[PATCH 0/5] fsi: Coldfire coprocessor offload

Benjamin Herrenschmidt benh at kernel.crashing.org
Thu Jul 12 13:48:42 AEST 2018

This series implements support for offloading the FSI protocol bitbanging
to the ColdFire secondary core of the Aspeed SoCs. The result increases
FSI performance by a factor of 4, and on systems that don't support async
FSI clock, provide much more regular and continuous clocking which helps

This series is much smaller than the previous submissions as I already
merged all the "preparatory" work into the FSI tree. This is now strictly
the coldfire support and is now only waiting for ack of the DT bindings
(and whatever other review comments might come my way) before I put it
into the FSI tree and sends it to Greg.

There are two dependencies to be able to build/use this. The above
prep work:


And the Aspeed GPIO driver changes for handling with GPIO lines ownership and
handshaking. The patches have been merged into the GPIO tree and a dedicated
immutable topic branch and can be found here:


Finally, the driver needs a machine specific firmware file. The firwmare
is open source and available at:


I will submit it to linux-firmware if there's enough popular demand ;-)

v2. Fix misuse of devm_kzalloc for objects containing a struct device
    in fsi-master-gpio and fsi-master-ast-cf (similar fixes for the
    various FSI drivers will come later a part of rework to move away
    from misc devs).

v3. Sparse fix and updated DT bindings as per Rob's comments.

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