Re: [GIT PULL] Ambient Light Sensors subsystem

From: Dima Zavin
Date: Mon Mar 08 2010 - 01:29:53 EST


On Sun, Mar 7, 2010 at 12:49 PM, Dmitry Torokhov
<dmitry.torokhov@xxxxxxxxx> wrote:
> On Wed, Mar 03, 2010 at 03:08:29PM -0800, Dima Zavin wrote:
>>
>> As it came up earlier in the thread, adding an ABS_AMBIENT_LIGHT_LEVEL
>> or equivalent is much simpler and provides a clean, concise, and
>> useful interface to userspace.
>>
>> Note that for many applications, you actually get configurable
>> threshold levels, and the hardware triggers an interrupt when the
>> light level crosses those thresholds. This makes using an input device
>> very useful, and that is in fact how we use ALS devices today. I have
>> several pieces of hardware that do this, and I don't see how this new
>> als subsystem helps me handle that problem. With the suggested API,
>> I'll have to poll the sysfs files manually to see if they've changed
>> (which is suboptimal), or still add a non-standard input device to do
>> what I want.
>>
>
> OK, so from what you are saying it looks you just like the _interface_,
> or transport, that input subsystem provides, not the fact that you
> considering the device to be a HID-type device. If this is the case then
> this indicates that we need to take another look at the proposed
> interface and make sure that it allows proper poll() support.

Yes, you are right. Though, the filtering that the input subsystem
provides can also be useful.

--Dima
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