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