1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Device driver for the Apple Desktop Bus
4 * and the /dev/adb device on macintoshes.
5 *
6 * Copyright (C) 1996 Paul Mackerras.
7 *
8 * Modified to declare controllers as structures, added
9 * client notification of bus reset and handles PowerBook
10 * sleep, by Benjamin Herrenschmidt.
11 *
12 * To do:
13 *
14 * - /sys/bus/adb to list the devices and infos
15 * - more /dev/adb to allow userland to receive the
16 * flow of auto-polling datas from a given device.
17 * - move bus probe to a kernel thread
18 */
19
20#include <linux/types.h>
21#include <linux/errno.h>
22#include <linux/kernel.h>
23#include <linux/slab.h>
24#include <linux/module.h>
25#include <linux/fs.h>
26#include <linux/mm.h>
27#include <linux/sched/signal.h>
28#include <linux/adb.h>
29#include <linux/cuda.h>
30#include <linux/pmu.h>
31#include <linux/notifier.h>
32#include <linux/wait.h>
33#include <linux/init.h>
34#include <linux/delay.h>
35#include <linux/spinlock.h>
36#include <linux/completion.h>
37#include <linux/device.h>
38#include <linux/kthread.h>
39#include <linux/platform_device.h>
40#include <linux/mutex.h>
41#include <linux/of.h>
42
43#include <linux/uaccess.h>
44#ifdef CONFIG_PPC
45#include <asm/machdep.h>
46#endif
47
48
49EXPORT_SYMBOL(adb_client_list);
50
51extern struct adb_driver via_macii_driver;
52extern struct adb_driver via_cuda_driver;
53extern struct adb_driver adb_iop_driver;
54extern struct adb_driver via_pmu_driver;
55extern struct adb_driver macio_adb_driver;
56
57static DEFINE_MUTEX(adb_mutex);
58static struct adb_driver *adb_driver_list[] = {
59#ifdef CONFIG_ADB_MACII
60 &via_macii_driver,
61#endif
62#ifdef CONFIG_ADB_CUDA
63 &via_cuda_driver,
64#endif
65#ifdef CONFIG_ADB_IOP
66 &adb_iop_driver,
67#endif
68#ifdef CONFIG_ADB_PMU
69 &via_pmu_driver,
70#endif
71#ifdef CONFIG_ADB_MACIO
72 &macio_adb_driver,
73#endif
74 NULL
75};
76
77static const struct class adb_dev_class = {
78 .name = "adb",
79};
80
81static struct adb_driver *adb_controller;
82BLOCKING_NOTIFIER_HEAD(adb_client_list);
83static int adb_got_sleep;
84static int adb_inited;
85static DEFINE_SEMAPHORE(adb_probe_mutex, 1);
86static int sleepy_trackpad;
87static int autopoll_devs;
88int __adb_probe_sync;
89
90static int adb_scan_bus(void);
91static int do_adb_reset_bus(void);
92static void adbdev_init(void);
93static int try_handler_change(int, int);
94
95static struct adb_handler {
96 void (*handler)(unsigned char *, int, int);
97 int original_address;
98 int handler_id;
99 int busy;
100} adb_handler[16];
101
102/*
103 * The adb_handler_mutex mutex protects all accesses to the original_address
104 * and handler_id fields of adb_handler[i] for all i, and changes to the
105 * handler field.
106 * Accesses to the handler field are protected by the adb_handler_lock
107 * rwlock. It is held across all calls to any handler, so that by the
108 * time adb_unregister returns, we know that the old handler isn't being
109 * called.
