c71bb4b4ce8476efbaa0e70bca1fccc3ab2666b5
[sfrench/cifs-2.6.git] / drivers / sh / maple / maple.c
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
29 MODULE_AUTHOR("Adrian McMenamin <adrian@mcmen.demon.co.uk>");
30 MODULE_DESCRIPTION("Maple bus driver for Dreamcast");
31 MODULE_LICENSE("GPL v2");
32 MODULE_SUPPORTED_DEVICE("{{SEGA, Dreamcast/Maple}}");
33
34 static void maple_dma_handler(struct work_struct *work);
35 static void maple_vblank_handler(struct work_struct *work);
36
37 static DECLARE_WORK(maple_dma_process, maple_dma_handler);
38 static DECLARE_WORK(maple_vblank_process, maple_vblank_handler);
39
40 static LIST_HEAD(maple_waitq);
41 static LIST_HEAD(maple_sentq);
42
43 /* mutex to protect queue of waiting packets */
44 static DEFINE_MUTEX(maple_wlist_lock);
45
46 static struct maple_driver maple_unsupported_device;
47 static struct device maple_bus;
48 static int subdevice_map[MAPLE_PORTS];
49 static unsigned long *maple_sendbuf, *maple_sendptr, *maple_lastptr;
50 static unsigned long maple_pnp_time;
51 static int started, scanning, fullscan;
52 static struct kmem_cache *maple_queue_cache;
53
54 struct maple_device_specify {
55         int port;
56         int unit;
57 };
58
59 static bool checked[MAPLE_PORTS];
60 static bool empty[MAPLE_PORTS];
61 static 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  */
70 int 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 }
79 EXPORT_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  */
88 void maple_driver_unregister(struct maple_driver *drv)
89 {
90         driver_unregister(&drv->drv);
91 }
92 EXPORT_SYMBOL_GPL(maple_driver_unregister);
93
94 /* set hardware registers to enable next round of dma */
95 static 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(PHYSADDR(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  */
120 void 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 }
129 EXPORT_SYMBOL_GPL(maple_getcond_callback);
130
131 static int maple_dma_done(void)
132 {
133         return (ctrl_inl(MAPLE_STATE) & 1) == 0;
134 }
135
136 static 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  */
156 int 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);
180 out:
181         return ret;
182 }
183 EXPORT_SYMBOL_GPL(maple_add_packet);
184
185 static 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
202 failed_p2:
203         kfree(mq);
204 failed_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
210 static 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
236 static 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  */
246 static 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++ = PHYSADDR(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 */
269 static 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
306 finish:
307         maple_dma_reset();
308 }
309
310 /* check if there is a driver registered likely to match this device */
311 static 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
324 static 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 */
330 static 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
383                 dev_set_name(&mdev->dev, "%d:0%d.%lX", mdev->port,
384                              mdev->unit, function);
385         }
386
387         mdev->function = function;
388         mdev->dev.release = &maple_release_device;
389
390         atomic_set(&mdev->busy, 0);
391         error = device_register(&mdev->dev);
392         if (error) {
393                 dev_warn(&mdev->dev, "could not register device at"
394                         " (%d, %d), with error 0x%X\n", mdev->unit,
395                         mdev->port, error);
396                 maple_free_dev(mdev);
397                 mdev = NULL;
398                 return;
399         }
400 }
401
402 /*
403  * if device has been registered for the given
404  * port and unit then return 1 - allows identification
405  * of which devices need to be attached or detached
406  */
407 static int check_maple_device(struct device *device, void *portptr)
408 {
409         struct maple_device_specify *ds;
410         struct maple_device *mdev;
411
412         ds = portptr;
413         mdev = to_maple_dev(device);
414         if (mdev->port == ds->port && mdev->unit == ds->unit)
415                 return 1;
416         return 0;
417 }
418
419 static int setup_maple_commands(struct device *device, void *ignored)
420 {
421         int add;
