Re: ALPS touchpad ot correctly recognized: GlidePoint vs DualPoint

["Pali Rohár" <pali.rohar@gmail.com>]

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On Monday 11 September 2017 13:26:30 Juanito wrote:
> Hi Masaki Ota,
> 
> Thanks!
> 
> On 11.09.2017 04:38, Masaki Ota wrote:
> > Hi, Juanito,
> > 
> > In my information, ALPS Touchpad is used on Thinkpad E series and L series.
> > I don't know the device that is ALPS Touchpad + other vendor TrackStick.
> > But Lenovo might use ALPS Touchpad on such a combination.
> > 
> 
> Well, that is probably my fault, as it is not the original touchpad that
> was delievered with the laptop. I bought the touchpad (that included
> the three buttons) separately because I didn't like the clickpad that
> came with my laptop.

Hi Juanito,

if you are still want to play with your touchpad hardware, I have a good
news for your.

It looks like that at least ALPS rushmore touchpads allow to receive RAW
PS/2 packets from trackstick to host kernel, without modifying them by
touchpad. Plus I was able to tell ALPS touchpad to start "mixing" those
RAW trackstick PS/2 packets with native touchpad packets.

On my configuration trackstick in RAW PS/2 mode by default talks with
standard bare 3 byte PS/2 protocol and touchpad in 6 byte ALPS protocol.
alps.c/psmouse.ko is already able to process and parse such mixed
packets. And trackstick can be switched to some extended 4 byte
protocol...

All this happen when passthrough mode is enabled.

From my understanding it seems that in normal mode, touchpad and
trackstick communicate with that 4 byte protocol and touchpad converts
it into 6 byte ALPS protocol and then send to kernel.

On thinkpads trackstick communicate with TPPS/2 protcol and above 4
byte. So in my opinion ALPS touchpad by default cannot understand it.
But you should be able to enter passthrough mode and then you would
receive that TPPS/2 in alps kernel code.

> > And I have found that the V7 protocol device has a special ID for Lenovo.
> > ALPS assigns the value that is the model type to 0xC399 address.
> > 
> > Could you check 0xC399 address value such like a below code?
> > reg_val = alps_command_mode_read_reg(psmouse, 0xC399);
> > 
> > If the value is 0x1 or 0x2 or 0x6 or 0x10 or 0xF, it has a Stick buttons.
> > 
> 
> I will check this as soon as I can (I don't have access to the laptop
> right now).
> 
> > Best Regards,
> > Masaki Ota
> > -----Original Message-----
> > From: Juanito [mailto:juam+kernel@posteo.net] 
> > Sent: Sunday, September 10, 2017 3:22 AM
> > To: Dmitry Torokhov <dmitry.torokhov@gmail.com>; Pali Rohár <pali.rohar@gmail.com>
> > Cc: 太田 真喜 Masaki Ota <masaki.ota@jp.alps.com>; linux-input@vger.kernel.org; Paul Donohue <linux-kernel@paulsd.com>
> > Subject: Re: ALPS touchpad ot correctly recognized: GlidePoint vs DualPoint
> > 
> > On 09/09/2017 08:12 PM, Dmitry Torokhov wrote:
> >> On Sat, Sep 09, 2017 at 10:36:06AM +0200, Pali Rohár wrote:
> >>> On Saturday 09 September 2017 10:12:42 Juanito wrote:
> >>>> Hello,
> >>>>
> >>>> On 09/08/2017 08:48 AM, Pali Rohár wrote:
> >>>>> On Friday 08 September 2017 07:00:34 Juanito wrote:
> >>>>>>> ThinkPad with ALPS? Should not be it Synaptic? Maybe 
> >>>>>>> miss-detection?
> >>>>>>
> >>>>>> Sorry, I forgot to mention this. The ThinkPad came with a clickpad 
> >>>>>> I **really** disliked, so I bought this on the Internet.
> >>>>>
> >>>>> So, here is a problem. ThinkPads works with Synaptic touchpads, not 
> >>>>> with ALPS.
> >>>>
> >>>> There definitely seems to be a problem here :)
> >>>>
> >>>> Do you mean that the alps code might not be detecting the trackpoint 
> >>>> because probably the red thingie works with synaptics?
> >>>>
> >>>> So could this be the situation:
> >>>> ALPS driver: Hey touchpad! Do you have a trackstick?
> >>>> ALPS touchpad: No, I don't.
> >>>> AD: Ok! (and thinks 'I am going to have to ignore all trackstick 
> >>>> packets that might arrive')
> >>>>
> >>>> So the driver understands that there can't possibly be any buttons 
> >>>> because there is no trackstick?
> >>>
> >>> IIRC ALPS touchpad hardware itself does not work with non-ALPS 
> >>> trackpoint.
> >>>
> >>> Masaki, any comments?
> >>>
> >>>>>> If by trackstick you mean the red thingie, it is **not** working.
> >>>>>
> >>>>> Ok. And it is working with your patch?
> >>>>
> >>>> No, it isn't :(
> >>>
> >>> I expected... You just created franken-hardware.
> >>>
> >>> Looks like with your hack patch it is possible to make buttons 
> >>> working, but I suspect that trackstick would.
> >>>
> >>> Maybe Masaki can provide more information about this fact if we can 
> >>> do anything.
> >>>
> >>> Dmitry, what you as maintainer going to do with this problem?
> >>
> >> It really depends on Ota-san response. If ALPS needs a special version 
> >> of firmware flashed for proper trackstick identification, then I guess 
> >> Juanito will have to carry a local patch. I do not think we want to 
> >> complicate the driver any further for supporting such after-market 
> >> modification.
> >>
> > 
> > If this only happens in this after-market (or franken-hardware...
> > hahaha), I'd totally understand if you didn't want to patch it upstream, although it would be nice for me :)
> > 
> >> Does booting with psmouse.proto=imps makes trackstick work?
> >>
> > 
> > I am afraid I can't test it now as I don't have access to the laptop. I won't be able to test until two weeks. Will definitely do as soon as I can.
> > 
> >> Thanks.
> >>
> > 
> > Thank **you** (Dmitry and everybody esle) for taking the time to look at this.
> > 
> > Juanito
> > 
> 
> 
> Thank you very much!
> 
> Best regards,
> Juanito
> 

-- 
Pali Rohár
pali.rohar@gmail.com

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