110 */
111static DEFINE_MUTEX(adb_handler_mutex);
112static DEFINE_RWLOCK(adb_handler_lock);
113
114#if 0
115static void printADBreply(struct adb_request *req)
116{
117 int i;
118
119 printk("adb reply (%d)", req->reply_len);
120 for(i = 0; i < req->reply_len; i++)
121 printk(" %x", req->reply[i]);
122 printk("\n");
123
124}
125#endif
126
127static int adb_scan_bus(void)
128{
129 int i, highFree=0, noMovement;
130 int devmask = 0;
131 struct adb_request req;
132
133 /* assumes adb_handler[] is all zeroes at this point */
134 for (i = 1; i < 16; i++) {
135 /* see if there is anything at address i */
136 adb_request(req: &req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, nbytes: 1,
137 (i << 4) | 0xf);
138 if (req.reply_len > 1)
139 /* one or more devices at this address */
140 adb_handler[i].original_address = i;
141 else if (i > highFree)
142 highFree = i;
143 }
144
145 /* Note we reset noMovement to 0 each time we move a device */
146 for (noMovement = 1; noMovement < 2 && highFree > 0; noMovement++) {
147 for (i = 1; i < 16; i++) {
148 if (adb_handler[i].original_address == 0)
149 continue;
150 /*
151 * Send a "talk register 3" command to address i
152 * to provoke a collision if there is more than
153 * one device at this address.
154 */
155 adb_request(req: &req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, nbytes: 1,
156 (i << 4) | 0xf);
157 /*
158 * Move the device(s) which didn't detect a
159 * collision to address `highFree'. Hopefully
160 * this only moves one device.
161 */
162 adb_request(req: &req, NULL, ADBREQ_SYNC, nbytes: 3,
163 (i<< 4) | 0xb, (highFree | 0x60), 0xfe);
164 /*
165 * See if anybody actually moved. This is suggested
166 * by HW TechNote 01:
167 *
168 * https://developer.apple.com/technotes/hw/hw_01.html
169 */
170 adb_request(req: &req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, nbytes: 1,
171 (highFree << 4) | 0xf);
172 if (req.reply_len <= 1) continue;
173 /*
174 * Test whether there are any device(s) left
175 * at address i.
176 */
177 adb_request(req: &req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, nbytes: 1,
178 (i << 4) | 0xf);
179 if (req.reply_len > 1) {
180 /*
181 * There are still one or more devices
182 * left at address i. Register the one(s)
183 * we moved to `highFree', and find a new
184 * value for highFree.
185 */
186 adb_handler[highFree].original_address =
187 adb_handler[i].original_address;
188 while (highFree > 0 &&
189 adb_handler[highFree].original_address)
190 highFree--;
191 if (highFree <= 0)
192 break;
193
194 noMovement = 0;
195 } else {
196 /*
197 * No devices left at address i; move the
198 * one(s) we moved to `highFree' back to i.
199 */
200 adb_request(req: &req, NULL, ADBREQ_SYNC, nbytes: 3,
201 (highFree << 4) | 0xb,
202 (i | 0x60), 0xfe);
203 }
204 }
205 }
206
207 /* Now fill in the handler_id field of the adb_handler entries. */
208 for (i = 1; i < 16; i++) {
209 if (adb_handler[i].original_address == 0)
210 continue;
211 adb_request(req: &req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, nbytes: 1,
212 (i << 4) | 0xf);
213 adb_handler[i].handler_id = req.reply[2];
214 printk(KERN_DEBUG "adb device [%d]: %d 0x%X\n", i,
215 adb_handler[i].original_address,
216 adb_handler[i].handler_id);
217 devmask |= 1 << i;
218 }
219 return devmask;
220}
221
222/*
223 * This kernel task handles ADB probing. It dies once probing is
224 * completed.
