Version:  2.6.34 2.6.35 2.6.36 2.6.37 2.6.38 2.6.39 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14

Linux/drivers/macintosh/adb.c

  1 /*
  2  * Device driver for the Apple Desktop Bus
  3  * and the /dev/adb device on macintoshes.
  4  *
  5  * Copyright (C) 1996 Paul Mackerras.
  6  *
  7  * Modified to declare controllers as structures, added
  8  * client notification of bus reset and handles PowerBook
  9  * sleep, by Benjamin Herrenschmidt.
 10  *
 11  * To do:
 12  *
 13  * - /sys/bus/adb to list the devices and infos
 14  * - more /dev/adb to allow userland to receive the
 15  *   flow of auto-polling datas from a given device.
 16  * - move bus probe to a kernel thread
 17  */
 18 
 19 #include <linux/types.h>
 20 #include <linux/errno.h>
 21 #include <linux/kernel.h>
 22 #include <linux/slab.h>
 23 #include <linux/module.h>
 24 #include <linux/fs.h>
 25 #include <linux/mm.h>
 26 #include <linux/sched.h>
 27 #include <linux/adb.h>
 28 #include <linux/cuda.h>
 29 #include <linux/pmu.h>
 30 #include <linux/notifier.h>
 31 #include <linux/wait.h>
 32 #include <linux/init.h>
 33 #include <linux/delay.h>
 34 #include <linux/spinlock.h>
 35 #include <linux/completion.h>
 36 #include <linux/device.h>
 37 #include <linux/kthread.h>
 38 #include <linux/platform_device.h>
 39 #include <linux/mutex.h>
 40 
 41 #include <asm/uaccess.h>
 42 #ifdef CONFIG_PPC
 43 #include <asm/prom.h>
 44 #include <asm/machdep.h>
 45 #endif
 46 
 47 
 48 EXPORT_SYMBOL(adb_client_list);
 49 
 50 extern struct adb_driver via_macii_driver;
 51 extern struct adb_driver via_maciisi_driver;
 52 extern struct adb_driver via_cuda_driver;
 53 extern struct adb_driver adb_iop_driver;
 54 extern struct adb_driver via_pmu_driver;
 55 extern struct adb_driver macio_adb_driver;
 56 
 57 static DEFINE_MUTEX(adb_mutex);
 58 static struct adb_driver *adb_driver_list[] = {
 59 #ifdef CONFIG_ADB_MACII
 60         &via_macii_driver,
 61 #endif
 62 #ifdef CONFIG_ADB_MACIISI
 63         &via_maciisi_driver,
 64 #endif
 65 #ifdef CONFIG_ADB_CUDA
 66         &via_cuda_driver,
 67 #endif
 68 #ifdef CONFIG_ADB_IOP
 69         &adb_iop_driver,
 70 #endif
 71 #if defined(CONFIG_ADB_PMU) || defined(CONFIG_ADB_PMU68K)
 72         &via_pmu_driver,
 73 #endif
 74 #ifdef CONFIG_ADB_MACIO
 75         &macio_adb_driver,
 76 #endif
 77         NULL
 78 };
 79 
 80 static struct class *adb_dev_class;
 81 
 82 static struct adb_driver *adb_controller;
 83 BLOCKING_NOTIFIER_HEAD(adb_client_list);
 84 static int adb_got_sleep;
 85 static int adb_inited;
 86 static DEFINE_SEMAPHORE(adb_probe_mutex);
 87 static int sleepy_trackpad;
 88 static int autopoll_devs;
 89 int __adb_probe_sync;
 90 
 91 static int adb_scan_bus(void);
 92 static int do_adb_reset_bus(void);
 93 static void adbdev_init(void);
 94 static int try_handler_change(int, int);
 95 
 96 static struct adb_handler {
 97         void (*handler)(unsigned char *, int, int);
 98         int original_address;
 99         int handler_id;
100         int busy;
101 } adb_handler[16];
102 
103 /*
104  * The adb_handler_mutex mutex protects all accesses to the original_address
105  * and handler_id fields of adb_handler[i] for all i, and changes to the
106  * handler field.
