[PATCH v2 0/2] Add QRTR MHI client driver

[PATCH v2 0/2] Add QRTR MHI client driver

[Manivannan Sadhasivam]

Hi Dave,

Here is the series adding MHI client driver support to Qualcomm IPC router
protocol. MHI is a newly added bus to kernel which is used to communicate to
external modems over a physical interface like PCI-E. This driver is used to
transfer the QMI messages between the host processor and external modems over
the "IPCR" channel.

For QRTR, this driver is just another driver acting as a transport layer like
SMD.

Currently this driver is needed to control the QCA6390 WLAN device from ath11k.
The ath11k MHI controller driver will take care of booting up QCA6390 and
bringing it to operating state. Later, this driver will be used to transfer QMI
messages over the MHI-IPCR channel.

The second patch of this series removes the ARCH_QCOM dependency for QRTR. This
is needed because the QRTR driver will be used with x86 machines as well to talk
to devices like QCA6390.

Thanks,
Mani

Changes in v2:

* Added cover letter
* Removed casting of void pointer.

Manivannan Sadhasivam (2):
  net: qrtr: Add MHI transport layer
  net: qrtr: Do not depend on ARCH_QCOM

 net/qrtr/Kconfig  |   8 ++-
 net/qrtr/Makefile |   2 +
 net/qrtr/mhi.c    | 127 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 136 insertions(+), 1 deletion(-)
 create mode 100644 net/qrtr/mhi.c

-- 
2.17.1

[PATCH v2 1/2] net: qrtr: Add MHI transport layer

[Manivannan Sadhasivam]

MHI is the transport layer used for communicating to the external modems.
Hence, this commit adds MHI transport layer support to QRTR for
transferring the QMI messages over IPC Router.

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 net/qrtr/Kconfig  |   7 +++
 net/qrtr/Makefile |   2 +
 net/qrtr/mhi.c    | 127 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 136 insertions(+)
 create mode 100644 net/qrtr/mhi.c

diff --git a/net/qrtr/Kconfig b/net/qrtr/Kconfig
index 63f89cc6e82c..8eb876471564 100644
--- a/net/qrtr/Kconfig
+++ b/net/qrtr/Kconfig
@@ -29,4 +29,11 @@ config QRTR_TUN
 	  implement endpoints of QRTR, for purpose of tunneling data to other
 	  hosts or testing purposes.
 
