On Mon, Jul 09, 2018 at 01:08:08PM -0700, Sujeev Dias wrote: > This is the initial skeleton driver for mhi bus stack. MHI Host > Interface is a communication protocol to be used by the host to > control and communcate with modem over a high speed peripheral bus. > This module will allow host to communicate with external devices that > support MHI protocol. > > Signed-off-by: Sujeev Dias <[email protected]> > Reviewed-by: Tony Truong <[email protected]> > Signed-off-by: Siddartha Mohanadoss <[email protected]> > --- > Documentation/00-INDEX | 2 + > Documentation/devicetree/bindings/bus/mhi.txt | 258 ++++++++++++
As Greg said, separate patch. > Documentation/mhi.txt | 235 +++++++++++ > drivers/bus/Kconfig | 8 + > drivers/bus/Makefile | 1 + > drivers/bus/mhi/Makefile | 6 + > drivers/bus/mhi/core/Makefile | 1 + > drivers/bus/mhi/core/mhi_init.c | 538 > ++++++++++++++++++++++++++ > drivers/bus/mhi/core/mhi_internal.h | 238 ++++++++++++ > drivers/bus/mhi/core/mhi_main.c | 122 ++++++ > include/linux/mhi.h | 341 ++++++++++++++++ > include/linux/mod_devicetable.h | 12 + > 12 files changed, 1762 insertions(+) > create mode 100644 Documentation/devicetree/bindings/bus/mhi.txt > create mode 100644 Documentation/mhi.txt > create mode 100644 drivers/bus/mhi/Makefile > create mode 100644 drivers/bus/mhi/core/Makefile > create mode 100644 drivers/bus/mhi/core/mhi_init.c > create mode 100644 drivers/bus/mhi/core/mhi_internal.h > create mode 100644 drivers/bus/mhi/core/mhi_main.c > create mode 100644 include/linux/mhi.h > diff --git a/Documentation/devicetree/bindings/bus/mhi.txt > b/Documentation/devicetree/bindings/bus/mhi.txt > new file mode 100644 > index 0000000..19deb84 > --- /dev/null > +++ b/Documentation/devicetree/bindings/bus/mhi.txt > @@ -0,0 +1,258 @@ > +MHI Host Interface > + > +MHI used by the host to control and communicate with modem over > +high speed peripheral bus. > + > +============== > +Node Structure > +============== > + > +Main node properties: > + > +- mhi,max-channels mhi is not a vendor. mhi-max-channels. Same for rest. Or maybe just drop 'mhi' completely. > + Usage: required > + Value type: <u32> > + Definition: Maximum number of channels supported by this controller > + > +- mhi,timeout > + Usage: optional > + Value type: <u32> > + Definition: Maximum timeout in ms wait for state and cmd completion Needs a unit suffix. > + > +- mhi,use-bb > + Usage: optional > + Value type: <bool> > + Definition: Set true, if PCIe controller does not have full access to host > + DDR, and we're using a dedicated memory pool like cma, or > + carveout pool. Pool must support atomic allocation. How is this related to PCI? "atomic allocation" has nothing to do with bindings. > + > +- mhi,buffer-len > + Usage: optional > + Value type: <bool> > + Definition: MHI automatically pre-allocate buffers for some channel. > + Set the length of buffer size to allocate. If not default > + size MHI_MAX_MTU will be used. > + > +============================ > +mhi channel node properties: > +============================ > + > +- reg > + Usage: required > + Value type: <u32> > + Definition: physical channel number > + > +- label > + Usage: required > + Value type: <string> > + Definition: given name for the channel Why does the user need this? > + > +- mhi,num-elements > + Usage: optional > + Value type: <u32> > + Definition: Number of elements transfer ring support > + > +- mhi,event-ring > + Usage: required > + Value type: <u32> > + Definition: Event ring index associated with this channel > + > +- mhi,chan-dir > + Usage: required > + Value type: <u32> > + Definition: Channel direction as defined by enum dma_data_direction > + 0 = Bidirectional data transfer > + 1 = UL data transfer > + 2 = DL data transfer > + 3 = No direction, not a regular data transfer channel > + > +- mhi,ee > + Usage: required > + Value type: <u32> > + Definition: Channel execution