> -----Original Message----- > From: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> > Sent: Friday, February 17, 2023 7:12 PM > > Hello Wentong, > > On Fri, Feb 17, 2023 at 06:20:10AM +0000, Wu, Wentong wrote: > > On Wednesday, February 15, 2023 5:43 PM, Laurent Pinchart wrote: > > > On Mon, Feb 13, 2023 at 10:23:44AM +0800, Wentong Wu wrote: > > > > Intel Visual Sensing Controller (IVSC), codenamed "Clover Falls", > > > > is a companion chip designed to provide secure and low power > > > > vision capability to IA platforms. IVSC is available in existing > > > > commercial platforms from multiple OEMs. > > > > > > > > The primary use case of IVSC is to bring in context awareness. > > > > IVSC interfaces directly with the platform main camera sensor via > > > > a CSI-2 link and processes the image data with the embedded AI > > > > engine. The detected events are sent over I2C to ISH (Intel Sensor > > > > Hub) for additional data fusion from multiple sensors. The fusion > > > > results are used to implement advanced use cases like: > > > > - Face detection to unlock screen > > > > - Detect user presence to manage backlight setting or waking up > > > > system > > > > > > Do you have plan to support these features in the ivsc driver in the future ? > > > > Not sure, but the first step is to upstream this driver. > > Sure, no problem. > > > > > Since the Image Processing Unit(IPU) used on the host processor > > > > needs to configure the CSI-2 link in normal camera usages, the > > > > CSI-2 link and camera sensor can only be used in > > > > mutually-exclusive ways by host IPU and IVSC. By default the IVSC > > > > owns the CSI-2 link and camera sensor. The IPU driver can take > > > > ownership of the CSI-2 link and camera sensor using interfaces provided by > this IVSC driver. > > > > > > > > Switching ownership requires an interface with two different > > > > hardware modules inside IVSC. The software interface to these > > > > modules is via Intel MEI (The Intel Management Engine) commands. > > > > These two hardware modules have two different MEI UUIDs to > > > > enumerate. These hardware modules are: > > > > - ACE (Algorithm Context Engine): This module is for algorithm > > > > computing when IVSC owns camera sensor. Also ACE module controls > > > > camera sensor's ownership. This hardware module is used to set > > > > ownership of camera sensor. > > > > - CSI (Camera Serial Interface): This module is used to route > > > > camera sensor data either to IVSC or to host for IPU driver and application. > > > > > > > > IVSC also provides a privacy mode. When privacy mode is turned on, > > > > camera sensor can't be used. This means that both ACE and host IPU > > > > can't get image data. And when this mode is turned on, host IPU > > > > driver is informed via a registered callback, so that user can be notified. > > > > > > How does the privacy mode work, and how can the user trust that the > > > closed- source IVSC and IME firmwares will honour the privacy settings ? > > > > No camera data will be allowed to go through IVSC, and then there will > > be no data on IVSC CSI transmitter side. > > But how can I be sure that the IVSC will not use the camera behind my back, if > it's all controlled through a closed-source firmware ? Actually I don't know how to answer your question, but this is guaranteed though we have no plan to open-source the firmware. > > > > > In summary, to acquire ownership of camera by IPU driver, first > > > > ACE module needs to be informed of ownership and then to setup > > > > MIPI CSI-2 link for the camera sensor and IPU. > > > > > > > > Implementation: > > > > There are two different drivers to handle ACE and CSI hardware > > > > modules inside IVSC. > > > > - mei_csi: MEI client driver to send commands and receive notifications > from CSI module. > > > > - mei_ace: MEI client driver to send commands and get status from ACE > module. > > > > Interface is exposed via ivsc.h to acquire and release camera > > > > sensor and > > > > CSI-2 link. > > > > > > Do I understand correctly, from your diagram below, that the > > > communication between the IME and IVSC goes through SPI ? > > > > > > > Below diagram shows connections of IVSC/ISH/IPU/Camera sensor. > > > > ------------------------------------------------------------------ > > > > ----------- > > > > | Host Processor | > > > > | | > > > > | ----------------- ----------------- --------------- | > > > > | | | | | | | I2C | > > > > | | IPU | | ISH | |camera driver|--| | > > > > | | | | | | | | | > > > > | ----------------- ----------------- --------------- | | > > > > | | | | | | > > > > | | | --------------- | | > > > > | | | | | | | > > > > | | | | IVSC driver | | | > > > > | | | | | | | > > > > | | | --------------- | | > > > > | | | | | | > > > > ----------------|-----------------------|----------------------|---------|--- > > > > | CSI | I2C |SPI | > > > > | | | | > > > > ----------------|-----------------------|---------------- | | > > > > | IVSC | | | | > > > > | | | | | > > > > | ----------------- ----------------- | | | > > > > | | | | | | | | > > > > | | CSI | | ACE | |------| | > > > > | | | | | | | > > > > | ----------------- ----------------- | | > > > > | | | I2C | | > > > > ----------------|-----------------------|---------------- | > > > > | CSI | | > > > > | | | > > > > -------------------------------- | > > > > | | I2C | > > > > | camera sensor |-----------------------------| > > > > | | > > > > -------------------------------- > > > > > > > > Wentong Wu (3): > > > > media: pci: intel: ivsc: Add CSI submodule > > > > media: pci: intel: ivsc: Add ACE submodule > > > > media: pci: intel: ivsc: Add acquire/release API for ivsc > > > > > > > > drivers/media/pci/Kconfig | 1 + > > > > drivers/media/pci/intel/Makefile | 2 + > > > > drivers/media/pci/intel/ivsc/Kconfig | 12 + > > > > drivers/media/pci/intel/ivsc/Makefile | 7 + > > > > drivers/media/pci/intel/ivsc/ivsc.c | 84 +++++ > > > > drivers/media/pci/intel/ivsc/mei_ace.c | 472 > > > > +++++++++++++++++++++++++ drivers/media/pci/intel/ivsc/mei_ace.h > > > > |> 36 ++ drivers/media/pci/intel/ivsc/mei_csi.c | 342 > > > > ++++++++++++++++++ drivers/media/pci/intel/ivsc/mei_csi.h | 60 ++++ > > > > include/linux/ivsc.h | 74 ++++ > > > > 10 files changed, 1090 insertions(+) create mode 100644 > > > > drivers/media/pci/intel/ivsc/Kconfig > > > > create mode 100644 drivers/media/pci/intel/ivsc/Makefile > > > > create mode 100644 drivers/media/pci/intel/ivsc/ivsc.c > > > > create mode 100644 drivers/media/pci/intel/ivsc/mei_ace.c > > > > create mode 100644 drivers/media/pci/intel/ivsc/mei_ace.h > > > > create mode 100644 drivers/media/pci/intel/ivsc/mei_csi.c > > > > create mode 100644 drivers/media/pci/intel/ivsc/mei_csi.h > > > > create mode 100644 include/linux/ivsc.h > > -- > Regards, > > Laurent Pinchart
