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         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");