Driver(s) for Synopsys' DesignWare USB OTG

Driver(s) for Synopsys' DesignWare USB OTG

[Nikolai Zhubr]

Hello developers,

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 
further steps.

Please CC me, I'm not subscribed to the lists.

Thank you.
Nikolai.

Re: Driver(s) for Synopsys' DesignWare USB OTG

[Peter Chen]

2012/1/8 Nikolai Zhubr <n-a-zhubr@yandex.ru>:
> Hello developers,
>
> 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 fo=
r
> 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 inclusio=
n
> into mainline) in order to avoid duplicate/uncoordinated work and waste o=
f
> 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). Usab=
le
> 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 mor=
e
> 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, bu=
t
> subsequently were apparently tested/corrected/updated by separate teams. =
It
> is not quite clear if all bugfixes were cross-applied carefully (if at al=
l).
> 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 bi=
t
> later. Meanwhile, I'd be happy to discuss the subject with whoever
> interested in order to plan my further steps.

Please see:
http://marc.info/?l=3Dlinux-usb&m=3D129906859817430&w=3D2

I am not sure we can combine all Synopsys USB drivers to single file, but w=
e
can try combine similar IP versions to one file, this work may need all Syn=
opsys
USB IP driver maintainer work together.


> Thank you.
> Nikolai.
> --
> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at =A0http://vger.kernel.org/majordomo-info.html



--=20
BR,
Peter Chen

Re: Driver(s) for Synopsys' DesignWare USB OTG

[Nikolai Zhubr]

Hello Piter,

08.01.2012 7:12, you wrote:
> 2012/1/8 Nikolai Zhubr<n-a-zhubr@yandex.ru>:
>> Hello developers,
>>
>> 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.
>>
[...trim...]
>
> Please see:
> http://marc.info/?l=linux-usb&m=129906859817430&w=2
Ah, thanks. So sadly uncoordinated work in this area is quite common. 
However, in case of Synopsys the situation is even more disappointing 
because initially it _was_ a single driver! What probably lacked was 
some shared repository and proper communication between developers to 
stay in sync. Maybe there were also licensing issues at some point, 
though currently file headers contain rather reasonable (imho) 
permissive license from Synopsys.

> I am not sure we can combine all Synopsys USB drivers to single file, but we

Synopsys driver which I examine consists of 16 files (each of 2 
versions), 200k lines total. I've already perpared some few smaller 
files for version merging. So probably it is doable, but quite a lot of 
work, therefore I wouldn't like it to be wasted.

> can try combine similar IP versions to one file, this work may need all Synopsys
> USB IP driver maintainer work together.

Exactly. This is why I'm now trying to find all relevant people to begin 
with.

Thank you.
Nikolai.

Please CC me, I'm not subscribed to the lists.


>
>
>> Thank you.
>> Nikolai.
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>
>

Re: Driver(s) for Synopsys' DesignWare USB OTG

[Peter Chen]

On Sun, Jan 08, 2012 at 04:56:49PM +0400, Nikolai Zhubr wrote:
> Hello Piter,
> 
> 08.01.2012 7:12, you wrote:
> >2012/1/8 Nikolai Zhubr<n-a-zhubr@yandex.ru>:
> >
> >Please see:
> >http://marc.info/?l=linux-usb&m=129906859817430&w=2
> Ah, thanks. So sadly uncoordinated work in this area is quite
> common. However, in case of Synopsys the situation is even more
> disappointing because initially it _was_ a single driver! What
> probably lacked was some shared repository and proper communication
> between developers to stay in sync. Maybe there were also licensing
> issues at some point, though currently file headers contain rather
> reasonable (imho) permissive license from Synopsys.
> 
> >I am not sure we can combine all Synopsys USB drivers to single file, but we
> 
> Synopsys driver which I examine consists of 16 files (each of 2
> versions), 200k lines total. I've already perpared some few smaller
> files for version merging. So probably it is doable, but quite a lot
> of work, therefore I wouldn't like it to be wasted.
I mean one file is just a common udc driver for all Synopsys, not all usb file.
For ehci, I think it will be easier to use single file as well as 
some specific SoC's quirks if needed.
For udc, as there is no standard spec for how usb device should be designed,
maybe different Synopsys IPs have a little different for work flow.
For otg, it  should be not difficult after we split PHY's operation
from the otg, as common otg operation is the same.
> 
> >can try combine similar IP versions to one file, this work may need all Synopsys
> >USB IP driver maintainer work together.
> 
> Exactly. This is why I'm now trying to find all relevant people to
> begin with.
I know someone(@Pengutronix and @linux.intel.com) is doing that. I think first
we should find which driver file at current code base is most capable and
compatible. I would like to help it, and verify it at Freescale i.MX SoCs.
> 
> Thank you.
> Nikolai.
> 
> Please CC me, I'm not subscribed to the lists.
> 
> 
> >
> >
> >>Thank you.
> >>Nikolai.
> >>--
> >>To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> >>the body of a message to majordomo@vger.kernel.org
> >>More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >
> >
> >
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

-- 

Best Regards,
Peter Chen

Re: Driver(s) for Synopsys' DesignWare USB OTG

[Nikolai Zhubr]

Hello Peter,

09.01.2012 6:12, Peter Chen:
>>> I am not sure we can combine all Synopsys USB drivers to single file, but we
>>
>> Synopsys driver which I examine consists of 16 files (each of 2
>> versions), 200k lines total. I've already perpared some few smaller
>> files for version merging. So probably it is doable, but quite a lot
>> of work, therefore I wouldn't like it to be wasted.
> I mean one file is just a common udc driver for all Synopsys, not all usb file.
> For ehci, I think it will be easier to use single file as well as
> some specific SoC's quirks if needed.
> For udc, as there is no standard spec for how usb device should be designed,
> maybe different Synopsys IPs have a little different for work flow.
> For otg, it  should be not difficult after we split PHY's operation
> from the otg, as common otg operation is the same.
>>
>>> can try combine similar IP versions to one file, this work may need all Synopsys
>>> USB IP driver maintainer work together.
>>
>> Exactly. This is why I'm now trying to find all relevant people to
>> begin with.
> I know someone(@Pengutronix and @linux.intel.com) is doing that. I think first
> we should find which driver file at current code base is most capable and
> compatible. I would like to help it, and verify it at Freescale i.MX SoCs.