107  * Accesses to the handler field are protected by the adb_handler_lock
108  * rwlock.  It is held across all calls to any handler, so that by the
109  * time adb_unregister returns, we know that the old handler isn't being
110  * called.
111  */
112 static DEFINE_MUTEX(adb_handler_mutex);
113 static DEFINE_RWLOCK(adb_handler_lock);
114 
115 #if 0
116 static void printADBreply(struct adb_request *req)
117 {
118         int i;
119 
120         printk("adb reply (%d)", req->reply_len);
121         for(i = 0; i < req->reply_len; i++)
122                 printk(" %x", req->reply[i]);
123         printk("\n");
124 
125 }
126 #endif
127 
128 static int adb_scan_bus(void)
129 {
130         int i, highFree=0, noMovement;
131         int devmask = 0;
132         struct adb_request req;
133         
134         /* assumes adb_handler[] is all zeroes at this point */
135         for (i = 1; i < 16; i++) {
136                 /* see if there is anything at address i */
137                 adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
138                             (i << 4) | 0xf);
139                 if (req.reply_len > 1)
140                         /* one or more devices at this address */
141                         adb_handler[i].original_address = i;
142                 else if (i > highFree)
143                         highFree = i;
144         }
145 
146         /* Note we reset noMovement to 0 each time we move a device */
147         for (noMovement = 1; noMovement < 2 && highFree > 0; noMovement++) {
148                 for (i = 1; i < 16; i++) {
149                         if (adb_handler[i].original_address == 0)
150                                 continue;
151                         /*
152                          * Send a "talk register 3" command to address i
153                          * to provoke a collision if there is more than
154                          * one device at this address.
155                          */
156                         adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
157                                     (i << 4) | 0xf);
158                         /*
159                          * Move the device(s) which didn't detect a
160                          * collision to address `highFree'.  Hopefully
161                          * this only moves one device.
162                          */
163                         adb_request(&req, NULL, ADBREQ_SYNC, 3,
164                                     (i<< 4) | 0xb, (highFree | 0x60), 0xfe);
165                         /*
166                          * See if anybody actually moved. This is suggested
167                          * by HW TechNote 01:
168                          *
169                          * http://developer.apple.com/technotes/hw/hw_01.html
170                          */
171                         adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
172                                     (highFree << 4) | 0xf);
173                         if (req.reply_len <= 1) continue;
174                         /*
175                          * Test whether there are any device(s) left
176                          * at address i.
177                          */
178                         adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
179                                     (i << 4) | 0xf);
180                         if (req.reply_len > 1) {
181                                 /*
182                                  * There are still one or more devices
183                                  * left at address i.  Register the one(s)
184                                  * we moved to `highFree', and find a new
185                                  * value for highFree.
186                                  */
187                                 adb_handler[highFree].original_address =
188                                         adb_handler[i].original_address;
189                                 while (highFree > 0 &&
190                                        adb_handler[highFree].original_address)
191                                         highFree--;
192                                 if (highFree <= 0)
193                                         break;
194 
195                                 noMovement = 0;
196                         }
197                         else {
198                                 /*
199                                  * No devices left at address i; move the
200                                  * one(s) we moved to `highFree' back to i.
201                                  */
202                                 adb_request(&req, NULL, ADBREQ_SYNC, 3,
203                                             (highFree << 4) | 0xb,
204                                             (i | 0x60), 0xfe);
205                         }
206                 }       
207         }
208 
209         /* Now fill in the handler_id field of the adb_handler entries. */
210         printk(KERN_DEBUG "adb devices:");
211         for (i = 1; i < 16; i++) {
212                 if (adb_handler[i].original_address == 0)
213                         continue;
214                 adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
215                             (i << 4) | 0xf);
216                 adb_handler[i].handler_id = req.reply[2];
217                 printk(" [%d]: %d %x", i, adb_handler[i].original_address,
218                        adb_handler[i].handler_id);
219                 devmask |= 1 << i;
220         }
221         printk("\n");
222         return devmask;
223 }
224 
225 /*
226  * This kernel task handles ADB probing. It dies once probing is
227  * completed.
