[PATCH v4 1/4] Documentation: fpga: dfl: Add documentation for DFHv1

[matthew . gerlach]

From: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>

Add documentation describing the extensions provided by Version
1 of the Device Feature Header (DFHv1).

Signed-off-by: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
---
v4: Remove marketing speak and separate v0 and v1 descriptions.
    Fix errors reported by "make htmldocs".

v3: no change

v2: s/GUILD/GUID/
    add picture
---
 Documentation/fpga/dfl.rst | 96 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)

diff --git a/Documentation/fpga/dfl.rst b/Documentation/fpga/dfl.rst
index 15b670926084..12365be435a8 100644
--- a/Documentation/fpga/dfl.rst
+++ b/Documentation/fpga/dfl.rst
@@ -561,6 +561,102 @@ new DFL feature via UIO direct access, its feature id should be added to the
 driver's id_table.
 
 
+Device Feature Header - Version 0
+===========================================
+The format of Version 0 of a Device Feature Header (DFH) is shown below::
+
+    +-----------------------------------------------------------------------+
+    |63 Type 60|59 DFH VER 52|51 Rsvd 41|40 EOL|39 Next 16|15 VER 12|11 ID 0| 0x00
+    +-----------------------------------------------------------------------+
+    |63                                 GUID_L                             0| 0x08
+    +-----------------------------------------------------------------------+
+    |63                                 GUID_H                             0| 0x10
+    +-----------------------------------------------------------------------+
+
+Offset 0x00
+Type - The type of DFH (e.g. FME, AFU, or private feature).
+DFH VER - The version of the DFH.
+Rsvd - Currently unused.
+EOL - Set if this DFH is the end of the Device Feature List (DFL).
+Next - The offset of the next DFH in the DFL from the start of the DFH.
+If EOL is set, Next refers to size of mmio for last feature in the list.
+ID - If Type field is 'private feature', then ID of the private feature.
+
+Offset 0x08
+GUID_L - Least significant 64 bits of a 128 bit Globally Unique Identifier
+if Type is FME or AFU.
+
+Offset 0x10
+GUID_H - Most significant 64 bits of a 128 bit Globally Unique Identifier
+if Type is FME or AFU.
+
+
+Device Feature Header - Version 1
+===========================================
+The format of Version 1 of a Device Feature Header (DFH) is shown below::
+
+    +-----------------------------------------------------------------------+
+    |63 Type 60|59 DFH VER 52|51 Rsvd 41|40 EOL|39 Next 16|15 VER 12|11 ID 0| 0x00
+    +-----------------------------------------------------------------------+
+    |63                                 GUID_L                             0| 0x08
+    +-----------------------------------------------------------------------+
+    |63                                 GUID_H                             0| 0x10
+    +-----------------------------------------------------------------------+
+    |63                 Address/Offset                            1|  Rel  0| 0x18
+    +-----------------------------------------------------------------------+
+    |63        Reg Size       32|Params 31|30 Group    16|15 Instance      0| 0x20
+    +-----------------------------------------------------------------------+
+    |63 Next      34|RSV33|EOP32|31 Param Version 16|15 Param ID           0| 0x28
+    +-----------------------------------------------------------------------+
+    |63                 Parameter Data                                     0| 0x30
+    +-----------------------------------------------------------------------+
+
+                                  ...
+
+    +-----------------------------------------------------------------------+
+    |63 Next parameter offset 32|31 Param Version 16|15 Param ID           0|
+    +-----------------------------------------------------------------------+
+    |63                 Parameter Data                                     0|
+    +-----------------------------------------------------------------------+
+
+Offset 0x00
+Type - The type of DFH (e.g. FME, AFU, or private feature).
+DFH VER - The version of the DFH.
+Rsvd - Currently unused.
+EOL - Set if this DFH is the end of the Device Feature List (DFL).
+Next - The offset of the next DFH in the DFL from the start of the DFH.
+If EOL is set, Next refers to size of mmio for last feature in the list.
+ID - If Type field is 'private feature', then ID of the private feature.
+
+Offset 0x08
+GUID_L - Least significant 64 bits of a 128 bit Globally Unique Identifier.
+
+Offset 0x10
+GUID_H - Most significant 64 bits of a 128 bit Globally Unique Identifier
+if Type is FME or AFU.
+
+Offset 0x18
+Address/Offset - If Rel bit is set, then high 63 bits of a 16 bit aligned
+absolute address for the location of the feature's registers.
+If Rel bit is clear, then the feature's registers start at the
+offset from the start of the DFH.
+
+Offset 0x20
+Reg Size - Size of feature's register set.
+Params - Set if DFH has one or more parameter blocks.
+Group - Id of group if feature is part of a group.
+Instance - Id of instance of feature within a group.
+
+Offset 0x28 if feature has parameters
+Next - High 30 bits of a 32 bit aligned offset to the next parameter block.
+If EOP set, size of last parameter.
+Param Version - Version of Param ID.
+Param ID - ID of parameter.
+
+Offset 0x30
+Parameter Data - Parameter data whose size and format is defined by version
+and ID of the parameter.
+
 Open discussion
 ===============
 FME driver exports one ioctl (DFL_FPGA_FME_PORT_PR) for partial reconfiguration
-- 
2.25.1