On Thu, 2018-07-12 at 17:53 +1000, Joel Stanley wrote:

On 12 July 2018 at 13:48, Benjamin Herrenschmidt
[off-list ref] wrote:

quoted

The Aspeed AST2x00 can contain a ColdFire v1 coprocessor which
is currently unused on OpenPower systems.

This adds an alternative to the fsi-master-gpio driver that
uses that coprocessor instead of bit banging from the ARM
core itself. The end result is about 4 times faster.

The firmware for the coprocessor and its source code can be
found at https://github.com/ozbenh/cf-fsi and is system specific.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 drivers/fsi/Kconfig                      |    9 +
 drivers/fsi/Makefile                     |    1 +
 drivers/fsi/cf-fsi-fw.h                  |  157 +++
 drivers/fsi/fsi-master-ast-cf.c          | 1438 ++++++++++++++++++++++
 include/trace/events/fsi_master_ast_cf.h |  150 +++
 5 files changed, 1755 insertions(+)
 create mode 100644 drivers/fsi/cf-fsi-fw.h
 create mode 100644 drivers/fsi/fsi-master-ast-cf.c
 create mode 100644 include/trace/events/fsi_master_ast_cf.h

diff --git a/drivers/fsi/Kconfig b/drivers/fsi/Kconfig
index 322cec393cf2..e0220d1e1357 100644
--- a/drivers/fsi/Kconfig
+++ b/drivers/fsi/Kconfig

@@ -27,6 +27,15 @@ config FSI_MASTER_HUB
        allow chaining of FSI links to an arbitrary depth.  This allows for
        a high target device fanout.

+config FSI_MASTER_AST_CF
+       tristate "FSI master based on Aspeed ColdFire coprocessor"
+       depends on GPIOLIB
+       depends on GPIO_ASPEED
+       ---help---
+       This option enables a FSI master using the AST2400 and AST2500 GPIO
+       lines driven by the internal ColdFire coprocessor. This requires
+       the corresponding machine specific ColdFire firmware to be available.

The "machine specific" part isn't true anymore, is it?

Right, I'll fixup the changelog before pushing if that's the last spin.

I gave this a spin on a palmetto and it appeared to work fine for me.

Tested-by: Joel Stanley <joel@jms.id.au>

Thanks !

Cheers,
Ben
.