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 (mbox->msg_sender_cb && arg) {
  63                 ret = mbox->msg_sender_cb(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         int ret = 0;
  78
  79         rq = blk_get_request(mbox->txq, WRITE, GFP_ATOMIC);
  80         if (unlikely(!rq)) {
  81                 ret = -ENOMEM;
  82                 goto fail;
  83         }
  84
  85         rq->data = (void *)msg;
  86         blk_insert_request(mbox->txq, rq, 0, arg);
  87  fail:
  88         return ret;
  89 }
  90 EXPORT_SYMBOL(omap_mbox_msg_send);
  91
  92 /*
  93  * Message receiver(workqueue)
  94  */
  95 static void mbox_msg_receiver(struct work_struct *work)
  96 {
  97         struct omap_mbox *mbox =
  98             container_of(work, struct omap_mbox, msg_receive);
  99         struct request_queue *q = mbox->rxq;
 100         struct request *rq;
 101         mbox_msg_t msg;
 102
 103         if (mbox->msg_receive_cb == NULL) {
 104                 sysfs_notify(&mbox->dev.kobj, NULL, "mbox");
 105                 return;
 106         }
 107
 108         while (1) {
 109                 rq = elv_next_request(q);
 110                 if (!rq)
 111                         break;
 112
 113                 msg = (mbox_msg_t)rq->data;
 114
 115                 blkdev_dequeue_request(rq);
 116                 end_that_request_last(rq, 0);
 117
 118                 if (mbox->msg_receive_cb)
 119                         mbox->msg_receive_cb(msg);
 120         }
 121 }
 122
 123 /*
 124  * Mailbox interrupt handler
 125  */
 126 static void mbox_txq_fn(request_queue_t *q)
 127 {
 128         struct omap_mbox *mbox = q->queuedata;
 129         int ret;
 130         struct request *rq;
 131
 132         while ((rq = elv_next_request(q)) != NULL) {
 133                 ret = __mbox_msg_send(mbox, (mbox_msg_t)rq->data, rq->special);
 134                 if (ret) {
 135                         blk_stop_queue(q);
 136                         enable_mbox_irq(mbox, IRQ_TX);
 137                         return;
 138                 }
 139                 blkdev_dequeue_request(rq);
 140                 end_that_request_last(rq, 0);
 141         }
 142 }
 143
 144 static void mbox_rxq_fn(request_queue_t *q)
 145 {
 146         struct request *rq;
 147         struct omap_mbox *mbox = q->queuedata;
 148         mbox_msg_t msg;
 149
 150         while (!mbox_fifo_empty(mbox)) {
 151                 rq = blk_get_request(q, WRITE, GFP_ATOMIC);
 152                 if (unlikely(!rq))
 153                         goto nomem;
 154
 155                 msg = mbox_fifo_read(mbox);
 156                 rq->data = (void *)msg;
 157
 158                 if (unlikely(mbox_seq_test(mbox, msg))) {
 159                         pr_info("mbox: Illegal seq bit!(%08x)\n", msg);
 160                         if (mbox->err_notify)
 161                                 mbox->err_notify();
 162                 }
 163
 164                 blk_insert_request(mbox->rxq, rq, 0, NULL);
 165                 if (mbox->ops->type == OMAP_MBOX_TYPE1)
 166                         break;
 167         }
 168
 169         /* no more messages in the fifo. clear IRQ source. */
 170         ack_mbox_irq(mbox, IRQ_RX);
 171         enable_mbox_irq(mbox, IRQ_RX);
 172  nomem:
 173         queue_work(mbox->workq, &mbox->msg_receive);
 174 }
 175
 176 static irqreturn_t mbox_interrupt(int irq, void *p)
 177 {
 178         struct omap_mbox *mbox = (struct omap_mbox *)p;
 179
 180         if (is_mbox_irq(mbox, IRQ_TX)) {
 181                 disable_mbox_irq(mbox, IRQ_TX);
 182                 ack_mbox_irq(mbox, IRQ_TX);
 183                 blk_start_queue(mbox->txq);
 184         }
 185
 186         if (is_mbox_irq(mbox, IRQ_RX)) {
 187                 disable_mbox_irq(mbox, IRQ_RX);
 188                 blk_start_queue(mbox->rxq);
 189         }
 190
