mailbox/omap: adapt to the new mailbox framework

The OMAP mailbox driver and its existing clients (remoteproc
for OMAP4+) are adapted to use the generic mailbox framework.

The main changes for the adaptation are:
  - The tasklet used for Tx is replaced with the state machine from
    the generic mailbox framework. The workqueue used for processing
    the received messages stays intact for minimizing the effects on
    the OMAP mailbox clients.
  - The existing exported client API, omap_mbox_get, omap_mbox_put and
    omap_mbox_send_msg are deleted, as the framework provides equivalent
    functionality. A OMAP-specific omap_mbox_request_channel is added
    though to support non-DT way of requesting mailboxes.
  - The OMAP mailbox driver is integrated with the mailbox framework
    through the proper implementations of mbox_chan_ops, except for
    .last_tx_done and .peek_data. The OMAP mailbox driver does not need
    these ops, as it is completely interrupt driven.
  - The OMAP mailbox driver uses a custom of_xlate controller ops that
    allows phandles for the pargs specifier instead of indexing to avoid
    any channel registration order dependencies.
  - The new framework does not support multiple clients operating on a
    single channel, so the reference counting logic is simplified.
  - The remoteproc driver (current client) is adapted to use the new API.
    The notifier callbacks used within this client is replaced with the
    regular callbacks from the newer framework.
  - The exported OMAP mailbox API are limited to omap_mbox_save_ctx,
    omap_mbox_restore_ctx, omap_mbox_enable_irq & omap_mbox_disable_irq,
    with the signature modified to take in the new mbox_chan handle instead
    of the OMAP specific omap_mbox handle. The first 2 will be removed when
    the OMAP mailbox driver is adapted to runtime_pm. The other exported
    API omap_mbox_request_channel will be removed once existing legacy
    users are converted to DT.

Signed-off-by: Suman Anna <s-anna@ti.com>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
diff --git a/drivers/remoteproc/omap_remoteproc.c b/drivers/remoteproc/omap_remoteproc.c
index 5168972..cf92f6e 100644
--- a/drivers/remoteproc/omap_remoteproc.c
+++ b/drivers/remoteproc/omap_remoteproc.c
@@ -27,6 +27,7 @@
 #include <linux/platform_device.h>
 #include <linux/dma-mapping.h>
 #include <linux/remoteproc.h>
+#include <linux/mailbox_client.h>
 #include <linux/omap-mailbox.h>
 
 #include <linux/platform_data/remoteproc-omap.h>
@@ -36,20 +37,19 @@
 
 /**
  * struct omap_rproc - omap remote processor state
- * @mbox: omap mailbox handle
- * @nb: notifier block that will be invoked on inbound mailbox messages
+ * @mbox: mailbox channel handle
+ * @client: mailbox client to request the mailbox channel
  * @rproc: rproc handle
  */
 struct omap_rproc {
-	struct omap_mbox *mbox;
-	struct notifier_block nb;
+	struct mbox_chan *mbox;
+	struct mbox_client client;
 	struct rproc *rproc;
 };
 
 /**
  * omap_rproc_mbox_callback() - inbound mailbox message handler
- * @this: notifier block
- * @index: unused
+ * @client: mailbox client pointer used for requesting the mailbox channel
  * @data: mailbox payload
  *
  * This handler is invoked by omap's mailbox driver whenever a mailbox
@@ -61,13 +61,13 @@
  * that indicates different events. Those values are deliberately very
  * big so they don't coincide with virtqueue indices.
  */
-static int omap_rproc_mbox_callback(struct notifier_block *this,
-					unsigned long index, void *data)
+static void omap_rproc_mbox_callback(struct mbox_client *client, void *data)
 {
-	mbox_msg_t msg = (mbox_msg_t) data;
-	struct omap_rproc *oproc = container_of(this, struct omap_rproc, nb);
+	struct omap_rproc *oproc = container_of(client, struct omap_rproc,
+						client);
 	struct device *dev = oproc->rproc->dev.parent;
 	const char *name = oproc->rproc->name;
+	u32 msg = (u32)data;
 
 	dev_dbg(dev, "mbox msg: 0x%x\n", msg);
 
@@ -84,8 +84,6 @@
 		if (rproc_vq_interrupt(oproc->rproc, msg) == IRQ_NONE)
 			dev_dbg(dev, "no message was found in vqid %d\n", msg);
 	}
-
-	return NOTIFY_DONE;
 }
 
 /* kick a virtqueue */
@@ -96,8 +94,8 @@
 	int ret;
 
 	/* send the index of the triggered virtqueue in the mailbox payload */
-	ret = omap_mbox_msg_send(oproc->mbox, vqid);
-	if (ret)
+	ret = mbox_send_message(oproc->mbox, (void *)vqid);
+	if (ret < 0)
 		dev_err(dev, "omap_mbox_msg_send failed: %d\n", ret);
 }
 
@@ -115,17 +113,22 @@
 	struct platform_device *pdev = to_platform_device(dev);
 	struct omap_rproc_pdata *pdata = pdev->dev.platform_data;
 	int ret;
+	struct mbox_client *client = &oproc->client;
 
 	if (pdata->set_bootaddr)
 		pdata->set_bootaddr(rproc->bootaddr);
 
-	oproc->nb.notifier_call = omap_rproc_mbox_callback;
+	client->dev = dev;
+	client->tx_done = NULL;
+	client->rx_callback = omap_rproc_mbox_callback;
+	client->tx_block = false;
+	client->knows_txdone = false;
 
-	/* every omap rproc is assigned a mailbox instance for messaging */
-	oproc->mbox = omap_mbox_get(pdata->mbox_name, &oproc->nb);
+	oproc->mbox = omap_mbox_request_channel(client, pdata->mbox_name);
 	if (IS_ERR(oproc->mbox)) {
-		ret = PTR_ERR(oproc->mbox);
-		dev_err(dev, "omap_mbox_get failed: %d\n", ret);
+		ret = -EBUSY;
+		dev_err(dev, "mbox_request_channel failed: %ld\n",
+			PTR_ERR(oproc->mbox));
 		return ret;
 	}
 
@@ -136,9 +139,9 @@
 	 * Note that the reply will _not_ arrive immediately: this message
 	 * will wait in the mailbox fifo until the remote processor is booted.
 	 */
-	ret = omap_mbox_msg_send(oproc->mbox, RP_MBOX_ECHO_REQUEST);
-	if (ret) {
-		dev_err(dev, "omap_mbox_get failed: %d\n", ret);
+	ret = mbox_send_message(oproc->mbox, (void *)RP_MBOX_ECHO_REQUEST);
+	if (ret < 0) {
+		dev_err(dev, "mbox_send_message failed: %d\n", ret);
 		goto put_mbox;
 	}
 
@@ -151,7 +154,7 @@
 	return 0;
 
 put_mbox:
-	omap_mbox_put(oproc->mbox, &oproc->nb);
+	mbox_free_channel(oproc->mbox);
 	return ret;
 }
 
@@ -168,7 +171,7 @@
 	if (ret)
 		return ret;
 
-	omap_mbox_put(oproc->mbox, &oproc->nb);
+	mbox_free_channel(oproc->mbox);
 
 	return 0;
 }