[Ce-android-mainline] timed gpio and timed output drivers

Shuah Khan shuahkhan at gmail.com
Mon Feb 27 23:01:00 UTC 2012


On Mon, Feb 27, 2012 at 2:51 PM, Colin Cross <ccross at android.com> wrote:
> On Mon, Feb 27, 2012 at 7:26 AM, Shuah Khan <shuahkhan at gmail.com> wrote:
>> I saw a timed_gpio patch come through on lkml. Looks like this driver
>> is being used and patched.  Could somebody from Andorid team comment
>> on the need for a special driver instead of using leds.
>
> It has been used in the past for vibrator control.  The main feature
> it provides vs. leds is one shot timed enables, which prevents a
> userspace crash from leaving the vibrator on, which would kill the
> battery very quickly.  Plus, putting the vibrator in /sys/class/leds
> is counterintuitive.
>
> It hasn't been used as much recently as more vibrators end up
> connected to PWM pins, on the SoC or PMIC, with custom apis.

Thanks Colin. This is good information. Do you believe it is worth
while to get this driver into upstream from the staging area given
that it is not used much? I can always try to make a case for it to be
included under gpio (I will get push back for sure on why not leds),
if there is a strong need for this functionality.

If there is no strong need, I can work on removing it from the staging area.

Thanks,
-- Shuah


More information about the Ce-android-mainline mailing list