I am looking for advice regarding the construction of a device driver for a MIPI CSI2 imager (a Sony IMX241) that is connected to a MIPI<->Parallel converter (Toshiba TC358748) wired into a parallel interface on a Soc (a Microchip/Atmel SAMAD2x device.) The Sony imager is controlled and configured via I2C, as is the Toshiba converter. I could write a single driver that configures both devices and treats them as a single device that just happens to use 2 i2c addresses. I could use the i2c_new_dummy() API to construct the device abstraction for the second physical device at probe time for the first physical device. Or I could do something smarter (or at least different), specifying the two devices independently via my device tree file, perhaps linking them together via "port" nodes. Currently, I use the "port" node concept to link an i2c imager to the Image System Controller (isc) node in the SAMA5 device. Perhaps that generalizes to a chain of nodes linked together... I don't know. I'm also not sure how these two devices might play into V4L2's "subdev" concept. Are they separate, independent sub devices of the ISC, or are they a single sub device. Any thoughts, intuition, pointers to existing code that addresses questions such as these, would be welcome. Thanks. --wpd
