net: wwan: Add MHI MBIM network driver

Add new wwan driver for MBIM over MHI. MBIM is a transport protocol
for IP packets, allowing packet aggregation and muxing. Initially
designed for USB bus, it is also exposed through MHI bus for QCOM
based PCIe wwan modems.

This driver supports the new wwan rtnetlink interface for multi-link
management and has been tested with Quectel EM120R-GL M2 module.
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/wwan/Kconfig

@@ -38,6 +38,18 @@ config MHI_WWAN_CTRL
 	  To compile this driver as a module, choose M here: the module will be
 	  called mhi_wwan_ctrl.
 
+config MHI_WWAN_MBIM
+        tristate "MHI WWAN MBIM network driver for QCOM-based PCIe modems"
+        depends on MHI_BUS
+        help
+          MHI WWAN MBIM is a WWAN network driver for QCOM-based PCIe modems.
+          It implements MBIM over MHI, for IP data aggregation and muxing.
+          A default wwan0 network interface is created for MBIM data session
+          ID 0. Additional links can be created via wwan rtnetlink type.
+
+          To compile this driver as a module, choose M here: the module will be
+          called mhi_wwan_mbim.
+
 config RPMSG_WWAN_CTRL
 	tristate "RPMSG WWAN control driver"
 	depends on RPMSG

drivers/net/wwan/Makefile

@@ -9,5 +9,6 @@ wwan-objs += wwan_core.o
 obj-$(CONFIG_WWAN_HWSIM) += wwan_hwsim.o
 
 obj-$(CONFIG_MHI_WWAN_CTRL) += mhi_wwan_ctrl.o
+obj-$(CONFIG_MHI_WWAN_MBIM) += mhi_wwan_mbim.o
 obj-$(CONFIG_RPMSG_WWAN_CTRL) += rpmsg_wwan_ctrl.o
 obj-$(CONFIG_IOSM) += iosm/