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-rw-r--r--arch/arm/plat-omap/mailbox.c509
1 files changed, 509 insertions, 0 deletions
diff --git a/arch/arm/plat-omap/mailbox.c b/arch/arm/plat-omap/mailbox.c
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index 000000000000..de7e6ef48bd0
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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>
33#include <asm/io.h>
34#include <asm/arch/mailbox.h>
35#include "mailbox.h"
36
37static struct omap_mbox *mboxes;
38static DEFINE_RWLOCK(mboxes_lock);
39
40/* Mailbox Sequence Bit function */
41void omap_mbox_init_seq(struct omap_mbox *mbox)
42{
43 mbox_seq_init(mbox);
44}
45EXPORT_SYMBOL(omap_mbox_init_seq);
46
47/*
48 * message sender
49 */
50static 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
74int 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}
93EXPORT_SYMBOL(omap_mbox_msg_send);
94
95static 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);
119 blkdev_dequeue_request(rq);
120 end_that_request_last(rq, 0);
121 spin_unlock(q->queue_lock);
122 }
123}
124
125/*
126 * Message receiver(workqueue)
127 */
128static 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
152 spin_lock_irqsave(q->queue_lock, flags);
153 blkdev_dequeue_request(rq);
154 end_that_request_last(rq, 0);
155 spin_unlock_irqrestore(q->queue_lock, flags);
156
157 mbox->rxq->callback((void *)msg);
158 }
159}
160
161/*
162 * Mailbox interrupt handler
163 */
164static void mbox_txq_fn(request_queue_t * q)
165{
166}
167
168static void mbox_rxq_fn(request_queue_t * q)
169{
170}
171
172static void __mbox_tx_interrupt(struct omap_mbox *mbox)
173{
174 disable_mbox_irq(mbox, IRQ_TX);
175 ack_mbox_irq(mbox, IRQ_TX);
176 schedule_work(&mbox->txq->work);
177}
178
179static void __mbox_rx_interrupt(struct omap_mbox *mbox)
180{
181 struct request *rq;
182 mbox_msg_t msg;
183 request_queue_t *q = mbox->rxq->queue;
184
185 disable_mbox_irq(mbox, IRQ_RX);
186
187 while (!mbox_fifo_empty(mbox)) {
188 rq = blk_get_request(q, WRITE, GFP_ATOMIC);
189 if (unlikely(!rq))
190 goto nomem;
191
192 msg = mbox_fifo_read(mbox);
193 rq->data = (void *)msg;
194
195 if (unlikely(mbox_seq_test(mbox, msg))) {
196 pr_info("mbox: Illegal seq bit!(%08x)\n", msg);
197 if (mbox->err_notify)
198 mbox->err_notify();
199 }
200
201 blk_insert_request(q, rq, 0, NULL);
202 if (mbox->ops->type == OMAP_MBOX_TYPE1)
203 break;
204 }
205
206 /* no more messages in the fifo. clear IRQ source. */
207 ack_mbox_irq(mbox, IRQ_RX);
208 enable_mbox_irq(mbox, IRQ_RX);
209 nomem:
210 schedule_work(&mbox->rxq->work);
211}
212
213static irqreturn_t mbox_interrupt(int irq, void *p)
214{
215 struct omap_mbox *mbox = (struct omap_mbox *)p;
216
217 if (is_mbox_irq(mbox, IRQ_TX))
218 __mbox_tx_interrupt(mbox);
219
220 if (is_mbox_irq(mbox, IRQ_RX))
221 __mbox_rx_interrupt(mbox);
222
223 return IRQ_HANDLED;
224}
225
226/*
227 * sysfs files
228 */
229static ssize_t
230omap_mbox_write(struct device *dev, struct device_attribute *attr,
231 const char * buf, size_t count)
232{
233 int ret;
234 mbox_msg_t *p = (mbox_msg_t *)buf;
