[PATCH v5 00/46] usb: gadget: rework ep matching and claiming mechanism

Hi,

On Fri, Jul 31, 2015 at 04:00:12PM +0200, Robert Baldyga wrote:

Hello,

This patch series reworks endpoint matching and claiming mechanism in
epautoconf. From v2 there are couple of new patches adding 'ep_match'
to usb_gadget_ops and removing chip-specific quirk handling from generic
code of autoconfig.

I'm not sure if this patch set isn't too long, as it has 46 patches,
but I decided to send it as single series to avoid problems with patch
applying order.

The aim of whole patchset is to rework epautoconf code to get rid of
things like name-based endpoint matching and UDC name-based quirks in
generic code. These needed to do some modifications in framework like
adding 'endpoint capabilities flags' feature or adding 'match_ep'.

Following paragraphs contain brief description of what modifications are
done by particular parts of this patch set:

Patch (1) introduces new safer endpoint claiming method, basing on new
'claimed' flag. It was discussed here [1]. I proposed this solution over
year ago and it was accepted, but I apparently forgot to send the final
version of my patch.

Patches (2-3) add the 'capabilities flags' structure and helper macros.
This solution is inspired by the 'feature flags' originally proposed
by Felipe Balbi in 2013 [2], but unfortunately implementation of this
feature has never been completed.

Patches (4-36) add' capabilites flags' support to all UDC drivers present
in the kernel tree. It's needed to be done before replacing old endpoint
matching mechanism, otherwise UDC drivers which doesn't set 'capabilities
flags' won't work with new matching function.

Patch (37) finally replaces old endpoint matching method with the new
one basing on capabilities flags.

These changes aims to get rid of code, which guesses endpoint capabilities
basing on it's name, and introduce new better replacement. In result
we have better way to describe types and directions supported by each
endpoint.

For example the old name-based method didn't allow to have endpoint
supporing two types of transfers - there were only ability to support
one or all of endpoint types. The 'capabilities flags' feature supply
precise, flexible and extensible mechanism of description of endpoint
hardware limitations, which is desired for proper endpoint matching.

Patch (38) removes chip-specific quirk from ep_matches() function.

Patches (39-40) remove code modifying endpoint and descriptor structures
from ep_matches() function and cleans it up to make it simpler and more
readable.

Patch (41) add 'match_ep' callback to usb_gadget_ops and make use of
it in epautoconf. This callback allows UDC drivers to supply non-standard
endpoint matching algorithms.

Patches (42-43) move ep_matches() and find_ep() functions outside
epautoconf and rename them to usb_gadget_ep_match_desc() and
gadget_find_ep_by_name(). It's because they may be useful in 'match_ep'
callbacks in UDC drivers to avoid writing repetitive code.

Patches (44-46) move chip-specific enpoint matching algorithms from
generic code of usb_ep_autoconfig_ss() function to UDC controller drivers
using 'match_ep' callback.

In the result we have epautoconf source free of chip-specific code, plus
two new mechanisms allowing to handle non-standard hardware limitations.

[1] https://lkml.org/lkml/2014/6/16/94
[2] http://www.spinics.net/lists/linux-usb/msg99662.html

adding these to my testing/next after fixing a few build warnings and
the comment I had on dwc3 patch. Let's hope it just works :-)

-- 
balbi
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