225 */
226static int
227adb_probe_task(void *x)
228{
229 pr_debug("adb: starting probe task...\n");
230 do_adb_reset_bus();
231 pr_debug("adb: finished probe task...\n");
232
233 up(sem: &adb_probe_mutex);
234
235 return 0;
236}
237
238static void
239__adb_probe_task(struct work_struct *bullshit)
240{
241 kthread_run(adb_probe_task, NULL, "kadbprobe");
242}
243
244static DECLARE_WORK(adb_reset_work, __adb_probe_task);
245
246int
247adb_reset_bus(void)
248{
249 if (__adb_probe_sync) {
250 do_adb_reset_bus();
251 return 0;
252 }
253
254 down(sem: &adb_probe_mutex);
255 schedule_work(work: &adb_reset_work);
256 return 0;
257}
258
259#ifdef CONFIG_PM
260/*
261 * notify clients before sleep
262 */
263static int __adb_suspend(struct platform_device *dev, pm_message_t state)
264{
265 adb_got_sleep = 1;
266 /* We need to get a lock on the probe thread */
267 down(sem: &adb_probe_mutex);
268 /* Stop autopoll */
269 if (adb_controller->autopoll)
270 adb_controller->autopoll(0);
271 blocking_notifier_call_chain(nh: &adb_client_list, val: ADB_MSG_POWERDOWN, NULL);
272
273 return 0;
274}
275
276static int adb_suspend(struct device *dev)
277{
278 return __adb_suspend(to_platform_device(dev), PMSG_SUSPEND);
279}
280
281static int adb_freeze(struct device *dev)
282{
283 return __adb_suspend(to_platform_device(dev), PMSG_FREEZE);
284}
285
286static int adb_poweroff(struct device *dev)
287{
288 return __adb_suspend(to_platform_device(dev), PMSG_HIBERNATE);
289}
290
291/*
292 * reset bus after sleep
293 */
294static int __adb_resume(struct platform_device *dev)
295{
296 adb_got_sleep = 0;
297 up(sem: &adb_probe_mutex);
298 adb_reset_bus();
299
300 return 0;
301}
302
303static int adb_resume(struct device *dev)
304{
305 return __adb_resume(to_platform_device(dev));
306}
307#endif /* CONFIG_PM */
308
309static int __init adb_init(void)
310{
311 struct adb_driver *driver;
312 int i;
313
314#ifdef CONFIG_PPC32
315 if (!machine_is(chrp) && !machine_is(powermac))
316 return 0;
317#endif
318#ifdef CONFIG_MAC
319 if (!MACH_IS_MAC)
320 return 0;
321#endif
322
323 /* xmon may do early-init */
324 if (adb_inited)
325 return 0;
326 adb_inited = 1;
327
328 adb_controller = NULL;
329
330 i = 0;
331 while ((driver = adb_driver_list[i++]) != NULL) {
332 if (!driver->probe()) {
333 adb_controller = driver;
334 break;
335 }
336 }
337 if (adb_controller != NULL && adb_controller->init &&
338 adb_controller->init())
339 adb_controller = NULL;
340 if (adb_controller == NULL) {
341 pr_warn("Warning: no ADB interface detected\n");
342 } else {
343#ifdef CONFIG_PPC
344 if (of_machine_is_compatible("AAPL,PowerBook1998") ||
345 of_machine_is_compatible("PowerBook1,1"))
346 sleepy_trackpad = 1;
347#endif /* CONFIG_PPC */
348
349 adbdev_init();
350 adb_reset_bus();
351 }
352 return 0;
353}
354
355device_initcall(adb_init);
356
357static int
358do_adb_reset_bus(void)
359{
360 int ret;
361
362 if (adb_controller == NULL)
363 return -ENXIO;
364
365 if (adb_controller->autopoll)
366 adb_controller->autopoll(0);
367
368 blocking_notifier_call_chain(nh: &adb_client_list,
369 val: ADB_MSG_PRE_RESET, NULL);
370
371 if (sleepy_trackpad) {
372 /* Let the trackpad settle down */
373 msleep(msecs: 500);
374 }
375
376 mutex_lock(&adb_handler_mutex);
377 write_lock_irq(&adb_handler_lock);
378 memset(adb_handler, 0, sizeof(adb_handler));
379 write_unlock_irq(&adb_handler_lock);
380
381 /* That one is still a bit synchronous, oh well... */
382 if (adb_controller->reset_bus)
383 ret = adb_controller->reset_bus();
384 else
385 ret = 0;
386
387 if (sleepy_trackpad) {
388 /* Let the trackpad settle down */
389 msleep(msecs: 1500);
390 }
391
392 if (!ret) {
393 autopoll_devs = adb_scan_bus();
394 if (adb_controller->autopoll)
395 adb_controller->autopoll(autopoll_devs);
396 }
397 mutex_unlock(lock: &adb_handler_mutex);
398
399 blocking_notifier_call_chain(nh: &adb_client_list,
400 val: ADB_MSG_POST_RESET, NULL);
401
402 return ret;
403}
404
405void
406adb_poll(void)
407{
408 if ((adb_controller == NULL)||(adb_controller->poll == NULL))
409 return;
410 adb_controller->poll();
411}
412EXPORT_SYMBOL(adb_poll);
413
414static void adb_sync_req_done(struct adb_request *req)
415{
416 struct completion *comp = req->arg;
417
418 complete(comp);
419}
420
421int
422adb_request(struct adb_request *req, void (*done)(struct adb_request *),
423 int flags, int nbytes, ...)
