From: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx> Add documentation describing the extentions provided by Version 1 of the Device Feature Header (DFHv1). Signed-off-by: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx> --- Documentation/fpga/dfl.rst | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/Documentation/fpga/dfl.rst b/Documentation/fpga/dfl.rst index 15b670926084..31699b89781e 100644 --- a/Documentation/fpga/dfl.rst +++ b/Documentation/fpga/dfl.rst @@ -561,6 +561,30 @@ new DFL feature via UIO direct access, its feature id should be added to the driver's id_table. +Extending the Device Feature Header - DFHv1 +=========================================== +The current 8 bytes of the Device Feature Header, hereafter referred to as +to DFHv0, provide very little opportunity for the hardware to describe itself +to software. Version 1 of the Device Feature Header (DFHv1) is being introduced +to provide increased flexibility and extensibility to hardware designs using +Device Feature Lists. The list below describes some of the goals behind the +changes in DFHv1: + +* Provide a standardized mechanism for features to describe + parameters/capabilities to software. +* Standardize the use of a GUID for all DFHv1 types. +* Decouple the location of the DFH from the register space of the feature itself. + +Modeled after PCI Capabilities, DFHv1 Parameters provide a mechanism to associate +a list of parameter values to a particular feature. + +With DFHv0, not all features types contained a GUID. DFHv1 makes the GUILD standard +across all types. + +With DFHv0, the register map of a given feature is located immediately following +the DFHv0 in the memory space. With DFHv1, the location of the feature register +map can be specified as an offset to the DFHv1 or as an absolute address. + Open discussion =============== FME driver exports one ioctl (DFL_FPGA_FME_PORT_PR) for partial reconfiguration -- 2.25.1