235 struct omap_mbox *mbox = dev_get_drvdata(dev);
236
237 for (; count >= sizeof(mbox_msg_t); count -= sizeof(mbox_msg_t)) {
238 ret = omap_mbox_msg_send(mbox, be32_to_cpu(*p), NULL);
239 if (ret)
240 return -EAGAIN;
241 p++;
242 }
243
244 return (size_t)((char *)p - buf);
245}
246
247static ssize_t
248omap_mbox_read(struct device *dev, struct device_attribute *attr, char *buf)
249{
250 unsigned long flags;
251 struct request *rq;
252 mbox_msg_t *p = (mbox_msg_t *) buf;
253 struct omap_mbox *mbox = dev_get_drvdata(dev);
254 struct request_queue *q = mbox->rxq->queue;
255
256 while (1) {
257 spin_lock_irqsave(q->queue_lock, flags);
258 rq = elv_next_request(q);
259 spin_unlock_irqrestore(q->queue_lock, flags);
260
261 if (!rq)
262 break;
263
264 *p = (mbox_msg_t) rq->data;
265
266 spin_lock_irqsave(q->queue_lock, flags);
267 blkdev_dequeue_request(rq);
268 end_that_request_last(rq, 0);
269 spin_unlock_irqrestore(q->queue_lock, flags);
270
271 if (unlikely(mbox_seq_test(mbox, *p))) {
272 pr_info("mbox: Illegal seq bit!(%08x) ignored\n", *p);
273 continue;
274 }
275 p++;
276 }
277
278 pr_debug("%02x %02x %02x %02x\n", buf[0], buf[1], buf[2], buf[3]);
279
280 return (size_t) ((char *)p - buf);
281}
282
283static DEVICE_ATTR(mbox, S_IRUGO | S_IWUSR, omap_mbox_read, omap_mbox_write);
284
285static ssize_t mbox_show(struct class *class, char *buf)
286{
287 return sprintf(buf, "mbox");
288}
289
290static CLASS_ATTR(mbox, S_IRUGO, mbox_show, NULL);
291
292static struct class omap_mbox_class = {
293 .name = "omap_mbox",
294};
295
296static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
297 request_fn_proc * proc,
298 void (*work) (struct work_struct *))
299{
300 request_queue_t *q;
301 struct omap_mbox_queue *mq;
302
303 mq = kzalloc(sizeof(struct omap_mbox_queue), GFP_KERNEL);
304 if (!mq)
305 return NULL;
306
307 spin_lock_init(&mq->lock);
308
309 q = blk_init_queue(proc, &mq->lock);
310 if (!q)
311 goto error;
312 q->queuedata = mbox;
313 mq->queue = q;
314
315 INIT_WORK(&mq->work, work);
316
317 return mq;
318error:
319 kfree(mq);
320 return NULL;
321}
322
323static void mbox_queue_free(struct omap_mbox_queue *q)
324{
325 blk_cleanup_queue(q->queue);
326 kfree(q);
327}
328
329static int omap_mbox_init(struct omap_mbox *mbox)
330{
331 int ret;
332 struct omap_mbox_queue *mq;
333
334 if (likely(mbox->ops->startup)) {
335 ret = mbox->ops->startup(mbox);
336 if (unlikely(ret))
337 return ret;
338 }
339
340 mbox->dev.class = &omap_mbox_class;
341 strlcpy(mbox->dev.bus_id, mbox->name, KOBJ_NAME_LEN);
342 dev_set_drvdata(&mbox->dev, mbox);
343
344 ret = device_register(&mbox->dev);
345 if (unlikely(ret))
346 goto fail_device_reg;
347
348 ret = device_create_file(&mbox->dev, &dev_attr_mbox);
349 if (unlikely(ret)) {
350 printk(KERN_ERR
351 "device_create_file failed: %d\n", ret);
352 goto fail_create_mbox;
353 }
354
355 ret = request_irq(mbox->irq, mbox_interrupt, IRQF_DISABLED,
356 mbox->name, mbox);
357 if (unlikely(ret)) {
358 printk(KERN_ERR
359 "failed to register mailbox interrupt:%d\n", ret);
360 goto fail_request_irq;
361 }
