[2/2] omap:mailbox-provide multiple reader support

Commit Message

Phil Carmody July 21, 2010, 9:45 a.m. UTC

None

Patch

diff --git a/arch/arm/plat-omap/include/plat/mailbox.h b/arch/arm/plat-omap/include/plat/mailbox.h
index 0486d64..c8e47d8 100644
--- a/arch/arm/plat-omap/include/plat/mailbox.h
+++ b/arch/arm/plat-omap/include/plat/mailbox.h
@@ -68,13 +68,15 @@  struct omap_mbox {
        void                    *priv;

        void                    (*err_notify)(void);
+       atomic_t                use_count;
+       struct blocking_notifier_head   notifier;
 };

 int omap_mbox_msg_send(struct omap_mbox *, mbox_msg_t msg);
 void omap_mbox_init_seq(struct omap_mbox *);

-struct omap_mbox *omap_mbox_get(const char *);
-void omap_mbox_put(struct omap_mbox *);
+struct omap_mbox *omap_mbox_get(const char *, struct notifier_block *nb);
+void omap_mbox_put(struct omap_mbox *, struct notifier_block *nb);

 int omap_mbox_register(struct device *parent, struct omap_mbox *);
 int omap_mbox_unregister(struct omap_mbox *);
diff --git a/arch/arm/plat-omap/mailbox.c b/arch/arm/plat-omap/mailbox.c
index baac315..f9f2af4 100644
--- a/arch/arm/plat-omap/mailbox.c
+++ b/arch/arm/plat-omap/mailbox.c
@@ -149,8 +149,8 @@  static void mbox_rx_work(struct work_struct *work)
                if (unlikely(len != sizeof(msg)))
                        pr_err("%s: kfifo_out anomaly detected\n", __func__);

-               if (mq->callback)
-                       mq->callback((void *)msg);
+               blocking_notifier_call_chain(&mq->mbox->notifier, len,
+                                                       (void *)msg);
        }
 }

@@ -252,28 +252,30 @@  static int omap_mbox_startup(struct omap_mbox *mbox)
                }
        }

-       ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
-                               mbox->name, mbox);
-       if (unlikely(ret)) {
-               printk(KERN_ERR
-                       "failed to register mailbox interrupt:%d\n", ret);
-               goto fail_request_irq;
-       }
+       if (atomic_inc_return(&mbox->use_count) == 1) {
+               ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
+                                       mbox->name, mbox);
+               if (unlikely(ret)) {
+                       printk(KERN_ERR "failed to register mailbox interrupt:"
+                                                               "%d\n", ret);
+                       goto fail_request_irq;
+               }

-       mq = mbox_queue_alloc(mbox, NULL, mbox_tx_tasklet);
-       if (!mq) {
-               ret = -ENOMEM;
-               goto fail_alloc_txq;
-       }
-       mbox->txq = mq;
+               mq = mbox_queue_alloc(mbox, NULL, mbox_tx_tasklet);
+               if (!mq) {
+                       ret = -ENOMEM;
+                       goto fail_alloc_txq;
+               }
+               mbox->txq = mq;

-       mq = mbox_queue_alloc(mbox, mbox_rx_work, NULL);
-       if (!mq) {
-               ret = -ENOMEM;
-               goto fail_alloc_rxq;
+               mq = mbox_queue_alloc(mbox, mbox_rx_work, NULL);
+               if (!mq) {
+                       ret = -ENOMEM;
+                       goto fail_alloc_rxq;
+               }
+               mbox->rxq = mq;
+               mq->mbox = mbox;
        }
-       mbox->rxq = mq;
-
        return 0;

  fail_alloc_rxq:
@@ -281,6 +283,7 @@  static int omap_mbox_startup(struct omap_mbox *mbox)
  fail_alloc_txq:
        free_irq(mbox->irq, mbox);
  fail_request_irq:
+       atomic_dec(&mbox->use_count);
        if (likely(mbox->ops->shutdown)) {
                if (atomic_dec_return(&mbox_refcount) == 0)
                        mbox->ops->shutdown(mbox);
@@ -291,10 +294,12 @@  static int omap_mbox_startup(struct omap_mbox *mbox)

 static void omap_mbox_fini(struct omap_mbox *mbox)
 {
-       mbox_queue_free(mbox->txq);
-       mbox_queue_free(mbox->rxq);

-       free_irq(mbox->irq, mbox);
+       if (atomic_dec_return(&mbox->use_count) == 0) {
+               mbox_queue_free(mbox->txq);
+               mbox_queue_free(mbox->rxq);
+               free_irq(mbox->irq, mbox);
+       }

        if (likely(mbox->ops->shutdown)) {
                if (atomic_dec_return(&mbox_refcount) == 0)
@@ -314,7 +319,7 @@  static struct omap_mbox **find_mboxes(const char *name)
        return p;
 }

-struct omap_mbox *omap_mbox_get(const char *name)
+struct omap_mbox *omap_mbox_get(const char *name, struct notifier_block *nb)
 {
        struct omap_mbox *mbox;
        int ret;
@@ -325,19 +330,21 @@  struct omap_mbox *omap_mbox_get(const char *name)
                spin_unlock(&mboxes_lock);
                return ERR_PTR(-ENOENT);
        }
-
        spin_unlock(&mboxes_lock);

        ret = omap_mbox_startup(mbox);
        if (ret)
                return ERR_PTR(-ENODEV);
+       if (nb)
+               blocking_notifier_chain_register(&mbox->notifier, nb);

        return mbox;
 }
 EXPORT_SYMBOL(omap_mbox_get);

-void omap_mbox_put(struct omap_mbox *mbox)
+void omap_mbox_put(struct omap_mbox *mbox, struct notifier_block *nb)
 {
+       blocking_notifier_chain_unregister(&mbox->notifier, nb);
        omap_mbox_fini(mbox);
 }
 EXPORT_SYMBOL(omap_mbox_put);
@@ -361,6 +368,8 @@  int omap_mbox_register(struct device *parent, struct omap_mbox *mbox)
        }
        *tmp = mbox;
        spin_unlock(&mboxes_lock);
+       BLOCKING_INIT_NOTIFIER_HEAD(&mbox->notifier);
+       atomic_set(&mbox->use_count, 0);

        return 0;