net: Add Qualcomm IPC router

Add an implementation of Qualcomm's IPC router protocol, used to
communicate with service providing remote processors.

Signed-off-by: Courtney Cavin <courtney.cavin@sonymobile.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
[bjorn: Cope with 0 being a valid node id and implement RTM_NEWADDR]
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/qrtr/smd.c b/net/qrtr/smd.c
new file mode 100644
index 0000000..84ebce7
--- /dev/null
+++ b/net/qrtr/smd.c
@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2015, Sony Mobile Communications Inc.
+ * Copyright (c) 2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only 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.
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/soc/qcom/smd.h>
+
+#include "qrtr.h"
+
+struct qrtr_smd_dev {
+	struct qrtr_endpoint ep;
+	struct qcom_smd_channel *channel;
+};
+
+/* from smd to qrtr */
+static int qcom_smd_qrtr_callback(struct qcom_smd_device *sdev,
+				  const void *data, size_t len)
+{
+	struct qrtr_smd_dev *qdev = dev_get_drvdata(&sdev->dev);
+	int rc;
+
+	if (!qdev)
+		return -EAGAIN;
+
+	rc = qrtr_endpoint_post(&qdev->ep, data, len);
+	if (rc == -EINVAL) {
+		dev_err(&sdev->dev, "invalid ipcrouter packet\n");
+		/* return 0 to let smd drop the packet */
+		rc = 0;
+	}
+
+	return rc;
+}
+
+/* from qrtr to smd */
+static int qcom_smd_qrtr_send(struct qrtr_endpoint *ep, struct sk_buff *skb)
+{
+	struct qrtr_smd_dev *qdev = container_of(ep, struct qrtr_smd_dev, ep);
+	int rc;
+
+	rc = skb_linearize(skb);
+	if (rc)
+		goto out;
+
+	rc = qcom_smd_send(qdev->channel, skb->data, skb->len);
+
+out:
+	if (rc)
+		kfree_skb(skb);
+	else
+		consume_skb(skb);
+	return rc;
+}
+
+static int qcom_smd_qrtr_probe(struct qcom_smd_device *sdev)
+{
+	struct qrtr_smd_dev *qdev;
+	int rc;
+
+	qdev = devm_kzalloc(&sdev->dev, sizeof(*qdev), GFP_KERNEL);
+	if (!qdev)
+		return -ENOMEM;
+
+	qdev->channel = sdev->channel;
+	qdev->ep.xmit = qcom_smd_qrtr_send;
+
+	rc = qrtr_endpoint_register(&qdev->ep, QRTR_EP_NID_AUTO);
+	if (rc)
+		return rc;
+
+	dev_set_drvdata(&sdev->dev, qdev);
+
+	dev_dbg(&sdev->dev, "Qualcomm SMD QRTR driver probed\n");
+
+	return 0;
+}
+
+static void qcom_smd_qrtr_remove(struct qcom_smd_device *sdev)
+{
+	struct qrtr_smd_dev *qdev = dev_get_drvdata(&sdev->dev);
+
+	qrtr_endpoint_unregister(&qdev->ep);
+
+	dev_set_drvdata(&sdev->dev, NULL);
+}
+
+static const struct qcom_smd_id qcom_smd_qrtr_smd_match[] = {
+	{ "IPCRTR" },
+	{}
+};
+
+static struct qcom_smd_driver qcom_smd_qrtr_driver = {
+	.probe = qcom_smd_qrtr_probe,
+	.remove = qcom_smd_qrtr_remove,
+	.callback = qcom_smd_qrtr_callback,
+	.smd_match_table = qcom_smd_qrtr_smd_match,
+	.driver = {
+		.name = "qcom_smd_qrtr",
+		.owner = THIS_MODULE,
+	},
+};
+
+module_qcom_smd_driver(qcom_smd_qrtr_driver);
+
+MODULE_DESCRIPTION("Qualcomm IPC-Router SMD interface driver");
+MODULE_LICENSE("GPL v2");