lkml.org 
[lkml]   [2005]   [Feb]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [rfc/rft] Fujitsu B-Series Lifebook PS/2 TouchScreen driver
    From
    Date
    Am Samstag, den 12.02.2005, 19:34 +0100 schrieb Vojtech Pavlik:
    > On Sat, Feb 12, 2005 at 06:01:19PM +0100, Kenan Esau wrote:
    > > Am Freitag, den 11.02.2005, 21:10 +0100 schrieb Vojtech Pavlik:
    > > > Hi!

    [...]

    > > As far as I can see the
    > > init-sequence is the one from Haralds xfree 3.3.6-driver. There is a
    > > reason why this sequence is not like that anymore in my driver.
    >
    > OK.
    >
    > > This
    > > sequence does not always work and there is not something like a "magic
    > > knock sequence".
    >
    > You mean that the only needed bit is setting the resolution to '7'?

    The lifebook touchscreen has some extensions to the standard protocol:

    0xe8 0x06: Stop absolute coordinate output
    0xe8 0x07: Start absolute coordinate outpout (3-byte packets)
    0xe8 0x08: Start absolute coord. output with 6-byte packets

    > > The lifebook-touchscreen hardware is a little bit slow
    > > and it happens quite often that it does not understand a command that
    > > you send.
    >
    > I don't believe this - the PS/2 protocol has handshakes for both sides,
    > so each side can slow down as much as it wants. PLUS, the clock is
    > driven by the device.

    I dont't know the PS2-specs. But I know the lifebook hardware quite
    well. While implementing my driver (for xfree 4.0 at that time) I
    noticed that it happens often that the device came back with an error or
    resend. I fixed this by just waiting a short time and then retry.

    If you agree I will take your patch as the basis and make it work. Now I
    know how you want it to look like.

    I think this was the kick in the ass I needed ;-)

    > > This is the reason why you often have to send a command
    > > several times until the hardware understands...
    > > Probably this was what was seen by Harald on the USB-bus and he just
    > > used this sequence.
    >
    > USB?!

    Yeah -- OK. PS2...

    [...]


    Greetings


    Kenan

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 14:10    [W:0.028 / U:1.052 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site