424{
425 va_list list;
426 int i;
427 int rc;
428 struct completion comp;
429
430 if ((adb_controller == NULL) || (adb_controller->send_request == NULL))
431 return -ENXIO;
432 if (nbytes < 1)
433 return -EINVAL;
434
435 req->nbytes = nbytes+1;
436 req->done = done;
437 req->reply_expected = flags & ADBREQ_REPLY;
438 req->data[0] = ADB_PACKET;
439 va_start(list, nbytes);
440 for (i = 0; i < nbytes; ++i)
441 req->data[i+1] = va_arg(list, int);
442 va_end(list);
443
444 if (flags & ADBREQ_NOSEND)
445 return 0;
446
447 /* Synchronous requests block using an on-stack completion */
448 if (flags & ADBREQ_SYNC) {
449 WARN_ON(done);
450 req->done = adb_sync_req_done;
451 req->arg = &comp;
452 init_completion(x: &comp);
453 }
454
455 rc = adb_controller->send_request(req, 0);
456
457 if ((flags & ADBREQ_SYNC) && !rc && !req->complete)
458 wait_for_completion(&comp);
459
460 return rc;
461}
462EXPORT_SYMBOL(adb_request);
463
464 /* Ultimately this should return the number of devices with
465 the given default id.
466 And it does it now ! Note: changed behaviour: This function
467 will now register if default_id _and_ handler_id both match
468 but handler_id can be left to 0 to match with default_id only.
469 When handler_id is set, this function will try to adjust
470 the handler_id id it doesn't match. */
471int
472adb_register(int default_id, int handler_id, struct adb_ids *ids,
473 void (*handler)(unsigned char *, int, int))
474{
475 int i;
476
477 mutex_lock(&adb_handler_mutex);
478 ids->nids = 0;
479 for (i = 1; i < 16; i++) {
480 if ((adb_handler[i].original_address == default_id) &&
481 (!handler_id || (handler_id == adb_handler[i].handler_id) ||
482 try_handler_change(i, handler_id))) {
483 if (adb_handler[i].handler) {
484 pr_err("Two handlers for ADB device %d\n",
485 default_id);
486 continue;
487 }
488 write_lock_irq(&adb_handler_lock);
489 adb_handler[i].handler = handler;
490 write_unlock_irq(&adb_handler_lock);
491 ids->id[ids->nids++] = i;
492 }
493 }
494 mutex_unlock(lock: &adb_handler_mutex);
495 return ids->nids;
496}
497EXPORT_SYMBOL(adb_register);
498
499int
500adb_unregister(int index)
501{
502 int ret = -ENODEV;
503
504 mutex_lock(&adb_handler_mutex);
505 write_lock_irq(&adb_handler_lock);
506 if (adb_handler[index].handler) {
507 while(adb_handler[index].busy) {
508 write_unlock_irq(&adb_handler_lock);
509 yield();
510 write_lock_irq(&adb_handler_lock);
511 }
512 ret = 0;
513 adb_handler[index].handler = NULL;
514 }
515 write_unlock_irq(&adb_handler_lock);
516 mutex_unlock(lock: &adb_handler_mutex);
517 return ret;
518}
519EXPORT_SYMBOL(adb_unregister);
520
521void
522adb_input(unsigned char *buf, int nb, int autopoll)
523{
524 int i, id;
525 static int dump_adb_input;
526 unsigned long flags;
527
528 void (*handler)(unsigned char *, int, int);
529
530 /* We skip keystrokes and mouse moves when the sleep process
531 * has been started. We stop autopoll, but this is another security
532 */
533 if (adb_got_sleep)
534 return;
535
536 id = buf[0] >> 4;
537 if (dump_adb_input) {