 191         return IRQ_HANDLED;
 192 }
 193
 194 /*
 195  * sysfs files
 196  */
 197 static ssize_t
 198 omap_mbox_write(struct device *dev, struct device_attribute *attr,
 199                 const char * buf, size_t count)
 200 {
 201         int ret;
 202         mbox_msg_t *p = (mbox_msg_t *)buf;
 203         struct omap_mbox *mbox = dev_get_drvdata(dev);
 204
 205         for (; count >= sizeof(mbox_msg_t); count -= sizeof(mbox_msg_t)) {
 206                 ret = omap_mbox_msg_send(mbox, be32_to_cpu(*p), NULL);
 207                 if (ret)
 208                         return -EAGAIN;
 209                 p++;
 210         }
 211
 212         return  (size_t)((char *)p - buf);
 213 }
 214
 215 static ssize_t
 216 omap_mbox_read(struct device *dev, struct device_attribute *attr,
 217                char * buf)
 218 {
 219         struct request *rq;
 220         mbox_msg_t *p = (mbox_msg_t *)buf;
 221         struct omap_mbox *mbox = dev_get_drvdata(dev);
 222         struct request_queue *q = mbox->rxq;
 223
 224         while ((rq = elv_next_request(q)) != NULL) {
 225                 *p = (mbox_msg_t)rq->data;
 226                 blkdev_dequeue_request(rq);
 227                 end_that_request_last(rq, 0);
 228
 229                 if (unlikely(mbox_seq_test(mbox, *p))) {
 230                         pr_info("mbox: Illegal seq bit!(%08x) ignored\n", *p);
 231                         continue;
 232                 }
 233                 p++;
 234         }
 235
 236         pr_debug("%02x %02x %02x %02x\n", buf[0], buf[1], buf[2], buf[3]);
 237
 238         return (size_t)((char *)p - buf);
 239 }
 240
 241 static DEVICE_ATTR(mbox, S_IRUGO | S_IWUSR, omap_mbox_read, omap_mbox_write);
 242
 243 static ssize_t mbox_show(struct class *class, char *buf)
 244 {
 245         return sprintf(buf, "mbox");
 246 }
 247
 248 static CLASS_ATTR(mbox, S_IRUGO, mbox_show, NULL);
 249
 250 static struct class omap_mbox_class = {
 251         .name = "omap_mbox",
 252 };
 253
 254 static int omap_mbox_init(struct omap_mbox *mbox)
 255 {
 256         int ret;
 257         request_queue_t *q;
 258
 259         if (likely(mbox->ops->startup)) {
 260                 ret = mbox->ops->startup(mbox);
 261                 if (unlikely(ret))
 262                         return ret;
 263         }
 264
 265         mbox->dev.class = &omap_mbox_class;
 266         strlcpy(mbox->dev.bus_id, mbox->name, KOBJ_NAME_LEN);
 267         dev_set_drvdata(&mbox->dev, mbox);
 268
 269         ret = device_register(&mbox->dev);
 270         if (unlikely(ret))
 271                 goto fail_device_reg;
 272
 273         ret = device_create_file(&mbox->dev, &dev_attr_mbox);
 274         if (unlikely(ret)) {
 275                 printk(KERN_ERR
 276                        "device_create_file failed: %d\n", ret);
 277                 goto fail_create_mbox;
 278         }
 279
 280         spin_lock_init(&mbox->lock);
 281         INIT_WORK(&mbox->msg_receive, mbox_msg_receiver);
 282
 283         ret = request_irq(mbox->irq, mbox_interrupt, IRQF_DISABLED,
 284                           mbox->name, mbox);
 285         if (unlikely(ret)) {
 286                 printk(KERN_ERR
 287                        "failed to register mailbox interrupt:%d\n", ret);
 288                 goto fail_request_irq;
 289         }
 290         enable_mbox_irq(mbox, IRQ_RX);
 291
 292         q = blk_init_queue(mbox_txq_fn, &mbox->lock);
 293         if (!q)
 294                 goto fail_blkinit_txq;
 295         mbox->txq = q;
 296         q->queuedata = mbox;
 297
 298         q = blk_init_queue(mbox_rxq_fn, &mbox->lock);
 299         if (!q)
 300                 goto fail_blkinit_rxq;
 301         mbox->rxq = q;
 302         q->queuedata = mbox;
 303
 304         return 0;
 305
 306  fail_blkinit_rxq:
 307         blk_cleanup_queue(mbox->txq);
 308  fail_blkinit_txq:
