This adds a few small quirks to handle the differences between
the STM32 and Ux500 cryp blocks. The following differences
are handled with special bool switch bits in the capabilities:
- The main difference is that some registers are removed, so we
add register offsets for all registers in the
per-variant data. Then we assign the right offsets for Ux500
vs the STM32 variants.
- The Ux500 does not support the aeads algorithms; gcm(aes)
and ccm(aes). Avoid registering them when running on Ux500.
- The Ux500 has a special "linear" key format and does some
elaborare bit swizzling of the key bits before writing them
into the key registers. This is written as an "application
note" inside the DB8500 design specification, and seems to
be the result of some mishap when assigning the data lines
to register bits. (STM32 has clearly fixed this.)
- The Ux500 does not have the KP "key prepare" bit in the
CR register. Instead, we need to set the KSE bit,
"key schedule encryption" bit which does the same thing
but is in bit 11 rather than being a special "algorithm
type" as on STM32. The algorithm must however be specified
as AES ECB while doing this.
- The Ux500 cannot just read out IV registers, we need to
set the KEYRDEN "key read enable" bit, as this protects
not just the key but also the IV from being read out.
Enable this bit before reading out the IV and disable it
afterwards.
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Acked by: Lionel Debieve <lionel.debieve@foss.st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
0b496efbd2