538 pr_info("adb packet: ");
539 for (i = 0; i < nb; ++i)
540 pr_cont(" %x", buf[i]);
541 pr_cont(", id = %d\n", id);
542 }
543 write_lock_irqsave(&adb_handler_lock, flags);
544 handler = adb_handler[id].handler;
545 if (handler != NULL)
546 adb_handler[id].busy = 1;
547 write_unlock_irqrestore(&adb_handler_lock, flags);
548 if (handler != NULL) {
549 (*handler)(buf, nb, autopoll);
550 wmb();
551 adb_handler[id].busy = 0;
552 }
553
554}
555
556/* Try to change handler to new_id. Will return 1 if successful. */
557static int try_handler_change(int address, int new_id)
558{
559 struct adb_request req;
560
561 if (adb_handler[address].handler_id == new_id)
562 return 1;
563 adb_request(&req, NULL, ADBREQ_SYNC, 3,
564 ADB_WRITEREG(address, 3), address | 0x20, new_id);
565 adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
566 ADB_READREG(address, 3));
567 if (req.reply_len < 2)
568 return 0;
569 if (req.reply[2] != new_id)
570 return 0;
571 adb_handler[address].handler_id = req.reply[2];
572
573 return 1;
574}
575
576int
577adb_try_handler_change(int address, int new_id)
578{
579 int ret;
580
581 mutex_lock(&adb_handler_mutex);
582 ret = try_handler_change(address, new_id);
583 mutex_unlock(lock: &adb_handler_mutex);
584 if (ret)
585 pr_debug("adb handler change: [%d] 0x%X\n", address, new_id);
586 return ret;
587}
588EXPORT_SYMBOL(adb_try_handler_change);
589
590int
591adb_get_infos(int address, int *original_address, int *handler_id)
592{
593 mutex_lock(&adb_handler_mutex);
594 *original_address = adb_handler[address].original_address;
595 *handler_id = adb_handler[address].handler_id;
596 mutex_unlock(lock: &adb_handler_mutex);
597
598 return (*original_address != 0);
599}
600
601
602/*
603 * /dev/adb device driver.
604 */
605
606#define ADB_MAJOR 56 /* major number for /dev/adb */
607
608struct adbdev_state {
609 spinlock_t lock;
610 atomic_t n_pending;
611 struct adb_request *completed;
612 wait_queue_head_t wait_queue;
613 int inuse;
614};
615
616static void adb_write_done(struct adb_request *req)
617{
618 struct adbdev_state *state = (struct adbdev_state *) req->arg;
619 unsigned long flags;
620
621 if (!req->complete) {
622 req->reply_len = 0;
623 req->complete = 1;
624 }
625 spin_lock_irqsave(&state->lock, flags);
626 atomic_dec(v: &state->n_pending);
627 if (!state->inuse) {
628 kfree(objp: req);
629 if (atomic_read(v: &state->n_pending) == 0) {
630 spin_unlock_irqrestore(lock: &state->lock, flags);
631 kfree(objp: state);
632 return;
633 }
634 } else {
635 struct adb_request **ap = &state->completed;
636 while (*ap != NULL)
637 ap = &(*ap)->next;
638 req->next = NULL;
639 *ap = req;
640 wake_up_interruptible(&state->wait_queue);
641 }
642 spin_unlock_irqrestore(lock: &state->lock, flags);
643}
644
645static int
646do_adb_query(struct adb_request *req)
647{
648 int ret = -EINVAL;
649
650 switch(req->data[1]) {
651 case ADB_QUERY_GETDEVINFO:
652 if (req->nbytes < 3 || req->data[2] >= 16)
653 break;
654 mutex_lock(&adb_handler_mutex);
655 req->reply[0] = adb_handler[req->data[2]].original_address;