Ok. Because my resources are limited (and my knowledge is actually 
limited too) I'll list what exactly I'm able (and willing) to do:

- split formatting/naming/uninteresting changes from algorythmical 
changes, prepare clean diffs as necessary (boring work, but anyway);
- bisect changes which make the driver stop working on my tablet;
- try whichever driver parameters and see what happens to my tablet;
- connect the tablet to a regular linux PC with USB cable, do some 
tests, capture traffic dumps as necessary;
- connect some devices to the tablet, do tests, report results;

and with some luck:
- prepare bufixes (depending very much on how simple is the bug).

So basically my effort would probably only be usefull in cooperation 
with someone with more knowledge and understanding of the situation in 
whole. Otherwise it would be more wasting of time.

If usb issues were solved, it might make some sense to try to create 
e.g. a generic openwrt target for 8726m-based tablet. (Of course it 
wouldn't allow to use the device for its intended purpose yet, but still 
might be interesting as kind of devel/testing reference option)


Thank you.
Nikolai.


>>
>> Thank you.
>> Nikolai.
>>
>> Please CC me, I'm not subscribed to the lists.
>>
>>
>>>
>>>
>>>> Thank you.
>>>> Nikolai.
>>>> --
>>>> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
>>>> the body of a message to majordomo@vger.kernel.org
>>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>>
>>>
>>>
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>

Re: Driver(s) for Synopsys' DesignWare USB OTG

[Leo Li]

On Sun, Jan 8, 2012 at 8:56 PM, Nikolai Zhubr <n-a-zhubr@yandex.ru> wrote:
> Hello Piter,
>
>
> 08.01.2012 7:12, you wrote:
>>
>> 2012/1/8 Nikolai Zhubr<n-a-zhubr@yandex.ru>:
>>>
>>> Hello developers,
>>>
>>> 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.
>>>
> [...trim...]
>>
>>
>> Please see:
>> http://marc.info/?l=linux-usb&m=129906859817430&w=2
>
> Ah, thanks. So sadly uncoordinated work in this area is quite common.
> However, in case of Synopsys the situation is even more disappointing
> because initially it _was_ a single driver! What probably lacked was some
> shared repository and proper communication between developers to stay in
> sync. Maybe there were also licensing issues at some point, though currently
> file headers contain rather reasonable (imho) permissive license from
> Synopsys.

I think the challenge of cooperation in situation like this is that
most companies don't like to advertise the source of the licensed IP
block.  Even the owner of the IP block doesn't list all users of the
block(maybe business requirement). It was really hard to find out if
the same IP has been used by anyone else.  Also the owner of this USB
IP block has been changed for several times(ARC, TDI, ChipIdea, and
Synopsys) which made it even more difficult to tell.

>
>
>> I am not sure we can combine all Synopsys USB drivers to single file, but
>> we
>
>
> Synopsys driver which I examine consists of 16 files (each of 2 versions),
> 200k lines total. I've already perpared some few smaller files for version
> merging. So probably it is doable, but quite a lot of work, therefore I
> wouldn't like it to be wasted.

I didn't examine the Synopsys driver myself.  But if it is so complex
as you described, it might be better to start with the in-tree drivers
IMO.

- Leo

Re: Driver(s) for Synopsys' DesignWare USB OTG

[Nikolai Zhubr]

Hello Leo,

09.01.2012 9:17, Leo Li:
> On Sun, Jan 8, 2012 at 8:56 PM, Nikolai Zhubr<n-a-zhubr@yandex.ru>  wrote:
>>> 2012/1/8 Nikolai Zhubr<n-a-zhubr@yandex.ru>:
>>>>
>>>> Hello developers,
>>>>
>>>> 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.
>>>>
[...trim...]
>
> I think the challenge of cooperation in situation like this is that
> most companies don't like to advertise the source of the licensed IP
> block.  Even the owner of the IP block doesn't list all users of the
> block(maybe business requirement). It was really hard to find out if
> the same IP has been used by anyone else.  Also the owner of this USB
> IP block has been changed for several times(ARC, TDI, ChipIdea, and
> Synopsys) which made it even more difficult to tell.

Ah, I see. It explains.
But communicating in private and keeping some public repository up to 
date would still be allowed I suppose?

>
>>
>>
>>> I am not sure we can combine all Synopsys USB drivers to single file, but
>>> we
>>
>>
>> Synopsys driver which I examine consists of 16 files (each of 2 versions),
>> 200k lines total. I've already perpared some few smaller files for version
>> merging. So probably it is doable, but quite a lot of work, therefore I
>> wouldn't like it to be wasted.
>
> I didn't examine the Synopsys driver myself.  But if it is so complex
> as you described, it might be better to start with the in-tree drivers
> IMO.

Unfortunately its far beyond my capabilities at the moment. Besides, it 
looks like huge effort has already been invested into the existing 
driver, so to me it seems fixing it rather than starting from scratch 
would be more realistic anyway (unless a company with unlimited 
resources step in...)


Thank you.
Nikolai.

>
> - Leo
>
>