1 files changed, 469 insertions, 0 deletions

diff --git a/drivers/mailbox/omap-mailbox.c b/drivers/mailbox/omap-mailbox.c
new file mode 100644
index 000000000000..d79a646b9042
--- /dev/null
+++ b/drivers/mailbox/omap-mailbox.c
@@ -0,0 +1,469 @@
+/*
+ * OMAP mailbox driver
+ *
+ * Copyright (C) 2006-2009 Nokia Corporation. All rights reserved.
+ *
+ * Contact: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/kfifo.h>
+#include <linux/err.h>
+#include <linux/notifier.h>
+#include <linux/module.h>
+
+#include "omap-mbox.h"
+
+static struct omap_mbox **mboxes;
+
+static int mbox_configured;
+static DEFINE_MUTEX(mbox_configured_lock);
+
+static unsigned int mbox_kfifo_size = CONFIG_OMAP_MBOX_KFIFO_SIZE;
+module_param(mbox_kfifo_size, uint, S_IRUGO);
+MODULE_PARM_DESC(mbox_kfifo_size, "Size of omap's mailbox kfifo (bytes)");
+
+/* Mailbox FIFO handle functions */
+static inline mbox_msg_t mbox_fifo_read(struct omap_mbox *mbox)
+{
+        return mbox->ops->fifo_read(mbox);
+}
+static inline void mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
+{
+        mbox->ops->fifo_write(mbox, msg);
+}
+static inline int mbox_fifo_empty(struct omap_mbox *mbox)
+{
+        return mbox->ops->fifo_empty(mbox);
+}
+static inline int mbox_fifo_full(struct omap_mbox *mbox)
+{
+        return mbox->ops->fifo_full(mbox);
+}
+
+/* Mailbox IRQ handle functions */
+static inline void ack_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+{
+        if (mbox->ops->ack_irq)
+                mbox->ops->ack_irq(mbox, irq);
+}
+static inline int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+{
+        return mbox->ops->is_irq(mbox, irq);
+}
+
+/*
+ * message sender
+ */
+static int __mbox_poll_for_space(struct omap_mbox *mbox)
+{
+        int ret = 0, i = 1000;
+
+        while (mbox_fifo_full(mbox)) {
+                if (mbox->ops->type == OMAP_MBOX_TYPE2)
+                        return -1;
+                if (--i == 0)
+                        return -1;
+                udelay(1);
+        }
+        return ret;
+}
+
+int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
+{
+        struct omap_mbox_queue *mq = mbox->txq;
+        int ret = 0, len;
+
+        spin_lock_bh(&mq->lock);
+
+        if (kfifo_avail(&mq->fifo) < sizeof(msg)) {
+                ret = -ENOMEM;
+                goto out;
+        }
+
+        if (kfifo_is_empty(&mq->fifo) && !__mbox_poll_for_space(mbox)) {
+                mbox_fifo_write(mbox, msg);
+                goto out;
+        }
+
+        len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
+        WARN_ON(len != sizeof(msg));
+
+        tasklet_schedule(&mbox->txq->tasklet);
+
+out:
+        spin_unlock_bh(&mq->lock);
+        return ret;
+}
+EXPORT_SYMBOL(omap_mbox_msg_send);
+
+void omap_mbox_save_ctx(struct omap_mbox *mbox)
+{
+        if (!mbox->ops->save_ctx) {
+                dev_err(mbox->dev, "%s:\tno save\n", __func__);
+                return;
+        }
+
+        mbox->ops->save_ctx(mbox);
+}
+EXPORT_SYMBOL(omap_mbox_save_ctx);
+
+void omap_mbox_restore_ctx(struct omap_mbox *mbox)
+{
+        if (!mbox->ops->restore_ctx) {
+                dev_err(mbox->dev, "%s:\tno restore\n", __func__);
+                return;
+        }
+
+        mbox->ops->restore_ctx(mbox);
+}
+EXPORT_SYMBOL(omap_mbox_restore_ctx);
+
+void omap_mbox_enable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+{
+        mbox->ops->enable_irq(mbox, irq);
+}
+EXPORT_SYMBOL(omap_mbox_enable_irq);
+
+void omap_mbox_disable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+{
+        mbox->ops->disable_irq(mbox, irq);
+}
+EXPORT_SYMBOL(omap_mbox_disable_irq);
+
+static void mbox_tx_tasklet(unsigned long tx_data)
+{
+        struct omap_mbox *mbox = (struct omap_mbox *)tx_data;
+        struct omap_mbox_queue *mq = mbox->txq;
+        mbox_msg_t msg;
+        int ret;
+
+        while (kfifo_len(&mq->fifo)) {
+                if (__mbox_poll_for_space(mbox)) {
+                        omap_mbox_enable_irq(mbox, IRQ_TX);
+                        break;
+                }
+
+                ret = kfifo_out(&mq->fifo, (unsigned char *)&msg,