228  */
229 static int
230 adb_probe_task(void *x)
231 {
232         printk(KERN_INFO "adb: starting probe task...\n");
233         do_adb_reset_bus();
234         printk(KERN_INFO "adb: finished probe task...\n");
235 
236         up(&adb_probe_mutex);
237 
238         return 0;
239 }
240 
241 static void
242 __adb_probe_task(struct work_struct *bullshit)
243 {
244         kthread_run(adb_probe_task, NULL, "kadbprobe");
245 }
246 
247 static DECLARE_WORK(adb_reset_work, __adb_probe_task);
248 
249 int
250 adb_reset_bus(void)
251 {
252         if (__adb_probe_sync) {
253                 do_adb_reset_bus();
254                 return 0;
255         }
256 
257         down(&adb_probe_mutex);
258         schedule_work(&adb_reset_work);
259         return 0;
260 }
261 
262 #ifdef CONFIG_PM
263 /*
264  * notify clients before sleep
265  */
266 static int adb_suspend(struct platform_device *dev, pm_message_t state)
267 {
268         adb_got_sleep = 1;
269         /* We need to get a lock on the probe thread */
270         down(&adb_probe_mutex);
271         /* Stop autopoll */
272         if (adb_controller->autopoll)
273                 adb_controller->autopoll(0);
274         blocking_notifier_call_chain(&adb_client_list, ADB_MSG_POWERDOWN, NULL);
275 
276         return 0;
277 }
278 
279 /*
280  * reset bus after sleep
281  */
282 static int adb_resume(struct platform_device *dev)
283 {
284         adb_got_sleep = 0;
285         up(&adb_probe_mutex);
286         adb_reset_bus();
287 
288         return 0;
289 }
290 #endif /* CONFIG_PM */
291 
292 static int __init adb_init(void)
293 {
294         struct adb_driver *driver;
295         int i;
296 
297 #ifdef CONFIG_PPC32
298         if (!machine_is(chrp) && !machine_is(powermac))
299                 return 0;
300 #endif
301 #ifdef CONFIG_MAC
302         if (!MACH_IS_MAC)
303                 return 0;
304 #endif
305 
306         /* xmon may do early-init */
307         if (adb_inited)
308                 return 0;
309         adb_inited = 1;
310                 
311         adb_controller = NULL;
312 
313         i = 0;
314         while ((driver = adb_driver_list[i++]) != NULL) {
315                 if (!driver->probe()) {
316                         adb_controller = driver;
317                         break;
318                 }
319         }
320         if (adb_controller != NULL && adb_controller->init &&
321             adb_controller->init())
322                 adb_controller = NULL;
323         if (adb_controller == NULL) {
324                 printk(KERN_WARNING "Warning: no ADB interface detected\n");
325         } else {
326 #ifdef CONFIG_PPC
327                 if (of_machine_is_compatible("AAPL,PowerBook1998") ||
328                         of_machine_is_compatible("PowerBook1,1"))
329                         sleepy_trackpad = 1;
330 #endif /* CONFIG_PPC */
331 
332                 adbdev_init();
333                 adb_reset_bus();
334         }
335         return 0;
336 }
337 
338 device_initcall(adb_init);
339 
340 static int
341 do_adb_reset_bus(void)
342 {
343         int ret;
344         
345         if (adb_controller == NULL)
346                 return -ENXIO;
347                 
348         if (adb_controller->autopoll)
349                 adb_controller->autopoll(0);
350 
351         blocking_notifier_call_chain(&adb_client_list,
352                 ADB_MSG_PRE_RESET, NULL);
353 
354         if (sleepy_trackpad) {
355                 /* Let the trackpad settle down */
356                 msleep(500);
357         }
358 
359         mutex_lock(&adb_handler_mutex);
360         write_lock_irq(&adb_handler_lock);
361         memset(adb_handler, 0, sizeof(adb_handler));
362         write_unlock_irq(&adb_handler_lock);
363 
364         /* That one is still a bit synchronous, oh well... */
365         if (adb_controller->reset_bus)
366                 ret = adb_controller->reset_bus();
367         else
368                 ret = 0;
369 
370         if (sleepy_trackpad) {
371                 /* Let the trackpad settle down */
372                 msleep(1500);
373         }
374 
375         if (!ret) {
376                 autopoll_devs = adb_scan_bus();
377                 if (adb_controller->autopoll)
378                         adb_controller->autopoll(autopoll_devs);
379         }
380         mutex_unlock(&adb_handler_mutex);
381 
382         blocking_notifier_call_chain(&adb_client_list,
383                 ADB_MSG_POST_RESET, NULL);
384         
385         return ret;
386 }
387 
388 void
389 adb_poll(void)
390 {
391         if ((adb_controller == NULL)||(adb_controller->poll == NULL))
392                 return;
393         adb_controller->poll();
394 }
395 
396 static void adb_sync_req_done(struct adb_request *req)
397 {
398         struct completion *comp = req->arg;
399 
400         complete(comp);
401 }
402 
403 int
404 adb_request(struct adb_request *req, void (*done)(struct adb_request *),
405             int flags, int nbytes, ...)
