7e1257af3d41f70e03795153a4dd672d087c42a8
[sfrench/cifs-2.6.git] / drivers / sh / maple / maple.c
1 /*
2  * Core maple bus functionality
3  *
4  *  Copyright (C) 2007, 2008 Adrian McMenamin
5  *  Copyright (C) 2001 - 2008 Paul Mundt
6  *
7  * Based on 2.4 code by:
8  *
9  *  Copyright (C) 2000-2001 YAEGASHI Takeshi
10  *  Copyright (C) 2001 M. R. Brown
11  *  Copyright (C) 2001 Paul Mundt
12  *
13  * and others.
14  *
15  * This file is subject to the terms and conditions of the GNU General Public
16  * License.  See the file "COPYING" in the main directory of this archive
17  * for more details.
18  */
19 #include <linux/init.h>
20 #include <linux/kernel.h>
21 #include <linux/device.h>
22 #include <linux/interrupt.h>
23 #include <linux/list.h>
24 #include <linux/io.h>
25 #include <linux/slab.h>
26 #include <linux/maple.h>
27 #include <linux/dma-mapping.h>
28 #include <linux/delay.h>
29 #include <asm/cacheflush.h>
30 #include <asm/dma.h>
31 #include <asm/io.h>
32 #include <mach/dma.h>
33 #include <mach/sysasic.h>
34
35 MODULE_AUTHOR("Yaegashi Takeshi, Paul Mundt, M. R. Brown, Adrian McMenamin");
36 MODULE_DESCRIPTION("Maple bus driver for Dreamcast");
37 MODULE_LICENSE("GPL v2");
38 MODULE_SUPPORTED_DEVICE("{{SEGA, Dreamcast/Maple}}");
39
40 static void maple_dma_handler(struct work_struct *work);
41 static void maple_vblank_handler(struct work_struct *work);
42
43 static DECLARE_WORK(maple_dma_process, maple_dma_handler);
44 static DECLARE_WORK(maple_vblank_process, maple_vblank_handler);
45
46 static LIST_HEAD(maple_waitq);
47 static LIST_HEAD(maple_sentq);
48
49 /* mutex to protect queue of waiting packets */
50 static DEFINE_MUTEX(maple_wlist_lock);
51
52 static struct maple_driver maple_dummy_driver;
53 static struct device maple_bus;
54 static int subdevice_map[MAPLE_PORTS];
55 static unsigned long *maple_sendbuf, *maple_sendptr, *maple_lastptr;
56 static unsigned long maple_pnp_time;
57 static int started, scanning, fullscan;
58 static struct kmem_cache *maple_queue_cache;
59
60 struct maple_device_specify {
61         int port;
62         int unit;
63 };
64
65 static bool checked[4];
66 static struct maple_device *baseunits[4];
67
68 /**
69  * maple_driver_register - register a maple driver
70  * @drv: maple driver to be registered.
71  *
72  * Registers the passed in @drv, while updating the bus type.
73  * Devices with matching function IDs will be automatically probed.
74  */
75 int maple_driver_register(struct maple_driver *drv)
76 {
77         if (!drv)
78                 return -EINVAL;
79
80         drv->drv.bus = &maple_bus_type;
81
82         return driver_register(&drv->drv);
83 }
84 EXPORT_SYMBOL_GPL(maple_driver_register);
85
86 /**
87  * maple_driver_unregister - unregister a maple driver.
88  * @drv: maple driver to unregister.
89  *
90  * Cleans up after maple_driver_register(). To be invoked in the exit
91  * path of any module drivers.
