1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
  4 */
  5
  6#include <linux/mhi.h>
  7#include <linux/mod_devicetable.h>
  8#include <linux/module.h>
  9#include <linux/skbuff.h>
 10#include <net/sock.h>
 11
 12#include "qrtr.h"
 13
 14struct qrtr_mhi_dev {
 15	struct qrtr_endpoint ep;
 16	struct mhi_device *mhi_dev;
 17	struct device *dev;
 18};
 19
 20/* From MHI to QRTR */
 21static void qcom_mhi_qrtr_dl_callback(struct mhi_device *mhi_dev,
 22				      struct mhi_result *mhi_res)
 23{
 24	struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
 25	int rc;
 26
 27	if (!qdev || mhi_res->transaction_status)
 28		return;
 29
 30	rc = qrtr_endpoint_post(&qdev->ep, mhi_res->buf_addr,
 31				mhi_res->bytes_xferd);
 32	if (rc == -EINVAL)
 33		dev_err(qdev->dev, "invalid ipcrouter packet\n");
 34}
 35
 36/* From QRTR to MHI */
 37static void qcom_mhi_qrtr_ul_callback(struct mhi_device *mhi_dev,
 38				      struct mhi_result *mhi_res)
 39{
 40	struct sk_buff *skb = mhi_res->buf_addr;
 41
 42	if (skb->sk)
 43		sock_put(skb->sk);
 44	consume_skb(skb);
 45}
 46
 47/* Send data over MHI */
 48static int qcom_mhi_qrtr_send(struct qrtr_endpoint *ep, struct sk_buff *skb)
 49{
 50	struct qrtr_mhi_dev *qdev = container_of(ep, struct qrtr_mhi_dev, ep);
 51	int rc;
 52
 53	if (skb->sk)
 54		sock_hold(skb->sk);
 55
 56	rc = skb_linearize(skb);
 57	if (rc)
 58		goto free_skb;
 59
 60	rc = mhi_queue_skb(qdev->mhi_dev, DMA_TO_DEVICE, skb, skb->len,
 61			   MHI_EOT);
 62	if (rc)
 63		goto free_skb;
 64
 65	return rc;
 66
 67free_skb:
 68	if (skb->sk)
 69		sock_put(skb->sk);
 70	kfree_skb(skb);
 71
 72	return rc;
 73}
 74
 75static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev,
 76			       const struct mhi_device_id *id)
 77{
 78	struct qrtr_mhi_dev *qdev;
 79	int rc;
 80
 81	qdev = devm_kzalloc(&mhi_dev->dev, sizeof(*qdev), GFP_KERNEL);
 82	if (!qdev)
 83		return -ENOMEM;
 84
 85	qdev->mhi_dev = mhi_dev;
 86	qdev->dev = &mhi_dev->dev;
 87	qdev->ep.xmit = qcom_mhi_qrtr_send;
 88
 89	dev_set_drvdata(&mhi_dev->dev, qdev);
 90	rc = qrtr_endpoint_register(&qdev->ep, QRTR_EP_NID_AUTO);
 91	if (rc)
 92		return rc;
 93
 94	/* start channels */
 95	rc = mhi_prepare_for_transfer_autoqueue(mhi_dev);
 96	if (rc) {
 97		qrtr_endpoint_unregister(&qdev->ep);
 98		return rc;
 99	}
100
101	dev_dbg(qdev->dev, "Qualcomm MHI QRTR driver probed\n");
102
103	return 0;
104}
105
106static void qcom_mhi_qrtr_remove(struct mhi_device *mhi_dev)
107{
108	struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
109
110	qrtr_endpoint_unregister(&qdev->ep);
111	mhi_unprepare_from_transfer(mhi_dev);
112	dev_set_drvdata(&mhi_dev->dev, NULL);
113}
114
115static const struct mhi_device_id qcom_mhi_qrtr_id_table[] = {
116	{ .chan = "IPCR" },
117	{}
118};
119MODULE_DEVICE_TABLE(mhi, qcom_mhi_qrtr_id_table);
120
121static struct mhi_driver qcom_mhi_qrtr_driver = {
122	.probe = qcom_mhi_qrtr_probe,
123	.remove = qcom_mhi_qrtr_remove,
124	.dl_xfer_cb = qcom_mhi_qrtr_dl_callback,
125	.ul_xfer_cb = qcom_mhi_qrtr_ul_callback,
126	.id_table = qcom_mhi_qrtr_id_table,
127	.driver = {
128		.name = "qcom_mhi_qrtr",
129	},
130};
131
132module_mhi_driver(qcom_mhi_qrtr_driver);
133
134MODULE_AUTHOR("Chris Lew <clew@codeaurora.org>");
135MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
136MODULE_DESCRIPTION("Qualcomm IPC-Router MHI interface driver");
137MODULE_LICENSE("GPL v2");