406 {
407         va_list list;
408         int i;
409         int rc;
410         struct completion comp;
411 
412         if ((adb_controller == NULL) || (adb_controller->send_request == NULL))
413                 return -ENXIO;
414         if (nbytes < 1)
415                 return -EINVAL;
416 
417         req->nbytes = nbytes+1;
418         req->done = done;
419         req->reply_expected = flags & ADBREQ_REPLY;
420         req->data[0] = ADB_PACKET;
421         va_start(list, nbytes);
422         for (i = 0; i < nbytes; ++i)
423                 req->data[i+1] = va_arg(list, int);
424         va_end(list);
425 
426         if (flags & ADBREQ_NOSEND)
427                 return 0;
428 
429         /* Synchronous requests block using an on-stack completion */
430         if (flags & ADBREQ_SYNC) {
431                 WARN_ON(done);
432                 req->done = adb_sync_req_done;
433                 req->arg = &comp;
434                 init_completion(&comp);
435         }
436 
437         rc = adb_controller->send_request(req, 0);
438 
439         if ((flags & ADBREQ_SYNC) && !rc && !req->complete)
440                 wait_for_completion(&comp);
441 
442         return rc;
443 }
444 
445  /* Ultimately this should return the number of devices with
446     the given default id.
447     And it does it now ! Note: changed behaviour: This function
448     will now register if default_id _and_ handler_id both match
449     but handler_id can be left to 0 to match with default_id only.
450     When handler_id is set, this function will try to adjust
451     the handler_id id it doesn't match. */
452 int
453 adb_register(int default_id, int handler_id, struct adb_ids *ids,
454              void (*handler)(unsigned char *, int, int))
455 {
456         int i;
457 
458         mutex_lock(&adb_handler_mutex);
459         ids->nids = 0;
460         for (i = 1; i < 16; i++) {
461                 if ((adb_handler[i].original_address == default_id) &&
462                     (!handler_id || (handler_id == adb_handler[i].handler_id) || 
463                     try_handler_change(i, handler_id))) {
464                         if (adb_handler[i].handler != 0) {
465                                 printk(KERN_ERR
466                                        "Two handlers for ADB device %d\n",
467                                        default_id);
468                                 continue;
469                         }
470                         write_lock_irq(&adb_handler_lock);
471                         adb_handler[i].handler = handler;
472                         write_unlock_irq(&adb_handler_lock);
473                         ids->id[ids->nids++] = i;
474                 }
475         }
476         mutex_unlock(&adb_handler_mutex);
477         return ids->nids;
478 }
479 
480 int
481 adb_unregister(int index)
482 {
483         int ret = -ENODEV;
484 
485         mutex_lock(&adb_handler_mutex);
486         write_lock_irq(&adb_handler_lock);
487         if (adb_handler[index].handler) {
