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");