ALPS v7 trackpad passthrough to Thinkpad trackpoint

ALPS v7 trackpad passthrough to Thinkpad trackpoint

[Ari Entlich]

Hello!

I'm an owner of a Thinkpad T440p, and was always unhappy with the
buttonless trackpad. I was ecstatic when I learned that trackpads from
the 50 series laptops, with buttons, are compatible with 40 series
laptops. I have since performed this mod, and all of the hardware
seems to be working.

The only problem I've been having is a software one. It seems that the
trackpad and trackpoint are usually arranged such that the trackpoint
is "behind" the trackpad and all communication with the trackpoint
goes through the trackpad. This allows the trackpad to provide an
abstraction of the trackpoint for OSes that don't explicitly support
it.

With my old trackpad, which was a Synaptics device, Linux would detect
the trackpoint as its own device with the TPPS/2 protocol. It seems
that it was able to do this because the Synaptics driver has support
for a "pass-through port" which allows the OS to send commands
directly to the trackpoint. However, the new trackpad that I received
is an ALPS v7 device. I see some references to passthrough support in
drivers/input/mouse/alps.c, but it doesn't appear to be used in the
same way as it is in the Synaptics driver and doesn't seem to be
supported at all for v7 devices. Therefore, instead of showing up as
its own special device, the trackpoint shows up as a "DualPoint
Stick". In general this is fine, because the trackpoint works.
However, the dedicated trackpoint driver allows you to modify a few
trackpoint-specific hardware settings, most notably the sensitivity.
This was much more of an issue before this:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=088df2ccef75754cc16a6ba31829d23bcb2b68ed
commit, but I still think it would be nice to be able to control my
hardware as much as possible.

Interestingly, I've been able to find very little discussion of this
limitation of the ALPS driver. Here are the few links that I've been
able to find:

https://bugzilla.kernel.org/show_bug.cgi?id=8864 (comment 24 seems
especially relevant)
https://bugzilla.redhat.com/show_bug.cgi?id=483224
http://www.spinics.net/lists/xorg/msg49549.html
http://thinkpad-forum.de/threads/185025-T*50-Clickpad-in-T*40-Trackpoint-Konfiguration
(German)

Since the trackpad that I received is from some Thinkpad model (I
don't know which one though), there presumably should be other 50
series Thinkpad users who are affected by this same issue. It could
just be that the number of people with the right device who use Linux
and want to adjust the hardware sensitivity and care enough to post
about it online is essentially zero, but I've had a hard time
convincing myself of this.

Comment 24 in the first link states that ALPS has been unwilling to
share the secret to the passthrough port for their hardware. However,
this comment is 8 years old, so I'm hoping things have changed. The
second and third links seem to be describing approximately the same
problem, with one difference being that disabling the trackpad in the
BIOS does not cause the trackpoint driver to be used for me - it only
causes the trackpad device to stop emitting events. Perhaps this is
because the buttons are now part of the trackpad device, or maybe it's
just because this is a non-standard mod. The fourth link seems to be
describing the exact problem that I'm having, however my ability to
read German is only as good as Google Translate ability to translate
it.

If there's anything that I can do to help get this implemented, please
let me know. I'd even be willing to try and figure out how the Windows
driver does this, if that becomes necessary.

Also: I am aware that sensitivity/speed/acceleration/whatever can be
adjusted somewhat through libinput settings. That is not what I'm
asking about, so please don't suggest it. :)

Thanks!

Ari

Re: ALPS v7 trackpad passthrough to Thinkpad trackpoint

[Pali Rohár]

On Thursday 06 August 2015 07:07:19 Ari Entlich wrote:
> Hello!
> 
> I'm an owner of a Thinkpad T440p, and was always unhappy with the
> buttonless trackpad. I was ecstatic when I learned that trackpads from
> the 50 series laptops, with buttons, are compatible with 40 series
> laptops. I have since performed this mod, and all of the hardware
> seems to be working.
> 
> The only problem I've been having is a software one. It seems that the
> trackpad and trackpoint are usually arranged such that the trackpoint
> is "behind" the trackpad and all communication with the trackpoint
> goes through the trackpad. This allows the trackpad to provide an
> abstraction of the trackpoint for OSes that don't explicitly support
> it.
> 
> With my old trackpad, which was a Synaptics device, Linux would detect
> the trackpoint as its own device with the TPPS/2 protocol. It seems
> that it was able to do this because the Synaptics driver has support
> for a "pass-through port" which allows the OS to send commands
> directly to the trackpoint. However, the new trackpad that I received
> is an ALPS v7 device. I see some references to passthrough support in
> drivers/input/mouse/alps.c, but it doesn't appear to be used in the
> same way as it is in the Synaptics driver and doesn't seem to be
> supported at all for v7 devices. Therefore, instead of showing up as
> its own special device, the trackpoint shows up as a "DualPoint
> Stick". In general this is fine, because the trackpoint works.
> However, the dedicated trackpoint driver allows you to modify a few
> trackpoint-specific hardware settings, most notably the sensitivity.
> This was much more of an issue before this:
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=088df2ccef75754cc16a6ba31829d23bcb2b68ed
> commit, but I still think it would be nice to be able to control my
> hardware as much as possible.
> 
> Interestingly, I've been able to find very little discussion of this
> limitation of the ALPS driver. Here are the few links that I've been
> able to find:
> 
> https://bugzilla.kernel.org/show_bug.cgi?id=8864 (comment 24 seems
> especially relevant)
> https://bugzilla.redhat.com/show_bug.cgi?id=483224
> http://www.spinics.net/lists/xorg/msg49549.html
> http://thinkpad-forum.de/threads/185025-T*50-Clickpad-in-T*40-Trackpoint-Konfiguration
> (German)
> 
> Since the trackpad that I received is from some Thinkpad model (I
> don't know which one though), there presumably should be other 50
> series Thinkpad users who are affected by this same issue. It could
> just be that the number of people with the right device who use Linux
> and want to adjust the hardware sensitivity and care enough to post
> about it online is essentially zero, but I've had a hard time
> convincing myself of this.
> 
> Comment 24 in the first link states that ALPS has been unwilling to
> share the secret to the passthrough port for their hardware. However,
> this comment is 8 years old, so I'm hoping things have changed. The
> second and third links seem to be describing approximately the same
> problem, with one difference being that disabling the trackpad in the
> BIOS does not cause the trackpoint driver to be used for me - it only
> causes the trackpad device to stop emitting events. Perhaps this is
> because the buttons are now part of the trackpad device, or maybe it's
> just because this is a non-standard mod. The fourth link seems to be
> describing the exact problem that I'm having, however my ability to
> read German is only as good as Google Translate ability to translate
> it.
> 
> If there's anything that I can do to help get this implemented, please
> let me know. I'd even be willing to try and figure out how the Windows
> driver does this, if that becomes necessary.
> 
> Also: I am aware that sensitivity/speed/acceleration/whatever can be
> adjusted somewhat through libinput settings. That is not what I'm
> asking about, so please don't suggest it. :)
> 
> Thanks!
> 
> Ari
> --
> To unsubscribe from this list: send the line "unsubscribe linux-input" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
> 

