 0,
477					MAPLE_COMMAND_DEVINFO, 0, NULL);
478				if (!locking)
479					break;
480				}
481			}
482
483		maple_pnp_time = jiffies + MAPLE_PNP_INTERVAL;
484	}
485
486finish:
487	maple_send();
488}
489
490/* handle devices added via hotplugs - placing them on queue for DEVINFO */
491static void maple_map_subunits(struct maple_device *mdev, int submask)
492{
493	int retval, k, devcheck;
494	struct maple_device *mdev_add;
495	struct maple_device_specify ds;
496
497	ds.port = mdev->port;
498	for (k = 0; k < 5; k++) {
499		ds.unit = k + 1;
500		retval =
501		    bus_for_each_dev(&maple_bus_type, NULL, &ds,
502				     check_maple_device);
503		if (retval) {
504			submask = submask >> 1;
505			continue;
506		}
507		devcheck = submask & 0x01;
508		if (devcheck) {
509			mdev_add = maple_alloc_dev(mdev->port, k + 1);
510			if (!mdev_add)
511				return;
512			atomic_set(&mdev_add->busy, 1);
513			maple_add_packet(mdev_add, 0, MAPLE_COMMAND_DEVINFO,
514				0, NULL);
515			/* mark that we are checking sub devices */
516			scanning = 1;
517		}
518		submask = submask >> 1;
519	}
520}
521
522/* mark a device as removed */
523static void maple_clean_submap(struct maple_device *mdev)
524{
525	int killbit;
526
527	killbit = (mdev->unit > 0 ? (1 << (mdev->unit - 1)) & 0x1f : 0x20);
528	killbit = ~killbit;
529	killbit &= 0xFF;
530	subdevice_map[mdev->port] = subdevice_map[mdev->port] & killbit;
531}
532
533/* handle empty port or hotplug removal */
534static void maple_response_none(struct maple_device *mdev)
535{
536	maple_clean_submap(mdev);
537
538	if (likely(mdev->unit != 0)) {
539		/*
540		* Block devices play up
541		* and give the impression they have
542		* been removed even when still in place or
543		* trip the mtd layer when they have
544		* really gone - this code traps that eventuality
545		* and ensures we aren't overloaded with useless
546		* error messages
547		*/
548		if (mdev->can_unload) {
549			if (!mdev->can_unload(mdev)) {
550				atomic_set(&mdev->busy, 2);
551				wake_up(&mdev->maple_wait);
552				return;
553			}
554		}
555
556		dev_info(&mdev->dev, "detaching device at (%d, %d)\n",
557			mdev->port, mdev->unit);
558		maple_detach_driver(mdev);
559		return;
560	} else {
561		if (!started || !fullscan) {
562			if (checked[mdev->port] == false) {
563				checked[mdev->port] = true;
564				empty[mdev->port] = true;
565				dev_info(&mdev->dev, "no devices"
566					" to port %d\n", mdev->port);
567			}
568			return;
569		}
570	}
571	/* Some hardware devices generate false detach messages on unit 0 */
572	atomic_set(&mdev->busy, 0);
573}
574
575/* preprocess hotplugs or scans */
576static void maple_response_devinfo(struct maple_device *mdev,
577				   char *recvbuf)
578{
579	char submask;
580	if (!started || (scanning == 2) || !fullscan) {
581		if ((mdev->unit == 0) && (checked[mdev->port] == false)) {
582			checked[mdev->port] = true;
583			maple_attach_driver(mdev);
584		} else {
585			if (mdev->unit != 0)
586				maple_attach_driver(mdev);
587			if (mdev->unit == 0) {
588				empty[mdev->port] = false;
589				maple_attach_driver(mdev);
590			}
591		}
592	}
593	if (mdev->unit == 0) {
594		submask = recvbuf[2] & 0x1F;
595		if (submask ^ subdevice_map[mdev->port]) {
596			maple_map_subunits(mdev, submask);
597			subdevice_map[mdev->port] = submask;
598		}
599	}
600}
601
602static void maple_response_fileerr(struct maple_device *mdev, void *recvbuf)
603{
604	if (mdev->fileerr_handler) {
605		mdev->fileerr_handler(mdev, recvbuf);
606		return;
607	} else
608		dev_warn(&mdev->dev, "device at (%d, %d) reports"
609			"file error 0x%X\n", mdev->port, mdev->unit,
