1 // SPDX-License-Identifier: GPL-2.0
3 * Device driver for the Apple Desktop Bus
4 * and the /dev/adb device on macintoshes.
6 * Copyright (C) 1996 Paul Mackerras.
8 * Modified to declare controllers as structures, added
9 * client notification of bus reset and handles PowerBook
10 * sleep, by Benjamin Herrenschmidt.
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
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>
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>
43 #include <linux/uaccess.h>
45 #include <asm/machdep.h>
49 EXPORT_SYMBOL(adb_client_list);
51 extern struct adb_driver via_macii_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;
57 static DEFINE_MUTEX(adb_mutex);
58 static struct adb_driver *adb_driver_list[] = {
59 #ifdef CONFIG_ADB_MACII
62 #ifdef CONFIG_ADB_CUDA
71 #ifdef CONFIG_ADB_MACIO
77 static const struct class adb_dev_class = {
81 static struct adb_driver *adb_controller;
82 BLOCKING_NOTIFIER_HEAD(adb_client_list);
83 static int adb_got_sleep;
84 static int adb_inited;
85 static DEFINE_SEMAPHORE(adb_probe_mutex, 1);
86 static int sleepy_trackpad;
87 static int autopoll_devs;
90 static int adb_scan_bus(void);
91 static int do_adb_reset_bus(void);
92 static void adbdev_init(void);
93 static int try_handler_change(int, int);
95 static struct adb_handler {
96 void (*handler)(unsigned char *, int, int);
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
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
111 static DEFINE_MUTEX(adb_handler_mutex);
112 static DEFINE_RWLOCK(adb_handler_lock);
115 static void printADBreply(struct adb_request *req)
119 printk("adb reply (%d)", req->reply_len);
120 for(i = 0; i < req->reply_len; i++)
121 printk(" %x", req->reply[i]);
127 static int adb_scan_bus(void)
129 int i, highFree=0, noMovement;
131 struct adb_request req;
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, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
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)
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)
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.
155 adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
158 * Move the device(s) which didn't detect a
159 * collision to address `highFree'. Hopefully
160 * this only moves one device.
162 adb_request(&req, NULL, ADBREQ_SYNC, 3,
163 (i<< 4) | 0xb, (highFree | 0x60), 0xfe);
165 * See if anybody actually moved. This is suggested
168 * https://developer.apple.com/technotes/hw/hw_01.html
170 adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
171 (highFree << 4) | 0xf);
172 if (req.reply_len <= 1) continue;
174 * Test whether there are any device(s) left
177 adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
179 if (req.reply_len > 1) {
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.
186 adb_handler[highFree].original_address =
187 adb_handler[i].original_address;
188 while (highFree > 0 &&
189 adb_handler[highFree].original_address)
197 * No devices left at address i; move the
198 * one(s) we moved to `highFree' back to i.
200 adb_request(&req, NULL, ADBREQ_SYNC, 3,
201 (highFree << 4) | 0xb,
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)
211 adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
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);
223 * This kernel task handles ADB probing. It dies once probing is
227 adb_probe_task(void *x)
229 pr_debug("adb: starting probe task...\n");
231 pr_debug("adb: finished probe task...\n");
233 up(&adb_probe_mutex);
239 __adb_probe_task(struct work_struct *bullshit)
241 kthread_run(adb_probe_task, NULL, "kadbprobe");
244 static DECLARE_WORK(adb_reset_work, __adb_probe_task);
249 if (__adb_probe_sync) {
254 down(&adb_probe_mutex);
255 schedule_work(&adb_reset_work);
261 * notify clients before sleep
263 static int __adb_suspend(struct platform_device *dev, pm_message_t state)
266 /* We need to get a lock on the probe thread */
267 down(&adb_probe_mutex);
269 if (adb_controller->autopoll)
270 adb_controller->autopoll(0);
271 blocking_notifier_call_chain(&adb_client_list, ADB_MSG_POWERDOWN, NULL);
276 static int adb_suspend(struct device *dev)
278 return __adb_suspend(to_platform_device(dev), PMSG_SUSPEND);
281 static int adb_freeze(struct device *dev)
283 return __adb_suspend(to_platform_device(dev), PMSG_FREEZE);
286 static int adb_poweroff(struct device *dev)
288 return __adb_suspend(to_platform_device(dev), PMSG_HIBERNATE);
292 * reset bus after sleep
