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                 if (__blk_end_request(rq, 0, 0))
 120                         BUG();
 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                 if (blk_end_request(rq, 0, 0))
 153                         BUG();
 154
 155                 mbox->rxq->callback((void *)msg);
 156         }
 157 }
 158
 159 /*
 160  * Mailbox interrupt handler
 161  */
 162 static void mbox_txq_fn(struct request_queue * q)
 163 {
 164 }
 165
 166 static void mbox_rxq_fn(struct request_queue * q)
 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;
 181         struct request_queue *q = mbox->rxq->queue;
 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 {
 213         struct omap_mbox *mbox = p;
 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
 264                 if (blk_end_request(rq, 0, 0))
 265                         BUG();
 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 {
 296         struct request_queue *q;
 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;
 337         strlcpy(mbox->dev.bus_id, mbox->name, KOBJ_NAME_LEN);
 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         }
 358         enable_mbox_irq(mbox, IRQ_RX);
 359
 360         mq = mbox_queue_alloc(mbox, mbox_txq_fn, mbox_tx_work);
 361         if (!mq) {
 362                 ret = -ENOMEM;
 363                 goto fail_alloc_txq;
 364         }
 365         mbox->txq = mq;
 366
 367         mq = mbox_queue_alloc(mbox, mbox_rxq_fn, mbox_rx_work);
 368         if (!mq) {
 369                 ret = -ENOMEM;
 370                 goto fail_alloc_rxq;
 371         }
 372         mbox->rxq = mq;
 373
 374         return 0;
 375
 376  fail_alloc_rxq:
 377         mbox_queue_free(mbox->txq);
 378  fail_alloc_txq:
 379         free_irq(mbox->irq, mbox);
 380  fail_request_irq:
 381         device_remove_file(&mbox->dev, &dev_attr_mbox);
 382  fail_create_mbox:
 383         device_unregister(&mbox->dev);
 384  fail_device_reg:
 385         if (unlikely(mbox->ops->shutdown))
 386                 mbox->ops->shutdown(mbox);
 387
 388         return ret;
 389 }
 390
 391 static void omap_mbox_fini(struct omap_mbox *mbox)
 392 {
 393         mbox_queue_free(mbox->txq);
 394         mbox_queue_free(mbox->rxq);
 395
 396         free_irq(mbox->irq, mbox);
 397         device_remove_file(&mbox->dev, &dev_attr_mbox);
 398         class_unregister(&omap_mbox_class);
 399
 400         if (unlikely(mbox->ops->shutdown))
 401                 mbox->ops->shutdown(mbox);
 402 }
 403
 404 static struct omap_mbox **find_mboxes(const char *name)
 405 {
 406         struct omap_mbox **p;
 407
 408         for (p = &mboxes; *p; p = &(*p)->next) {
 409                 if (strcmp((*p)->name, name) == 0)
 410                         break;
 411         }
 412
 413         return p;
 414 }
 415
 416 struct omap_mbox *omap_mbox_get(const char *name)
 417 {
 418         struct omap_mbox *mbox;
 419         int ret;
 420
 421         read_lock(&mboxes_lock);
 422         mbox = *(find_mboxes(name));
 423         if (mbox == NULL) {
 424                 read_unlock(&mboxes_lock);
 425                 return ERR_PTR(-ENOENT);
 426         }
 427
 428         read_unlock(&mboxes_lock);
 429
 430         ret = omap_mbox_init(mbox);
 431         if (ret)
 432                 return ERR_PTR(-ENODEV);
 433
 434         return mbox;
 435 }
 436 EXPORT_SYMBOL(omap_mbox_get);
 437
 438 void omap_mbox_put(struct omap_mbox *mbox)
 439 {
 440         omap_mbox_fini(mbox);
 441 }
 442 EXPORT_SYMBOL(omap_mbox_put);
 443
 444 int omap_mbox_register(struct omap_mbox *mbox)
 445 {
 446         int ret = 0;
 447         struct omap_mbox **tmp;
 448
 449         if (!mbox)
 450                 return -EINVAL;
 451         if (mbox->next)
 452                 return -EBUSY;
 453
 454         write_lock(&mboxes_lock);
 455         tmp = find_mboxes(mbox->name);
 456         if (*tmp)
 457                 ret = -EBUSY;
 458         else
 459                 *tmp = mbox;
 460         write_unlock(&mboxes_lock);
 461
 462         return ret;
 463 }
 464 EXPORT_SYMBOL(omap_mbox_register);
 465
 466 int omap_mbox_unregister(struct omap_mbox *mbox)
 467 {
 468         struct omap_mbox **tmp;
 469
 470         write_lock(&mboxes_lock);
 471         tmp = &mboxes;
 472         while (*tmp) {
 473                 if (mbox == *tmp) {
 474                         *tmp = mbox->next;
 475                         mbox->next = NULL;
 476                         write_unlock(&mboxes_lock);
 477                         return 0;
 478                 }
 479                 tmp = &(*tmp)->next;
 480         }
 481         write_unlock(&mboxes_lock);
 482
 483         return -EINVAL;
 484 }
 485 EXPORT_SYMBOL(omap_mbox_unregister);
 486
 487 static int __init omap_mbox_class_init(void)
 488 {
 489         int ret = class_register(&omap_mbox_class);
 490         if (!ret)
 491                 ret = class_create_file(&omap_mbox_class, &class_attr_mbox);
 492
 493         return ret;
 494 }
 495
 496 static void __exit omap_mbox_class_exit(void)
 497 {
 498         class_remove_file(&omap_mbox_class, &class_attr_mbox);
 499         class_unregister(&omap_mbox_class);
 500 }
 501
 502 subsys_initcall(omap_mbox_class_init);
 503 module_exit(omap_mbox_class_exit);
 504
 505 MODULE_LICENSE("GPL");