610			((int *)recvbuf)[1]);
611}
612
613static void maple_port_rescan(void)
614{
615	int i;
616	struct maple_device *mdev;
617
618	fullscan = 1;
619	for (i = 0; i < MAPLE_PORTS; i++) {
620		if (checked[i] == false) {
621			fullscan = 0;
622			mdev = baseunits[i];
623			maple_add_packet(mdev, 0, MAPLE_COMMAND_DEVINFO,
624				0, NULL);
625		}
626	}
627}
628
629/* maple dma end bottom half - implemented via workqueue */
630static void maple_dma_handler(struct work_struct *work)
631{
632	struct mapleq *mq, *nmq;
633	struct maple_device *mdev;
634	char *recvbuf;
635	enum maple_code code;
636
637	if (!maple_dma_done())
638		return;
639	ctrl_outl(0, MAPLE_ENABLE);
640	if (!list_empty(&maple_sentq)) {
641		list_for_each_entry_safe(mq, nmq, &maple_sentq, list) {
642			mdev = mq->dev;
643			recvbuf = mq->recvbuf->buf;
644			dma_cache_sync(&mdev->dev, recvbuf, 0x400,
645				DMA_FROM_DEVICE);
646			code = recvbuf[0];
647			kfree(mq->sendbuf);
648			list_del_init(&mq->list);
649			switch (code) {
650			case MAPLE_RESPONSE_NONE:
651				maple_response_none(mdev);
652				break;
653
654			case MAPLE_RESPONSE_DEVINFO:
655				maple_response_devinfo(mdev, recvbuf);
656				atomic_set(&mdev->busy, 0);
657				break;
658
659			case MAPLE_RESPONSE_DATATRF:
660				if (mdev->callback)
661					mdev->callback(mq);
662				atomic_set(&mdev->busy, 0);
663				wake_up(&mdev->maple_wait);
664				break;
665
666			case MAPLE_RESPONSE_FILEERR:
667				maple_response_fileerr(mdev, recvbuf);
668				atomic_set(&mdev->busy, 0);
669				wake_up(&mdev->maple_wait);
670				break;
671
672			case MAPLE_RESPONSE_AGAIN:
673			case MAPLE_RESPONSE_BADCMD:
674			case MAPLE_RESPONSE_BADFUNC:
675				dev_warn(&mdev->dev, "non-fatal error"
676					" 0x%X at (%d, %d)\n", code,
677					mdev->port, mdev->unit);
678				atomic_set(&mdev->busy, 0);
679				break;
680
681			case MAPLE_RESPONSE_ALLINFO:
682				dev_notice(&mdev->dev, "extended"
683				" device information request for (%d, %d)"
684				" but call is not supported\n", mdev->port,
685				mdev->unit);
686				atomic_set(&mdev->busy, 0);
687				break;
688
689			case MAPLE_RESPONSE_OK:
690				atomic_set(&mdev->busy, 0);
691				wake_up(&mdev->maple_wait);
692				break;
693
694			default:
695				break;
696			}
697		}
698		/* if scanning is 1 then we have subdevices to check */
699		if (scanning == 1) {
700			maple_send();
701			scanning = 2;
702		} else
703			scanning = 0;
704		/*check if we have actually tested all ports yet */
705		if (!fullscan)
706			maple_port_rescan();
707		/* mark that we have been through the first scan */
708		started = 1;
709	}
710	maple_send();
711}
712
713static irqreturn_t maple_dma_interrupt(int irq, void *dev_id)
714{
715	/* Load everything into the bottom half */
716	schedule_work(&maple_dma_process);
717	return IRQ_HANDLED;
718}
719
720static irqreturn_t maple_vblank_interrupt(int irq, void *dev_id)
721{
722	schedule_work(&maple_vblank_process);
723	return IRQ_HANDLED;
724}
725
726static int maple_set_dma_interrupt_handler(void)
727{
728	return request_irq(HW_EVENT_MAPLE_DMA, maple_dma_interrupt,
729		IRQF_SHARED, "maple bus DMA", &maple_unsupported_device);
730}
731
732static int maple_set_vblank_interrupt_handler(void)
733{
734	return request_irq(HW_EVENT_VSYNC, maple_vblank_interrupt,
735		IRQF_SHARED, "maple bus VBLANK", &maple_unsupported_device);
736}
737
738static int maple_get_dma_buffer(void)
739{
740	maple_sendbuf =
741	    (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
742				      MAPLE_DMA_PAGES);
743	if (!maple_sendbuf)
744		return -ENOMEM;
745	return 0;
746}
747