294 static int __adb_resume(struct platform_device *dev)
297 up(&adb_probe_mutex);
303 static int adb_resume(struct device *dev)
305 return __adb_resume(to_platform_device(dev));
307 #endif /* CONFIG_PM */
309 static int __init adb_init(void)
311 struct adb_driver *driver;
315 if (!machine_is(chrp) && !machine_is(powermac))
323 /* xmon may do early-init */
328 adb_controller = NULL;
331 while ((driver = adb_driver_list[i++]) != NULL) {
332 if (!driver->probe()) {
333 adb_controller = driver;
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");
344 if (of_machine_is_compatible("AAPL,PowerBook1998") ||
345 of_machine_is_compatible("PowerBook1,1"))
347 #endif /* CONFIG_PPC */
355 device_initcall(adb_init);
358 do_adb_reset_bus(void)
362 if (adb_controller == NULL)
365 if (adb_controller->autopoll)
366 adb_controller->autopoll(0);
368 blocking_notifier_call_chain(&adb_client_list,
369 ADB_MSG_PRE_RESET, NULL);
371 if (sleepy_trackpad) {
372 /* Let the trackpad settle down */
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);
381 /* That one is still a bit synchronous, oh well... */
382 if (adb_controller->reset_bus)
383 ret = adb_controller->reset_bus();
387 if (sleepy_trackpad) {
388 /* Let the trackpad settle down */
393 autopoll_devs = adb_scan_bus();
394 if (adb_controller->autopoll)
395 adb_controller->autopoll(autopoll_devs);
397 mutex_unlock(&adb_handler_mutex);
399 blocking_notifier_call_chain(&adb_client_list,
400 ADB_MSG_POST_RESET, NULL);
408 if ((adb_controller == NULL)||(adb_controller->poll == NULL))
410 adb_controller->poll();
412 EXPORT_SYMBOL(adb_poll);
414 static void adb_sync_req_done(struct adb_request *req)
416 struct completion *comp = req->arg;
422 adb_request(struct adb_request *req, void (*done)(struct adb_request *),
423 int flags, int nbytes, ...)
428 struct completion comp;
430 if ((adb_controller == NULL) || (adb_controller->send_request == NULL))
435 req->nbytes = nbytes+1;
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);
444 if (flags & ADBREQ_NOSEND)
447 /* Synchronous requests block using an on-stack completion */
448 if (flags & ADBREQ_SYNC) {
450 req->done = adb_sync_req_done;
452 init_completion(&comp);
455 rc = adb_controller->send_request(req, 0);
457 if ((flags & ADBREQ_SYNC) && !rc && !req->complete)
458 wait_for_completion(&comp);
462 EXPORT_SYMBOL(adb_request);
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. */
472 adb_register(int default_id, int handler_id, struct adb_ids *ids,
473 void (*handler)(unsigned char *, int, int))
477 mutex_lock(&adb_handler_mutex);
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",
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;
494 mutex_unlock(&adb_handler_mutex);
497 EXPORT_SYMBOL(adb_register);
500 adb_unregister(int index)
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);
510 write_lock_irq(&adb_handler_lock);
513 adb_handler[index].handler = NULL;
515 write_unlock_irq(&adb_handler_lock);
516 mutex_unlock(&adb_handler_mutex);
519 EXPORT_SYMBOL(adb_unregister);
522 adb_input(unsigned char *buf, int nb, int autopoll)
525 static int dump_adb_input;
528 void (*handler)(unsigned char *, int, int);
530 /* We skip keystrokes and mouse moves when the sleep process
531 * has been started. We stop autopoll, but this is another security
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);
543 write_lock_irqsave(&adb_handler_lock, flags);
544 handler = adb_handler[id].handler;
546 adb_handler[id].busy = 1;
547 write_unlock_irqrestore(&adb_handler_lock, flags);
548 if (handler != NULL) {
549 (*handler)(buf, nb, autopoll);
551 adb_handler[id].busy = 0;
556 /* Try to change handler to new_id. Will return 1 if successful. */
557 static int try_handler_change(int address, int new_id)
559 struct adb_request req;
561 if (adb_handler[address].handler_id == new_id)
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)
569 if (req.reply[2] != new_id)
571 adb_handler[address].handler_id = req.reply[2];
577 adb_try_handler_change(int address, int new_id)
581 mutex_lock(&adb_handler_mutex);
582 ret = try_handler_change(address, new_id);
583 mutex_unlock(&adb_handler_mutex);
585 pr_debug("adb handler change: [%d] 0x%X\n", address, new_id);
588 EXPORT_SYMBOL(adb_try_handler_change);
591 adb_get_infos(int address, int *original_address, int *handler_id)
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(&adb_handler_mutex);
598 return (*original_address != 0);
603 * /dev/adb device driver.