+                                                                sizeof(msg));
+                WARN_ON(ret != sizeof(msg));
+
+                mbox_fifo_write(mbox, msg);
+        }
+}
+
+/*
+ * Message receiver(workqueue)
+ */
+static void mbox_rx_work(struct work_struct *work)
+{
+        struct omap_mbox_queue *mq =
+                        container_of(work, struct omap_mbox_queue, work);
+        mbox_msg_t msg;
+        int len;
+
+        while (kfifo_len(&mq->fifo) >= sizeof(msg)) {
+                len = kfifo_out(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
+                WARN_ON(len != sizeof(msg));
+
+                blocking_notifier_call_chain(&mq->mbox->notifier, len,
+                                                                (void *)msg);
+                spin_lock_irq(&mq->lock);
+                if (mq->full) {
+                        mq->full = false;
+                        omap_mbox_enable_irq(mq->mbox, IRQ_RX);
+                }
+                spin_unlock_irq(&mq->lock);
+        }
+}
+
+/*
+ * Mailbox interrupt handler
+ */
+static void __mbox_tx_interrupt(struct omap_mbox *mbox)
+{
+        omap_mbox_disable_irq(mbox, IRQ_TX);
+        ack_mbox_irq(mbox, IRQ_TX);
+        tasklet_schedule(&mbox->txq->tasklet);
+}
+
+static void __mbox_rx_interrupt(struct omap_mbox *mbox)
+{
+        struct omap_mbox_queue *mq = mbox->rxq;
+        mbox_msg_t msg;
+        int len;
+
+        while (!mbox_fifo_empty(mbox)) {
+                if (unlikely(kfifo_avail(&mq->fifo) < sizeof(msg))) {
+                        omap_mbox_disable_irq(mbox, IRQ_RX);
+                        mq->full = true;
+                        goto nomem;
+                }
+
+                msg = mbox_fifo_read(mbox);
+
+                len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
+                WARN_ON(len != sizeof(msg));
+
+                if (mbox->ops->type == OMAP_MBOX_TYPE1)
+                        break;
+        }
+
+        /* no more messages in the fifo. clear IRQ source. */
+        ack_mbox_irq(mbox, IRQ_RX);
+nomem:
+        schedule_work(&mbox->rxq->work);
+}
+
+static irqreturn_t mbox_interrupt(int irq, void *p)
+{
+        struct omap_mbox *mbox = p;
+
+        if (is_mbox_irq(mbox, IRQ_TX))
+                __mbox_tx_interrupt(mbox);
+
+        if (is_mbox_irq(mbox, IRQ_RX))
+                __mbox_rx_interrupt(mbox);
+
+        return IRQ_HANDLED;
+}
+
+static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
+                                        void (*work) (struct work_struct *),
+                                        void (*tasklet)(unsigned long))
+{
+        struct omap_mbox_queue *mq;
+
+        mq = kzalloc(sizeof(struct omap_mbox_queue), GFP_KERNEL);
+        if (!mq)
+                return NULL;
+
+        spin_lock_init(&mq->lock);
+
+        if (kfifo_alloc(&mq->fifo, mbox_kfifo_size, GFP_KERNEL))
+                goto error;
+
+        if (work)
+                INIT_WORK(&mq->work, work);
+
+        if (tasklet)
+                tasklet_init(&mq->tasklet, tasklet, (unsigned long)mbox);
+        return mq;
+error:
+        kfree(mq);
+        return NULL;
+}
+
+static void mbox_queue_free(struct omap_mbox_queue *q)
+{
+        kfifo_free(&q->fifo);
+        kfree(q);
+}
+
+static int omap_mbox_startup(struct omap_mbox *mbox)
+{
+        int ret = 0;
+        struct omap_mbox_queue *mq;
+
+        mutex_lock(&mbox_configured_lock);
+        if (!mbox_configured++) {
+                if (likely(mbox->ops->startup)) {
+                        ret = mbox->ops->startup(mbox);
+                        if (unlikely(ret))
+                                goto fail_startup;
+                } else
+                        goto fail_startup;
+        }
+
+        if (!mbox->use_count++) {
+                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;
+                }
+                mbox->rxq = mq;
+                mq->mbox = mbox;
+                ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
+                                                        mbox->name, mbox);
