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
14 struct 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 */
qcom_mhi_qrtr_dl_callback(struct mhi_device * mhi_dev,struct mhi_result * mhi_res)21 static 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 */
qcom_mhi_qrtr_ul_callback(struct mhi_device * mhi_dev,struct mhi_result * mhi_res)37 static 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 */
qcom_mhi_qrtr_send(struct qrtr_endpoint * ep,struct sk_buff * skb)48 static 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
67 free_skb:
68 if (skb->sk)
69 sock_put(skb->sk);
70 kfree_skb(skb);
71
72 return rc;
73 }
74
qcom_mhi_qrtr_probe(struct mhi_device * mhi_dev,const struct mhi_device_id * id)75 static 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 /* start channels */
82 rc = mhi_prepare_for_transfer(mhi_dev);
83 if (rc)
84 return rc;
85
86 qdev = devm_kzalloc(&mhi_dev->dev, sizeof(*qdev), GFP_KERNEL);
87 if (!qdev)
88 return -ENOMEM;
89
90 qdev->mhi_dev = mhi_dev;
91 qdev->dev = &mhi_dev->dev;
92 qdev->ep.xmit = qcom_mhi_qrtr_send;
93
94 dev_set_drvdata(&mhi_dev->dev, qdev);
95 rc = qrtr_endpoint_register(&qdev->ep, QRTR_EP_NID_AUTO);
96 if (rc)
97 return rc;
98
99 dev_dbg(qdev->dev, "Qualcomm MHI QRTR driver probed\n");
100
101 return 0;
102 }
103
qcom_mhi_qrtr_remove(struct mhi_device * mhi_dev)104 static void qcom_mhi_qrtr_remove(struct mhi_device *mhi_dev)
105 {
106 struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
107
108 qrtr_endpoint_unregister(&qdev->ep);
109 mhi_unprepare_from_transfer(mhi_dev);
110 dev_set_drvdata(&mhi_dev->dev, NULL);
111 }
112
113 static const struct mhi_device_id qcom_mhi_qrtr_id_table[] = {
114 { .chan = "IPCR" },
115 {}
116 };
117 MODULE_DEVICE_TABLE(mhi, qcom_mhi_qrtr_id_table);
118
119 static struct mhi_driver qcom_mhi_qrtr_driver = {
120 .probe = qcom_mhi_qrtr_probe,
121 .remove = qcom_mhi_qrtr_remove,
122 .dl_xfer_cb = qcom_mhi_qrtr_dl_callback,
123 .ul_xfer_cb = qcom_mhi_qrtr_ul_callback,
124 .id_table = qcom_mhi_qrtr_id_table,
125 .driver = {
126 .name = "qcom_mhi_qrtr",
127 },
128 };
129
130 module_mhi_driver(qcom_mhi_qrtr_driver);
131
132 MODULE_AUTHOR("Chris Lew <clew@codeaurora.org>");
133 MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
134 MODULE_DESCRIPTION("Qualcomm IPC-Router MHI interface driver");
135 MODULE_LICENSE("GPL v2");
136