enviornment as defined by enum MHI_EE > + 1 = Bootloader stage > + 2 = AMSS mode > + > +- mhi,pollcfg > + Usage: optional > + Value type: <u32> > + Definition: MHI poll configuration, valid only when burst mode is enabled > + 0 = Use default (device specific) polling configuration > + For UL channels, value specifies the timer to poll MHI context in > + milliseconds. > + For DL channels, the threshold to poll the MHI context in multiple of > + eight ring element. > + > +- mhi,data-type > + Usage: required > + Value type: <u32> > + Definition: Data transfer type accepted as defined by enum MHI_XFER_TYPE > + 0 = accept cpu address for buffer > + 1 = accept skb > + 2 = accept scatterlist > + 3 = offload channel, does not accept any transfer type > + > +- mhi,doorbell-mode > + Usage: required > + Value type: <u32> > + Definition: Channel doorbell mode configuration as defined by enum > + MHI_BRSTMODE > + 2 = burst mode disabled > + 3 = burst mode enabled > + > +- mhi,lpm-notify > + Usage: optional > + Value type: <bool> > + Definition: This channel master require low power mode enter and exit > + notifications from mhi bus master. > + > +- mhi,offload-chan > + Usage: optional > + Value type: <bool> > + Definition: Client managed channel, MHI host only involved in setting up > + the data path, not involved in active data path. > + > +- mhi,db-mode-switch > + Usage: optional > + Value type: <bool> > + Definition: Must switch to doorbell mode whenever MHI M0 state transition > + happens. > + > +- mhi,auto-queue > + Usage: optional > + Value type: <bool> > + Definition: MHI bus driver will pre-allocate buffers for this channel and > + queue to hardware. If set, client not allowed to queue buffers. Valid > + only for downlink direction. > + > +- mhi,auto-start > + Usage: optional > + Value type: <bool> > + Definition: MHI host driver to automatically start channels once mhi device > + driver probe is complete. This should be only set true if initial > + handshake iniaitead by external modem. typo > + > +========================== > +mhi event node properties: > +========================== > + > +- mhi,num-elements > + Usage: required > + Value type: <u32> > + Definition: Number of elements event ring support > + > +- mhi,intmod > + Usage: required > + Value type: <u32> > + Definition: interrupt moderation time in ms > + > +- mhi,msi > + Usage: required > + Value type: <u32> > + Definition: MSI associated with this event ring > + > +- mhi,chan > + Usage: optional > + Value type: <u32> > + Definition: Dedicated channel number, if it's a dedicated event ring > + > +- mhi,priority > + Usage: required > + Value type: <u32> > + Definition: Event ring priority, set to 1 for now > + > +- mhi,brstmode > + Usage: required > + Value type: <u32> > + Definition: Event doorbell mode configuration as defined by > + enum MHI_BRSTMODE > + 2 = burst mode disabled > + 3 = burst mode enabled > + > +- mhi,data-type > + Usage: optional > + Value type: <u32> > + Definition: Type of data this event ring will process as defined > + by enum mhi_er_data_type > + 0 = process data packets (default) > + 1 = process mhi control packets > + > +- mhi,hw-ev > + Usage: optional > + Value type: <bool> > + Definition: Event ring associated with hardware channels > + > +- mhi,client-manage > + Usage: optional > + Value type: <bool> > + Definition: Client manages the event ring (use by napi_poll) > + > +- mhi,offload > + Usage: optional > + Value type: <bool> > + Definition: Event ring associated with offload channel This is a lot of properties. I suspect that many of these should be implied by the modem device or be driver settings. If the modems are PCI devices, then you should be able to determine a lot from the PCI VID/PIDs. I'm not sure that a bus is appropriate here either. This looks like the next layer up. How's it different than a programming model for some ethernet NIC? Rob
