From mboxrd@z Thu Jan 1 00:00:00 1970 From: pavel@ucw.cz (Pavel Machek) Date: Fri, 18 May 2018 09:21:09 +0200 Subject: [PATCH 4/4] omap4-droid4: Use software debounce for gpio-keys In-Reply-To: <20180517233542.30629-5-tony@atomide.com> References: <20180517233542.30629-1-tony@atomide.com> <20180517233542.30629-5-tony@atomide.com> Message-ID: <20180518072109.GA31304@amd> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi! > The default value of 5ms will use GPIO hardware based debounce clocks > that will keep L4PER from idling consuming about extra 30mW. > > Use a value of 10ms that is above the hardware debounce maximum of > 7.95ms forcing software based debouncing. > > This allows droid4 to enter PER retention during idle as long as UARTs > are idled and USB modules unloaded or unbound. > > Note that there seems to be a pending issue with having droid 4 enter core > retention during idle where GPIO bank 1 needs to be reset late after init > for some reason to not block core retention. In addition to that, we are > also missing GPIO related PM runtime calls for omap4 that will be posted > separately. Thanks, will take a look. BTW, did you notice that debouncing is wrong on most of the keyboard? If you double click a key (most will do, for example "J") it will fail to recognize second release and instead of expected "jj", you get autorepeat ("jjjjjjjjjjjjjjjjjjjjjj..."). Ok, I guess main keyboard is not on GPIO... Best regards, Pavel > @@ -128,6 +128,7 @@ > gpios = <&gpio5 26 GPIO_ACTIVE_LOW>; /* gpio154 */ > linux,code = ; > linux,can-disable; > + debounce-interval = <10>; I'd say this subtlety is worth a comment. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 181 bytes Desc: Digital signature URL: