Aspeed SPI driver upstreaming

[Brad Bishop]

Thanks for the reply Patrick.

On Fri, May 20, 2022 at 04:10:51PM -0500, Patrick Williams wrote:
>I don't know the details here.  There was some dispute between the MTD
>maintainers and work that others were doing in this area that has made
>it difficult for us to get additional patches in until someone refactors
>the Aspeed driver how upstream wants.  (last I was aware)

Right, this work has just recently been done: 
https://lore.kernel.org/lkml/20220503060634.122722-1-clg@kaod.org/ 
(thanks Cedric, IBM, and anyone else that helped!)

>I am not using the aspeed-spi driver in these conditions.  After
>initially setting this up we did some testing with the TPM driver and
>realized that it wasn't working.  It turns out that the Aspeed hardware
>is incapable of bi-directional transactions (bytes going out MOSI and in
>MISO at the same time), which is required by the TCG TPM protocol.
>We've ended up having to use the GPIO-SPI bitbang driver for talking
>with SPI-based TPMs.

Good to know!  Thanks for the information,

Brad