362 enable_mbox_irq(mbox, IRQ_RX);
363
364 mq = mbox_queue_alloc(mbox, mbox_txq_fn, mbox_tx_work);
365 if (!mq) {
366 ret = -ENOMEM;
367 goto fail_alloc_txq;
368 }
369 mbox->txq = mq;
370
371 mq = mbox_queue_alloc(mbox, mbox_rxq_fn, mbox_rx_work);
372 if (!mq) {
373 ret = -ENOMEM;
374 goto fail_alloc_rxq;
375 }
376 mbox->rxq = mq;
377
378 return 0;
379
380 fail_alloc_rxq:
381 mbox_queue_free(mbox->txq);
382 fail_alloc_txq:
383 free_irq(mbox->irq, mbox);
384 fail_request_irq:
385 device_remove_file(&mbox->dev, &dev_attr_mbox);
386 fail_create_mbox:
387 device_unregister(&mbox->dev);
388 fail_device_reg:
389 if (unlikely(mbox->ops->shutdown))
390 mbox->ops->shutdown(mbox);
391
392 return ret;
393}
394
395static void omap_mbox_fini(struct omap_mbox *mbox)
396{
397 mbox_queue_free(mbox->txq);
398 mbox_queue_free(mbox->rxq);
399
400 free_irq(mbox->irq, mbox);
401 device_remove_file(&mbox->dev, &dev_attr_mbox);
402 class_unregister(&omap_mbox_class);
403
404 if (unlikely(mbox->ops->shutdown))
405 mbox->ops->shutdown(mbox);
406}
407
408static struct omap_mbox **find_mboxes(const char *name)
409{
410 struct omap_mbox **p;
411
412 for (p = &mboxes; *p; p = &(*p)->next) {
413 if (strcmp((*p)->name, name) == 0)
414 break;
415 }
416
417 return p;
418}
419
420struct omap_mbox *omap_mbox_get(const char *name)
421{
422 struct omap_mbox *mbox;
423 int ret;
424
425 read_lock(&mboxes_lock);
426 mbox = *(find_mboxes(name));
427 if (mbox == NULL) {
428 read_unlock(&mboxes_lock);
429 return ERR_PTR(-ENOENT);
430 }
431
432 read_unlock(&mboxes_lock);
433
434 ret = omap_mbox_init(mbox);
435 if (ret)
436 return ERR_PTR(-ENODEV);
437
438 return mbox;
439}
440EXPORT_SYMBOL(omap_mbox_get);
441
442void omap_mbox_put(struct omap_mbox *mbox)
443{
444 omap_mbox_fini(mbox);
445}
446EXPORT_SYMBOL(omap_mbox_put);
447
448int omap_mbox_register(struct omap_mbox *mbox)
449{
450 int ret = 0;
451 struct omap_mbox **tmp;
452
453 if (!mbox)
454 return -EINVAL;
455 if (mbox->next)
456 return -EBUSY;
457
458 write_lock(&mboxes_lock);
459 tmp = find_mboxes(mbox->name);
460 if (*tmp)
461 ret = -EBUSY;
462 else
463 *tmp = mbox;
464 write_unlock(&mboxes_lock);
465
466 return ret;
467}
468EXPORT_SYMBOL(omap_mbox_register);
469
470int omap_mbox_unregister(struct omap_mbox *mbox)
471{
472 struct omap_mbox **tmp;
473
474 write_lock(&mboxes_lock);
475 tmp = &mboxes;
476 while (*tmp) {
477 if (mbox == *tmp) {
478 *tmp = mbox->next;
479 mbox->next = NULL;
480 write_unlock(&mboxes_lock);
481 return 0;
482 }
483 tmp = &(*tmp)->next;
484 }
485 write_unlock(&mboxes_lock);
486
487 return -EINVAL;
488}
489EXPORT_SYMBOL(omap_mbox_unregister);
490
491static int __init omap_mbox_class_init(void)
492{
493 int ret = class_register(&omap_mbox_class);
494 if (!ret)
495 ret = class_create_file(&omap_mbox_class, &class_attr_mbox);
496
497 return ret;
498}
499
500static void __exit omap_mbox_class_exit(void)
501{
502 class_remove_file(&omap_mbox_class, &class_attr_mbox);
503 class_unregister(&omap_mbox_class);
504}
505
506subsys_initcall(omap_mbox_class_init);
507module_exit(omap_mbox_class_exit);
508
509MODULE_LICENSE("GPL");