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340a614a HD |
1 | /* |
2 | * OMAP mailbox driver | |
3 | * | |
4 | * Copyright (C) 2006 Nokia Corporation. All rights reserved. | |
5 | * | |
6 | * Contact: Toshihiro Kobayashi <toshihiro.kobayashi@nokia.com> | |
7 | * Restructured by Hiroshi DOYU <Hiroshi.DOYU@nokia.com> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License | |
11 | * version 2 as published by the Free Software Foundation. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, but | |
14 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | * General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * along with this program; if not, write to the Free Software | |
20 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA | |
21 | * 02110-1301 USA | |
22 | * | |
23 | */ | |
24 | ||
25 | #include <linux/init.h> | |
26 | #include <linux/module.h> | |
27 | #include <linux/sched.h> | |
28 | #include <linux/interrupt.h> | |
29 | #include <linux/device.h> | |
30 | #include <linux/blkdev.h> | |
31 | #include <linux/err.h> | |
32 | #include <linux/delay.h> | |
fced80c7 | 33 | #include <linux/io.h> |
a09e64fb | 34 | #include <mach/mailbox.h> |
340a614a HD |
35 | #include "mailbox.h" |
36 | ||
37 | static struct omap_mbox *mboxes; | |
38 | static DEFINE_RWLOCK(mboxes_lock); | |
39 | ||
40 | /* Mailbox Sequence Bit function */ | |
41 | void omap_mbox_init_seq(struct omap_mbox *mbox) | |
42 | { | |
43 | mbox_seq_init(mbox); | |
44 | } | |
45 | EXPORT_SYMBOL(omap_mbox_init_seq); | |
46 | ||
47 | /* | |
48 | * message sender | |
49 | */ | |
50 | static int __mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg, void *arg) | |
51 | { | |
52 | int ret = 0, i = 1000; | |
53 | ||
54 | while (mbox_fifo_full(mbox)) { | |
55 | if (mbox->ops->type == OMAP_MBOX_TYPE2) | |
56 | return -1; | |
57 | if (--i == 0) | |
58 | return -1; | |
59 | udelay(1); | |
60 | } | |
61 | ||
62 | if (arg && mbox->txq->callback) { | |
63 | ret = mbox->txq->callback(arg); | |
64 | if (ret) | |
65 | goto out; | |
66 | } | |
67 | ||
68 | mbox_seq_toggle(mbox, &msg); | |
69 | mbox_fifo_write(mbox, msg); | |
70 | out: | |
71 | return ret; | |
72 | } | |
73 | ||
74 | int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg, void* arg) | |
75 | { | |
76 | struct request *rq; | |
77 | struct request_queue *q = mbox->txq->queue; | |
78 | int ret = 0; | |
79 | ||
80 | rq = blk_get_request(q, WRITE, GFP_ATOMIC); | |
81 | if (unlikely(!rq)) { | |
82 | ret = -ENOMEM; | |
83 | goto fail; | |
84 | } | |
85 | ||
86 | rq->data = (void *)msg; | |
87 | blk_insert_request(q, rq, 0, arg); | |
88 | ||
89 | schedule_work(&mbox->txq->work); | |
90 | fail: | |
91 | return ret; | |
92 | } | |
93 | EXPORT_SYMBOL(omap_mbox_msg_send); | |
94 | ||
95 | static void mbox_tx_work(struct work_struct *work) | |
96 | { | |
97 | int ret; | |
98 | struct request *rq; | |
99 | struct omap_mbox_queue *mq = container_of(work, | |