488                 while(adb_handler[index].busy) {
489                         write_unlock_irq(&adb_handler_lock);
490                         yield();
491                         write_lock_irq(&adb_handler_lock);
492                 }
493                 ret = 0;
494                 adb_handler[index].handler = NULL;
495         }
496         write_unlock_irq(&adb_handler_lock);
497         mutex_unlock(&adb_handler_mutex);
498         return ret;
499 }
500 
501 void
502 adb_input(unsigned char *buf, int nb, int autopoll)
503 {
504         int i, id;
505         static int dump_adb_input = 0;
506         unsigned long flags;
507         
508         void (*handler)(unsigned char *, int, int);
509 
510         /* We skip keystrokes and mouse moves when the sleep process
511          * has been started. We stop autopoll, but this is another security
512          */
513         if (adb_got_sleep)
514                 return;
515                 
516         id = buf[0] >> 4;
517         if (dump_adb_input) {
518                 printk(KERN_INFO "adb packet: ");
519                 for (i = 0; i < nb; ++i)
520                         printk(" %x", buf[i]);
521                 printk(", id = %d\n", id);
522         }
523         write_lock_irqsave(&adb_handler_lock, flags);
524         handler = adb_handler[id].handler;
525         if (handler != NULL)
526                 adb_handler[id].busy = 1;
527         write_unlock_irqrestore(&adb_handler_lock, flags);
528         if (handler != NULL) {
529                 (*handler)(buf, nb, autopoll);
530                 wmb();
531                 adb_handler[id].busy = 0;
532         }
533                 
534 }
535 
536 /* Try to change handler to new_id. Will return 1 if successful. */
537 static int try_handler_change(int address, int new_id)
538 {
539         struct adb_request req;
540 
541         if (adb_handler[address].handler_id == new_id)
542             return 1;
543         adb_request(&req, NULL, ADBREQ_SYNC, 3,
544             ADB_WRITEREG(address, 3), address | 0x20, new_id);
545         adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
546             ADB_READREG(address, 3));
547         if (req.reply_len < 2)
548             return 0;
549         if (req.reply[2] != new_id)
550             return 0;
551         adb_handler[address].handler_id = req.reply[2];
552 
553         return 1;
554 }
555 
556 int
557 adb_try_handler_change(int address, int new_id)
558 {
559         int ret;
560 
561         mutex_lock(&adb_handler_mutex);
562         ret = try_handler_change(address, new_id);
563         mutex_unlock(&adb_handler_mutex);
564         return ret;
565 }
566 
567 int
568 adb_get_infos(int address, int *original_address, int *handler_id)
569 {
570         mutex_lock(&adb_handler_mutex);
571         *original_address = adb_handler[address].original_address;
572         *handler_id = adb_handler[address].handler_id;
573         mutex_unlock(&adb_handler_mutex);
574 
575         return (*original_address != 0);
576 }
577 
578 
579 /*
580  * /dev/adb device driver.
