Dmitry Torokhov wrote:
> On Tue, Dec 01, 2009 at 05:00:40PM -0200, Mauro Carvalho Chehab wrote:
>> Dmitry Torokhov wrote:
>>> On Tue, Dec 01, 2009 at 03:29:44PM -0200, Mauro Carvalho Chehab wrote:
>>>> For sure we need to add an EVIOSETPROTO ioctl to allow the driver 
>>>> to change the protocol in runtime.
>>> Mauro,
>>> I think this kind of confuguration belongs to lirc device space,
>>> not input/evdev. This is the same as protocol selection for psmouse
>>> module: while it is normally auto-detected we have sysfs attribute to
>>> force one or another and it is tied to serio device, not input
>>> device.
>> Dmitry,
>> This has nothing to do with the raw interface nor with lirc. This problem 
>> happens with the evdev interface and already affects the in-kernel drivers.
>> In this case, psmouse is not a good example. With a mouse, when a movement
>> occurs, you'll receive some data from its port. So, a software can autodetect
>> the protocol. The same principle can be used also with a raw pulse/space
>> interface, where software can autodetect the protocol.
> Or, in certain cases, it can not.
> [... skipped rationale for adding a way to control protocol (with which
> I agree) ...]
>> To solve this, we really need to extend evdev API to do 3 things: enumberate 
>> the
>> supported protocols, get the current protocol(s), and select the protocol(s) 
>> that
>> will be used by a newer table.
> And here we start disagreeing. My preference would be for adding this
> API on lirc device level (i.e. /syc/class/lirc/lircX/blah namespace),
> since it only applicable to IR, not to input devices in general.
> Once you selected proper protocol(s) and maybe instantiated several
> input devices then udev (by examining input device capabilities and
> optionally looking up at the parent device properties) would use
> input evdev API to load proper keymap. Because translation of
> driver-specific codes into standard key definitions is in the input
> realm. Reading these driver-specific codes from hardware is outside of
> input layer domain.
> Just as psmouse ability to specify protocol is not shoved into evdev;
> just as atkbd quirks (force release key list and other driver-specific
> options) are not in evdev either; we should not overload evdev interface
> with IR-specific items.

I'm not against mapping those features as sysfs atributes, but they don't belong
to lirc, as far as I understand. From all we've discussed, we'll create a lirc
interface to allow the direct usage of raw IO. However, IR protocol is a 
that is not related to raw IO mode but, instead, to evdev mode.

We might add a /sys/class/IR and add IR specific stuff there, but it seems
overkill to me and will hide the fact that those parameters are part of the 

So, I would just add the IR sysfs parameters at the /sys/class/input, if
the device is an IR (or create it is /sys/class/input/IR).

I agree that the code to implement the IR specific sysfs parameter should be 
oustide input core, as they're specific to IR implementations.

Would this work for you?


To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to
More majordomo info at

Reply via email to