On Wed, Dec 02, 2009 at 10:37:02AM -0500, Jon Smirl wrote: > On Wed, Dec 2, 2009 at 4:38 AM, Dmitry Torokhov > <dmitry.torokhov@xxxxxxxxx> wrote: > > On Tue, Dec 01, 2009 at 07:05:49PM -0200, Mauro Carvalho Chehab wrote: > >> 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 property > >> that is not related to raw IO mode but, instead, to evdev mode. > >> > > > > Why would protocol relate to evdev node? Evdev does not really care what > > how the fact that a certain button was pressed was communicated to it. > > It may be deliveretd through PS/2 port, or maybe it was Bluetooth HID, > > or USB HID or USB boot protocol or some custom protocol, or RC-5, NEC or > > some custom IR protocol. It makes no difference _whatsoever_ to evdev > > nor any users of evdev care about protocol used by underlying hardware > > device to transmit the data. > > > >> 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 evdev > >> interface. > >> > >> 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 kept > >> oustide input core, as they're specific to IR implementations. > >> > >> Would this work for you? > > > > I am seeing a little bit differently structured subsystem for IR at the > > moment. I think we should do something like this: > > > > - receivers create /sys/class/lirc devices. These devices provide API > > with a ring buffer (fifo) for the raw data stream coming from (and to) > > them. > > The FIFO will have to appear as a /dev/device or be in debugfs. GregKH > sent earlier mail telling me to get the FIFO out of sysfs. > No, I expect it not to be directly exposed to userspace at all, just a part of in-kernel subsystem API. This is the way interfaces/decoders will communicate with drivers. lirc_dev interface will take data from fifo and send to userspace. > > - we allow registering several data interfaces/decoders that can be bound > > (manually or maybe automatically) to lirc devices. lirc devices may > > provide hints as to which interface(s) better suited for handling the > > data coming form particular receiver. Several interfaces may be bound > > to one device at a time. > > - one of the interfaces is interface implementing current lirc_dev > > - other interfaces may be in-kernel RC-5 decoder or other decoders. > > decoders will create instances of input devices (for each > > remote/substream that they can recognize). > > This includes defining IR events for evdev with vendor/device/command triplets? No, I believe that adding EV_IR type of events to evdev would be a mistake. > You need those standard events to make apps IR aware. > But I do not want to make application IR-aware. If applications want to be IR-aware they can work with lircd. I want applications react to buttons/actions no matter which device issues those as long as the codes are the same. IOW if you happen to have multimedia-type USB keyboard that has button for play and you have a IR that has that button as well I'd expect application to perform the same response (start playing). > LIRC will also need to inject those events after decoding pulse data. > LIRC will need to inject EV_KEY events. > > > > This way there is clear layering, protocol selection is kept at lirc > > level. > > Did you checkout capabilities bits in evdev? Not sure if I understand the question.. Yes, I am aware that evdev presents capabilities of the device userspace; no, I do not think that they are applicable here (since there won't be EV_IR events). -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