92  */
93 void maple_driver_unregister(struct maple_driver *drv)
94 {
95         driver_unregister(&drv->drv);
96 }
97 EXPORT_SYMBOL_GPL(maple_driver_unregister);
98
99 /* set hardware registers to enable next round of dma */
100 static void maplebus_dma_reset(void)
101 {
102         ctrl_outl(MAPLE_MAGIC, MAPLE_RESET);
103         /* set trig type to 0 for software trigger, 1 for hardware (VBLANK) */
104         ctrl_outl(1, MAPLE_TRIGTYPE);
105         ctrl_outl(MAPLE_2MBPS | MAPLE_TIMEOUT(50000), MAPLE_SPEED);
106         ctrl_outl(PHYSADDR(maple_sendbuf), MAPLE_DMAADDR);
107         ctrl_outl(1, MAPLE_ENABLE);
108 }
109
110 /**
111  * maple_getcond_callback - setup handling MAPLE_COMMAND_GETCOND
112  * @dev: device responding
113  * @callback: handler callback
114  * @interval: interval in jiffies between callbacks
115  * @function: the function code for the device
116  */
117 void maple_getcond_callback(struct maple_device *dev,
118                         void (*callback) (struct mapleq *mq),
119                         unsigned long interval, unsigned long function)
120 {
121         dev->callback = callback;
122         dev->interval = interval;
123         dev->function = cpu_to_be32(function);
124         dev->when = jiffies;
125 }
126 EXPORT_SYMBOL_GPL(maple_getcond_callback);
127
128 static int maple_dma_done(void)
129 {
130         return (ctrl_inl(MAPLE_STATE) & 1) == 0;
131 }
132
133 static void maple_release_device(struct device *dev)
134 {
135         struct maple_device *mdev;
136         struct mapleq *mq;
137         if (!dev)
138                 return;
139         mdev = to_maple_dev(dev);
140         mq = mdev->mq;
141         if (mq) {
142                 if (mq->recvbufdcsp)
143                         kmem_cache_free(maple_queue_cache, mq->recvbufdcsp);
144                 kfree(mq);
145                 mq = NULL;
146         }
147         kfree(mdev);
148 }
149
150 /**
151  * maple_add_packet - add a single instruction to the queue
152  * @mdev: maple device
153  * @function: function on device being queried
154  * @command: maple command to add
155  * @length: length of command string (in 32 bit words)
156  * @data: remainder of command string
157  */
158 int maple_add_packet(struct maple_device *mdev, u32 function, u32 command,
159         size_t length, void *data)
160 {
161         int locking, ret = 0;
162         void *sendbuf = NULL;
163
164         mutex_lock(&maple_wlist_lock);
165         /* bounce if device already locked */
166         locking = mutex_is_locked(&mdev->mq->mutex);
167         if (locking) {
168                 ret = -EBUSY;
169                 goto out;
170         }
171
172         mutex_lock(&mdev->mq->mutex);
173
174         if (length) {
175                 sendbuf = kmalloc(length * 4, GFP_KERNEL);
176                 if (!sendbuf) {
177                         mutex_unlock(&mdev->mq->mutex);
178                         ret = -ENOMEM;
179                         goto out;
180                 }
181                 ((__be32 *)sendbuf)[0] = cpu_to_be32(function);
182         }
183
184         mdev->mq->command = command;
185         mdev->mq->length = length;
186         if (length > 1)
187                 memcpy(sendbuf + 4, data, (length - 1) * 4);
188         mdev->mq->sendbuf = sendbuf;
189
190         list_add(&mdev->mq->list, &maple_waitq);
191 out:
192         mutex_unlock(&maple_wlist_lock);
193         return ret;
194 }
195 EXPORT_SYMBOL_GPL(maple_add_packet);
196
197 /**
198  * maple_add_packet_sleeps - add a single instruction to the queue
199  * @mdev: maple device
200  * @function: function on device being queried
201  * @command: maple command to add
202  * @length: length of command string (in 32 bit words)
203  * @data: remainder of command string
204  *
205  * Same as maple_add_packet(), but waits for the lock to become free.