+config QRTR_MHI
+	tristate "MHI IPC Router channels"
+	depends on MHI_BUS
+	help
+	  Say Y here to support MHI based ipcrouter channels. MHI is the
+	  transport used for communicating to external modems.
+
 endif # QRTR
diff --git a/net/qrtr/Makefile b/net/qrtr/Makefile
index 32d4e923925d..1b1411d158a7 100644
--- a/net/qrtr/Makefile
+++ b/net/qrtr/Makefile
@@ -5,3 +5,5 @@ obj-$(CONFIG_QRTR_SMD) += qrtr-smd.o
 qrtr-smd-y	:= smd.o
 obj-$(CONFIG_QRTR_TUN) += qrtr-tun.o
 qrtr-tun-y	:= tun.o
+obj-$(CONFIG_QRTR_MHI) += qrtr-mhi.o
+qrtr-mhi-y	:= mhi.o
diff --git a/net/qrtr/mhi.c b/net/qrtr/mhi.c
new file mode 100644
index 000000000000..ff0c41467fc1
--- /dev/null
+++ b/net/qrtr/mhi.c
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/mhi.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+
+#include "qrtr.h"
+
+struct qrtr_mhi_dev {
+	struct qrtr_endpoint ep;
+	struct mhi_device *mhi_dev;
+	struct device *dev;
+};
+
+/* From MHI to QRTR */
+static void qcom_mhi_qrtr_dl_callback(struct mhi_device *mhi_dev,
+				      struct mhi_result *mhi_res)
+{
+	struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
+	int rc;
+
+	if (!qdev || mhi_res->transaction_status)
+		return;
+
+	rc = qrtr_endpoint_post(&qdev->ep, mhi_res->buf_addr,
+				mhi_res->bytes_xferd);
+	if (rc == -EINVAL)
+		dev_err(qdev->dev, "invalid ipcrouter packet\n");
+}
+
+/* From QRTR to MHI */
+static void qcom_mhi_qrtr_ul_callback(struct mhi_device *mhi_dev,
+				      struct mhi_result *mhi_res)
+{
+	struct sk_buff *skb = mhi_res->buf_addr;
+
+	if (skb->sk)
+		sock_put(skb->sk);
+	consume_skb(skb);
+}
+
+/* Send data over MHI */
+static int qcom_mhi_qrtr_send(struct qrtr_endpoint *ep, struct sk_buff *skb)
+{
+	struct qrtr_mhi_dev *qdev = container_of(ep, struct qrtr_mhi_dev, ep);
+	int rc;
+
+	rc = skb_linearize(skb);
+	if (rc)
+		goto free_skb;
+
+	rc = mhi_queue_skb(qdev->mhi_dev, DMA_TO_DEVICE, skb, skb->len,
+			   MHI_EOT);
+	if (rc)
+		goto free_skb;
+
+	if (skb->sk)
+		sock_hold(skb->sk);
+
+	return rc;
+
+free_skb:
+	kfree_skb(skb);
+
+	return rc;
+}
+
+static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev,
+			       const struct mhi_device_id *id)
+{
+	struct qrtr_mhi_dev *qdev;
+	int rc;
+
+	qdev = devm_kzalloc(&mhi_dev->dev, sizeof(*qdev), GFP_KERNEL);
+	if (!qdev)
+		return -ENOMEM;
+
+	qdev->mhi_dev = mhi_dev;
+	qdev->dev = &mhi_dev->dev;
+	qdev->ep.xmit = qcom_mhi_qrtr_send;
+
+	dev_set_drvdata(&mhi_dev->dev, qdev);
+	rc = qrtr_endpoint_register(&qdev->ep, QRTR_EP_NID_AUTO);
+	if (rc)
+		return rc;
+
+	dev_dbg(qdev->dev, "Qualcomm MHI QRTR driver probed\n");
+
+	return 0;
+}
+
+static void qcom_mhi_qrtr_remove(struct mhi_device *mhi_dev)
+{
+	struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
+
+	qrtr_endpoint_unregister(&qdev->ep);
+	dev_set_drvdata(&mhi_dev->dev, NULL);
+}
+
+static const struct mhi_device_id qcom_mhi_qrtr_id_table[] = {
+	{ .chan = "IPCR" },
+	{}
+};
+MODULE_DEVICE_TABLE(mhi, qcom_mhi_qrtr_id_table);
+
+static struct mhi_driver qcom_mhi_qrtr_driver = {
+	.probe = qcom_mhi_qrtr_probe,
+	.remove = qcom_mhi_qrtr_remove,
+	.dl_xfer_cb = qcom_mhi_qrtr_dl_callback,
+	.ul_xfer_cb = qcom_mhi_qrtr_ul_callback,
+	.id_table = qcom_mhi_qrtr_id_table,
+	.driver = {
+		.name = "qcom_mhi_qrtr",
+	},
+};
+
+module_mhi_driver(qcom_mhi_qrtr_driver);
+
+MODULE_AUTHOR("Chris Lew <clew@codeaurora.org>");
+MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
+MODULE_DESCRIPTION("Qualcomm IPC-Router MHI interface driver");
+MODULE_LICENSE("GPL v2");
-- 
2.17.1

[PATCH v2 2/2] net: qrtr: Do not depend on ARCH_QCOM

[Manivannan Sadhasivam]

IPC Router protocol is also used by external modems for exchanging the QMI
messages. Hence, it doesn't always depend on Qualcomm platforms. One such
instance is the QCA6390 WLAN device connected to x86 machine.

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 net/qrtr/Kconfig | 1 -
 1 file changed, 1 deletion(-)

diff --git a/net/qrtr/Kconfig b/net/qrtr/Kconfig
index 8eb876471564..f362ca316015 100644
--- a/net/qrtr/Kconfig
+++ b/net/qrtr/Kconfig
@@ -4,7 +4,6 @@
 
 config QRTR
 	tristate "Qualcomm IPC Router support"
-	depends on ARCH_QCOM || COMPILE_TEST
 	---help---
 	  Say Y if you intend to use Qualcomm IPC router protocol.  The
 	  protocol is used to communicate with services provided by other
-- 
2.17.1

Re: [PATCH v2 0/2] Add QRTR MHI client driver

[David Miller]

From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Date: Thu,  7 May 2020 18:23:04 +0530

> Here is the series adding MHI client driver support to Qualcomm IPC router
> protocol. MHI is a newly added bus to kernel which is used to communicate to
> external modems over a physical interface like PCI-E. This driver is used to
> transfer the QMI messages between the host processor and external modems over
> the "IPCR" channel.
> 
> For QRTR, this driver is just another driver acting as a transport layer like
> SMD.
> 
> Currently this driver is needed to control the QCA6390 WLAN device from ath11k.
> The ath11k MHI controller driver will take care of booting up QCA6390 and
> bringing it to operating state. Later, this driver will be used to transfer QMI
> messages over the MHI-IPCR channel.
> 
> The second patch of this series removes the ARCH_QCOM dependency for QRTR. This
> is needed because the QRTR driver will be used with x86 machines as well to talk
> to devices like QCA6390.

Series applied to net-next, thanks.