Hello,

ALPS devices does not support pass-throw mode like Synaptics devices.
But our ALPS driver is good and can detect packet from device contains
data for touchpad or trackpoint. So ALPS driver create two input devices
and send events to userspace via correct input device and userspace see
that there are two different devices (touchpad and trackstick) and not
one "combined".

Looks like that ALPS devices does not support any speed or acceleration
configuration, so everything needs to be implemented in software -- in
userspace. X drivers already have such configuration ether via xorg.conf
or runtime via xinput. Speed or acceleration can be configured per input
device, so this is something which you probably want.

-- 
Pali Rohár
pali.rohar@gmail.com
--
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Re: ALPS v7 trackpad passthrough to Thinkpad trackpoint

[Ari Entlich]

On Fri, Aug 7, 2015 at 9:26 AM, Pali Rohár <pali.rohar@gmail.com> wrote:
> Hello,
>
> ALPS devices does not support pass-throw mode like Synaptics devices.

Hmm... Then what are all of these references to passthrough in alps.c?
Does the alps driver use the term "passthrough" in a different way
than the synaptics driver does?

Are we 100% sure that alps devices can't do this? Is there any
possibility that we just don't know how to do it?

Thanks.

Ari

> But our ALPS driver is good and can detect packet from device contains
> data for touchpad or trackpoint. So ALPS driver create two input devices
> and send events to userspace via correct input device and userspace see
> that there are two different devices (touchpad and trackstick) and not
> one "combined".
>
> Looks like that ALPS devices does not support any speed or acceleration
> configuration, so everything needs to be implemented in software -- in
> userspace. X drivers already have such configuration ether via xorg.conf
> or runtime via xinput. Speed or acceleration can be configured per input
> device, so this is something which you probably want.
>
> --
> Pali Rohár
> pali.rohar@gmail.com
--
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Re: ALPS v7 trackpad passthrough to Thinkpad trackpoint

[Pali Rohár]

On Friday 07 August 2015 09:41:07 Ari Entlich wrote:
> On Fri, Aug 7, 2015 at 9:26 AM, Pali Rohár <pali.rohar@gmail.com> wrote:
> > Hello,
> >
> > ALPS devices does not support pass-throw mode like Synaptics devices.
> 
> Hmm... Then what are all of these references to passthrough in alps.c?
> Does the alps driver use the term "passthrough" in a different way
> than the synaptics driver does?
> 

For some old ALPS devices which use V1 and V2 protocols (with flag
ALPS_PASS) there is something like that. On that devices touchpad is
behind trackpoint HW. But you cannot wait for data or poll for both
devices at same time -- you need to choose if tou want to talk directly
to touchpad (via passthrough mode) or just to trackpoint. I think
because of this limitation ALPS driver implement all logic in one
driver...

Above was for old ALPS devices. New ALPS devices with V3 or V5 protocols
have trackpoint behind touchpad, so normally OS communicate with
touchpad (and not with trackstick like before). But here touchpad sends
data for both touchpad and trackstick events and so OS does not have
normal access to "hidden" trackstick.

There is a way "jump" into passthrough mode and talk directly to
trackpoint. But it is used only for configuring trackstick and currently
it is used to configure trackstick so it send data (via touchpad) in
format which is supported by our ALPS driver.

On the other hand, synaptics driver and devices support full
"encapsulation" or how can I call it of serio PS/2 device and in this
case you can use full set of PS/2 commands directly with trackstick
(behind synaptics touchpad). ALPS devices do not support something like
that.

> Are we 100% sure that alps devices can't do this? Is there any
> possibility that we just don't know how to do it?
> 

Note I just wrote information which I understand from driver source code
and with "playing" with touchpads. There can be some mistakes (so
somebody can correct me), but this is how I understand this situation.

I do not have access and I have never seen any "official" documentation.
I can say, that current ALPS driver in kernel does not support it for
100% sure. But maybe we just missing some information which allows us to
do it.

