Re: ALPS touchpad with new Dell not recognised

[Vojtech Pavlik <vojtech@suse.cz>]

On Sun, Aug 05, 2007 at 08:45:29AM +1000, William Pettersson wrote:
> Hi,
> This patch adds support for the Alps touchpad on my Dell Vostro 1400 to
> the linux kernel.
> 
> Signed-off-by: William Pettersson <william.pettersson@gmail.com>
> 
> Vojtech, I went over my debug info again with your thoughts in mind, and
> you were right.  The highest bit is always set in the sync byte of the
> protocol.  It must have been luck that it didn't drop sync while it was
> testing.  So a mask and bit of 0xCF does work.  I then decided to go
> through the logs more thoroughly, and determine if I could make this
> mask more rigid.  Turns out that a bit of 0xCF and a mask of 0xFF also
> works.

Just one more question: Have you checked that the 0xcf doesn't change
when you press any of the ALPS buttons? Including those associated with
the passthrough? Some bits in the sync byte might still be mapped to
these.

> I've also attached the output dumps.  The one labelled mouse.nosync.log
> is the the one that I first worked on.  However, it was hard to see
> where the start of the packets were, so I modified alps.c to give me the
> output shown in alps-packets.log (I can submit this patch if you deem it
> useful too).  It was once I did this that I saw straight away what the
> bit0 had to be.  And then mouse.alps.log is just i8042.debug output
> after my patch has been applied.
> 
> William
> 
> Vojtech Pavlik wrote:
> > On Sat, Aug 04, 2007 at 10:15:54PM +1000, William Pettersson wrote:
> >
> >   
> >> Hi LKML,
> >> Thanks to Vojtech for some advice, I finally got something happening
> >> with this.  Turns out I had to add support for a new model in alps.c,
> >> the attached file does this successfully for my laptop.  It'd be nice to
> >> have others test it, but I am yet to find anyone else who has this same
> >> laptop, with the same mouse issues I have.
> >>
> >> With this patch, I now get a functioning touchpad, including side
> >> scrolling, circle scrolling, corner taps etc.  However, I did have to
> >> ramp the configuration numbers up significantly from my old Thinkpad
> >> with its synaptics touchpad.
> >>     
> >
> > That is normal. The ALPS's have very much different parameters -
> > sensitivity, resolution, etc., so that the settings aren't easily
> > comparable.
> >
> >   
> >> Minspeed is now 0.8 and maxspeed is 10. 
> >> Also the VertScrollDelta is 10.  I don't know whether these numbers are
> >> crazy high, or just normal for the Alps though.
> >>     
> >
> > I don't remember exactly myself - I'm only interested in the low level
> > of the protocol - making sure the kernel delivers correctly decoded data
> > to userspace.
> >
> > Please send the patch to Dmitry Torokhov, who is nowadays a maintainer
> > of this driver and the input subsystem. And don't forget to add a
> > description of the patch and a "Signed-off-by:" line.
> >
> > I'm quite surprised you needed the value of 0x4f, I'd expect the highest
> > bit always set in the sync byte of the protocol. Can you send me (and
> > dmitry) the dump data you gathered using i8042.debug?
> >
> > Thanks,
> > 	Vojtech
> >
> >   
> >> --- drivers/input/mouse/alps.c.old	2007-07-31 21:42:37.000000000 +1000
> >> +++ drivers/input/mouse/alps.c	2007-08-04 21:45:43.000000000 +1000
> >> @@ -53,6 +53,7 @@
> >>  	{ { 0x20, 0x02, 0x0e },	0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT }, /* XXX */
> >>  	{ { 0x22, 0x02, 0x0a },	0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT },
> >>  	{ { 0x22, 0x02, 0x14 }, 0xff, 0xff, ALPS_PASS | ALPS_DUALPOINT }, /* Dell Latitude D600 */
> >> +	{ { 0x73, 0x02, 0x50 }, 0x4f, 0x4f, ALPS_FW_BK_1 } /* Dell Vostro 1400 */
> >>  };
> >>     
> >
> >   

> --- drivers/input/mouse/alps.c.old	2007-07-31 21:42:37.000000000 +1000
> +++ drivers/input/mouse/alps.c	2007-08-05 08:34:00.000000000 +1000
> @@ -53,6 +53,7 @@
>  	{ { 0x20, 0x02, 0x0e },	0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT }, /* XXX */
>  	{ { 0x22, 0x02, 0x0a },	0xf8, 0xf8, ALPS_PASS | ALPS_DUALPOINT },
>  	{ { 0x22, 0x02, 0x14 }, 0xff, 0xff, ALPS_PASS | ALPS_DUALPOINT }, /* Dell Latitude D600 */
> +	{ { 0x73, 0x02, 0x50 }, 0xcf, 0xff, ALPS_FW_BK_1 } /* Dell Vostro 1400 */
>  };
>  
>  /*





-- 
Vojtech Pavlik
Director SuSE Labs