+                if (unlikely(ret)) {
+                        pr_err("failed to register mailbox interrupt:%d\n",
+                                                                        ret);
+                        goto fail_request_irq;
+                }
+
+                omap_mbox_enable_irq(mbox, IRQ_RX);
+        }
+        mutex_unlock(&mbox_configured_lock);
+        return 0;
+
+fail_request_irq:
+        mbox_queue_free(mbox->rxq);
+fail_alloc_rxq:
+        mbox_queue_free(mbox->txq);
+fail_alloc_txq:
+        if (mbox->ops->shutdown)
+                mbox->ops->shutdown(mbox);
+        mbox->use_count--;
+fail_startup:
+        mbox_configured--;
+        mutex_unlock(&mbox_configured_lock);
+        return ret;
+}
+
+static void omap_mbox_fini(struct omap_mbox *mbox)
+{
+        mutex_lock(&mbox_configured_lock);
+
+        if (!--mbox->use_count) {
+                omap_mbox_disable_irq(mbox, IRQ_RX);
+                free_irq(mbox->irq, mbox);
+                tasklet_kill(&mbox->txq->tasklet);
+                flush_work(&mbox->rxq->work);
+                mbox_queue_free(mbox->txq);
+                mbox_queue_free(mbox->rxq);
+        }
+
+        if (likely(mbox->ops->shutdown)) {
+                if (!--mbox_configured)
+                        mbox->ops->shutdown(mbox);
+        }
+
+        mutex_unlock(&mbox_configured_lock);
+}
+
+struct omap_mbox *omap_mbox_get(const char *name, struct notifier_block *nb)
+{
+        struct omap_mbox *_mbox, *mbox = NULL;
+        int i, ret;
+
+        if (!mboxes)
+                return ERR_PTR(-EINVAL);
+
+        for (i = 0; (_mbox = mboxes[i]); i++) {
+                if (!strcmp(_mbox->name, name)) {
+                        mbox = _mbox;
+                        break;
+                }
+        }
+
+        if (!mbox)
+                return ERR_PTR(-ENOENT);
+
+        if (nb)
+                blocking_notifier_chain_register(&mbox->notifier, nb);
+
+        ret = omap_mbox_startup(mbox);
+        if (ret) {
+                blocking_notifier_chain_unregister(&mbox->notifier, nb);
+                return ERR_PTR(-ENODEV);
+        }
+
+        return mbox;
+}
+EXPORT_SYMBOL(omap_mbox_get);
+
+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);
+
+static struct class omap_mbox_class = { .name = "mbox", };
+
+int omap_mbox_register(struct device *parent, struct omap_mbox **list)
+{
+        int ret;
+        int i;
+
+        mboxes = list;
+        if (!mboxes)
+                return -EINVAL;
+
+        for (i = 0; mboxes[i]; i++) {
+                struct omap_mbox *mbox = mboxes[i];
+                mbox->dev = device_create(&omap_mbox_class,
+                                parent, 0, mbox, "%s", mbox->name);
+                if (IS_ERR(mbox->dev)) {
+                        ret = PTR_ERR(mbox->dev);
+                        goto err_out;
+                }
+
+                BLOCKING_INIT_NOTIFIER_HEAD(&mbox->notifier);
+        }
+        return 0;
+
+err_out:
+        while (i--)
+                device_unregister(mboxes[i]->dev);
+        return ret;
+}
+EXPORT_SYMBOL(omap_mbox_register);
+
+int omap_mbox_unregister(void)
+{
+        int i;
+
+        if (!mboxes)
+                return -EINVAL;
+
+        for (i = 0; mboxes[i]; i++)
+                device_unregister(mboxes[i]->dev);
+        mboxes = NULL;
+        return 0;
+}
+EXPORT_SYMBOL(omap_mbox_unregister);
+
+static int __init omap_mbox_init(void)
+{
+        int err;
+
+        err = class_register(&omap_mbox_class);
+        if (err)
+                return err;
+
+        /* kfifo size sanity check: alignment and minimal size */
+        mbox_kfifo_size = ALIGN(mbox_kfifo_size, sizeof(mbox_msg_t));
+        mbox_kfifo_size = max_t(unsigned int, mbox_kfifo_size,
+                                                        sizeof(mbox_msg_t));
+
+        return 0;
+}
+subsys_initcall(omap_mbox_init);
+
+static void __exit omap_mbox_exit(void)
+{
+        class_unregister(&omap_mbox_class);
+}
+module_exit(omap_mbox_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
+MODULE_AUTHOR("Toshihiro Kobayashi");
+MODULE_AUTHOR("Hiroshi DOYU");