422         struct maple_device *mdev = to_maple_dev(device);
423         if (mdev->interval > 0 && atomic_read(&mdev->busy) == 0 &&
424                 time_after(jiffies, mdev->when)) {
425                 /* bounce if we cannot add */
426                 add = maple_add_packet(mdev,
427                         be32_to_cpu(mdev->devinfo.function),
428                         MAPLE_COMMAND_GETCOND, 1, NULL);
429                 if (!add)
430                         mdev->when = jiffies + mdev->interval;
431         } else {
432                 if (time_after(jiffies, maple_pnp_time))
433                         /* Ensure we don't have block reads and devinfo
434                         * calls interfering with one another - so flag the
435                         * device as busy */
436                         if (atomic_read(&mdev->busy) == 0) {
437                                 atomic_set(&mdev->busy, 1);
438                                 maple_add_packet(mdev, 0,
439                                         MAPLE_COMMAND_DEVINFO, 0, NULL);
440                         }
441         }
442         return 0;
443 }
444
445 /* VBLANK bottom half - implemented via workqueue */
446 static void maple_vblank_handler(struct work_struct *work)
447 {
448         int x, locking;
449         struct maple_device *mdev;
450
451         if (!maple_dma_done())
452                 return;
453
454         ctrl_outl(0, MAPLE_ENABLE);
455
456         if (!list_empty(&maple_sentq))
457                 goto finish;
458
459         /*
460         * Set up essential commands - to fetch data and
461         * check devices are still present
462         */
463         bus_for_each_dev(&maple_bus_type, NULL, NULL,
464                 setup_maple_commands);
465
466         if (time_after(jiffies, maple_pnp_time)) {
467                 /*
468                 * Scan the empty ports - bus is flakey and may have
469                 * mis-reported emptyness
470                 */
471                 for (x = 0; x < MAPLE_PORTS; x++) {
472                         if (checked[x] && empty[x]) {
473                                 mdev = baseunits[x];
474                                 if (!mdev)
475                                         break;
476                                 atomic_set(&mdev->busy, 1);
477                                 locking = maple_add_packet(mdev, 0,
478                                         MAPLE_COMMAND_DEVINFO, 0, NULL);
479                                 if (!locking)
480                                         break;
481                                 }
482                         }
483
484                 maple_pnp_time = jiffies + MAPLE_PNP_INTERVAL;
485         }
486
487 finish:
488         maple_send();
489 }
490
491 /* handle devices added via hotplugs - placing them on queue for DEVINFO */
492 static void maple_map_subunits(struct maple_device *mdev, int submask)
493 {
494         int retval, k, devcheck;
495         struct maple_device *mdev_add;
496         struct maple_device_specify ds;
497
498         ds.port = mdev->port;
499         for (k = 0; k < 5; k++) {
500                 ds.unit = k + 1;
501                 retval =
502                     bus_for_each_dev(&maple_bus_type, NULL, &ds,
503                                      check_maple_device);
504                 if (retval) {
505                         submask = submask >> 1;
506                         continue;
507                 }
508                 devcheck = submask & 0x01;
509                 if (devcheck) {
510                         mdev_add = maple_alloc_dev(mdev->port, k + 1);
511                         if (!mdev_add)
512                                 return;
513                         atomic_set(&mdev_add->busy, 1);
514                         maple_add_packet(mdev_add, 0, MAPLE_COMMAND_DEVINFO,
515                                 0, NULL);
516                         /* mark that we are checking sub devices */
517                         scanning = 1;
518                 }
519                 submask = submask >> 1;
520         }
521 }
522
523 /* mark a device as removed */
524 static void maple_clean_submap(struct maple_device *mdev)
525 {
526         int killbit;
527
528         killbit = (mdev->unit > 0 ? (1 << (mdev->unit - 1)) & 0x1f : 0x20);
529         killbit = ~killbit;
530         killbit &= 0xFF;
