CSIdrivers

CSIdrivers are software components that manage camera sensor interfaces in computing platforms. They implement the interface between image sensors that use the Camera Serial Interface (CSI), most commonly CSI-2, and the host processor. CSIdrivers are typically platform- and vendor-specific, delivered as kernel modules or drivers within an operating system's multimedia stack. They handle sensor initialization, clock and power management, lane configuration, and data routing to memory.

Core responsibilities include sensor enumeration and configuration over I2C or CCI, sensor power sequencing, MIPI D-PHY (or C-PHY) lane setup, and data capture and streaming to DMA buffers. They integrate with higher-level video subsystems such as V4L2 in Linux or Windows Imaging to provide a usable video capture interface. CSIdrivers also provide error handling, frame synchronization, and support for features exposed by sensors, such as auto exposure, white balance, and binning.

Architectural context varies by platform. In Linux, CSI drivers are typically part of the media controller framework and connect subdevices representing sensors, PHYs, and bridges, feeding data into video pipelines via V4L2. On other platforms, CSIdrivers may be integrated into vendor-specific SoC stacks or Windows imaging subsystems. The drivers often work in concert with sensor drivers, clock and power managers, and data path components to ensure reliable, real-time image capture.

Development and maintenance emphasize conformance with CSI-2 and its physical layer specifications, robust handling of clocking and bandwidth, and thorough testing with real sensors and test patterns. Proper calibration and error reporting are essential for reliable image capture across devices.