100 | struct omap_mbox_queue, work); | |
101 | struct omap_mbox *mbox = mq->queue->queuedata; | |
102 | struct request_queue *q = mbox->txq->queue; | |
103 | ||
104 | while (1) { | |
105 | spin_lock(q->queue_lock); | |
106 | rq = elv_next_request(q); | |
107 | spin_unlock(q->queue_lock); | |
108 | ||
109 | if (!rq) | |
110 | break; | |
111 | ||
112 | ret = __mbox_msg_send(mbox, (mbox_msg_t) rq->data, rq->special); | |
113 | if (ret) { | |
114 | enable_mbox_irq(mbox, IRQ_TX); | |
115 | return; | |
116 | } | |
117 | ||
118 | spin_lock(q->queue_lock); | |
650e9cfd KU |
119 | if (__blk_end_request(rq, 0, 0)) |
120 | BUG(); | |
340a614a HD |
121 | spin_unlock(q->queue_lock); |
122 | } | |
123 | } | |
124 | ||
125 | /* | |
126 | * Message receiver(workqueue) | |
127 | */ | |
128 | static void mbox_rx_work(struct work_struct *work) | |
129 | { | |
130 | struct omap_mbox_queue *mq = | |
131 | container_of(work, struct omap_mbox_queue, work); | |
132 | struct omap_mbox *mbox = mq->queue->queuedata; | |
133 | struct request_queue *q = mbox->rxq->queue; | |
134 | struct request *rq; | |
135 | mbox_msg_t msg; | |
136 | unsigned long flags; | |
137 | ||
138 | if (mbox->rxq->callback == NULL) { | |
139 | sysfs_notify(&mbox->dev.kobj, NULL, "mbox"); | |
140 | return; | |
141 | } | |
142 | ||
143 | while (1) { | |
144 | spin_lock_irqsave(q->queue_lock, flags); | |
145 | rq = elv_next_request(q); | |
146 | spin_unlock_irqrestore(q->queue_lock, flags); | |
147 | if (!rq) | |
148 | break; | |
149 | ||
150 | msg = (mbox_msg_t) rq->data; | |
151 | ||
650e9cfd KU |
152 | if (blk_end_request(rq, 0, 0)) |
153 | BUG(); | |
340a614a HD |
154 | |
155 | mbox->rxq->callback((void *)msg); | |
156 | } | |
157 | } | |
158 | ||
159 | /* | |
160 | * Mailbox interrupt handler | |
161 | */ | |
165125e1 | 162 | static void mbox_txq_fn(struct request_queue * q) |
340a614a HD |
163 | { |
164 | } | |
165 | ||
165125e1 | 166 | static void mbox_rxq_fn(struct request_queue * q) |
340a614a HD |
167 | { |
168 | } | |
169 | ||
170 | static void __mbox_tx_interrupt(struct omap_mbox *mbox) | |
171 | { | |
172 | disable_mbox_irq(mbox, IRQ_TX); | |
173 | ack_mbox_irq(mbox, IRQ_TX); | |
174 | schedule_work(&mbox->txq->work); | |
175 | } | |
176 | ||
177 | static void __mbox_rx_interrupt(struct omap_mbox *mbox) | |
178 | { | |
179 | struct request *rq; | |
180 | mbox_msg_t msg; | |
165125e1 | 181 | struct request_queue *q = mbox->rxq->queue; |
340a614a HD |
182 | |
183 | disable_mbox_irq(mbox, IRQ_RX); | |
184 | ||
185 | while (!mbox_fifo_empty(mbox)) { | |
186 | rq = blk_get_request(q, WRITE, GFP_ATOMIC); | |
187 | if (unlikely(!rq)) | |
188 | goto nomem; | |
189 | ||
190 | msg = mbox_fifo_read(mbox); | |
191 | rq->data = (void *)msg; | |
192 | ||
193 | if (unlikely(mbox_seq_test(mbox, msg))) { | |
194 | pr_info("mbox: Illegal seq bit!(%08x)\n", msg); | |
195 | if (mbox->err_notify) | |
196 | mbox->err_notify(); | |