606 #define ADB_MAJOR 56 /* major number for /dev/adb */
608 struct adbdev_state {
611 struct adb_request *completed;
612 wait_queue_head_t wait_queue;
616 static void adb_write_done(struct adb_request *req)
618 struct adbdev_state *state = (struct adbdev_state *) req->arg;
621 if (!req->complete) {
625 spin_lock_irqsave(&state->lock, flags);
626 atomic_dec(&state->n_pending);
629 if (atomic_read(&state->n_pending) == 0) {
630 spin_unlock_irqrestore(&state->lock, flags);
635 struct adb_request **ap = &state->completed;
640 wake_up_interruptible(&state->wait_queue);
642 spin_unlock_irqrestore(&state->lock, flags);
646 do_adb_query(struct adb_request *req)
650 switch(req->data[1]) {
651 case ADB_QUERY_GETDEVINFO:
652 if (req->nbytes < 3 || req->data[2] >= 16)
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(&adb_handler_mutex);
667 static int adb_open(struct inode *inode, struct file *file)
669 struct adbdev_state *state;
672 mutex_lock(&adb_mutex);
673 if (iminor(inode) > 0 || adb_controller == NULL) {
677 state = kmalloc(sizeof(struct adbdev_state), GFP_KERNEL);
682 file->private_data = state;
683 spin_lock_init(&state->lock);
684 atomic_set(&state->n_pending, 0);
685 state->completed = NULL;
686 init_waitqueue_head(&state->wait_queue);
690 mutex_unlock(&adb_mutex);
694 static int adb_release(struct inode *inode, struct file *file)
696 struct adbdev_state *state = file->private_data;
699 mutex_lock(&adb_mutex);
701 file->private_data = NULL;
702 spin_lock_irqsave(&state->lock, flags);
703 if (atomic_read(&state->n_pending) == 0
704 && state->completed == NULL) {
705 spin_unlock_irqrestore(&state->lock, flags);
709 spin_unlock_irqrestore(&state->lock, flags);
712 mutex_unlock(&adb_mutex);
716 static ssize_t adb_read(struct file *file, char __user *buf,
717 size_t count, loff_t *ppos)
720 struct adbdev_state *state = file->private_data;
721 struct adb_request *req;
722 DECLARE_WAITQUEUE(wait, current);
727 if (count > sizeof(req->reply))
728 count = sizeof(req->reply);
731 spin_lock_irqsave(&state->lock, flags);
732 add_wait_queue(&state->wait_queue, &wait);
733 set_current_state(TASK_INTERRUPTIBLE);
736 req = state->completed;
738 state->completed = req->next;
739 else if (atomic_read(&state->n_pending) == 0)
741 if (req != NULL || ret != 0)
744 if (file->f_flags & O_NONBLOCK) {
748 if (signal_pending(current)) {
752 spin_unlock_irqrestore(&state->lock, flags);
754 spin_lock_irqsave(&state->lock, flags);
757 set_current_state(TASK_RUNNING);
758 remove_wait_queue(&state->wait_queue, &wait);
759 spin_unlock_irqrestore(&state->lock, flags);
764 ret = req->reply_len;
767 if (ret > 0 && copy_to_user(buf, req->reply, ret))
774 static ssize_t adb_write(struct file *file, const char __user *buf,
775 size_t count, loff_t *ppos)
778 struct adbdev_state *state = file->private_data;
779 struct adb_request *req;
781 if (count < 2 || count > sizeof(req->data))
783 if (adb_controller == NULL)
786 req = kmalloc(sizeof(struct adb_request),
792 req->done = adb_write_done;
793 req->arg = (void *) state;
797 if (copy_from_user(req->data, buf, count))
800 atomic_inc(&state->n_pending);
802 /* If a probe is in progress or we are sleeping, wait for it to complete */
803 down(&adb_probe_mutex);
805 /* Queries are special requests sent to the ADB driver itself */
806 if (req->data[0] == ADB_QUERY) {
808 ret = do_adb_query(req);
811 up(&adb_probe_mutex);
813 /* Special case for ADB_BUSRESET request, all others are sent to
815 else if ((req->data[0] == ADB_PACKET) && (count > 1)
816 && (req->data[1] == ADB_BUSRESET)) {
817 ret = do_adb_reset_bus();
818 up(&adb_probe_mutex);
819 atomic_dec(&state->n_pending);
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);
829 up(&adb_probe_mutex);
833 atomic_dec(&state->n_pending);
843 static const struct file_operations adb_fops = {
844 .owner = THIS_MODULE,
849 .release = adb_release,
853 static const struct dev_pm_ops adb_dev_pm_ops = {
854 .suspend = adb_suspend,
855 .resume = adb_resume,
856 /* Hibernate hooks */
857 .freeze = adb_freeze,
859 .poweroff = adb_poweroff,
860 .restore = adb_resume,
864 static struct platform_driver adb_pfdrv = {
868 .pm = &adb_dev_pm_ops,
873 static struct platform_device adb_pfdev = {
878 adb_dummy_probe(struct platform_device *dev)
880 if (dev == &adb_pfdev)
888 if (register_chrdev(ADB_MAJOR, "adb", &adb_fops)) {
889 pr_err("adb: unable to get major %d\n", ADB_MAJOR);
893 if (class_register(&adb_dev_class))
896 device_create(&adb_dev_class, NULL, MKDEV(ADB_MAJOR, 0), NULL, "adb");
898 platform_device_register(&adb_pfdev);
899 platform_driver_probe(&adb_pfdrv, adb_dummy_probe);