581  */
582 
583 #define ADB_MAJOR       56      /* major number for /dev/adb */
584 
585 struct adbdev_state {
586         spinlock_t      lock;
587         atomic_t        n_pending;
588         struct adb_request *completed;
589         wait_queue_head_t wait_queue;
590         int             inuse;
591 };
592 
593 static void adb_write_done(struct adb_request *req)
594 {
595         struct adbdev_state *state = (struct adbdev_state *) req->arg;
596         unsigned long flags;
597 
598         if (!req->complete) {
599                 req->reply_len = 0;
600                 req->complete = 1;
601         }
602         spin_lock_irqsave(&state->lock, flags);
603         atomic_dec(&state->n_pending);
604         if (!state->inuse) {
605                 kfree(req);
606                 if (atomic_read(&state->n_pending) == 0) {
607                         spin_unlock_irqrestore(&state->lock, flags);
608                         kfree(state);
609                         return;
610                 }
611         } else {
612                 struct adb_request **ap = &state->completed;
613                 while (*ap != NULL)
614                         ap = &(*ap)->next;
615                 req->next = NULL;
616                 *ap = req;
617                 wake_up_interruptible(&state->wait_queue);
618         }
619         spin_unlock_irqrestore(&state->lock, flags);
620 }
621 
622 static int
623 do_adb_query(struct adb_request *req)
624 {
625         int     ret = -EINVAL;
626 
627         switch(req->data[1])
628         {
629         case ADB_QUERY_GETDEVINFO:
630                 if (req->nbytes < 3)
631                         break;
632                 mutex_lock(&adb_handler_mutex);
633                 req->reply[0] = adb_handler[req->data[2]].original_address;
634                 req->reply[1] = adb_handler[req->data[2]].handler_id;
635                 mutex_unlock(&adb_handler_mutex);
636                 req->complete = 1;
637                 req->reply_len = 2;
638                 adb_write_done(req);
639                 ret = 0;
640                 break;
641         }
642         return ret;
643 }
644 
645 static int adb_open(struct inode *inode, struct file *file)
646 {
647         struct adbdev_state *state;
648         int ret = 0;
649 
650         mutex_lock(&adb_mutex);
651         if (iminor(inode) > 0 || adb_controller == NULL) {
652                 ret = -ENXIO;
653                 goto out;
654         }
655         state = kmalloc(sizeof(struct adbdev_state), GFP_KERNEL);
656         if (state == 0) {
657                 ret = -ENOMEM;
658                 goto out;
659         }
660         file->private_data = state;
661         spin_lock_init(&state->lock);
662         atomic_set(&state->n_pending, 0);
663         state->completed = NULL;
664         init_waitqueue_head(&state->wait_queue);
665         state->inuse = 1;
666 
667 out:
668         mutex_unlock(&adb_mutex);
669         return ret;
670 }
671 
672 static int adb_release(struct inode *inode, struct file *file)
673 {
674         struct adbdev_state *state = file->private_data;
675         unsigned long flags;
676 
677         mutex_lock(&adb_mutex);
678         if (state) {
679                 file->private_data = NULL;
680                 spin_lock_irqsave(&state->lock, flags);
681                 if (atomic_read(&state->n_pending) == 0
682                     && state->completed == NULL) {
683                         spin_unlock_irqrestore(&state->lock, flags);
684                         kfree(state);
685                 } else {
686                         state->inuse = 0;
687                         spin_unlock_irqrestore(&state->lock, flags);
688                 }
689         }
690         mutex_unlock(&adb_mutex);
691         return 0;
692 }
693 
694 static ssize_t adb_read(struct file *file, char __user *buf,
695                         size_t count, loff_t *ppos)
696 {
697         int ret = 0;
698         struct adbdev_state *state = file->private_data;
699         struct adb_request *req;
700         DECLARE_WAITQUEUE(wait,current);
701         unsigned long flags;
702 
703         if (count < 2)
704                 return -EINVAL;
705         if (count > sizeof(req->reply))
706                 count = sizeof(req->reply);
707         if (!access_ok(VERIFY_WRITE, buf, count))
708                 return -EFAULT;
709 
710         req = NULL;
711         spin_lock_irqsave(&state->lock, flags);
712         add_wait_queue(&state->wait_queue, &wait);
713         set_current_state(TASK_INTERRUPTIBLE);
714 
715         for (;;) {
716                 req = state->completed;
717                 if (req != NULL)
718                         state->completed = req->next;
719                 else if (atomic_read(&state->n_pending) == 0)
720                         ret = -EIO;
721                 if (req != NULL || ret != 0)
722                         break;
723                 
