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 */
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 */
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 */
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
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 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
106 static 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
115 static const struct mhi_device_id qcom_mhi_qrtr_id_table[] = {
116 { .chan = "IPCR" },
117 {}
118 };
119 MODULE_DEVICE_TABLE(mhi, qcom_mhi_qrtr_id_table);
120
121 static int __maybe_unused qcom_mhi_qrtr_pm_suspend_late(struct device *dev)
122 {
123 struct mhi_device *mhi_dev = container_of(dev, struct mhi_device, dev);
124 enum mhi_state state;
125
126 state = mhi_get_mhi_state(mhi_dev->mhi_cntrl);
127 /*
128 * If the device is in suspend state, then no need for the
129 * client driver to unprepare the channels.
130 */
131 if (state == MHI_STATE_M3)
132 return 0;
133
134 mhi_unprepare_from_transfer(mhi_dev);
135
136 return 0;
137 }
138
139 static int __maybe_unused qcom_mhi_qrtr_pm_resume_early(struct device *dev)
140 {
141 struct mhi_device *mhi_dev = container_of(dev, struct mhi_device, dev);
142 enum mhi_state state;
143 int rc;
144
145 state = mhi_get_mhi_state(mhi_dev->mhi_cntrl);
146 /*
147 * If the device is in suspend state, we won't unprepare channels
148 * in suspend callback, therefore no need to prepare channels when
149 * resume.
150 */
151 if (state == MHI_STATE_M3)
152 return 0;
153
154 rc = mhi_prepare_for_transfer_autoqueue(mhi_dev);
155 if (rc)
156 dev_err(dev, "failed to prepare for autoqueue transfer %d\n", rc);
157
158 return rc;
159 }
160
161 static const struct dev_pm_ops qcom_mhi_qrtr_pm_ops = {
162 SET_LATE_SYSTEM_SLEEP_PM_OPS(qcom_mhi_qrtr_pm_suspend_late,
163 qcom_mhi_qrtr_pm_resume_early)
164 };
165
166 static struct mhi_driver qcom_mhi_qrtr_driver = {
167 .probe = qcom_mhi_qrtr_probe,
168 .remove = qcom_mhi_qrtr_remove,
169 .dl_xfer_cb = qcom_mhi_qrtr_dl_callback,
170 .ul_xfer_cb = qcom_mhi_qrtr_ul_callback,
171 .id_table = qcom_mhi_qrtr_id_table,
172 .driver = {
173 .name = "qcom_mhi_qrtr",
174 .pm = &qcom_mhi_qrtr_pm_ops,
175 },
176 };
177
178 module_mhi_driver(qcom_mhi_qrtr_driver);
179
180 MODULE_AUTHOR("Chris Lew <clew@codeaurora.org>");
181 MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
182 MODULE_DESCRIPTION("Qualcomm IPC-Router MHI interface driver");
183 MODULE_LICENSE("GPL v2");
184
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