RE: [RFC] Staging:IIO: New ABI

From: Hennerich, Michael
Date: Tue Jan 26 2010 - 04:55:57 EST

>From: Dmitry Torokhov [mailto:dmitry.torokhov@xxxxxxxxx]
>On Fri, Jan 22, 2010 at 04:31:12PM -0800, Greg KH wrote:
>> On Fri, Jan 22, 2010 at 04:14:15PM -0800, Dmitry Torokhov wrote:
>> > On Fri, Jan 22, 2010 at 12:47:18PM -0800, Greg KH wrote:
>> > > On Wed, Jan 20, 2010 at 04:53:21PM +0000, Jonathan Cameron wrote:
>> > > > I am not aware of these. Could you direct me to the current api? Also note that these
>> > > > aren't the actual alarms, merely a means of enabling the relevant event on the related
>> > > > event character device.
>> > >
>> > > Hm, I thought we had an accelerator interface somewhere...
>> > >
>> >
>> > Nope. And I am also interested in this since I am sittign on a bunch of
>> > accelerometers, magnetometers, etc drivers that are trying to plug into
>> > input sysbsystem and quite unsure what to do with them.
>> >
>> > It was OK whch HDAPS and friends when they were using input for
>> > secondary, toyish purposes, but these new drivers trying to use input
>> > devnts as primary API and I am unsure if it is the best solution.
>> > Accelerometer might be used as an input device but not always an input
>> > device.
>> Yeah, I see it using a joystick interface, which might be acceptable for
>> "toy" devices like you say.
>> But for "real" ones, we should do something else.
>> Maybe, for devices that are going to be used by, like the "toy"
>> ones, we stick with the current input interface, but for others, we use
>> a "real" interface, probably through hwmon, so that users can get the
>> real data out in a consistant manner.
>I'd rather have all of them use real interface and then have a bridge
>to input module to enable toyish mode (unless the device in question
>is really truly an input device).

I really don't see that hwmon provides facilities like input/evdev does.
Queuing of events with time stamping and multiple reader support.
The adxl34x accelerometer driver for example is really intended to be a input device.
Send EV_KEY for x,y,z_TAP detections, send EV_KEY for 3D orientation sensing, and EV_ABS for acceleration.
With very minor platform data customization you can use this device for game controls or GUI interaction.
A few examples include digital picture frames, ebook readers, etc.


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