LXR linux/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
  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        /* 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
 104static 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
 113static const struct mhi_device_id qcom_mhi_qrtr_id_table[] = {
 114        { .chan = "IPCR" },
 115        {}
 116};
 117MODULE_DEVICE_TABLE(mhi, qcom_mhi_qrtr_id_table);
 118
 119static 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
 130module_mhi_driver(qcom_mhi_qrtr_driver);
 131
 132MODULE_AUTHOR("Chris Lew <clew@codeaurora.org>");
 133MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
 134MODULE_DESCRIPTION("Qualcomm IPC-Router MHI interface driver");
 135MODULE_LICENSE("GPL v2");
 136