206  */
207 int maple_add_packet_sleeps(struct maple_device *mdev, u32 function,
208         u32 command, size_t length, void *data)
209 {
210         int locking, ret = 0;
211         void *sendbuf = NULL;
212
213         locking = mutex_lock_interruptible(&mdev->mq->mutex);
214         if (locking) {
215                 ret = -EIO;
216                 goto out;
217         }
218
219         if (length) {
220                 sendbuf = kmalloc(length * 4, GFP_KERNEL);
221                 if (!sendbuf) {
222                         mutex_unlock(&mdev->mq->mutex);
223                         ret = -ENOMEM;
224                         goto out;
225                 }
226                 ((__be32 *)sendbuf)[0] = cpu_to_be32(function);
227         }
228
229         mdev->mq->command = command;
230         mdev->mq->length = length;
231         if (length > 1)
232                 memcpy(sendbuf + 4, data, (length - 1) * 4);
233         mdev->mq->sendbuf = sendbuf;
234
235         mutex_lock(&maple_wlist_lock);
236         list_add(&mdev->mq->list, &maple_waitq);
237         mutex_unlock(&maple_wlist_lock);
238 out:
239         return ret;
240 }
241 EXPORT_SYMBOL_GPL(maple_add_packet_sleeps);
242
243 static struct mapleq *maple_allocq(struct maple_device *mdev)
244 {
245         struct mapleq *mq;
246
247         mq = kmalloc(sizeof(*mq), GFP_KERNEL);
248         if (!mq)
249                 goto failed_nomem;
250
251         mq->dev = mdev;
252         mq->recvbufdcsp = kmem_cache_zalloc(maple_queue_cache, GFP_KERNEL);
253         mq->recvbuf = (void *) P2SEGADDR(mq->recvbufdcsp);
254         if (!mq->recvbuf)
255                 goto failed_p2;
256         /*
257          * most devices do not need the mutex - but
258          * anything that injects block reads or writes
259          * will rely on it
260          */
261         mutex_init(&mq->mutex);
262
263         return mq;
264
265 failed_p2:
266         kfree(mq);
267 failed_nomem:
268         return NULL;
269 }
270
271 static struct maple_device *maple_alloc_dev(int port, int unit)
272 {
273         struct maple_device *mdev;
274
275         mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
276         if (!mdev)
277                 return NULL;
278
279         mdev->port = port;
280         mdev->unit = unit;
281         mdev->mq = maple_allocq(mdev);
282
283         if (!mdev->mq) {
284                 kfree(mdev);
285                 return NULL;
286         }
287         mdev->dev.bus = &maple_bus_type;
288         mdev->dev.parent = &maple_bus;
289         return mdev;
290 }
291
292 static void maple_free_dev(struct maple_device *mdev)
293 {
294         if (!mdev)
295                 return;
296         if (mdev->mq) {
297                 if (mdev->mq->recvbufdcsp)
298                         kmem_cache_free(maple_queue_cache,
299                                 mdev->mq->recvbufdcsp);
300                 kfree(mdev->mq);
301         }
302         kfree(mdev);
303 }
304
305 /* process the command queue into a maple command block
306  * terminating command has bit 32 of first long set to 0
307  */
308 static void maple_build_block(struct mapleq *mq)
309 {
310         int port, unit, from, to, len;
311         unsigned long *lsendbuf = mq->sendbuf;
312
313         port = mq->dev->port & 3;
314         unit = mq->dev->unit;
315         len = mq->length;
316         from = port << 6;
317         to = (port << 6) | (unit > 0 ? (1 << (unit - 1)) & 0x1f : 0x20);
318
319         *maple_lastptr &= 0x7fffffff;
320         maple_lastptr = maple_sendptr;
321
322         *maple_sendptr++ = (port << 16) | len | 0x80000000;
323         *maple_sendptr++ = PHYSADDR(mq->recvbuf);
324         *maple_sendptr++ =
325             mq->command | (to << 8) | (from << 16) | (len << 24);
326         while (len-- > 0)
327                 *maple_sendptr++ = *lsendbuf++;
328 }
329
330 /* build up command queue */
331 static void maple_send(void)
332 {
333         int i, maple_packets = 0;
334         struct mapleq *mq, *nmq;
335
336         if (!list_empty(&maple_sentq))
337                 return;
