[sw/dif] Deprecate the use of operation results.
Operation result types result in additional boilerplate code that do not
bring any value to the user, resulting in overall, overly verbose code
that is cumbersome to integrate.
This commit deprecates the use of operation result types as part of
lowrisc/opentitan#6137.
Signed-off-by: Miguel Osorio <miguelosorio@google.com>
diff --git a/sw/device/lib/dif/README.md b/sw/device/lib/dif/README.md
index 1227776..6670231 100644
--- a/sw/device/lib/dif/README.md
+++ b/sw/device/lib/dif/README.md
@@ -148,10 +148,17 @@
* `kDif<ip>BadArg`, with value 2, to denote that the caller supplied
incorrect arguments. This value must only be returned if the function has
not caused any side-effects.
-* `dif_<ip>_<operation>_result_t` is an enum representing more specific failure
- modes. These specific return code enums can be shared between multiple DIFs
- that fail in the same way. `<operation>` need not correspond to a DIF name if
- more than one DIF uses these return codes.
+
+ Additional, specific return code constants must all be defined after
+ these three general constants, and may cover more specific forms of the
+ return codes defined above.
+* **DEPRECATED** `dif_<ip>_<operation>_result_t` is an enum representing more
+ specific failure modes. These specific return code enums can be shared
+ between multiple DIFs that fail in the same way. `<operation>` need not
+ correspond to a DIF name if more than one DIF uses these return codes.
+
+ Operation return codes are being deprecated. See GitHub issue
+ [#6137](https://github.com/lowRISC/opentitan/issues/6137) for more details.
The first three constants in these specific enums must define the following
constants:
