[BLOCK] Get rid of request_queue_t typedef
[linux-2.6.git] / arch / arm / plat-omap / mailbox.c
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
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);
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  */
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
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  */
164 static void mbox_txq_fn(struct request_queue * q)
165 {
166 }
167
168 static void mbox_rxq_fn(struct request_queue * q)
169 {
170 }
171
172 static 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
179 static void __mbox_rx_interrupt(struct omap_mbox *mbox)
180 {
181         struct request *rq;
182         mbox_msg_t msg;
183         struct request_queue *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
213 static 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  */
229 static ssize_t
230 omap_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
247 static ssize_t
248 omap_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
283 static DEVICE_ATTR(mbox, S_IRUGO | S_IWUSR, omap_mbox_read, omap_mbox_write);
284
285 static ssize_t mbox_show(struct class *class, char *buf)
286 {
287         return sprintf(buf, "mbox");
288 }
289
290 static CLASS_ATTR(mbox, S_IRUGO, mbox_show, NULL);
291
292 static struct class omap_mbox_class = {
293         .name = "omap_mbox",
294 };
295
296 static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
297                                         request_fn_proc * proc,
298                                         void (*work) (struct work_struct *))
299 {
300         struct request_queue *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;
318 error:
319         kfree(mq);
320         return NULL;
321 }
322
323 static void mbox_queue_free(struct omap_mbox_queue *q)
324 {
325         blk_cleanup_queue(q->queue);
326         kfree(q);
327 }
328
329 static 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
395 static 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
408 static 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
420 struct 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 }
440 EXPORT_SYMBOL(omap_mbox_get);
441
442 void omap_mbox_put(struct omap_mbox *mbox)
443 {
444         omap_mbox_fini(mbox);
445 }
446 EXPORT_SYMBOL(omap_mbox_put);
447
448 int 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 }
468 EXPORT_SYMBOL(omap_mbox_register);
469
470 int 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 }
489 EXPORT_SYMBOL(omap_mbox_unregister);
490
491 static 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
500 static 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
506 subsys_initcall(omap_mbox_class_init);
507 module_exit(omap_mbox_class_exit);
508
509 MODULE_LICENSE("GPL");