xref: /kernel/linux/linux-5.10/net/qrtr/mhi.c (revision 8c2ecf20) 
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	dev_dbg(qdev->dev, "Qualcomm MHI QRTR driver probed\n");
95
96	return 0;
97}
98
99static void qcom_mhi_qrtr_remove(struct mhi_device *mhi_dev)
100{
101	struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
102
103	qrtr_endpoint_unregister(&qdev->ep);
104	dev_set_drvdata(&mhi_dev->dev, NULL);
105}
106
107static const struct mhi_device_id qcom_mhi_qrtr_id_table[] = {
108	{ .chan = "IPCR" },
109	{}
110};
111MODULE_DEVICE_TABLE(mhi, qcom_mhi_qrtr_id_table);
112
113static struct mhi_driver qcom_mhi_qrtr_driver = {
114	.probe = qcom_mhi_qrtr_probe,
115	.remove = qcom_mhi_qrtr_remove,
116	.dl_xfer_cb = qcom_mhi_qrtr_dl_callback,
117	.ul_xfer_cb = qcom_mhi_qrtr_ul_callback,
118	.id_table = qcom_mhi_qrtr_id_table,
119	.driver = {
120		.name = "qcom_mhi_qrtr",
121	},
122};
123
124module_mhi_driver(qcom_mhi_qrtr_driver);
125
126MODULE_AUTHOR("Chris Lew <clew@codeaurora.org>");
127MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
128MODULE_DESCRIPTION("Qualcomm IPC-Router MHI interface driver");
129MODULE_LICENSE("GPL v2");
130