197 | } | |
198 | ||
199 | blk_insert_request(q, rq, 0, NULL); | |
200 | if (mbox->ops->type == OMAP_MBOX_TYPE1) | |
201 | break; | |
202 | } | |
203 | ||
204 | /* no more messages in the fifo. clear IRQ source. */ | |
205 | ack_mbox_irq(mbox, IRQ_RX); | |
206 | enable_mbox_irq(mbox, IRQ_RX); | |
207 | nomem: | |
208 | schedule_work(&mbox->rxq->work); | |
209 | } | |
210 | ||
211 | static irqreturn_t mbox_interrupt(int irq, void *p) | |
212 | { | |
2a7057e3 | 213 | struct omap_mbox *mbox = p; |
340a614a HD |
214 | |
215 | if (is_mbox_irq(mbox, IRQ_TX)) | |
216 | __mbox_tx_interrupt(mbox); | |
217 | ||
218 | if (is_mbox_irq(mbox, IRQ_RX)) | |
219 | __mbox_rx_interrupt(mbox); | |
220 | ||
221 | return IRQ_HANDLED; | |
222 | } | |
223 | ||
224 | /* | |
225 | * sysfs files | |
226 | */ | |
227 | static ssize_t | |
228 | omap_mbox_write(struct device *dev, struct device_attribute *attr, | |
229 | const char * buf, size_t count) | |
230 | { | |
231 | int ret; | |
232 | mbox_msg_t *p = (mbox_msg_t *)buf; | |
233 | struct omap_mbox *mbox = dev_get_drvdata(dev); | |
234 | ||
235 | for (; count >= sizeof(mbox_msg_t); count -= sizeof(mbox_msg_t)) { | |
236 | ret = omap_mbox_msg_send(mbox, be32_to_cpu(*p), NULL); | |
237 | if (ret) | |
238 | return -EAGAIN; | |
239 | p++; | |
240 | } | |
241 | ||
242 | return (size_t)((char *)p - buf); | |
243 | } | |
244 | ||
245 | static ssize_t | |
246 | omap_mbox_read(struct device *dev, struct device_attribute *attr, char *buf) | |
247 | { | |
248 | unsigned long flags; | |
249 | struct request *rq; | |
250 | mbox_msg_t *p = (mbox_msg_t *) buf; | |
251 | struct omap_mbox *mbox = dev_get_drvdata(dev); | |
252 | struct request_queue *q = mbox->rxq->queue; | |
253 | ||
254 | while (1) { | |
255 | spin_lock_irqsave(q->queue_lock, flags); | |
256 | rq = elv_next_request(q); | |
257 | spin_unlock_irqrestore(q->queue_lock, flags); | |
258 | ||
259 | if (!rq) | |
260 | break; | |
261 | ||
262 | *p = (mbox_msg_t) rq->data; | |
263 | ||
650e9cfd KU |
264 | if (blk_end_request(rq, 0, 0)) |
265 | BUG(); | |
340a614a HD |
266 | |
267 | if (unlikely(mbox_seq_test(mbox, *p))) { | |
268 | pr_info("mbox: Illegal seq bit!(%08x) ignored\n", *p); | |
269 | continue; | |
270 | } | |
271 | p++; | |
272 | } | |
273 | ||
274 | pr_debug("%02x %02x %02x %02x\n", buf[0], buf[1], buf[2], buf[3]); | |
275 | ||
276 | return (size_t) ((char *)p - buf); | |
277 | } | |
278 | ||
279 | static DEVICE_ATTR(mbox, S_IRUGO | S_IWUSR, omap_mbox_read, omap_mbox_write); | |
280 | ||
281 | static ssize_t mbox_show(struct class *class, char *buf) | |
282 | { | |
283 | return sprintf(buf, "mbox"); | |
284 | } | |
285 | ||
286 | static CLASS_ATTR(mbox, S_IRUGO, mbox_show, NULL); | |
287 | ||
288 | static struct class omap_mbox_class = { | |
289 | .name = "omap_mbox", | |
290 | }; | |
291 | ||
292 | static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox, | |
293 | request_fn_proc * proc, | |