338         mutex_lock(&maple_wlist_lock);
339         if (list_empty(&maple_waitq) || !maple_dma_done()) {
340                 mutex_unlock(&maple_wlist_lock);
341                 return;
342         }
343         mutex_unlock(&maple_wlist_lock);
344         maple_lastptr = maple_sendbuf;
345         maple_sendptr = maple_sendbuf;
346         mutex_lock(&maple_wlist_lock);
347         list_for_each_entry_safe(mq, nmq, &maple_waitq, list) {
348                 maple_build_block(mq);
349                 list_move(&mq->list, &maple_sentq);
350                 if (maple_packets++ > MAPLE_MAXPACKETS)
351                         break;
352         }
353         mutex_unlock(&maple_wlist_lock);
354         if (maple_packets > 0) {
355                 for (i = 0; i < (1 << MAPLE_DMA_PAGES); i++)
356                         dma_cache_sync(0, maple_sendbuf + i * PAGE_SIZE,
357                                        PAGE_SIZE, DMA_BIDIRECTIONAL);
358         }
359 }
360
361 /* check if there is a driver registered likely to match this device */
362 static int check_matching_maple_driver(struct device_driver *driver,
363                                         void *devptr)
364 {
365         struct maple_driver *maple_drv;
366         struct maple_device *mdev;
367
368         mdev = devptr;
369         maple_drv = to_maple_driver(driver);
370         if (mdev->devinfo.function & cpu_to_be32(maple_drv->function))
371                 return 1;
372         return 0;
373 }
374
375 static void maple_detach_driver(struct maple_device *mdev)
376 {
377         if (!mdev)
378                 return;
379         device_unregister(&mdev->dev);
380         mdev = NULL;
381 }
382
383 /* process initial MAPLE_COMMAND_DEVINFO for each device or port */
384 static void maple_attach_driver(struct maple_device *mdev)
385 {
386         char *p, *recvbuf;
387         unsigned long function;
388         int matched, retval;
389
390         recvbuf = mdev->mq->recvbuf;
391         /* copy the data as individual elements in
392         * case of memory optimisation */
393         memcpy(&mdev->devinfo.function, recvbuf + 4, 4);
394         memcpy(&mdev->devinfo.function_data[0], recvbuf + 8, 12);
395         memcpy(&mdev->devinfo.area_code, recvbuf + 20, 1);
396         memcpy(&mdev->devinfo.connector_direction, recvbuf + 21, 1);
397         memcpy(&mdev->devinfo.product_name[0], recvbuf + 22, 30);
398         memcpy(&mdev->devinfo.product_licence[0], recvbuf + 52, 60);
399         memcpy(&mdev->devinfo.standby_power, recvbuf + 112, 2);
400         memcpy(&mdev->devinfo.max_power, recvbuf + 114, 2);
401         memcpy(mdev->product_name, mdev->devinfo.product_name, 30);
402         mdev->product_name[30] = '\0';
403         memcpy(mdev->product_licence, mdev->devinfo.product_licence, 60);
404         mdev->product_licence[60] = '\0';
405
406         for (p = mdev->product_name + 29; mdev->product_name <= p; p--)
407                 if (*p == ' ')
408                         *p = '\0';
409                 else
410                         break;
411         for (p = mdev->product_licence + 59; mdev->product_licence <= p; p--)
412                 if (*p == ' ')
413                         *p = '\0';
414                 else
415                         break;
416
417         printk(KERN_INFO "Maple device detected: %s\n",
418                 mdev->product_name);
419         printk(KERN_INFO "Maple device: %s\n", mdev->product_licence);
420
421         function = be32_to_cpu(mdev->devinfo.function);
422
423         if (function > 0x200) {
424                 /* Do this silently - as not a real device */
425                 function = 0;
426                 mdev->driver = &maple_dummy_driver;
427                 dev_set_name(&mdev->dev, "%d:0.port", mdev->port);
428         } else {
429                 printk(KERN_INFO
430                         "Maple bus at (%d, %d): Function 0x%lX\n",
431                         mdev->port, mdev->unit, function);
432
433                 matched =
434                         bus_for_each_drv(&maple_bus_type, NULL, mdev,