 309         free_irq(mbox->irq, mbox);
 310  fail_request_irq:
 311         device_remove_file(&mbox->dev, &dev_attr_mbox);
 312  fail_create_mbox:
 313         device_unregister(&mbox->dev);
 314  fail_device_reg:
 315         if (unlikely(mbox->ops->shutdown))
 316                 mbox->ops->shutdown(mbox);
 317
 318         return ret;
 319 }
 320
 321 static void omap_mbox_fini(struct omap_mbox *mbox)
 322 {
 323         blk_cleanup_queue(mbox->txq);
 324         blk_cleanup_queue(mbox->rxq);
 325
 326         flush_workqueue(mbox->workq);
 327         destroy_workqueue(mbox->workq);
 328
 329         free_irq(mbox->irq, mbox);
 330         device_remove_file(&mbox->dev, &dev_attr_mbox);
 331         class_unregister(&omap_mbox_class);
 332
 333         if (unlikely(mbox->ops->shutdown))
 334                 mbox->ops->shutdown(mbox);
 335 }
 336
 337 static struct omap_mbox **find_mboxes(const char *name)
 338 {
 339         struct omap_mbox **p;
 340
 341         for (p = &mboxes; *p; p = &(*p)->next) {
 342                 if (strcmp((*p)->name, name) == 0)
 343                         break;
 344         }
 345
 346         return p;
 347 }
 348
 349 struct omap_mbox *omap_mbox_get(const char *name)
 350 {
 351         struct omap_mbox *mbox;
 352         char queue_name[MBOX_NAME_LEN];
 353         int ret;
 354
 355         read_lock(&mboxes_lock);
 356         mbox = *(find_mboxes(name));
 357         if (mbox == NULL) {
 358                 read_unlock(&mboxes_lock);
 359                 return ERR_PTR(-ENOENT);
 360         }
 361
 362         strcpy(queue_name, "mailbox/");
 363         strcat(queue_name, mbox->name);
 364         mbox->workq = create_singlethread_workqueue(queue_name);
 365
 366         read_unlock(&mboxes_lock);
 367
 368         ret = omap_mbox_init(mbox);
 369         if (ret)
 370                 return ERR_PTR(-ENODEV);
 371
 372         return mbox;
 373 }
 374 EXPORT_SYMBOL(omap_mbox_get);
 375
 376 void omap_mbox_put(struct omap_mbox *mbox)
 377 {
 378         omap_mbox_fini(mbox);
 379 }
 380 EXPORT_SYMBOL(omap_mbox_put);
 381
 382 int omap_mbox_register(struct omap_mbox *mbox)
 383 {
 384         int ret = 0;
 385         struct omap_mbox **tmp;
 386
 387         if (!mbox)
 388                 return -EINVAL;
 389         if (mbox->next)
 390                 return -EBUSY;
 391
 392         write_lock(&mboxes_lock);
 393         tmp = find_mboxes(mbox->name);
 394         if (*tmp)
 395                 ret = -EBUSY;
 396         else
 397                 *tmp = mbox;
 398         write_unlock(&mboxes_lock);
 399
 400         return ret;
 401 }
 402 EXPORT_SYMBOL(omap_mbox_register);
 403
 404 int omap_mbox_unregister(struct omap_mbox *mbox)
 405 {
 406         struct omap_mbox **tmp;
 407
 408         write_lock(&mboxes_lock);
 409         tmp = &mboxes;
 410         while (*tmp) {
 411                 if (mbox == *tmp) {
 412                         *tmp = mbox->next;
 413                         mbox->next = NULL;
 414                         write_unlock(&mboxes_lock);
 415                         return 0;
 416                 }
 417                 tmp = &(*tmp)->next;
 418         }
 419         write_unlock(&mboxes_lock);
 420
 421         return -EINVAL;
 422 }
 423 EXPORT_SYMBOL(omap_mbox_unregister);
 424
 425 static int __init omap_mbox_class_init(void)
 426 {
 427         int ret = class_register(&omap_mbox_class);
 428         if (!ret)
 429                 ret = class_create_file(&omap_mbox_class, &class_attr_mbox);
 430
 431         return ret;
 432 }
 433
 434 static void __exit omap_mbox_class_exit(void)
 435 {
 436         class_remove_file(&omap_mbox_class, &class_attr_mbox);
 437         class_unregister(&omap_mbox_class);
 438 }
 439
 440 subsys_initcall(omap_mbox_class_init);
 441 module_exit(omap_mbox_class_exit);
 442
 443 MODULE_LICENSE("GPL");