656 req->reply[1] = adb_handler[req->data[2]].handler_id;
657 mutex_unlock(lock: &adb_handler_mutex);
658 req->complete = 1;
659 req->reply_len = 2;
660 adb_write_done(req);
661 ret = 0;
662 break;
663 }
664 return ret;
665}
666
667static int adb_open(struct inode *inode, struct file *file)
668{
669 struct adbdev_state *state;
670 int ret = 0;
671
672 mutex_lock(&adb_mutex);
673 if (iminor(inode) > 0 || adb_controller == NULL) {
674 ret = -ENXIO;
675 goto out;
676 }
677 state = kmalloc(size: sizeof(struct adbdev_state), GFP_KERNEL);
678 if (!state) {
679 ret = -ENOMEM;
680 goto out;
681 }
682 file->private_data = state;
683 spin_lock_init(&state->lock);
684 atomic_set(v: &state->n_pending, i: 0);
685 state->completed = NULL;
686 init_waitqueue_head(&state->wait_queue);
687 state->inuse = 1;
688
689out:
690 mutex_unlock(lock: &adb_mutex);
691 return ret;
692}
693
694static int adb_release(struct inode *inode, struct file *file)
695{
696 struct adbdev_state *state = file->private_data;
697 unsigned long flags;
698
699 mutex_lock(&adb_mutex);
700 if (state) {
701 file->private_data = NULL;
702 spin_lock_irqsave(&state->lock, flags);
703 if (atomic_read(v: &state->n_pending) == 0
704 && state->completed == NULL) {
705 spin_unlock_irqrestore(lock: &state->lock, flags);
706 kfree(objp: state);
707 } else {
708 state->inuse = 0;
709 spin_unlock_irqrestore(lock: &state->lock, flags);
710 }
711 }
712 mutex_unlock(lock: &adb_mutex);
713 return 0;
714}
715
716static ssize_t adb_read(struct file *file, char __user *buf,
717 size_t count, loff_t *ppos)
718{
719 int ret = 0;
720 struct adbdev_state *state = file->private_data;
721 struct adb_request *req;
722 DECLARE_WAITQUEUE(wait, current);
723 unsigned long flags;
724
725 if (count < 2)
726 return -EINVAL;
727 if (count > sizeof(req->reply))
728 count = sizeof(req->reply);
729
730 req = NULL;
731 spin_lock_irqsave(&state->lock, flags);
732 add_wait_queue(wq_head: &state->wait_queue, wq_entry: &wait);
733 set_current_state(TASK_INTERRUPTIBLE);
734
735 for (;;) {
736 req = state->completed;
737 if (req != NULL)
738 state->completed = req->next;
739 else if (atomic_read(v: &state->n_pending) == 0)
740 ret = -EIO;
741 if (req != NULL || ret != 0)
742 break;
743
744 if (file->f_flags & O_NONBLOCK) {
745 ret = -EAGAIN;
746 break;
747 }
748 if (signal_pending(current)) {
749 ret = -ERESTARTSYS;
750 break;
751 }
752 spin_unlock_irqrestore(lock: &state->lock, flags);
753 schedule();
754 spin_lock_irqsave(&state->lock, flags);
755 }
756
757 set_current_state(TASK_RUNNING);
758 remove_wait_queue(wq_head: &state->wait_queue, wq_entry: &wait);
759 spin_unlock_irqrestore(lock: &state->lock, flags);
760
761 if (ret)
762 return ret;
763
764 ret = req->reply_len;
765 if (ret > count)
766 ret = count;
767 if (ret > 0 && copy_to_user(to: buf, from: req->reply, n: ret))
768 ret = -EFAULT;
769
770 kfree(objp: req);
771 return ret;
772}
773
774static ssize_t adb_write(struct file *file, const char __user *buf,
775 size_t count, loff_t *ppos)