435                                 check_matching_maple_driver);
436
437                 if (matched == 0) {
438                         /* Driver does not exist yet */
439                         printk(KERN_INFO
440                                 "No maple driver found.\n");
441                         mdev->driver = &maple_dummy_driver;
442                 }
443                 dev_set_name(&mdev->dev, "%d:0%d.%lX", mdev->port,
444                              mdev->unit, function);
445         }
446         mdev->function = function;
447         mdev->dev.release = &maple_release_device;
448         retval = device_register(&mdev->dev);
449         if (retval) {
450                 printk(KERN_INFO
451                 "Maple bus: Attempt to register device"
452                 " (%x, %x) failed.\n",
453                 mdev->port, mdev->unit);
454                 maple_free_dev(mdev);
455                 mdev = NULL;
456                 return;
457         }
458 }
459
460 /*
461  * if device has been registered for the given
462  * port and unit then return 1 - allows identification
463  * of which devices need to be attached or detached
464  */
465 static int detach_maple_device(struct device *device, void *portptr)
466 {
467         struct maple_device_specify *ds;
468         struct maple_device *mdev;
469
470         ds = portptr;
471         mdev = to_maple_dev(device);
472         if (mdev->port == ds->port && mdev->unit == ds->unit)
473                 return 1;
474         return 0;
475 }
476
477 static int setup_maple_commands(struct device *device, void *ignored)
478 {
479         int add;
480         struct maple_device *maple_dev = to_maple_dev(device);
481
482         if ((maple_dev->interval > 0)
483             && time_after(jiffies, maple_dev->when)) {
484                 /* bounce if we cannot lock */
485                 add = maple_add_packet(maple_dev,
486                         be32_to_cpu(maple_dev->devinfo.function),
487                         MAPLE_COMMAND_GETCOND, 1, NULL);
488                 if (!add)
489                         maple_dev->when = jiffies + maple_dev->interval;
490         } else {
491                 if (time_after(jiffies, maple_pnp_time))
492                         /* This will also bounce */
493                         maple_add_packet(maple_dev, 0,
494                                 MAPLE_COMMAND_DEVINFO, 0, NULL);
495         }
496         return 0;
497 }
498
499 /* VBLANK bottom half - implemented via workqueue */
500 static void maple_vblank_handler(struct work_struct *work)
501 {
502         if (!list_empty(&maple_sentq) || !maple_dma_done())
503                 return;
504
505         ctrl_outl(0, MAPLE_ENABLE);
506
507         bus_for_each_dev(&maple_bus_type, NULL, NULL,
508                          setup_maple_commands);
509
510         if (time_after(jiffies, maple_pnp_time))
511                 maple_pnp_time = jiffies + MAPLE_PNP_INTERVAL;
512
513         mutex_lock(&maple_wlist_lock);
514         if (!list_empty(&maple_waitq) && list_empty(&maple_sentq)) {
515                 mutex_unlock(&maple_wlist_lock);
516                 maple_send();
517         } else {
518                 mutex_unlock(&maple_wlist_lock);
519         }
520
521         maplebus_dma_reset();
522 }
523
524 /* handle devices added via hotplugs - placing them on queue for DEVINFO*/
525 static void maple_map_subunits(struct maple_device *mdev, int submask)
526 {
527         int retval, k, devcheck;
528         struct maple_device *mdev_add;
529         struct maple_device_specify ds;
530
531         ds.port = mdev->port;
532         for (k = 0; k < 5; k++) {
533                 ds.unit = k + 1;
534                 retval =
535                     bus_for_each_dev(&maple_bus_type, NULL, &ds,
536                                      detach_maple_device);
537                 if (retval) {
538                         submask = submask >> 1;
539                         continue;
540                 }
541                 devcheck = submask & 0x01;
542                 if (devcheck) {