But in my opinion ALPS firmware which is running in ALPS touchpad does
not support something like full passthrough to trackpoint device like
synaptics. For me it does not make sense to add such function into
firmware, because it already send all needed data for OS to allow
processing both touchpad and trackpoint data.

Questions are: Do we need full access to trackpoint hardware? Do we know
if trackpoint (used by ALPS input solutions) supports configuring speed
or acceleration in hardware? It is really not easier to do it in
software?

> Thanks.
> 
> Ari
> 
> > But our ALPS driver is good and can detect packet from device contains
> > data for touchpad or trackpoint. So ALPS driver create two input devices
> > and send events to userspace via correct input device and userspace see
> > that there are two different devices (touchpad and trackstick) and not
> > one "combined".
> >
> > Looks like that ALPS devices does not support any speed or acceleration
> > configuration, so everything needs to be implemented in software -- in
> > userspace. X drivers already have such configuration ether via xorg.conf
> > or runtime via xinput. Speed or acceleration can be configured per input
> > device, so this is something which you probably want.
> >
> > --
> > Pali Rohár
> > pali.rohar@gmail.com

-- 
Pali Rohár
pali.rohar@gmail.com
--
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Re: ALPS v7 trackpad passthrough to Thinkpad trackpoint

[Ari Entlich]

On Fri, Aug 7, 2015 at 10:12 AM, Pali Rohár <pali.rohar@gmail.com> wrote:
> For some old ALPS devices which use V1 and V2 protocols (with flag
> ALPS_PASS) there is something like that. On that devices touchpad is
> behind trackpoint HW. But you cannot wait for data or poll for both
> devices at same time -- you need to choose if tou want to talk directly
> to touchpad (via passthrough mode) or just to trackpoint. I think
> because of this limitation ALPS driver implement all logic in one
> driver...
>
> Above was for old ALPS devices. New ALPS devices with V3 or V5 protocols
> have trackpoint behind touchpad, so normally OS communicate with
> touchpad (and not with trackstick like before). But here touchpad sends
> data for both touchpad and trackstick events and so OS does not have
> normal access to "hidden" trackstick.
>
> There is a way "jump" into passthrough mode and talk directly to
> trackpoint. But it is used only for configuring trackstick and currently
> it is used to configure trackstick so it send data (via touchpad) in
> format which is supported by our ALPS driver.
>
> On the other hand, synaptics driver and devices support full
> "encapsulation" or how can I call it of serio PS/2 device and in this
> case you can use full set of PS/2 commands directly with trackstick
> (behind synaptics touchpad). ALPS devices do not support something like
> that.

It looks to me like the Synaptics passthrough is implemented primarily
via the ability to write directly to the trackpoint. Events coming
from the trackpoint are implemented similarly to the ALPS driver - by
redirecting trackpoint events to the second device which the driver
creates for the trackpoint.

> Note I just wrote information which I understand from driver source code
> and with "playing" with touchpads. There can be some mistakes (so
> somebody can correct me), but this is how I understand this situation.
>
> I do not have access and I have never seen any "official" documentation.
> I can say, that current ALPS driver in kernel does not support it for
> 100% sure. But maybe we just missing some information which allows us to
> do it.
>
> But in my opinion ALPS firmware which is running in ALPS touchpad does
> not support something like full passthrough to trackpoint device like
> synaptics. For me it does not make sense to add such function into
> firmware, because it already send all needed data for OS to allow
> processing both touchpad and trackpoint data.

The issue isn't so much getting information from the trackpoint but
sending information TO it. The trackpoint driver is able to send
special commands to the trackpoint to modify its behavior. As far as I
can tell, this is pretty much the only thing it does. See
drivers/input/mouse/trackpoint.c for details.

> Questions are: Do we need full access to trackpoint hardware? Do we know
> if trackpoint (used by ALPS input solutions) supports configuring speed
> or acceleration in hardware? It is really not easier to do it in
> software?

As I mentioned in my first email, I'm aware that mouse behavior can be
modified in userspace. However, that's not what I'm asking about. I
want to have the same capabilities with this device as I had with the
old one, if at all possible. And anyways, there are some things that
the trackpoint driver can do that cannot be done in software.

Ari

> --
> Pali Rohár
> pali.rohar@gmail.com
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Re: ALPS v7 trackpad passthrough to Thinkpad trackpoint

[Ari Entlich]

Can anybody else weigh in on this? I'm especially curious whether [1]
is still relevant, so I've CC'd the author.

Thanks.

