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"); 134