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 const struct class adb_dev_class = { |
78 | .name = "adb" , |
79 | }; |
80 | |
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; |
88 | int __adb_probe_sync; |
89 | |
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); |
94 | |
95 | static 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 | */ |
111 | static DEFINE_MUTEX(adb_handler_mutex); |
112 | static DEFINE_RWLOCK(adb_handler_lock); |
113 | |
114 | #if 0 |
115 | static 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 | |
127 | static 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 | */ |
226 | static int |
227 | adb_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 | |
238 | static void |
239 | __adb_probe_task(struct work_struct *bullshit) |
240 | { |
241 | kthread_run(adb_probe_task, NULL, "kadbprobe" ); |
242 | } |
243 | |
244 | static DECLARE_WORK(adb_reset_work, __adb_probe_task); |
245 | |
246 | int |
247 | adb_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 | */ |
263 | static 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 | |
276 | static int adb_suspend(struct device *dev) |
277 | { |
278 | return __adb_suspend(to_platform_device(dev), PMSG_SUSPEND); |
279 | } |
280 | |
281 | static int adb_freeze(struct device *dev) |
282 | { |
283 | return __adb_suspend(to_platform_device(dev), PMSG_FREEZE); |
284 | } |
285 | |
286 | static 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 | */ |
294 | static 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 | |
303 | static int adb_resume(struct device *dev) |
304 | { |
305 | return __adb_resume(to_platform_device(dev)); |
306 | } |
307 | #endif /* CONFIG_PM */ |
308 | |
309 | static 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 | |
355 | device_initcall(adb_init); |
356 | |
357 | static int |
358 | do_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 | |
405 | void |
406 | adb_poll(void) |
407 | { |
408 | if ((adb_controller == NULL)||(adb_controller->poll == NULL)) |
409 | return; |
410 | adb_controller->poll(); |
411 | } |
412 | EXPORT_SYMBOL(adb_poll); |
413 | |
414 | static void adb_sync_req_done(struct adb_request *req) |
415 | { |
416 | struct completion *comp = req->arg; |
417 | |
418 | complete(comp); |
419 | } |
420 | |
421 | int |
422 | adb_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 = ∁ |
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 | } |
462 | EXPORT_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. */ |
471 | int |
472 | adb_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 | } |
497 | EXPORT_SYMBOL(adb_register); |
498 | |
499 | int |
500 | adb_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 | } |
519 | EXPORT_SYMBOL(adb_unregister); |
520 | |
521 | void |
522 | adb_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. */ |
557 | static 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 | |
576 | int |
577 | adb_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 | } |
588 | EXPORT_SYMBOL(adb_try_handler_change); |
589 | |
590 | int |
591 | adb_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 | |
608 | struct 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 | |
616 | static 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 | |
645 | static int |
646 | do_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 | |
667 | static 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 | |
689 | out: |
690 | mutex_unlock(lock: &adb_mutex); |
691 | return ret; |
692 | } |
693 | |
694 | static 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 | |
716 | static 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 | |
774 | static 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 | |
838 | out: |
839 | kfree(objp: req); |
840 | return ret; |
841 | } |
842 | |
843 | static 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 |
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, |
858 | .thaw = adb_resume, |
859 | .poweroff = adb_poweroff, |
860 | .restore = adb_resume, |
861 | }; |
862 | #endif |
863 | |
864 | static 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 | |
873 | static struct platform_device adb_pfdev = { |
874 | .name = "adb" , |
875 | }; |
876 | |
877 | static int __init |
878 | adb_dummy_probe(struct platform_device *dev) |
879 | { |
880 | if (dev == &adb_pfdev) |
881 | return 0; |
882 | return -ENODEV; |
883 | } |
884 | |
885 | static void __init |
886 | adbdev_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 | |