Ari

[1] https://bugzilla.kernel.org/show_bug.cgi?id=8864#c24

On Fri, Aug 7, 2015 at 12:35 PM, Ari Entlich <atrigent@gmail.com> wrote:
> On Fri, Aug 7, 2015 at 10:12 AM, Pali Rohár <pali.rohar@gmail.com> wrote:
>> For some old ALPS devices which use V1 and V2 protocols (with flag
>> ALPS_PASS) there is something like that. On that devices touchpad is
>> behind trackpoint HW. But you cannot wait for data or poll for both
>> devices at same time -- you need to choose if tou want to talk directly
>> to touchpad (via passthrough mode) or just to trackpoint. I think
>> because of this limitation ALPS driver implement all logic in one
>> driver...
>>
>> Above was for old ALPS devices. New ALPS devices with V3 or V5 protocols
>> have trackpoint behind touchpad, so normally OS communicate with
>> touchpad (and not with trackstick like before). But here touchpad sends
>> data for both touchpad and trackstick events and so OS does not have
>> normal access to "hidden" trackstick.
>>
>> There is a way "jump" into passthrough mode and talk directly to
>> trackpoint. But it is used only for configuring trackstick and currently
>> it is used to configure trackstick so it send data (via touchpad) in
>> format which is supported by our ALPS driver.
>>
>> On the other hand, synaptics driver and devices support full
>> "encapsulation" or how can I call it of serio PS/2 device and in this
>> case you can use full set of PS/2 commands directly with trackstick
>> (behind synaptics touchpad). ALPS devices do not support something like
>> that.
>
> It looks to me like the Synaptics passthrough is implemented primarily
> via the ability to write directly to the trackpoint. Events coming
> from the trackpoint are implemented similarly to the ALPS driver - by
> redirecting trackpoint events to the second device which the driver
> creates for the trackpoint.
>
>> Note I just wrote information which I understand from driver source code
>> and with "playing" with touchpads. There can be some mistakes (so
>> somebody can correct me), but this is how I understand this situation.
>>
>> I do not have access and I have never seen any "official" documentation.
>> I can say, that current ALPS driver in kernel does not support it for
>> 100% sure. But maybe we just missing some information which allows us to
>> do it.
>>
>> But in my opinion ALPS firmware which is running in ALPS touchpad does
>> not support something like full passthrough to trackpoint device like
>> synaptics. For me it does not make sense to add such function into
>> firmware, because it already send all needed data for OS to allow
>> processing both touchpad and trackpoint data.
>
> The issue isn't so much getting information from the trackpoint but
> sending information TO it. The trackpoint driver is able to send
> special commands to the trackpoint to modify its behavior. As far as I
> can tell, this is pretty much the only thing it does. See
> drivers/input/mouse/trackpoint.c for details.
>
>> Questions are: Do we need full access to trackpoint hardware? Do we know
>> if trackpoint (used by ALPS input solutions) supports configuring speed
>> or acceleration in hardware? It is really not easier to do it in
>> software?
>
> As I mentioned in my first email, I'm aware that mouse behavior can be
> modified in userspace. However, that's not what I'm asking about. I
> want to have the same capabilities with this device as I had with the
> old one, if at all possible. And anyways, there are some things that
> the trackpoint driver can do that cannot be done in software.
>
> Ari
>
>> --
>> Pali Rohár
>> pali.rohar@gmail.com
--
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Re: ALPS v7 trackpad passthrough to Thinkpad trackpoint

[Pali Rohár]

On Friday 07 August 2015 12:35:33 Ari Entlich wrote:
> On Fri, Aug 7, 2015 at 10:12 AM, Pali Rohár <pali.rohar@gmail.com> wrote:
> > For some old ALPS devices which use V1 and V2 protocols (with flag
> > ALPS_PASS) there is something like that. On that devices touchpad is
> > behind trackpoint HW. But you cannot wait for data or poll for both
> > devices at same time -- you need to choose if tou want to talk directly
> > to touchpad (via passthrough mode) or just to trackpoint. I think
> > because of this limitation ALPS driver implement all logic in one
> > driver...
> >
> > Above was for old ALPS devices. New ALPS devices with V3 or V5 protocols
> > have trackpoint behind touchpad, so normally OS communicate with
> > touchpad (and not with trackstick like before). But here touchpad sends
> > data for both touchpad and trackstick events and so OS does not have
> > normal access to "hidden" trackstick.
> >
> > There is a way "jump" into passthrough mode and talk directly to
> > trackpoint. But it is used only for configuring trackstick and currently
> > it is used to configure trackstick so it send data (via touchpad) in
> > format which is supported by our ALPS driver.
> >
> > On the other hand, synaptics driver and devices support full
> > "encapsulation" or how can I call it of serio PS/2 device and in this
> > case you can use full set of PS/2 commands directly with trackstick
> > (behind synaptics touchpad). ALPS devices do not support something like
> > that.
> 
> It looks to me like the Synaptics passthrough is implemented primarily
> via the ability to write directly to the trackpoint. Events coming
> from the trackpoint are implemented similarly to the ALPS driver - by
> redirecting trackpoint events to the second device which the driver
> creates for the trackpoint.
> 

No, passthrough for ALPS and Synaptics differ. Synaptics driver exports
full serio PS/2 bus on which can be attached psmouse.ko driver with full
mouse detection (or any other serio driver) and so there can be full
TPPS/2 trackpoint.c protocol driver.

ALPS allows us for *some* protocol version passthrough data directly to
touchpad (or trackpoint) device. There is no support to exporting full
serio bus with PS/2 access to it (like for Synaptics hardware).

> > Note I just wrote information which I understand from driver source code
> > and with "playing" with touchpads. There can be some mistakes (so
> > somebody can correct me), but this is how I understand this situation.
> >
> > I do not have access and I have never seen any "official" documentation.
> > I can say, that current ALPS driver in kernel does not support it for
> > 100% sure. But maybe we just missing some information which allows us to
> > do it.
> >
> > But in my opinion ALPS firmware which is running in ALPS touchpad does
> > not support something like full passthrough to trackpoint device like
> > synaptics. For me it does not make sense to add such function into
> > firmware, because it already send all needed data for OS to allow
> > processing both touchpad and trackpoint data.
> 
> The issue isn't so much getting information from the trackpoint but
> sending information TO it. The trackpoint driver is able to send

But because we do not have direct access to serio PS/2 bus to trackpoint
hardware, we cannot use trackpoint.c driver and so trackpoint.c code is
for ALPS devices useless.