531         subdevice_map[mdev->port] = subdevice_map[mdev->port] & killbit;
532 }
533
534 /* handle empty port or hotplug removal */
535 static void maple_response_none(struct maple_device *mdev)
536 {
537         maple_clean_submap(mdev);
538
539         if (likely(mdev->unit != 0)) {
540                 /*
541                 * Block devices play up
542                 * and give the impression they have
543                 * been removed even when still in place or
544                 * trip the mtd layer when they have
545                 * really gone - this code traps that eventuality
546                 * and ensures we aren't overloaded with useless
547                 * error messages
548                 */
549                 if (mdev->can_unload) {
550                         if (!mdev->can_unload(mdev)) {
551                                 atomic_set(&mdev->busy, 2);
552                                 wake_up(&mdev->maple_wait);
553                                 return;
554                         }
555                 }
556
557                 dev_info(&mdev->dev, "detaching device at (%d, %d)\n",
558                         mdev->port, mdev->unit);
559                 maple_detach_driver(mdev);
560                 return;
561         } else {
562                 if (!started || !fullscan) {
563                         if (checked[mdev->port] == false) {
564                                 checked[mdev->port] = true;
565                                 empty[mdev->port] = true;
566                                 dev_info(&mdev->dev, "no devices"
567                                         " to port %d\n", mdev->port);
568                         }
569                         return;
570                 }
571         }
572         /* Some hardware devices generate false detach messages on unit 0 */
573         atomic_set(&mdev->busy, 0);
574 }
575
576 /* preprocess hotplugs or scans */
577 static void maple_response_devinfo(struct maple_device *mdev,
578                                    char *recvbuf)
579 {
580         char submask;
581         if (!started || (scanning == 2) || !fullscan) {
582                 if ((mdev->unit == 0) && (checked[mdev->port] == false)) {
583                         checked[mdev->port] = true;
584                         maple_attach_driver(mdev);
585                 } else {
586                         if (mdev->unit != 0)
587                                 maple_attach_driver(mdev);
588                         if (mdev->unit == 0) {
589                                 empty[mdev->port] = false;
590                                 maple_attach_driver(mdev);
591                         }
592                 }
593         }
594         if (mdev->unit == 0) {
595                 submask = recvbuf[2] & 0x1F;
596                 if (submask ^ subdevice_map[mdev->port]) {
597                         maple_map_subunits(mdev, submask);
598                         subdevice_map[mdev->port] = submask;
599                 }
600         }
601 }
602
603 static void maple_response_fileerr(struct maple_device *mdev, void *recvbuf)
604 {
605         if (mdev->fileerr_handler) {
606                 mdev->fileerr_handler(mdev, recvbuf);
607                 return;
608         } else
609                 dev_warn(&mdev->dev, "device at (%d, %d) reports"
610                         "file error 0x%X\n", mdev->port, mdev->unit,
611                         ((int *)recvbuf)[1]);
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                         maple_add_packet(mdev, 0, MAPLE_COMMAND_DEVINFO,
625                                 0, NULL);
626                 }
627         }
628 }
629
630 /* maple dma end bottom half - implemented via workqueue */
631 static void maple_dma_handler(struct work_struct *work)
632 {
633         struct mapleq *mq, *nmq;
634         struct maple_device *mdev;
635         char *recvbuf;
636         enum maple_code code;
637
638         if (!maple_dma_done())
639                 return;
640         ctrl_outl(0, MAPLE_ENABLE);
641         if (!list_empty(&maple_sentq)) {
642                 list_for_each_entry_safe(mq, nmq, &maple_sentq, list) {
643                         mdev = mq->dev;
644                         recvbuf = mq->recvbuf->buf;
645                         dma_cache_sync(&mdev->dev, recvbuf, 0x400,
646                                 DMA_FROM_DEVICE);
647                         code = recvbuf[0];