543                         mdev_add = maple_alloc_dev(mdev->port, k + 1);
544                         if (!mdev_add)
545                                 return;
546                         maple_add_packet(mdev_add, 0, MAPLE_COMMAND_DEVINFO,
547                                 0, NULL);
548                         /* mark that we are checking sub devices */
549                         scanning = 1;
550                 }
551                 submask = submask >> 1;
552         }
553 }
554
555 /* mark a device as removed */
556 static void maple_clean_submap(struct maple_device *mdev)
557 {
558         int killbit;
559
560         killbit = (mdev->unit > 0 ? (1 << (mdev->unit - 1)) & 0x1f : 0x20);
561         killbit = ~killbit;
562         killbit &= 0xFF;
563         subdevice_map[mdev->port] = subdevice_map[mdev->port] & killbit;
564 }
565
566 /* handle empty port or hotplug removal */
567 static void maple_response_none(struct maple_device *mdev,
568                                 struct mapleq *mq)
569 {
570         if (mdev->unit != 0) {
571                 list_del(&mq->list);
572                 maple_clean_submap(mdev);
573                 printk(KERN_INFO
574                        "Maple bus device detaching at (%d, %d)\n",
575                        mdev->port, mdev->unit);
576                 maple_detach_driver(mdev);
577                 return;
578         }
579         if (!started || !fullscan) {
580                 if (checked[mdev->port] == false) {
581                         checked[mdev->port] = true;
582                         printk(KERN_INFO "No maple devices attached"
583                                 " to port %d\n", mdev->port);
584                 }
585                 return;
586         }
587         maple_clean_submap(mdev);
588 }
589
590 /* preprocess hotplugs or scans */
591 static void maple_response_devinfo(struct maple_device *mdev,
592                                    char *recvbuf)
593 {
594         char submask;
595         if (!started || (scanning == 2) || !fullscan) {
596                 if ((mdev->unit == 0) && (checked[mdev->port] == false)) {
597                         checked[mdev->port] = true;
598                         maple_attach_driver(mdev);
599                 } else {
600                         if (mdev->unit != 0)
601                                 maple_attach_driver(mdev);
602                 }
603                 return;
604         }
605         if (mdev->unit == 0) {
606                 submask = recvbuf[2] & 0x1F;
607                 if (submask ^ subdevice_map[mdev->port]) {
608                         maple_map_subunits(mdev, submask);
609                         subdevice_map[mdev->port] = submask;
610                 }
611         }
612 }
613
614 static void maple_port_rescan(void)
615 {
616         int i;
617         struct maple_device *mdev;
618
619         fullscan = 1;
620         for (i = 0; i < MAPLE_PORTS; i++) {
621                 if (checked[i] == false) {
622                         fullscan = 0;
623                         mdev = baseunits[i];
624                         /*
625                          *  test lock in case scan has failed
626                          *  but device is still locked
627                          */
628                         if (mutex_is_locked(&mdev->mq->mutex))
629                                 mutex_unlock(&mdev->mq->mutex);
630                         maple_add_packet(mdev, 0, MAPLE_COMMAND_DEVINFO,
631                                 0, NULL);
632                 }
633         }
634 }
635
636 /* maple dma end bottom half - implemented via workqueue */
637 static void maple_dma_handler(struct work_struct *work)
638 {
639         struct mapleq *mq, *nmq;
640         struct maple_device *dev;
641         char *recvbuf;
642         enum maple_code code;
643
644         if (!maple_dma_done())
645                 return;
646         ctrl_outl(0, MAPLE_ENABLE);
647         if (!list_empty(&maple_sentq)) {
648                 list_for_each_entry_safe(mq, nmq, &maple_sentq, list) {
649                         recvbuf = mq->recvbuf;
