Hi Aleksander, > > The IOSM (IPC over Shared Memory) driver is a PCIe host driver > > implemented 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. Any front end application ( > > eg: Modem Manager) could easily manage the MBIM interface to enable > data communication towards WWAN. > > > > Intel M.2 modem uses 2 BAR regions. The first region is dedicated to > > Doorbell register for IRQs and the second region is used as scratchpad > > area for book keeping modem execution stage details along with host > > system shared memory region context details. The upper edge of the > > driver exposes the control and data channels for user space > > application interaction. At lower edge these data and control channels > > are associated to pipes. The pipes are lowest level interfaces used > > over PCIe as a logical channel for message exchange. A single channel maps > to UL and DL pipe and are initialized on device open. > > > > On UL path, driver copies application sent data to SKBs associate it > > with transfer descriptor and puts it on to ring buffer for DMA > > transfer. Once information has been updated in shared memory region, > > host gives a Doorbell to modem to perform DMA and modem uses MSI to > communicate back to host. > > For receiving data in DL path, SKBs are pre-allocated during pipe open > > and transfer descriptors are given to modem for DMA transfer. > > > > The driver exposes two types of ports, namely "wwanctrl", a char > > device node which is used for MBIM control operation and "INMx",(x = > > 0,1,2..7) network interfaces for IP data communication. > > Is there any plan to integrate this driver in the new "wwan" subsystem so > that the character device for MBIM control is exposed in the same format > (i.e. same name rules and such) as with the MHI driver? > Yes, we are working on it. The next version of driver would have these adaptation to expose MBIM "WWAN Port". Regards, Chetan