294 | void (*work) (struct work_struct *)) | |
295 | { | |
165125e1 | 296 | struct request_queue *q; |
340a614a HD |
297 | struct omap_mbox_queue *mq; |
298 | ||
299 | mq = kzalloc(sizeof(struct omap_mbox_queue), GFP_KERNEL); | |
300 | if (!mq) | |
301 | return NULL; | |
302 | ||
303 | spin_lock_init(&mq->lock); | |
304 | ||
305 | q = blk_init_queue(proc, &mq->lock); | |
306 | if (!q) | |
307 | goto error; | |
308 | q->queuedata = mbox; | |
309 | mq->queue = q; | |
310 | ||
311 | INIT_WORK(&mq->work, work); | |
312 | ||
313 | return mq; | |
314 | error: | |
315 | kfree(mq); | |
316 | return NULL; | |
317 | } | |
318 | ||
319 | static void mbox_queue_free(struct omap_mbox_queue *q) | |
320 | { | |
321 | blk_cleanup_queue(q->queue); | |
322 | kfree(q); | |
323 | } | |
324 | ||
325 | static int omap_mbox_init(struct omap_mbox *mbox) | |
326 | { | |
327 | int ret; | |
328 | struct omap_mbox_queue *mq; | |
329 | ||
330 | if (likely(mbox->ops->startup)) { | |
331 | ret = mbox->ops->startup(mbox); | |
332 | if (unlikely(ret)) | |
333 | return ret; | |
334 | } | |
335 | ||
336 | mbox->dev.class = &omap_mbox_class; | |
3f978704 | 337 | dev_set_name(&mbox->dev, "%s", mbox->name); |
340a614a HD |
338 | dev_set_drvdata(&mbox->dev, mbox); |
339 | ||
340 | ret = device_register(&mbox->dev); | |
341 | if (unlikely(ret)) | |
342 | goto fail_device_reg; | |
343 | ||
344 | ret = device_create_file(&mbox->dev, &dev_attr_mbox); | |
345 | if (unlikely(ret)) { | |
346 | printk(KERN_ERR | |
347 | "device_create_file failed: %d\n", ret); | |
348 | goto fail_create_mbox; | |
349 | } | |
350 | ||
351 | ret = request_irq(mbox->irq, mbox_interrupt, IRQF_DISABLED, | |
352 | mbox->name, mbox); | |
353 | if (unlikely(ret)) { | |
354 | printk(KERN_ERR | |
355 | "failed to register mailbox interrupt:%d\n", ret); | |
356 | goto fail_request_irq; | |
357 | } | |
340a614a HD |
358 | |
359 | mq = mbox_queue_alloc(mbox, mbox_txq_fn, mbox_tx_work); | |
360 | if (!mq) { | |
361 | ret = -ENOMEM; | |
362 | goto fail_alloc_txq; | |
363 | } | |
364 | mbox->txq = mq; | |
365 | ||
366 | mq = mbox_queue_alloc(mbox, mbox_rxq_fn, mbox_rx_work); | |
367 | if (!mq) { | |
368 | ret = -ENOMEM; | |
369 | goto fail_alloc_rxq; | |
370 | } | |
371 | mbox->rxq = mq; | |
372 | ||
373 | return 0; | |
374 | ||
375 | fail_alloc_rxq: | |
376 | mbox_queue_free(mbox->txq); | |
377 | fail_alloc_txq: | |
378 | free_irq(mbox->irq, mbox); | |
379 | fail_request_irq: | |
380 | device_remove_file(&mbox->dev, &dev_attr_mbox); | |
381 | fail_create_mbox: | |
382 | device_unregister(&mbox->dev); | |
383 | fail_device_reg: | |
384 | if (unlikely(mbox->ops->shutdown)) | |
385 | mbox->ops->shutdown(mbox); | |
386 | ||
387 | return ret; | |
388 | } | |
389 | ||
390 | static void omap_mbox_fini(struct omap_mbox *mbox) | |
391 | { | |
392 | mbox_queue_free(mbox->txq); | |
393 | mbox_queue_free(mbox->rxq); | |
394 | ||
395 | free_irq(mbox->irq, mbox); | |
