From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: H Hartley Sweeten <hartleys@visionengravers.com>
Cc: "linux-input@vger.kernel.org" <linux-input@vger.kernel.org>
Subject: Re: Question: I2C touchscreen controller
Date: Wed, 24 Aug 2011 12:54:36 -0700 [thread overview]
Message-ID: <20110824195436.GA13228@core.coreip.homeip.net> (raw)
In-Reply-To: <ADE657CA350FB648AAC2C43247A983F001F3885759E3@AUSP01VMBX24.collaborationhost.net>
Hi Hartley,
On Wed, Aug 24, 2011 at 01:23:59PM -0500, H Hartley Sweeten wrote:
> Hello all,
>
> I have a question...
>
> Are there any I2C touchscreen controllers that do not need irq support?
>
> I have a system with an I2C bus available to connect to the touchscreen
> controller but I don't have an IRQ pin available. Right now I'm just
> trying to discover if there is a possible solution or if I will need to
> modify my board somehow to get an IRQ.
Without IRQ you are limited to polling mode which, for touchscreens,
needs to be done at fairly high rate to provide adequate responsiveness.
This, in turn, will put considerable load on the system thus driving up
power requirements... IOW not very suitable for production use, that is
why I've been asking people to submit IRQ-driven drivers, if at all
possible.
If polling is your only option then input-polldev is your friend.
--
Dmitry
next prev parent reply other threads:[~2011-08-24 19:54 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-24 18:23 Question: I2C touchscreen controller H Hartley Sweeten
2011-08-24 19:54 ` Dmitry Torokhov [this message]
2011-08-24 20:19 ` H Hartley Sweeten
2011-08-24 20:46 ` Dmitry Torokhov
2011-08-25 7:23 ` Henrik Rydberg
2011-08-26 17:06 ` H Hartley Sweeten
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