648                         kfree(mq->sendbuf);
649                         list_del_init(&mq->list);
650                         switch (code) {
651                         case MAPLE_RESPONSE_NONE:
652                                 maple_response_none(mdev);
653                                 break;
654
655                         case MAPLE_RESPONSE_DEVINFO:
656                                 maple_response_devinfo(mdev, recvbuf);
657                                 atomic_set(&mdev->busy, 0);
658                                 break;
659
660                         case MAPLE_RESPONSE_DATATRF:
661                                 if (mdev->callback)
662                                         mdev->callback(mq);
663                                 atomic_set(&mdev->busy, 0);
664                                 wake_up(&mdev->maple_wait);
665                                 break;
666
667                         case MAPLE_RESPONSE_FILEERR:
668                                 maple_response_fileerr(mdev, recvbuf);
669                                 atomic_set(&mdev->busy, 0);
670                                 wake_up(&mdev->maple_wait);
671                                 break;
672
673                         case MAPLE_RESPONSE_AGAIN:
674                         case MAPLE_RESPONSE_BADCMD:
675                         case MAPLE_RESPONSE_BADFUNC:
676                                 dev_warn(&mdev->dev, "non-fatal error"
677                                         " 0x%X at (%d, %d)\n", code,
678                                         mdev->port, mdev->unit);
679                                 atomic_set(&mdev->busy, 0);
680                                 break;
681
682                         case MAPLE_RESPONSE_ALLINFO:
683                                 dev_notice(&mdev->dev, "extended"
684                                 " device information request for (%d, %d)"
685                                 " but call is not supported\n", mdev->port,
686                                 mdev->unit);
687                                 atomic_set(&mdev->busy, 0);
688                                 break;
689
690                         case MAPLE_RESPONSE_OK:
691                                 atomic_set(&mdev->busy, 0);
692                                 wake_up(&mdev->maple_wait);
693                                 break;
694
695                         default:
696                                 break;
697                         }
698                 }
699                 /* if scanning is 1 then we have subdevices to check */
700                 if (scanning == 1) {
701                         maple_send();
702                         scanning = 2;
703                 } else
704                         scanning = 0;
705                 /*check if we have actually tested all ports yet */
706                 if (!fullscan)
707                         maple_port_rescan();
708                 /* mark that we have been through the first scan */
709                 started = 1;
710         }
711         maple_send();
712 }
713
714 static irqreturn_t maple_dma_interrupt(int irq, void *dev_id)
715 {
716         /* Load everything into the bottom half */
717         schedule_work(&maple_dma_process);
718         return IRQ_HANDLED;
719 }
720
721 static irqreturn_t maple_vblank_interrupt(int irq, void *dev_id)
722 {
723         schedule_work(&maple_vblank_process);
724         return IRQ_HANDLED;
725 }
726
727 static int maple_set_dma_interrupt_handler(void)
728 {
729         return request_irq(HW_EVENT_MAPLE_DMA, maple_dma_interrupt,
730                 IRQF_SHARED, "maple bus DMA", &maple_unsupported_device);
731 }
732
733 static int maple_set_vblank_interrupt_handler(void)
734 {
735         return request_irq(HW_EVENT_VSYNC, maple_vblank_interrupt,
736                 IRQF_SHARED, "maple bus VBLANK", &maple_unsupported_device);
737 }
738
739 static int maple_get_dma_buffer(void)
740 {
741         maple_sendbuf =
742             (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
743                                       MAPLE_DMA_PAGES);
744         if (!maple_sendbuf)
745                 return -ENOMEM;
746         return 0;
747 }
748
749 static int maple_match_bus_driver(struct device *devptr,
750                                   struct device_driver *drvptr)
751 {
752         struct maple_driver *maple_drv = to_maple_driver(drvptr);