> special commands to the trackpoint to modify its behavior. As far as I
> can tell, this is pretty much the only thing it does. See
> drivers/input/mouse/trackpoint.c for details.
> 
> > Questions are: Do we need full access to trackpoint hardware? Do we know
> > if trackpoint (used by ALPS input solutions) supports configuring speed
> > or acceleration in hardware? It is really not easier to do it in
> > software?
> 
> As I mentioned in my first email, I'm aware that mouse behavior can be
> modified in userspace. However, that's not what I'm asking about. I
> want to have the same capabilities with this device as I had with the
> old one, if at all possible.

Ok, which are those capabilities?

> And anyways, there are some things that
> the trackpoint driver can do that cannot be done in software.
> 

What cannot be done in software? I still think that trackpoint is
"stupid" HW with firmware which doing all that magic. And I do not see
reason why something implement in firmware software cannot be done in
userspace application (or in kernel driver if it makes sense).

> Ari
> 
> > --
> > Pali Rohár
> > pali.rohar@gmail.com

-- 
Pali Rohár
pali.rohar@gmail.com
--
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Re: ALPS v7 trackpad passthrough to Thinkpad trackpoint

[Dmitry Torokhov]

On Thu, Aug 13, 2015 at 01:03:17PM +0200, Pali Rohár wrote:
> On Friday 07 August 2015 12:35:33 Ari Entlich wrote:
> > On Fri, Aug 7, 2015 at 10:12 AM, Pali Rohár <pali.rohar@gmail.com> wrote:
> > > For some old ALPS devices which use V1 and V2 protocols (with flag
> > > ALPS_PASS) there is something like that. On that devices touchpad is
> > > behind trackpoint HW. But you cannot wait for data or poll for both
> > > devices at same time -- you need to choose if tou want to talk directly
> > > to touchpad (via passthrough mode) or just to trackpoint. I think
> > > because of this limitation ALPS driver implement all logic in one
> > > driver...
> > >
> > > Above was for old ALPS devices. New ALPS devices with V3 or V5 protocols
> > > have trackpoint behind touchpad, so normally OS communicate with
> > > touchpad (and not with trackstick like before). But here touchpad sends
> > > data for both touchpad and trackstick events and so OS does not have
> > > normal access to "hidden" trackstick.
> > >
> > > There is a way "jump" into passthrough mode and talk directly to
> > > trackpoint. But it is used only for configuring trackstick and currently
> > > it is used to configure trackstick so it send data (via touchpad) in
> > > format which is supported by our ALPS driver.
> > >
> > > On the other hand, synaptics driver and devices support full
> > > "encapsulation" or how can I call it of serio PS/2 device and in this
> > > case you can use full set of PS/2 commands directly with trackstick
> > > (behind synaptics touchpad). ALPS devices do not support something like
> > > that.
> > 
> > It looks to me like the Synaptics passthrough is implemented primarily
> > via the ability to write directly to the trackpoint. Events coming
> > from the trackpoint are implemented similarly to the ALPS driver - by
> > redirecting trackpoint events to the second device which the driver
> > creates for the trackpoint.
> > 
> 
> No, passthrough for ALPS and Synaptics differ. Synaptics driver exports
> full serio PS/2 bus on which can be attached psmouse.ko driver with full
> mouse detection (or any other serio driver) and so there can be full
> TPPS/2 trackpoint.c protocol driver.
> 
> ALPS allows us for *some* protocol version passthrough data directly to
> touchpad (or trackpoint) device. There is no support to exporting full
> serio bus with PS/2 access to it (like for Synaptics hardware).

At least we do not know how to detect and activate it even if it exists.

Let's add some ALPS people to the thread: maybe they could share some
details on accessing trackpoints behind the touchpads with us.

Thanks.

-- 
Dmitry
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Re: ALPS v7 trackpad passthrough to Thinkpad trackpoint

[Dmitry Torokhov]

Hi Vadim,

On Thu, Aug 13, 2015 at 06:11:22PM -0600, Vadim Klishko wrote:
> I am not sure I understand what details you are looking for, but as
> far as I know, the only way a command sent to an Alps device from the
> host could reach the trackstick is when the touchpad chip is in
> pass-thru mode.

We are looking for information on how to detect whether a device
supports pass-through mode and how to activate it. IOW we are looking
for the protocol specs for the PS/2 flavor used by ALPS devices. So far
we had to deduce many of the details itself and it would be great if
manufacturer would share the information with us sol that we could
improve support for the devices in Linux kernel.

Thanks.

