[mythtv-users] TiVo Slide Remote, Linux and Scan Codes

Jarod Wilson jarod at wilsonet.com
Tue Sep 7 13:38:54 UTC 2010


On Tue, Sep 7, 2010 at 8:48 AM, Wayne Thomas <waynethomas69 at gmail.com> wrote:
> On Tue, Sep 7, 2010 at 7:01 AM, Wayne Thomas <waynethomas69 at gmail.com> wrote:
>>> Live TV:
>>> drivers/hid/hid-input.c: HID Event: 0xffff 0x0
>>> drivers/hid/hid-input.c: HID Event: 0xffff 0x3e
>>> drivers/hid/hid-input.c: HID Event: 0xffff 0x3e
>>> drivers/hid/hid-input.c: HID Event: 0xffff 0x0
>>> drivers/hid/hid-input.c: HID Event: 0xc 0x20
>>
>> Can you confirm what that is the output of?

That's from pressing the live tv button. And I can now confirm that
indeed, most key presses are followed by a trailing 0xc 0x20.

> > I have nothing to compare
>> to, but that could be the result of a combination key press (i.e
>> Shift+"+10").  I am also suspicious that the 0xffff events might be
>> the result of the hid-driver not supporting a particular UP as that
>> value doesn't make sense (nor does the sequence).

0xffff is part of the range in the hid spec listed as "vendor-specific".

> ...and looking at jmk's hexdump for the select key...
>
>> hexdump /dev/usb/hiddev0
>> 0000000 0000 000c 0000 0000 0041 000c 0001 0000
>> 0000010 0041 000c 0000 0000 0000 000c 0001 0000
>> 0000020 0020 000c 0053 0000
>
> ...there does appear to be more than a single 'key-press' occurring.
> It looks to my like the output represents a key with output 0x000
> being pressed (which is ignored by hid-input by the way), 0x41 being
> pressed then released, 0x000 being released, and then, well, I'm not
> sure what the that last bit is.  Everything for 'select' is on the
> consumer page and the 0x000 is just ignored anyway which explains why
> only adding 0x41 to hid-input.c worked.
> With the output for Live TV the equivalent outputs appear to be on a
> usage page 0xffff which isn't defined as a relevant page (yet).
> HID_USAGE_PAGE is defined as 0xffff0000, but that is actually a mask
> for extracting the usage page as opposed to being the usage page.

Yes, its the mask, but in looking at the spec, its also a valid
vendor-specific usage page.

> Not
> sure what the last bit is but it is the same as that for the select
> key.  I will have a look at the output of some keys that represent
> multiple key-presses tonight to see if I can work out what this last
> bit is.
>
> If the usage page is in fact 0xffff I would recommend expanding the
> topseed driver to deal with this as the Input Devs are actually trying
> to prevent a proliferation of specific quirky drivers.  I would also
> be tempted to rename the driver to something more appropriate like
> hid-remotes but that is another story all together...

At the moment, I have all keys working after an 8-line addition to
hid-input.c. Basically, just mimic the HID_UP_FOOVENDOR cases. Going
to clean things up a bit and send in an rfc patch, see what Jiri and
Dmitry and company think.

-- 
Jarod Wilson
jarod at wilsonet.com


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