allow creation of multiple arm rpmsg channels

This commit introduces support for accessing multiple channels
through the arm rpmsg driver.
To do this, information connecting rpmsg endpoints, mailbox channels
and mailbox names are stored for each created endpoint.
rpmsg endpoints and now to be created by referring to mailbox
names defined in the device-tree.

Signed-off-by: Morten Borup Petersen <morten.petersen@arm.com>

1 files changed, 60 insertions, 9 deletions

diff --git a/drivers/rpmsg/rpmsg_arm_mailbox.c b/drivers/rpmsg/rpmsg_arm_mailbox.c
index af6c47737d06..1cf7e20142e2 100644
--- a/drivers/rpmsg/rpmsg_arm_mailbox.c
+++ b/drivers/rpmsg/rpmsg_arm_mailbox.c
@@ -25,35 +25,80 @@
 #define RPMSG_ADDR_ANY	0xFFFFFFFF
 #define TX_TIMEOUT	500 /*by half second*/
 
-struct rpmsg_endpoint *eptg;
+struct arm_ept_info {
+	struct rpmsg_channel_info info;
+	struct rpmsg_endpoint *ept;
+	struct mbox_client *cl;
+
+	struct list_head node;
+};
 
-static void message_from_se(struct mbox_client *cl, void *mssg)
+static LIST_HEAD(arm_ept_infos);
+
+static void arm_msg_rx_handler(struct mbox_client *cl, void *mssg)
 {
-	eptg->cb(eptg->rpdev, mssg, 4, eptg->priv, RPMSG_ADDR_ANY);
+	struct arm_ept_info *it = NULL;
+
+	list_for_each_entry(it, &arm_ept_infos, node) {
+		if (it->cl == cl) {
+			struct rpmsg_endpoint *ept = it->ept;
+
+			ept->cb(ept->rpdev, mssg, 4, ept->priv, RPMSG_ADDR_ANY);
+			return;
+		}
+	}
 }
 
 
 static void arm_destroy_ept(struct rpmsg_endpoint *ept)
 {
+	struct arm_ept_info *it = NULL;
+
+	list_for_each_entry(it, &arm_ept_infos, node) {
+		if (it->ept == ept) {
+			list_del(&it->node);
+			kfree(it);
+			break;
+		}
+	}
 	kfree(ept);
 }
 
 static int arm_send(struct rpmsg_endpoint *ept, void *data, int len)
 {
+	struct arm_ept_info *it = NULL;
+	struct arm_ept_info *arm_ept = NULL;
 	struct mbox_client *cl;
 	struct mbox_chan *mbox;
 
+	// Locate registered endpoint
+	list_for_each_entry(it, &arm_ept_infos, node) {
+		if (it->ept == ept) {
+			arm_ept = it;
+			break;
+		}
+	}
+
+	if (arm_ept == NULL) {
+		dev_printk(KERN_ERR, cl->dev,
+			   "RPMsg ARM: Invalid endpoint\n");
+		return -1;
+	}
+
 	cl = kzalloc(sizeof(struct mbox_client), GFP_KERNEL);
 	cl->dev = ept->rpdev->dev.parent;
-	cl->rx_callback = message_from_se;
+	cl->rx_callback = arm_msg_rx_handler;
 	cl->tx_done = NULL; /* operate in blocking mode */
 	cl->tx_block = true;
 	cl->tx_tout = TX_TIMEOUT; /* by half a second */
 	cl->knows_txdone = false; /* depending upon protocol */
+	arm_ept->cl = cl;
 
-	mbox = mbox_request_channel(cl, 0);
-	if (mbox == NULL) {
-		dev_printk(KERN_ERR, cl->dev, "\nCannot get the channel\n");
+	mbox = mbox_request_channel_byname(cl, arm_ept->info.name);
+	if (IS_ERR_OR_NULL(mbox)) {
+		dev_printk(KERN_ERR, cl->dev,
+		 "RPMsg ARM: Cannot get channel by name: '%s'\n",
+		 arm_ept->info.name);
 		return -1;
 	}
 	mbox_send_message(mbox, data);
@@ -71,6 +116,7 @@ static struct rpmsg_endpoint *arm_create_ept(struct rpmsg_device *rpdev,
 		rpmsg_rx_cb_t cb, void *priv, struct rpmsg_channel_info chinfo)
 {
 	struct rpmsg_endpoint *ept;
+	struct arm_ept_info *ept_mbox;
 
 	ept = kzalloc(sizeof(*ept), GFP_KERNEL);
 	if (!ept)
@@ -81,8 +127,13 @@ static struct rpmsg_endpoint *arm_create_ept(struct rpmsg_device *rpdev,
 	ept->cb = cb;
 	ept->priv = priv;
 	ept->ops = &arm_endpoint_ops;
-	eptg = ept;
 
+	// store chinfo for determining destination mailbox when sending
+	ept_mbox = kzalloc(sizeof(*ept_mbox), GFP_KERNEL);
+	ept_mbox->info = chinfo;
+	strncpy(ept_mbox->info.name, chinfo.name, RPMSG_NAME_SIZE);
+	ept_mbox->ept = ept;
+	list_add(&ept_mbox->node, &arm_ept_infos);
 	return ept;
 }
 
@@ -112,7 +163,7 @@ static int client_probe(struct platform_device *pdev)
 	rpdev->ops = &arm_device_ops;
 
 	/* Assign public information to the rpmsg_device */
-	strncpy(rpdev->id.name, RPMSG_NAME, strlen(RPMSG_NAME));
+	memcpy(rpdev->id.name, RPMSG_NAME, strlen(RPMSG_NAME));
 
 	rpdev->dev.parent = dev;
 	rpdev->dev.release = arm_release_device;