Previously on ACPI platforms, sensors that are intended to be connected
to an IPU device for use with the ipu3-cio2 driver lacking the necessary
connection information in firmware. IPU bridge driver is to connect
sensors to IPU device via software nodes.

Currently IVSC located between IPU device and sensors is available in
existing commercial platforms from multiple OEMs. But the connection
information between them in firmware is also not enough to build V4L2
connection graph. This patch parses the connection properties from the
SSDB buffer in DSDT and build the connection using software nodes.

IVSC driver is based on MEI framework (previously known as HECI), it
has two MEI clients, MEI CSI and MEI ACE. Both clients are used to
communicate messages with IVSC firmware. Linux abstracts MEI client
as a device, whose bus type is MEI. And the device is addressed by a
GUID/UUID which is part of the device name of MEI client. After figured
out MEI CSI via the UUID composed device name, this patch setup the
connection between MEI CSI and IPU, and the connection between MEI CSI
and sensor via software nodes.
Signed-off-by: Wentong Wu <wentong.wu@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>