> 
> 
> ----- Original Message ----- 
> From: "Dmitry Torokhov" <dmitry.torokhov@gmail.com>
> To: "Pali Rohár" <pali.rohar@gmail.com>
> Cc: "Ari Entlich" <atrigent@gmail.com>; <linux-input@vger.kernel.org>; "Masaki Ota" <012nexus@gmail.com>; "Tommy Will" <tommywill2011@gmail.com>; "Yunkang Tang" <yunkang.tang@cn.alps.com>; "Qiting Chen" <qiting.chen@cn.alps.com>; "Qiting Chen" <elaineee66@gmail.com>; <vadim@cirque.com>
> Sent: Thursday, August 13, 2015 4:48 PM
> Subject: Re: ALPS v7 trackpad passthrough to Thinkpad trackpoint
> 
> 
> > On Thu, Aug 13, 2015 at 01:03:17PM +0200, Pali Rohár wrote:
> >> On Friday 07 August 2015 12:35:33 Ari Entlich wrote:
> >> > On Fri, Aug 7, 2015 at 10:12 AM, Pali Rohár <pali.rohar@gmail.com> wrote:
> >> > > For some old ALPS devices which use V1 and V2 protocols (with flag
> >> > > ALPS_PASS) there is something like that. On that devices touchpad is
> >> > > behind trackpoint HW. But you cannot wait for data or poll for both
> >> > > devices at same time -- you need to choose if tou want to talk directly
> >> > > to touchpad (via passthrough mode) or just to trackpoint. I think
> >> > > because of this limitation ALPS driver implement all logic in one
> >> > > driver...
> >> > >
> >> > > Above was for old ALPS devices. New ALPS devices with V3 or V5 protocols
> >> > > have trackpoint behind touchpad, so normally OS communicate with
> >> > > touchpad (and not with trackstick like before). But here touchpad sends
> >> > > data for both touchpad and trackstick events and so OS does not have
> >> > > normal access to "hidden" trackstick.
> >> > >
> >> > > There is a way "jump" into passthrough mode and talk directly to
> >> > > trackpoint. But it is used only for configuring trackstick and currently
> >> > > it is used to configure trackstick so it send data (via touchpad) in
> >> > > format which is supported by our ALPS driver.
> >> > >
> >> > > On the other hand, synaptics driver and devices support full
> >> > > "encapsulation" or how can I call it of serio PS/2 device and in this
> >> > > case you can use full set of PS/2 commands directly with trackstick
> >> > > (behind synaptics touchpad). ALPS devices do not support something like
> >> > > that.
> >> > 
> >> > It looks to me like the Synaptics passthrough is implemented primarily
> >> > via the ability to write directly to the trackpoint. Events coming
> >> > from the trackpoint are implemented similarly to the ALPS driver - by
> >> > redirecting trackpoint events to the second device which the driver
> >> > creates for the trackpoint.
> >> > 
> >> 
> >> No, passthrough for ALPS and Synaptics differ. Synaptics driver exports
> >> full serio PS/2 bus on which can be attached psmouse.ko driver with full
> >> mouse detection (or any other serio driver) and so there can be full
> >> TPPS/2 trackpoint.c protocol driver.
> >> 
> >> ALPS allows us for *some* protocol version passthrough data directly to
> >> touchpad (or trackpoint) device. There is no support to exporting full
> >> serio bus with PS/2 access to it (like for Synaptics hardware).
> > 
> > At least we do not know how to detect and activate it even if it exists.
> > 
> > Let's add some ALPS people to the thread: maybe they could share some
> > details on accessing trackpoints behind the touchpads with us.
> > 
> > Thanks.
> > 
> > -- 
> > Dmitry
> 
> -- 
> This message and any attachment are confidential. It may also be privileged 
> or otherwise protected by work product immunity or other legal rules. If 
> you have received it by mistake, please let us know by e-mail reply and 
> delete it from your system, you may not copy this message or disclose its 
> contents to anyone.
> Cirque Corporation

-- 
Dmitry
--
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Re: ALPS v7 trackpad passthrough to Thinkpad trackpoint

[Vadim Klishko]

> On Thu, Aug 13, 2015 at 06:11:22PM -0600, Vadim Klishko wrote:
>> I am not sure I understand what details you are looking for, but as
>> far as I know, the only way a command sent to an Alps device from the
>> host could reach the trackstick is when the touchpad chip is in
>> pass-thru mode.
> 
> We are looking for information on how to detect whether a device
> supports pass-through mode and how to activate it. IOW we are looking
> for the protocol specs for the PS/2 flavor used by ALPS devices. So far
> we had to deduce many of the details itself and it would be great if
> manufacturer would share the information with us sol that we could
> improve support for the devices in Linux kernel.
> 
OK, got it. It may take some time.


