Treuzell kernel module
===================================
Treuzell is the Breton word for a bridge. This kernel module works as a bridge
between the interface of a Prophesee sensor, such as a dedicated IP instantiated
in a FPGA fabric, or a MIPI CSI interface, and a communication medium more
widely used on computeurs, such as USB3.
The module is split in sevral parts as follow:
## Psee Video
The Prophesee video driver provides methods for register read and write on the
video IP (including the sensor when the IP intergrates the bus master) and get
the event stream from the sensor. Currently, the only supported interface is
Prophesee's video IP directly mapped on AXI, but other implementations, such as
a standard CSI interface for data and an I2C link for register access, should
be developed in the future.
Required properties:
- compatible: should be "psee,video".
- reg: physical base address of FPGA registers and length of memory mapped
region.
- dmas: list of DMA and channel numbers that the driver may use.
- dma-names: identifiers for the DMA channels. The driver will use the channel
called "output" to get the event stream out of the video IP.
Optional properties:
- memory-region: reserved memory to be converted to mem resource and declared
as coherent memory to be used for DMA allocations
Example:
zynq_ps_axi_lite: zynq_ps_axi_lite@a0000000 {
compatible ="psee,video";
reg = <0x0 0xa0000000 0x0 0x40000>;
dmas = <&zynq_processing_system_u_axi_dma 0
&zynq_processing_system_u_axi_dma 1>;
dma-names = "input", "output";
};
## Treuzell USB gadget function
This gadget function works as a consumer for the data provided by the video
interface. On USB, it creates an interface with a vendor-specific class,
implementing a Prophesee proprietary (and yet undocumented) protocol, using
subclass and protocol 0.
The interface provides 2 endpoints for control, and one IN endpoint to stream
data to the host. In alternate config, the streaming endpoint is isochronous.
The control endpoints allow to read and write registers on the video interface
and get various information on the system.