[PATCH V4 16/16] net: iosm: infrastructure
From: M Chetan Kumar <hidden>
Date: 2021-06-08 17:06:44
Also in:
netdev
Subsystem:
documentation, intel wwan iosm driver, networking drivers, networking [general], the rest, wwan drivers · Maintainers:
Jonathan Corbet, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Loic Poulain, Sergey Ryazanov
1) Kconfig & Makefile changes for IOSM Driver compilation. 2) Add IOSM Driver documentation. 3) Modified MAINTAINER file for IOSM Driver addition. Signed-off-by: M Chetan Kumar <redacted> --- v4: Adapt to wwan subsystem rtnet_link framework. v3: * Clean-up driver/net Kconfig & Makefile (Changes available as part of wwan subsystem). * Removed NET dependency key word from iosm Kconfig. * Removed IOCTL section from documentation. v2: * Moved driver documentation to RsT file. * Modified if_link.h file to support link type iosm. --- .../networking/device_drivers/index.rst | 1 + .../networking/device_drivers/wwan/index.rst | 18 ++++ .../networking/device_drivers/wwan/iosm.rst | 96 +++++++++++++++++++ MAINTAINERS | 7 ++ drivers/net/wwan/Kconfig | 12 +++ drivers/net/wwan/Makefile | 1 + drivers/net/wwan/iosm/Makefile | 26 +++++ 7 files changed, 161 insertions(+) create mode 100644 Documentation/networking/device_drivers/wwan/index.rst create mode 100644 Documentation/networking/device_drivers/wwan/iosm.rst create mode 100644 drivers/net/wwan/iosm/Makefile
diff --git a/Documentation/networking/device_drivers/index.rst b/Documentation/networking/device_drivers/index.rst
index d8279de7bf25..3a5a1d46e77e 100644
--- a/Documentation/networking/device_drivers/index.rst
+++ b/Documentation/networking/device_drivers/index.rst@@ -18,6 +18,7 @@ Contents: qlogic/index wan/index wifi/index + wwan/index .. only:: subproject and html
diff --git a/Documentation/networking/device_drivers/wwan/index.rst b/Documentation/networking/device_drivers/wwan/index.rst
new file mode 100644
index 000000000000..1cb8c7371401
--- /dev/null
+++ b/Documentation/networking/device_drivers/wwan/index.rst@@ -0,0 +1,18 @@ +.. SPDX-License-Identifier: GPL-2.0-only + +WWAN Device Drivers +=================== + +Contents: + +.. toctree:: + :maxdepth: 2 + + iosm + +.. only:: subproject and html + + Indices + ======= + + * :ref:`genindex`
diff --git a/Documentation/networking/device_drivers/wwan/iosm.rst b/Documentation/networking/device_drivers/wwan/iosm.rst
new file mode 100644
index 000000000000..b83a8a239c22
--- /dev/null
+++ b/Documentation/networking/device_drivers/wwan/iosm.rst@@ -0,0 +1,96 @@ +.. SPDX-License-Identifier: GPL-2.0-only + +.. Copyright (C) 2020-21 Intel Corporation + +.. _iosm_driver_doc: + +=========================================== +IOSM Driver for Intel M.2 PCIe based Modems +=========================================== +The IOSM (IPC over Shared Memory) driver is a WWAN PCIe host driver developed +for linux or chrome platform for data exchange over PCIe interface between +Host platform & Intel M.2 Modem. The driver exposes interface conforming to the +MBIM protocol [1]. Any front end application ( eg: Modem Manager) could easily +manage the MBIM interface to enable data communication towards WWAN. + +Basic usage +=========== +MBIM functions are inactive when unmanaged. The IOSM driver only provides a +userspace interface MBIM "WWAN PORT" representing MBIM control channel and does +not play any role in managing the functionality. It is the job of a userspace +application to detect port enumeration and enable MBIM functionality. + +Examples of few such userspace application are: +- mbimcli (included with the libmbim [2] library), and +- Modem Manager [3] + +Management Applications to carry out below required actions for establishing +MBIM IP session: +- open the MBIM control channel +- configure network connection settings +- connect to network +- configure IP network interface + +Management application development +================================== +The driver and userspace interfaces are described below. The MBIM protocol is +described in [1] Mobile Broadband Interface Model v1.0 Errata-1. + +MBIM control channel userspace ABI +---------------------------------- + +/dev/wwan0p3MBIM character device +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +The driver exposes an MBIM interface to the MBIM function by implementing +MBIM WWAN Port. The userspace end of the control channel pipe is a +/dev/wwan0p3MBIM character device. Application shall use this interface for +MBIM protocol communication. + +Fragmentation +~~~~~~~~~~~~~ +The userspace application is responsible for all control message fragmentation +and defragmentation as per MBIM specification. + +/dev/wwan0p3MBIM write() +~~~~~~~~~~~~~~~~~~~~~ +The MBIM control messages from the management application must not exceed the +negotiated control message size. + +/dev/wwan0p3MBIM read() +~~~~~~~~~~~~~~~~~~~~ +The management application must accept control messages of up the negotiated +control message size. + +MBIM data channel userspace ABI +------------------------------- + +wwan0-X network device +~~~~~~~~~~~~~~~~~~~~ +The IOSM driver exposes IP link interface "wwan0-X" of type "wwan" for IP +traffic. Iproute network utility is used for creating "wwan0-X" network +interface and for associating it with MBIM IP session. The Driver supports +upto 8 IP sessions for simultaneous IP communication. + +The userspace management application is responsible for creating new IP link +prior to establishing MBIM IP session where the SessionId is greater than 0. + +For example, creating new IP link for a MBIM IP session with SessionId 1: + + ip link add dev wwan0-1 parentdev-name wwan0 type wwan linkid 1 + +The driver will automatically map the "wwan0-1" network device to MBIM IP +session 1. + +References +========== +[1] "MBIM (Mobile Broadband Interface Model) Errata-1" + - https://www.usb.org/document-library/ + +[2] libmbim - "a glib-based library for talking to WWAN modems and + devices which speak the Mobile Interface Broadband Model (MBIM) + protocol" + - http://www.freedesktop.org/wiki/Software/libmbim/ + +[3] Modem Manager - "a DBus-activated daemon which controls mobile + broadband (2G/3G/4G) devices and connections" + - http://www.freedesktop.org/wiki/Software/ModemManager/
diff --git a/MAINTAINERS b/MAINTAINERS
index b706dd20ff2b..52f1fc58f33b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS@@ -9452,6 +9452,13 @@ L: Dell.Client.Kernel@dell.com S: Maintained F: drivers/platform/x86/intel-wmi-thunderbolt.c +INTEL WWAN IOSM DRIVER +M: M Chetan Kumar <m.chetan.kumar@intel.com> +M: Intel Corporation <linuxwwan@intel.com> +L: netdev@vger.kernel.org +S: Maintained +F: drivers/net/wwan/iosm/ + INTEL(R) TRACE HUB M: Alexander Shishkin <alexander.shishkin@linux.intel.com> S: Supported
diff --git a/drivers/net/wwan/Kconfig b/drivers/net/wwan/Kconfig
index 7ad1920120bc..d91bc646706e 100644
--- a/drivers/net/wwan/Kconfig
+++ b/drivers/net/wwan/Kconfig@@ -34,4 +34,16 @@ config MHI_WWAN_CTRL To compile this driver as a module, choose M here: the module will be called mhi_wwan_ctrl. +config IOSM + tristate "IOSM Driver for Intel M.2 WWAN Device" + select WWAN_CORE + depends on INTEL_IOMMU + help + This driver enables Intel M.2 WWAN Device communication. + + If you have one of those Intel M.2 WWAN Modules and wish to use it in + Linux say Y/M here. + + If unsure, say N. + endif # WWAN
diff --git a/drivers/net/wwan/Makefile b/drivers/net/wwan/Makefile
index 556cd90958ca..5ff6725943da 100644
--- a/drivers/net/wwan/Makefile
+++ b/drivers/net/wwan/Makefile@@ -7,3 +7,4 @@ obj-$(CONFIG_WWAN_CORE) += wwan.o wwan-objs += wwan_core.o obj-$(CONFIG_MHI_WWAN_CTRL) += mhi_wwan_ctrl.o +obj-$(CONFIG_IOSM) += iosm/
diff --git a/drivers/net/wwan/iosm/Makefile b/drivers/net/wwan/iosm/Makefile
new file mode 100644
index 000000000000..cdeeb9357af6
--- /dev/null
+++ b/drivers/net/wwan/iosm/Makefile@@ -0,0 +1,26 @@ +# SPDX-License-Identifier: (GPL-2.0-only) +# +# Copyright (C) 2020-21 Intel Corporation. +# + +iosm-y = \ + iosm_ipc_task_queue.o \ + iosm_ipc_imem.o \ + iosm_ipc_imem_ops.o \ + iosm_ipc_mmio.o \ + iosm_ipc_port.o \ + iosm_ipc_wwan.o \ + iosm_ipc_uevent.o \ + iosm_ipc_pm.o \ + iosm_ipc_pcie.o \ + iosm_ipc_irq.o \ + iosm_ipc_chnl_cfg.o \ + iosm_ipc_protocol.o \ + iosm_ipc_protocol_ops.o \ + iosm_ipc_mux.o \ + iosm_ipc_mux_codec.o + +obj-$(CONFIG_IOSM) := iosm.o + +# compilation flags +ccflags-y += -DDEBUG
--
2.25.1