>> 
>> 
>> ----- Original Message ----- 
>> From: "Dmitry Torokhov" <dmitry.torokhov@gmail.com>
>> To: "Pali Rohár" <pali.rohar@gmail.com>
>> Cc: "Ari Entlich" <atrigent@gmail.com>; <linux-input@vger.kernel.org>; "Masaki Ota" <012nexus@gmail.com>; "Tommy Will" <tommywill2011@gmail.com>; "Yunkang Tang" <yunkang.tang@cn.alps.com>; "Qiting Chen" <qiting.chen@cn.alps.com>; "Qiting Chen" <elaineee66@gmail.com>; <vadim@cirque.com>
>> Sent: Thursday, August 13, 2015 4:48 PM
>> Subject: Re: ALPS v7 trackpad passthrough to Thinkpad trackpoint
>> 
>> 
>> > On Thu, Aug 13, 2015 at 01:03:17PM +0200, Pali Rohár wrote:
>> >> On Friday 07 August 2015 12:35:33 Ari Entlich wrote:
>> >> > On Fri, Aug 7, 2015 at 10:12 AM, Pali Rohár <pali.rohar@gmail.com> wrote:
>> >> > > For some old ALPS devices which use V1 and V2 protocols (with flag
>> >> > > ALPS_PASS) there is something like that. On that devices touchpad is
>> >> > > behind trackpoint HW. But you cannot wait for data or poll for both
>> >> > > devices at same time -- you need to choose if tou want to talk directly
>> >> > > to touchpad (via passthrough mode) or just to trackpoint. I think
>> >> > > because of this limitation ALPS driver implement all logic in one
>> >> > > driver...
>> >> > >
>> >> > > Above was for old ALPS devices. New ALPS devices with V3 or V5 protocols
>> >> > > have trackpoint behind touchpad, so normally OS communicate with
>> >> > > touchpad (and not with trackstick like before). But here touchpad sends
>> >> > > data for both touchpad and trackstick events and so OS does not have
>> >> > > normal access to "hidden" trackstick.
>> >> > >
>> >> > > There is a way "jump" into passthrough mode and talk directly to
>> >> > > trackpoint. But it is used only for configuring trackstick and currently
>> >> > > it is used to configure trackstick so it send data (via touchpad) in
>> >> > > format which is supported by our ALPS driver.
>> >> > >
>> >> > > On the other hand, synaptics driver and devices support full
>> >> > > "encapsulation" or how can I call it of serio PS/2 device and in this
>> >> > > case you can use full set of PS/2 commands directly with trackstick
>> >> > > (behind synaptics touchpad). ALPS devices do not support something like
>> >> > > that.
>> >> > 
>> >> > It looks to me like the Synaptics passthrough is implemented primarily
>> >> > via the ability to write directly to the trackpoint. Events coming
>> >> > from the trackpoint are implemented similarly to the ALPS driver - by
>> >> > redirecting trackpoint events to the second device which the driver
>> >> > creates for the trackpoint.
>> >> > 
>> >> 
>> >> No, passthrough for ALPS and Synaptics differ. Synaptics driver exports
>> >> full serio PS/2 bus on which can be attached psmouse.ko driver with full
>> >> mouse detection (or any other serio driver) and so there can be full
>> >> TPPS/2 trackpoint.c protocol driver.
>> >> 
>> >> ALPS allows us for *some* protocol version passthrough data directly to
>> >> touchpad (or trackpoint) device. There is no support to exporting full
>> >> serio bus with PS/2 access to it (like for Synaptics hardware).
>> > 
>> > At least we do not know how to detect and activate it even if it exists.
>> > 
>> > Let's add some ALPS people to the thread: maybe they could share some
>> > details on accessing trackpoints behind the touchpads with us.
>> > 
>> > Thanks.
>> > 
>> > -- 
>> > Dmitry
>> 
>> -- 
>> This message and any attachment are confidential. It may also be privileged 
>> or otherwise protected by work product immunity or other legal rules. If 
>> you have received it by mistake, please let us know by e-mail reply and 
>> delete it from your system, you may not copy this message or disclose its 
>> contents to anyone.
>> Cirque Corporation
> 
> -- 
> Dmitry

-- 
This message and any attachment are confidential. It may also be privileged 
or otherwise protected by work product immunity or other legal rules. If 
you have received it by mistake, please let us know by e-mail reply and 
delete it from your system, you may not copy this message or disclose its 
contents to anyone.
Cirque Corporation
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Re: ALPS v7 trackpad passthrough to Thinkpad trackpoint

[Ari Entlich]

On Thu, Aug 13, 2015 at 8:25 PM, Vadim Klishko <vadim@cirque.com> wrote:
> OK, got it. It may take some time.

Just to make sure: are you saying that there definitely is some
incantation for v7 devices that the Linux driver doesn't know about
and that will allow sending commands directly to the trackpoint? If
so, that's awesome! From looking at the commit log for the alps
driver, it looks like ALPS people have been helping out a bit
recently, which is a great trend. Releasing the full spec would be the
ultimate gesture of good-will to the open-source community. If that
happens, I'll be happy for whatever small part I played in making it
happen.

However, for impatient people (such as me), I'm wondering whether it
would be possible to reveal specifically the passthrough incantation
in advance of the full spec, assuming it is not too complex. I know
how involved it can be to release hardware specs, and I'm anxious to
try some of this out.

Thanks!

Ari

> --
> This message and any attachment are confidential. It may also be privileged
> or otherwise protected by work product immunity or other legal rules. If
> you have received it by mistake, please let us know by e-mail reply and
> delete it from your system, you may not copy this message or disclose its
> contents to anyone.
> Cirque Corporation

Re: ALPS v7 trackpad passthrough to Thinkpad trackpoint

[Pali Rohár]

On Thursday 13 August 2015 18:25:16 Vadim Klishko wrote:
> > On Thu, Aug 13, 2015 at 06:11:22PM -0600, Vadim Klishko wrote:
> >> I am not sure I understand what details you are looking for, but as
> >> far as I know, the only way a command sent to an Alps device from the
> >> host could reach the trackstick is when the touchpad chip is in
> >> pass-thru mode.
> > 
> > We are looking for information on how to detect whether a device
> > supports pass-through mode and how to activate it. IOW we are looking
> > for the protocol specs for the PS/2 flavor used by ALPS devices. So far
> > we had to deduce many of the details itself and it would be great if
> > manufacturer would share the information with us sol that we could
> > improve support for the devices in Linux kernel.
> > 
> OK, got it. It may take some time.
> 

Hi Vadim! Now after more months, do you have some news about this?