650                         code = recvbuf[0];
651                         dev = mq->dev;
652                         kfree(mq->sendbuf);
653                         mutex_unlock(&mq->mutex);
654                         list_del_init(&mq->list);
655
656                         switch (code) {
657                         case MAPLE_RESPONSE_NONE:
658                                 maple_response_none(dev, mq);
659                                 break;
660
661                         case MAPLE_RESPONSE_DEVINFO:
662                                 maple_response_devinfo(dev, recvbuf);
663                                 break;
664
665                         case MAPLE_RESPONSE_DATATRF:
666                                 if (dev->callback)
667                                         dev->callback(mq);
668                                 break;
669
670                         case MAPLE_RESPONSE_FILEERR:
671                         case MAPLE_RESPONSE_AGAIN:
672                         case MAPLE_RESPONSE_BADCMD:
673                         case MAPLE_RESPONSE_BADFUNC:
674                                 printk(KERN_DEBUG
675                                        "Maple non-fatal error 0x%X\n",
676                                        code);
677                                 break;
678
679                         case MAPLE_RESPONSE_ALLINFO:
680                                 printk(KERN_DEBUG
681                                        "Maple - extended device information"
682                                         " not supported\n");
683                                 break;
684
685                         case MAPLE_RESPONSE_OK:
686                                 break;
687
688                         default:
689                                 break;
690                         }
691                 }
692                 /* if scanning is 1 then we have subdevices to check */
693                 if (scanning == 1) {
694                         maple_send();
695                         scanning = 2;
696                 } else
697                         scanning = 0;
698                 /*check if we have actually tested all ports yet */
699                 if (!fullscan)
700                         maple_port_rescan();
701                 /* mark that we have been through the first scan */
702                 if (started == 0)
703                         started = 1;
704         }
705         maplebus_dma_reset();
706 }
707
708 static irqreturn_t maplebus_dma_interrupt(int irq, void *dev_id)
709 {
710         /* Load everything into the bottom half */
711         schedule_work(&maple_dma_process);
712         return IRQ_HANDLED;
713 }
714
715 static irqreturn_t maplebus_vblank_interrupt(int irq, void *dev_id)
716 {
717         schedule_work(&maple_vblank_process);
718         return IRQ_HANDLED;
719 }
720
721 static int maple_set_dma_interrupt_handler(void)
722 {
723         return request_irq(HW_EVENT_MAPLE_DMA, maplebus_dma_interrupt,
724                 IRQF_SHARED, "maple bus DMA", &maple_dummy_driver);
725 }
726
727 static int maple_set_vblank_interrupt_handler(void)
728 {
729         return request_irq(HW_EVENT_VSYNC, maplebus_vblank_interrupt,
730                 IRQF_SHARED, "maple bus VBLANK", &maple_dummy_driver);
731 }
732
733 static int maple_get_dma_buffer(void)
734 {
735         maple_sendbuf =
736             (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
737                                       MAPLE_DMA_PAGES);
738         if (!maple_sendbuf)
739                 return -ENOMEM;
740         return 0;
741 }
742
743 static int match_maple_bus_driver(struct device *devptr,
744                                   struct device_driver *drvptr)
745 {
746         struct maple_driver *maple_drv = to_maple_driver(drvptr);
747         struct maple_device *maple_dev = to_maple_dev(devptr);
748
749         /* Trap empty port case */
750         if (maple_dev->devinfo.function == 0xFFFFFFFF)
751                 return 0;
752         else if (maple_dev->devinfo.function &
753                  cpu_to_be32(maple_drv->function))