724                 if (file->f_flags & O_NONBLOCK) {
725                         ret = -EAGAIN;
726                         break;
727                 }
728                 if (signal_pending(current)) {
729                         ret = -ERESTARTSYS;
730                         break;
731                 }
732                 spin_unlock_irqrestore(&state->lock, flags);
733                 schedule();
734                 spin_lock_irqsave(&state->lock, flags);
735         }
736 
737         set_current_state(TASK_RUNNING);
738         remove_wait_queue(&state->wait_queue, &wait);
739         spin_unlock_irqrestore(&state->lock, flags);
740         
741         if (ret)
742                 return ret;
743 
744         ret = req->reply_len;
745         if (ret > count)
746                 ret = count;
747         if (ret > 0 && copy_to_user(buf, req->reply, ret))
748                 ret = -EFAULT;
749 
750         kfree(req);
751         return ret;
752 }
753 
754 static ssize_t adb_write(struct file *file, const char __user *buf,
755                          size_t count, loff_t *ppos)
756 {
757         int ret/*, i*/;
758         struct adbdev_state *state = file->private_data;
759         struct adb_request *req;
760 
761         if (count < 2 || count > sizeof(req->data))
762                 return -EINVAL;
763         if (adb_controller == NULL)
764                 return -ENXIO;
765         if (!access_ok(VERIFY_READ, buf, count))
766                 return -EFAULT;
767 
768         req = kmalloc(sizeof(struct adb_request),
769                                              GFP_KERNEL);
770         if (req == NULL)
771                 return -ENOMEM;
772 
773         req->nbytes = count;
774         req->done = adb_write_done;
775         req->arg = (void *) state;
776         req->complete = 0;
777         
778         ret = -EFAULT;
779         if (copy_from_user(req->data, buf, count))
780                 goto out;
781 
782         atomic_inc(&state->n_pending);
783 
784         /* If a probe is in progress or we are sleeping, wait for it to complete */
785         down(&adb_probe_mutex);
786 
787         /* Queries are special requests sent to the ADB driver itself */
788         if (req->data[0] == ADB_QUERY) {
789                 if (count > 1)
790                         ret = do_adb_query(req);
791                 else
792                         ret = -EINVAL;
793                 up(&adb_probe_mutex);
794         }
795         /* Special case for ADB_BUSRESET request, all others are sent to
796            the controller */
797         else if ((req->data[0] == ADB_PACKET)&&(count > 1)
798                 &&(req->data[1] == ADB_BUSRESET)) {
799                 ret = do_adb_reset_bus();
800                 up(&adb_probe_mutex);
801                 atomic_dec(&state->n_pending);
802                 if (ret == 0)
803                         ret = count;
804                 goto out;
805         } else {        
806                 req->reply_expected = ((req->data[1] & 0xc) == 0xc);
807                 if (adb_controller && adb_controller->send_request)
808                         ret = adb_controller->send_request(req, 0);
809                 else
810                         ret = -ENXIO;
811                 up(&adb_probe_mutex);
812         }
813 
814         if (ret != 0) {
815                 atomic_dec(&state->n_pending);
816                 goto out;
817         }
818         return count;
819 
820 out:
821         kfree(req);
822         return ret;
823 }
824 
825 static const struct file_operations adb_fops = {
826         .owner          = THIS_MODULE,
827         .llseek         = no_llseek,
828         .read           = adb_read,
829         .write          = adb_write,
830         .open           = adb_open,
831         .release        = adb_release,
832 };
833 
834 static struct platform_driver adb_pfdrv = {
835         .driver = {
836                 .name = "adb",
837         },
838 #ifdef CONFIG_PM
839         .suspend = adb_suspend,
840         .resume = adb_resume,
841 #endif
842 };
843 
844 static struct platform_device adb_pfdev = {
845         .name = "adb",
846 };
847 
848 static int __init
849 adb_dummy_probe(struct platform_device *dev)
850 {
851         if (dev == &adb_pfdev)
852                 return 0;
853         return -ENODEV;
854 }
855 
856 static void __init
857 adbdev_init(void)
858 {
859         if (register_chrdev(ADB_MAJOR, "adb", &adb_fops)) {
860                 printk(KERN_ERR "adb: unable to get major %d\n", ADB_MAJOR);
861                 return;
862         }
863 
864         adb_dev_class = class_create(THIS_MODULE, "adb");
865         if (IS_ERR(adb_dev_class))
866                 return;
867         device_create(adb_dev_class, NULL, MKDEV(ADB_MAJOR, 0), NULL, "adb");
868 
869         platform_device_register(&adb_pfdev);
870         platform_driver_probe(&adb_pfdrv, adb_dummy_probe);
871 }
872 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us