396 | device_remove_file(&mbox->dev, &dev_attr_mbox); | |
397 | class_unregister(&omap_mbox_class); | |
398 | ||
399 | if (unlikely(mbox->ops->shutdown)) | |
400 | mbox->ops->shutdown(mbox); | |
401 | } | |
402 | ||
403 | static struct omap_mbox **find_mboxes(const char *name) | |
404 | { | |
405 | struct omap_mbox **p; | |
406 | ||
407 | for (p = &mboxes; *p; p = &(*p)->next) { | |
408 | if (strcmp((*p)->name, name) == 0) | |
409 | break; | |
410 | } | |
411 | ||
412 | return p; | |
413 | } | |
414 | ||
415 | struct omap_mbox *omap_mbox_get(const char *name) | |
416 | { | |
417 | struct omap_mbox *mbox; | |
418 | int ret; | |
419 | ||
420 | read_lock(&mboxes_lock); | |
421 | mbox = *(find_mboxes(name)); | |
422 | if (mbox == NULL) { | |
423 | read_unlock(&mboxes_lock); | |
424 | return ERR_PTR(-ENOENT); | |
425 | } | |
426 | ||
427 | read_unlock(&mboxes_lock); | |
428 | ||
429 | ret = omap_mbox_init(mbox); | |
430 | if (ret) | |
431 | return ERR_PTR(-ENODEV); | |
432 | ||
433 | return mbox; | |
434 | } | |
435 | EXPORT_SYMBOL(omap_mbox_get); | |
436 | ||
437 | void omap_mbox_put(struct omap_mbox *mbox) | |
438 | { | |
439 | omap_mbox_fini(mbox); | |
440 | } | |
441 | EXPORT_SYMBOL(omap_mbox_put); | |
442 | ||
443 | int omap_mbox_register(struct omap_mbox *mbox) | |
444 | { | |
445 | int ret = 0; | |
446 | struct omap_mbox **tmp; | |
447 | ||
448 | if (!mbox) | |
449 | return -EINVAL; | |
450 | if (mbox->next) | |
451 | return -EBUSY; | |
452 | ||
453 | write_lock(&mboxes_lock); | |
454 | tmp = find_mboxes(mbox->name); | |
455 | if (*tmp) | |
456 | ret = -EBUSY; | |
457 | else | |
458 | *tmp = mbox; | |
459 | write_unlock(&mboxes_lock); | |
460 | ||
461 | return ret; | |
462 | } | |
463 | EXPORT_SYMBOL(omap_mbox_register); | |
464 | ||
465 | int omap_mbox_unregister(struct omap_mbox *mbox) | |
466 | { | |
467 | struct omap_mbox **tmp; | |
468 | ||
469 | write_lock(&mboxes_lock); | |
470 | tmp = &mboxes; | |
471 | while (*tmp) { | |
472 | if (mbox == *tmp) { | |
473 | *tmp = mbox->next; | |
474 | mbox->next = NULL; | |
475 | write_unlock(&mboxes_lock); | |
476 | return 0; | |
477 | } | |
478 | tmp = &(*tmp)->next; | |
479 | } | |
480 | write_unlock(&mboxes_lock); | |
481 | ||
482 | return -EINVAL; | |
483 | } | |
484 | EXPORT_SYMBOL(omap_mbox_unregister); | |
485 | ||
486 | static int __init omap_mbox_class_init(void) | |
487 | { | |
488 | int ret = class_register(&omap_mbox_class); | |
489 | if (!ret) | |
490 | ret = class_create_file(&omap_mbox_class, &class_attr_mbox); | |
491 | ||
492 | return ret; | |
493 | } | |
494 | ||
495 | static void __exit omap_mbox_class_exit(void) | |
496 | { | |
497 | class_remove_file(&omap_mbox_class, &class_attr_mbox); | |
498 | class_unregister(&omap_mbox_class); | |
499 | } | |
500 | ||
501 | subsys_initcall(omap_mbox_class_init); | |
502 | module_exit(omap_mbox_class_exit); | |
503 | ||
504 | MODULE_LICENSE("GPL"); |