776{
777 int ret/*, i*/;
778 struct adbdev_state *state = file->private_data;
779 struct adb_request *req;
780
781 if (count < 2 || count > sizeof(req->data))
782 return -EINVAL;
783 if (adb_controller == NULL)
784 return -ENXIO;
785
786 req = kmalloc(size: sizeof(struct adb_request),
787 GFP_KERNEL);
788 if (req == NULL)
789 return -ENOMEM;
790
791 req->nbytes = count;
792 req->done = adb_write_done;
793 req->arg = (void *) state;
794 req->complete = 0;
795
796 ret = -EFAULT;
797 if (copy_from_user(to: req->data, from: buf, n: count))
798 goto out;
799
800 atomic_inc(v: &state->n_pending);
801
802 /* If a probe is in progress or we are sleeping, wait for it to complete */
803 down(sem: &adb_probe_mutex);
804
805 /* Queries are special requests sent to the ADB driver itself */
806 if (req->data[0] == ADB_QUERY) {
807 if (count > 1)
808 ret = do_adb_query(req);
809 else
810 ret = -EINVAL;
811 up(sem: &adb_probe_mutex);
812 }
813 /* Special case for ADB_BUSRESET request, all others are sent to
814 the controller */
815 else if ((req->data[0] == ADB_PACKET) && (count > 1)
816 && (req->data[1] == ADB_BUSRESET)) {
817 ret = do_adb_reset_bus();
818 up(sem: &adb_probe_mutex);
819 atomic_dec(v: &state->n_pending);
820 if (ret == 0)
821 ret = count;
822 goto out;
823 } else {
824 req->reply_expected = ((req->data[1] & 0xc) == 0xc);
825 if (adb_controller && adb_controller->send_request)
826 ret = adb_controller->send_request(req, 0);
827 else
828 ret = -ENXIO;
829 up(sem: &adb_probe_mutex);
830 }
831
832 if (ret != 0) {
833 atomic_dec(v: &state->n_pending);
834 goto out;
835 }
836 return count;
837
838out:
839 kfree(objp: req);
840 return ret;
841}
842
843static const struct file_operations adb_fops = {
844 .owner = THIS_MODULE,
845 .llseek = no_llseek,
846 .read = adb_read,
847 .write = adb_write,
848 .open = adb_open,
849 .release = adb_release,
850};
851
852#ifdef CONFIG_PM
853static const struct dev_pm_ops adb_dev_pm_ops = {
854 .suspend = adb_suspend,
855 .resume = adb_resume,
856 /* Hibernate hooks */
857 .freeze = adb_freeze,
858 .thaw = adb_resume,
859 .poweroff = adb_poweroff,
860 .restore = adb_resume,
861};
862#endif
863
864static struct platform_driver adb_pfdrv = {
865 .driver = {
866 .name = "adb",
867#ifdef CONFIG_PM
868 .pm = &adb_dev_pm_ops,
869#endif
870 },
871};
872
873static struct platform_device adb_pfdev = {
874 .name = "adb",
875};
876
877static int __init
878adb_dummy_probe(struct platform_device *dev)
879{
880 if (dev == &adb_pfdev)
881 return 0;
882 return -ENODEV;
883}
884
885static void __init
886adbdev_init(void)
887{
888 if (register_chrdev(ADB_MAJOR, name: "adb", fops: &adb_fops)) {
889 pr_err("adb: unable to get major %d\n", ADB_MAJOR);
890 return;
891 }
892
893 if (class_register(class: &adb_dev_class))
894 return;
895
896 device_create(cls: &adb_dev_class, NULL, MKDEV(ADB_MAJOR, 0), NULL, fmt: "adb");
897
898 platform_device_register(&adb_pfdev);
899 platform_driver_probe(&adb_pfdrv, adb_dummy_probe);
900}
901

source code of linux/drivers/macintosh/adb.c