Hello Wentong, 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 ? > 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 ? > 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