> 
> >> 
> >> 
> >> ----- Original Message ----- 
> >> From: "Dmitry Torokhov" <dmitry.torokhov@gmail.com>
> >> To: "Pali Rohár" <pali.rohar@gmail.com>
> >> Cc: "Ari Entlich" <atrigent@gmail.com>; <linux-input@vger.kernel.org>; "Masaki Ota" <012nexus@gmail.com>; "Tommy Will" <tommywill2011@gmail.com>; "Yunkang Tang" <yunkang.tang@cn.alps.com>; "Qiting Chen" <qiting.chen@cn.alps.com>; "Qiting Chen" <elaineee66@gmail.com>; <vadim@cirque.com>
> >> Sent: Thursday, August 13, 2015 4:48 PM
> >> Subject: Re: ALPS v7 trackpad passthrough to Thinkpad trackpoint
> >> 
> >> 
> >> > On Thu, Aug 13, 2015 at 01:03:17PM +0200, Pali Rohár wrote:
> >> >> On Friday 07 August 2015 12:35:33 Ari Entlich wrote:
> >> >> > On Fri, Aug 7, 2015 at 10:12 AM, Pali Rohár <pali.rohar@gmail.com> wrote:
> >> >> > > For some old ALPS devices which use V1 and V2 protocols (with flag
> >> >> > > ALPS_PASS) there is something like that. On that devices touchpad is
> >> >> > > behind trackpoint HW. But you cannot wait for data or poll for both
> >> >> > > devices at same time -- you need to choose if tou want to talk directly
> >> >> > > to touchpad (via passthrough mode) or just to trackpoint. I think
> >> >> > > because of this limitation ALPS driver implement all logic in one
> >> >> > > driver...
> >> >> > >
> >> >> > > Above was for old ALPS devices. New ALPS devices with V3 or V5 protocols
> >> >> > > have trackpoint behind touchpad, so normally OS communicate with
> >> >> > > touchpad (and not with trackstick like before). But here touchpad sends
> >> >> > > data for both touchpad and trackstick events and so OS does not have
> >> >> > > normal access to "hidden" trackstick.
> >> >> > >
> >> >> > > There is a way "jump" into passthrough mode and talk directly to
> >> >> > > trackpoint. But it is used only for configuring trackstick and currently
> >> >> > > it is used to configure trackstick so it send data (via touchpad) in
> >> >> > > format which is supported by our ALPS driver.
> >> >> > >
> >> >> > > On the other hand, synaptics driver and devices support full
> >> >> > > "encapsulation" or how can I call it of serio PS/2 device and in this
> >> >> > > case you can use full set of PS/2 commands directly with trackstick
> >> >> > > (behind synaptics touchpad). ALPS devices do not support something like
> >> >> > > that.
> >> >> > 
> >> >> > It looks to me like the Synaptics passthrough is implemented primarily
> >> >> > via the ability to write directly to the trackpoint. Events coming
> >> >> > from the trackpoint are implemented similarly to the ALPS driver - by
> >> >> > redirecting trackpoint events to the second device which the driver
> >> >> > creates for the trackpoint.
> >> >> > 
> >> >> 
> >> >> No, passthrough for ALPS and Synaptics differ. Synaptics driver exports
> >> >> full serio PS/2 bus on which can be attached psmouse.ko driver with full
> >> >> mouse detection (or any other serio driver) and so there can be full
> >> >> TPPS/2 trackpoint.c protocol driver.
> >> >> 
> >> >> ALPS allows us for *some* protocol version passthrough data directly to
> >> >> touchpad (or trackpoint) device. There is no support to exporting full
> >> >> serio bus with PS/2 access to it (like for Synaptics hardware).
> >> > 
> >> > At least we do not know how to detect and activate it even if it exists.
> >> > 
> >> > Let's add some ALPS people to the thread: maybe they could share some
> >> > details on accessing trackpoints behind the touchpads with us.
> >> > 
> >> > Thanks.
> >> > 
> >> > -- 
> >> > Dmitry
> >> 
> >> -- 
> >> This message and any attachment are confidential. It may also be privileged 
> >> or otherwise protected by work product immunity or other legal rules. If 
> >> you have received it by mistake, please let us know by e-mail reply and 
> >> delete it from your system, you may not copy this message or disclose its 
> >> contents to anyone.
> >> Cirque Corporation
> > 
> > -- 
> > Dmitry
> 

-- 
Pali Rohár
pali.rohar@gmail.com
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Re: ALPS v7 trackpad passthrough to Thinkpad trackpoint

[Ari Entlich]

On Thu, Jan 21, 2016 at 8:50 PM, Vadim Klishko <vadim@cirque.com> wrote:
> However, it looks like you already know everything there is to know about
> how to set the trackpad in pass-thru mode and how to check if there is a
> trackstick behind the trackpad. The code is already in alps.c

The original question was specifically about devices which use the v7
protocol. It looks to me like alps.c only includes code for
passthrough on v2 and v3 devices, unless alps_passthrough_mode_v2 or
alps_passthrough_mode_v3 would also work on v7 devices. I believe we
would also need to know whether passthrough support is always present
on v7 devices with tracksticks or whether its presence needs to be
detected somehow.

Also, neither of these passthrough modes are being used to provide a
full serio device for the trackstick, but that might just be a
limitation of the driver.

Thanks.

Ari

Re: ALPS v7 trackpad passthrough to Thinkpad trackpoint

[Pali Rohár]

On Thursday 21 January 2016 22:38:57 Ari Entlich wrote:
> On Thu, Jan 21, 2016 at 8:50 PM, Vadim Klishko <vadim@cirque.com> wrote:
> > However, it looks like you already know everything there is to know about
> > how to set the trackpad in pass-thru mode and how to check if there is a
> > trackstick behind the trackpad. The code is already in alps.c
> 
> The original question was specifically about devices which use the v7
> protocol. It looks to me like alps.c only includes code for
> passthrough on v2 and v3 devices, unless alps_passthrough_mode_v2 or
> alps_passthrough_mode_v3 would also work on v7 devices. I believe we
> would also need to know whether passthrough support is always present
> on v7 devices with tracksticks or whether its presence needs to be
> detected somehow.

For v7 see my patch which was finally after Alex testing included:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=dae928ec3c29e7e16723c9c4c1299e00f4e9e949

> Also, neither of these passthrough modes are being used to provide a
> full serio device for the trackstick, but that might just be a
> limitation of the driver.

Yes, question for Vadim about providing full serio passthrough
trackstick device reminds open.

-- 
Pali Rohár
pali.rohar@gmail.com
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