diff --git a/drivers/bus/mhi/ep/Kconfig b/drivers/bus/mhi/ep/Kconfig index 90ab3b040672..9edb81b39890 100644 --- a/drivers/bus/mhi/ep/Kconfig +++ b/drivers/bus/mhi/ep/Kconfig @@ -8,3 +8,5 @@ config MHI_BUS_EP MHI_BUS_EP implements the MHI protocol for the endpoint devices, such as SDX55 modem connected to the host machine over PCIe. + +source "drivers/bus/mhi/ep/clients/Kconfig" diff --git a/drivers/bus/mhi/ep/Makefile b/drivers/bus/mhi/ep/Makefile index aad85f180b70..ab36ef2a40ab 100644 --- a/drivers/bus/mhi/ep/Makefile +++ b/drivers/bus/mhi/ep/Makefile @@ -1,2 +1,3 @@ obj-$(CONFIG_MHI_BUS_EP) += mhi_ep.o mhi_ep-y := main.o mmio.o ring.o sm.o +obj-y += clients/ diff --git a/drivers/bus/mhi/ep/clients/Kconfig b/drivers/bus/mhi/ep/clients/Kconfig new file mode 100644 index 000000000000..4cf27184058c --- /dev/null +++ b/drivers/bus/mhi/ep/clients/Kconfig @@ -0,0 +1,16 @@ +# SPDX-License-Identifier: GPL-2.0 + +config MHI_BUS_EP_LOOPBACK + tristate "MHI Endpoint LOOPBACK client driver" + depends on MHI_BUS_EP + help + MHI Endpoint LOOPBACK client driver that binds to the MHI LOOPBACK + channel as defined in the MHI specification. The LOOPBACK channel is + implemented by MHI-based endpoint devices (modems, WLAN) in the field, + where the endpoint firmware echoes back whatever the host sends. + + This driver receives data on the uplink channel and echoes it back on + the downlink channel for testing the MHI endpoint data path. + + To compile this driver as a module, choose M here. The module + will be called mhi_ep_loopback. diff --git a/drivers/bus/mhi/ep/clients/Makefile b/drivers/bus/mhi/ep/clients/Makefile new file mode 100644 index 000000000000..71dc91cc63b0 --- /dev/null +++ b/drivers/bus/mhi/ep/clients/Makefile @@ -0,0 +1,2 @@ +obj-$(CONFIG_MHI_BUS_EP_LOOPBACK) += mhi_ep_loopback.o +mhi_ep_loopback-y += loopback.o diff --git a/drivers/bus/mhi/ep/clients/loopback.c b/drivers/bus/mhi/ep/clients/loopback.c new file mode 100644 index 000000000000..c7452428d0b7 --- /dev/null +++ b/drivers/bus/mhi/ep/clients/loopback.c @@ -0,0 +1,126 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. + */ + +#include +#include +#include + +struct mhi_ep_loopback { + struct workqueue_struct *wq; + struct mhi_ep_device *mdev; +}; + +struct mhi_ep_loopback_work { + struct mhi_ep_device *mdev; + struct work_struct work; + void *buf; + size_t len; +}; + +static void mhi_ep_loopback_work_handler(struct work_struct *work) +{ + struct mhi_ep_loopback_work *mhi_ep_lb_work = container_of(work, + struct mhi_ep_loopback_work, work); + int ret; + + ret = mhi_ep_queue_buf(mhi_ep_lb_work->mdev, mhi_ep_lb_work->buf, + mhi_ep_lb_work->len); + if (ret) { + dev_err(&mhi_ep_lb_work->mdev->dev, "Failed to queue buffer: %d\n", ret); + kfree(mhi_ep_lb_work->buf); + } + + kfree(mhi_ep_lb_work); +} + +static void mhi_ep_loopback_ul_callback(struct mhi_ep_device *mhi_dev, + struct mhi_result *mhi_res) +{ + struct mhi_ep_loopback *mhi_ep_lb = dev_get_drvdata(&mhi_dev->dev); + struct mhi_ep_loopback_work *mhi_ep_lb_work; + void *buf; + + if (!mhi_ep_lb) + return; + + if (!mhi_res->transaction_status) { + if (!mhi_res->bytes_xferd) + return; + + buf = kmemdup(mhi_res->buf_addr, mhi_res->bytes_xferd, GFP_KERNEL); + if (!buf) + return; + + mhi_ep_lb_work = kmalloc_obj(*mhi_ep_lb_work, GFP_KERNEL); + if (!mhi_ep_lb_work) { + kfree(buf); + return; + } + + INIT_WORK(&mhi_ep_lb_work->work, mhi_ep_loopback_work_handler); + mhi_ep_lb_work->mdev = mhi_dev; + mhi_ep_lb_work->buf = buf; + mhi_ep_lb_work->len = mhi_res->bytes_xferd; + + queue_work(mhi_ep_lb->wq, &mhi_ep_lb_work->work); + } +} + +static void mhi_ep_loopback_dl_callback(struct mhi_ep_device *mhi_dev, + struct mhi_result *mhi_res) +{ + kfree(mhi_res->buf_addr); +} + +static int mhi_ep_loopback_probe(struct mhi_ep_device *mhi_dev, const struct mhi_device_id *id) +{ + struct mhi_ep_loopback *mhi_ep_lb; + + mhi_ep_lb = devm_kzalloc(&mhi_dev->dev, sizeof(*mhi_ep_lb), GFP_KERNEL); + if (!mhi_ep_lb) + return -ENOMEM; + + mhi_ep_lb->wq = alloc_ordered_workqueue("mhi_ep_loopback", WQ_MEM_RECLAIM); + if (!mhi_ep_lb->wq) { + dev_err(&mhi_dev->dev, "Failed to create workqueue\n"); + return -ENOMEM; + } + + mhi_ep_lb->mdev = mhi_dev; + dev_set_drvdata(&mhi_dev->dev, mhi_ep_lb); + + return 0; +} + +static void mhi_ep_loopback_remove(struct mhi_ep_device *mhi_dev) +{ + struct mhi_ep_loopback *mhi_ep_lb = dev_get_drvdata(&mhi_dev->dev); + + destroy_workqueue(mhi_ep_lb->wq); +} + +static const struct mhi_device_id mhi_ep_loopback_id_table[] = { + { .chan = "LOOPBACK" }, + { } +}; +MODULE_DEVICE_TABLE(mhi, mhi_ep_loopback_id_table); + +static struct mhi_ep_driver mhi_ep_loopback_driver = { + .probe = mhi_ep_loopback_probe, + .remove = mhi_ep_loopback_remove, + .dl_xfer_cb = mhi_ep_loopback_dl_callback, + .ul_xfer_cb = mhi_ep_loopback_ul_callback, + .id_table = mhi_ep_loopback_id_table, + .driver = { + .name = "mhi_ep_loopback", + }, +}; + +module_mhi_ep_driver(mhi_ep_loopback_driver); + +MODULE_AUTHOR("Krishna Chaitanya Chundru "); +MODULE_AUTHOR("Sumit Kumar "); +MODULE_DESCRIPTION("MHI Endpoint Loopback driver"); +MODULE_LICENSE("GPL");