net/qrtr/mhi.c

   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         rc = skb_linearize(skb);
  54         if (rc)
  55                 goto free_skb;
  56
  57         rc = mhi_queue_skb(qdev->mhi_dev, DMA_TO_DEVICE, skb, skb->len,
  58                            MHI_EOT);
  59         if (rc)
  60                 goto free_skb;
  61
  62         if (skb->sk)
  63                 sock_hold(skb->sk);
  64
  65         return rc;
  66
  67 free_skb:
  68         kfree_skb(skb);
  69
  70         return rc;
  71 }
  72
  73 static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev,
  74                                const struct mhi_device_id *id)
  75 {
  76         struct qrtr_mhi_dev *qdev;
  77         int rc;
  78
  79         /* start channels */
  80         rc = mhi_prepare_for_transfer(mhi_dev);
  81         if (rc)
  82                 return rc;
  83
  84         qdev = devm_kzalloc(&mhi_dev->dev, sizeof(*qdev), GFP_KERNEL);
  85         if (!qdev)
  86                 return -ENOMEM;
  87
  88         qdev->mhi_dev = mhi_dev;
  89         qdev->dev = &mhi_dev->dev;
  90         qdev->ep.xmit = qcom_mhi_qrtr_send;
  91
  92         dev_set_drvdata(&mhi_dev->dev, qdev);
  93         rc = qrtr_endpoint_register(&qdev->ep, QRTR_EP_NID_AUTO);
  94         if (rc)
  95                 return rc;
  96
  97         dev_dbg(qdev->dev, "Qualcomm MHI QRTR driver probed\n");
  98
  99         return 0;
 100 }
 101
 102 static void qcom_mhi_qrtr_remove(struct mhi_device *mhi_dev)
 103 {
 104         struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
 105
 106         qrtr_endpoint_unregister(&qdev->ep);
 107         mhi_unprepare_from_transfer(mhi_dev);
 108         dev_set_drvdata(&mhi_dev->dev, NULL);
 109 }
 110
 111 static const struct mhi_device_id qcom_mhi_qrtr_id_table[] = {
 112         { .chan = "IPCR" },
 113         {}
 114 };
 115 MODULE_DEVICE_TABLE(mhi, qcom_mhi_qrtr_id_table);
 116
 117 static struct mhi_driver qcom_mhi_qrtr_driver = {
 118         .probe = qcom_mhi_qrtr_probe,
 119         .remove = qcom_mhi_qrtr_remove,
 120         .dl_xfer_cb = qcom_mhi_qrtr_dl_callback,
 121         .ul_xfer_cb = qcom_mhi_qrtr_ul_callback,
 122         .id_table = qcom_mhi_qrtr_id_table,
 123         .driver = {
 124                 .name = "qcom_mhi_qrtr",
 125         },
 126 };
 127
 128 module_mhi_driver(qcom_mhi_qrtr_driver);
 129
 130 MODULE_AUTHOR("Chris Lew <clew@codeaurora.org>");
 131 MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
 132 MODULE_DESCRIPTION("Qualcomm IPC-Router MHI interface driver");
 133 MODULE_LICENSE("GPL v2");