748static int maple_match_bus_driver(struct device *devptr,
749				  struct device_driver *drvptr)
750{
751	struct maple_driver *maple_drv = to_maple_driver(drvptr);
752	struct maple_device *maple_dev = to_maple_dev(devptr);
753
754	/* Trap empty port case */
755	if (maple_dev->devinfo.function == 0xFFFFFFFF)
756		return 0;
757	else if (maple_dev->devinfo.function &
758		 cpu_to_be32(maple_drv->function))
759		return 1;
760	return 0;
761}
762
763static int maple_bus_uevent(struct device *dev,
764			    struct kobj_uevent_env *env)
765{
766	return 0;
767}
768
769static void maple_bus_release(struct device *dev)
770{
771}
772
773static struct maple_driver maple_unsupported_device = {
774	.drv = {
775		.name = "maple_unsupported_device",
776		.bus = &maple_bus_type,
777	},
778};
779/*
780 * maple_bus_type - core maple bus structure
781 */
782struct bus_type maple_bus_type = {
783	.name = "maple",
784	.match = maple_match_bus_driver,
785	.uevent = maple_bus_uevent,
786};
787EXPORT_SYMBOL_GPL(maple_bus_type);
788
789static struct device maple_bus = {
790	.init_name = "maple",
791	.release = maple_bus_release,
792};
793
794static int __init maple_bus_init(void)
795{
796	int retval, i;
797	struct maple_device *mdev[MAPLE_PORTS];
798
799	ctrl_outl(0, MAPLE_ENABLE);
800
801	retval = device_register(&maple_bus);
802	if (retval)
803		goto cleanup;
804
805	retval = bus_register(&maple_bus_type);
806	if (retval)
807		goto cleanup_device;
808
809	retval = driver_register(&maple_unsupported_device.drv);
810	if (retval)
811		goto cleanup_bus;
812
813	/* allocate memory for maple bus dma */
814	retval = maple_get_dma_buffer();
815	if (retval) {
816		dev_err(&maple_bus, "failed to allocate DMA buffers\n");
817		goto cleanup_basic;
818	}
819
820	/* set up DMA interrupt handler */
821	retval = maple_set_dma_interrupt_handler();
822	if (retval) {
823		dev_err(&maple_bus, "bus failed to grab maple "
824			"DMA IRQ\n");
825		goto cleanup_dma;
826	}
827
828	/* set up VBLANK interrupt handler */
829	retval = maple_set_vblank_interrupt_handler();
830	if (retval) {
831		dev_err(&maple_bus, "bus failed to grab VBLANK IRQ\n");
832		goto cleanup_irq;
833	}
834
835	maple_queue_cache = KMEM_CACHE(maple_buffer, SLAB_HWCACHE_ALIGN);
836
837	if (!maple_queue_cache)
838		goto cleanup_bothirqs;
839
840	INIT_LIST_HEAD(&maple_waitq);
841	INIT_LIST_HEAD(&maple_sentq);
842
843	/* setup maple ports */
844	for (i = 0; i < MAPLE_PORTS; i++) {
845		checked[i] = false;
846		empty[i] = false;
847		mdev[i] = maple_alloc_dev(i, 0);
848		if (!mdev[i]) {
849			while (i-- > 0)
850				maple_free_dev(mdev[i]);
851			goto cleanup_cache;
852		}
853		baseunits[i] = mdev[i];
854		atomic_set(&mdev[i]->busy, 1);
855		maple_add_packet(mdev[i], 0, MAPLE_COMMAND_DEVINFO, 0, NULL);
856		subdevice_map[i] = 0;
857	}
858
859	maple_pnp_time = jiffies + HZ;
860	/* prepare initial queue */
861	maple_send();
862	dev_info(&maple_bus, "bus core now registered\n");
863
864	return 0;
865
866cleanup_cache:
867	kmem_cache_destroy(maple_queue_cache);
868
869cleanup_bothirqs:
870	free_irq(HW_EVENT_VSYNC, 0);
871
872cleanup_irq:
873	free_irq(HW_EVENT_MAPLE_DMA, 0);
874
875cleanup_dma:
876	free_pages((unsigned long) maple_sendbuf, MAPLE_DMA_PAGES);
877
878cleanup_basic:
879	driver_unregister(&maple_unsupported_device.drv);
880
881cleanup_bus:
882	bus_unregister(&maple_bus_type);
883
884cleanup_device:
885	device_unregister(&maple_bus);
886
887cleanup:
888	printk(KERN_ERR "Maple bus registration failed\n");
889	return retval;
890}
891/* Push init to later to ensure hardware gets detected */
892fs_initcall(maple_bus_init);
893