Driver(s) for Synopsys' DesignWare USB OTG
n-a-zhubr at yandex.ru
Sun Jan 8 04:30:10 EST 2012
I'm trying to find/combine/fix a driver for Synopsys' DesignWare USB
controller. This thing is USB 2.0 host/slave/otg capable and is used in
various SoCs including Amlogic 8726M, Ralink RT305x, and probably more.
There is some code floating around, partly usable, but all I could see
for now is really not perfect. I also saw commit logs on linuxppc-dev,
but failed to find out what repository they are related to. I'd like to
know if someone is currently developing/testing/maintaining the driver
or is planning to do so in the near future (in a FOSS-friendly manner -
making development results public immediately and with eventual goal of
inclusion into mainline) in order to avoid duplicate/uncoordinated work
and waste of effort.
I'm currently examining 2 versions (That is, 2 sets of files):
1. From android kernel for 8726m-based tablets (like the one I own).
Usable to some extent, but there are issues (e.g. it looks like certain
packets get corrupted, reproducibly, relevant dumps are available)
2. From openwrt kernel for RT305x-based routers. The code looks a bit
more tidy, but not quite well updated (slave-mode parts are unused in
openwrt and they can not even be compiled for modern kernels without
certain patching; have not tried host-mode on the hardware yet)
Quite obviously both versions originated from the same code initially,
but subsequently were apparently tested/corrected/updated by separate
teams. It is not quite clear if all bugfixes were cross-applied
carefully (if at all). I was initially hoping that compare and bisect
will just do the job, but the driver is quite huge... and some files
have diverged substantially in the 2 versions, so at the moment I'm a
bit fed up and will probably resume a bit later. Meanwhile, I'd be happy
to discuss the subject with whoever interested in order to plan my
Please CC me, I'm not subscribed to the lists.
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