net/qrtr/mhi.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
0004  */
0005
0006 #include <linux/mhi.h>
0007 #include <linux/mod_devicetable.h>
0008 #include <linux/module.h>
0009 #include <linux/skbuff.h>
0010 #include <net/sock.h>
0011
0012 #include "qrtr.h"
0013
0014 struct qrtr_mhi_dev {
0015     struct qrtr_endpoint ep;
0016     struct mhi_device *mhi_dev;
0017     struct device *dev;
0018 };
0019
0020 /* From MHI to QRTR */
0021 static void qcom_mhi_qrtr_dl_callback(struct mhi_device *mhi_dev,
0022                       struct mhi_result *mhi_res)
0023 {
0024     struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
0025     int rc;
0026
0027     if (!qdev || mhi_res->transaction_status)
0028         return;
0029
0030     rc = qrtr_endpoint_post(&qdev->ep, mhi_res->buf_addr,
0031                 mhi_res->bytes_xferd);
0032     if (rc == -EINVAL)
0033         dev_err(qdev->dev, "invalid ipcrouter packet\n");
0034 }
0035
0036 /* From QRTR to MHI */
0037 static void qcom_mhi_qrtr_ul_callback(struct mhi_device *mhi_dev,
0038                       struct mhi_result *mhi_res)
0039 {
0040     struct sk_buff *skb = mhi_res->buf_addr;
0041
0042     if (skb->sk)
0043         sock_put(skb->sk);
0044     consume_skb(skb);
0045 }
0046
0047 /* Send data over MHI */
0048 static int qcom_mhi_qrtr_send(struct qrtr_endpoint *ep, struct sk_buff *skb)
0049 {
0050     struct qrtr_mhi_dev *qdev = container_of(ep, struct qrtr_mhi_dev, ep);
0051     int rc;
0052
0053     if (skb->sk)
0054         sock_hold(skb->sk);
0055
0056     rc = skb_linearize(skb);
0057     if (rc)
0058         goto free_skb;
0059
0060     rc = mhi_queue_skb(qdev->mhi_dev, DMA_TO_DEVICE, skb, skb->len,
0061                MHI_EOT);
0062     if (rc)
0063         goto free_skb;
0064
0065     return rc;
0066
0067 free_skb:
0068     if (skb->sk)
0069         sock_put(skb->sk);
0070     kfree_skb(skb);
0071
0072     return rc;
0073 }
0074
0075 static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev,
0076                    const struct mhi_device_id *id)
0077 {
0078     struct qrtr_mhi_dev *qdev;
0079     int rc;
0080
0081     qdev = devm_kzalloc(&mhi_dev->dev, sizeof(*qdev), GFP_KERNEL);
0082     if (!qdev)
0083         return -ENOMEM;
0084
0085     qdev->mhi_dev = mhi_dev;
0086     qdev->dev = &mhi_dev->dev;
0087     qdev->ep.xmit = qcom_mhi_qrtr_send;
0088
0089     dev_set_drvdata(&mhi_dev->dev, qdev);
0090     rc = qrtr_endpoint_register(&qdev->ep, QRTR_EP_NID_AUTO);
0091     if (rc)
0092         return rc;
0093
0094     /* start channels */
0095     rc = mhi_prepare_for_transfer_autoqueue(mhi_dev);
0096     if (rc) {
0097         qrtr_endpoint_unregister(&qdev->ep);
0098         return rc;
0099     }
0100
0101     dev_dbg(qdev->dev, "Qualcomm MHI QRTR driver probed\n");
0102
0103     return 0;
0104 }
0105
0106 static void qcom_mhi_qrtr_remove(struct mhi_device *mhi_dev)
0107 {
0108     struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
0109
0110     qrtr_endpoint_unregister(&qdev->ep);
0111     mhi_unprepare_from_transfer(mhi_dev);
0112     dev_set_drvdata(&mhi_dev->dev, NULL);
0113 }
0114
0115 static const struct mhi_device_id qcom_mhi_qrtr_id_table[] = {
0116     { .chan = "IPCR" },
0117     {}
0118 };
0119 MODULE_DEVICE_TABLE(mhi, qcom_mhi_qrtr_id_table);
0120
0121 static struct mhi_driver qcom_mhi_qrtr_driver = {
0122     .probe = qcom_mhi_qrtr_probe,
0123     .remove = qcom_mhi_qrtr_remove,
0124     .dl_xfer_cb = qcom_mhi_qrtr_dl_callback,
0125     .ul_xfer_cb = qcom_mhi_qrtr_ul_callback,
0126     .id_table = qcom_mhi_qrtr_id_table,
0127     .driver = {
0128         .name = "qcom_mhi_qrtr",
0129     },
0130 };
0131
0132 module_mhi_driver(qcom_mhi_qrtr_driver);
0133
0134 MODULE_AUTHOR("Chris Lew <clew@codeaurora.org>");
0135 MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
0136 MODULE_DESCRIPTION("Qualcomm IPC-Router MHI interface driver");
0137 MODULE_LICENSE("GPL v2");