754                 return 1;
755         return 0;
756 }
757
758 static int maple_bus_uevent(struct device *dev,
759                             struct kobj_uevent_env *env)
760 {
761         return 0;
762 }
763
764 static void maple_bus_release(struct device *dev)
765 {
766 }
767
768 static struct maple_driver maple_dummy_driver = {
769         .drv = {
770                 .name = "maple_dummy_driver",
771                 .bus = &maple_bus_type,
772         },
773 };
774
775 struct bus_type maple_bus_type = {
776         .name = "maple",
777         .match = match_maple_bus_driver,
778         .uevent = maple_bus_uevent,
779 };
780 EXPORT_SYMBOL_GPL(maple_bus_type);
781
782 static struct device maple_bus = {
783         .init_name = "maple",
784         .release = maple_bus_release,
785 };
786
787 static int __init maple_bus_init(void)
788 {
789         int retval, i;
790         struct maple_device *mdev[MAPLE_PORTS];
791         ctrl_outl(0, MAPLE_STATE);
792
793         retval = device_register(&maple_bus);
794         if (retval)
795                 goto cleanup;
796
797         retval = bus_register(&maple_bus_type);
798         if (retval)
799                 goto cleanup_device;
800
801         retval = driver_register(&maple_dummy_driver.drv);
802         if (retval)
803                 goto cleanup_bus;
804
805         /* allocate memory for maple bus dma */
806         retval = maple_get_dma_buffer();
807         if (retval) {
808                 printk(KERN_INFO
809                        "Maple bus: Failed to allocate Maple DMA buffers\n");
810                 goto cleanup_basic;
811         }
812
813         /* set up DMA interrupt handler */
814         retval = maple_set_dma_interrupt_handler();
815         if (retval) {
816                 printk(KERN_INFO
817                        "Maple bus: Failed to grab maple DMA IRQ\n");
818                 goto cleanup_dma;
819         }
820
821         /* set up VBLANK interrupt handler */
822         retval = maple_set_vblank_interrupt_handler();
823         if (retval) {
824                 printk(KERN_INFO "Maple bus: Failed to grab VBLANK IRQ\n");
825                 goto cleanup_irq;
826         }
827
828         maple_queue_cache =
829             kmem_cache_create("maple_queue_cache", 0x400, 0,
830                               SLAB_HWCACHE_ALIGN, NULL);
831
832         if (!maple_queue_cache)
833                 goto cleanup_bothirqs;
834
835         INIT_LIST_HEAD(&maple_waitq);
836         INIT_LIST_HEAD(&maple_sentq);
837
838         /* setup maple ports */
839         for (i = 0; i < MAPLE_PORTS; i++) {
840                 checked[i] = false;
841                 mdev[i] = maple_alloc_dev(i, 0);
842                 baseunits[i] = mdev[i];
843                 if (!mdev[i]) {
844                         while (i-- > 0)
845                                 maple_free_dev(mdev[i]);
846                         goto cleanup_cache;
847                 }
848                 maple_add_packet(mdev[i], 0, MAPLE_COMMAND_DEVINFO, 0, NULL);
849                 subdevice_map[i] = 0;
850         }
851
852         /* setup maplebus hardware */
853         maplebus_dma_reset();
854         /* initial detection */
855         maple_send();
856         maple_pnp_time = jiffies;
857         printk(KERN_INFO "Maple bus core now registered.\n");
858
859         return 0;
860
861 cleanup_cache:
862         kmem_cache_destroy(maple_queue_cache);
863
864 cleanup_bothirqs:
865         free_irq(HW_EVENT_VSYNC, 0);
866
867 cleanup_irq:
868         free_irq(HW_EVENT_MAPLE_DMA, 0);
869
870 cleanup_dma:
871         free_pages((unsigned long) maple_sendbuf, MAPLE_DMA_PAGES);
872
873 cleanup_basic:
874         driver_unregister(&maple_dummy_driver.drv);
875
876 cleanup_bus:
877         bus_unregister(&maple_bus_type);
878
879 cleanup_device:
880         device_unregister(&maple_bus);
881
882 cleanup:
883         printk(KERN_INFO "Maple bus registration failed\n");
884         return retval;
885 }
886 /* Push init to later to ensure hardware gets detected */
887 fs_initcall(maple_bus_init);