753         struct maple_device *maple_dev = to_maple_dev(devptr);
754
755         /* Trap empty port case */
756         if (maple_dev->devinfo.function == 0xFFFFFFFF)
757                 return 0;
758         else if (maple_dev->devinfo.function &
759                  cpu_to_be32(maple_drv->function))
760                 return 1;
761         return 0;
762 }
763
764 static int maple_bus_uevent(struct device *dev,
765                             struct kobj_uevent_env *env)
766 {
767         return 0;
768 }
769
770 static void maple_bus_release(struct device *dev)
771 {
772 }
773
774 static struct maple_driver maple_unsupported_device = {
775         .drv = {
776                 .name = "maple_unsupported_device",
777                 .bus = &maple_bus_type,
778         },
779 };
780 /**
781  * maple_bus_type - core maple bus structure
782  */
783 struct bus_type maple_bus_type = {
784         .name = "maple",
785         .match = maple_match_bus_driver,
786         .uevent = maple_bus_uevent,
787 };
788 EXPORT_SYMBOL_GPL(maple_bus_type);
789
790 static struct device maple_bus = {
791         .init_name = "maple",
792         .release = maple_bus_release,
793 };
794
795 static int __init maple_bus_init(void)
796 {
797         int retval, i;
798         struct maple_device *mdev[MAPLE_PORTS];
799
800         ctrl_outl(0, MAPLE_ENABLE);
801
802         retval = device_register(&maple_bus);
803         if (retval)
804                 goto cleanup;
805
806         retval = bus_register(&maple_bus_type);
807         if (retval)
808                 goto cleanup_device;
809
810         retval = driver_register(&maple_unsupported_device.drv);
811         if (retval)
812                 goto cleanup_bus;
813
814         /* allocate memory for maple bus dma */
815         retval = maple_get_dma_buffer();
816         if (retval) {
817                 dev_err(&maple_bus, "failed to allocate DMA buffers\n");
818                 goto cleanup_basic;
819         }
820
821         /* set up DMA interrupt handler */
822         retval = maple_set_dma_interrupt_handler();
823         if (retval) {
824                 dev_err(&maple_bus, "bus failed to grab maple "
825                         "DMA IRQ\n");
826                 goto cleanup_dma;
827         }
828
829         /* set up VBLANK interrupt handler */
830         retval = maple_set_vblank_interrupt_handler();
831         if (retval) {
832                 dev_err(&maple_bus, "bus failed to grab VBLANK IRQ\n");
833                 goto cleanup_irq;
834         }
835
836         maple_queue_cache = KMEM_CACHE(maple_buffer, SLAB_HWCACHE_ALIGN);
837
838         if (!maple_queue_cache)
839                 goto cleanup_bothirqs;
840
841         INIT_LIST_HEAD(&maple_waitq);
842         INIT_LIST_HEAD(&maple_sentq);
843
844         /* setup maple ports */
845         for (i = 0; i < MAPLE_PORTS; i++) {
846                 checked[i] = false;
847                 empty[i] = false;
848                 mdev[i] = maple_alloc_dev(i, 0);
849                 if (!mdev[i]) {
850                         while (i-- > 0)
851                                 maple_free_dev(mdev[i]);
852                         goto cleanup_cache;
853                 }
854                 baseunits[i] = mdev[i];
855                 atomic_set(&mdev[i]->busy, 1);
856                 maple_add_packet(mdev[i], 0, MAPLE_COMMAND_DEVINFO, 0, NULL);
857                 subdevice_map[i] = 0;
858         }
859
860         maple_pnp_time = jiffies + HZ;
861         /* prepare initial queue */
862         maple_send();
863         dev_info(&maple_bus, "bus core now registered\n");
864
865         return 0;
866
867 cleanup_cache:
868         kmem_cache_destroy(maple_queue_cache);
869
870 cleanup_bothirqs:
871         free_irq(HW_EVENT_VSYNC, 0);
872
873 cleanup_irq:
874         free_irq(HW_EVENT_MAPLE_DMA, 0);
875
876 cleanup_dma:
877         free_pages((unsigned long) maple_sendbuf, MAPLE_DMA_PAGES);
878
879 cleanup_basic:
880         driver_unregister(&maple_unsupported_device.drv);
881
882 cleanup_bus:
883         bus_unregister(&maple_bus_type);
884
885 cleanup_device:
886         device_unregister(&maple_bus);
887
888 cleanup:
889         printk(KERN_ERR "Maple bus registration failed\n");
890         return retval;
891 }
892 /* Push init to later to ensure hardware gets detected */
893 fs_initcall(maple_bus_init);