From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH 2/4] PM: Workaround for taking care of gpio clocks Date: Fri, 22 Aug 2008 21:06:49 +0300 Message-ID: <20080822180648.GE8233@atomide.com> References: <87iqu2rac0.fsf@trdhcp146196.ntc.nokia.com> <1218786439-28070-1-git-send-email-jouni.hogander@nokia.com> <20080820113715.GC29374@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mho-01-bos.mailhop.org ([63.208.196.178]:57407 "EHLO mho-01-bos.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751055AbYHVSHA (ORCPT ); Fri, 22 Aug 2008 14:07:00 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Tero.Kristo@nokia.com Cc: jouni.hogander@nokia.com, linux-omap@vger.kernel.org * Tero.Kristo@nokia.com [080821 14:08]: > > > >-----Original Message----- > >From: linux-omap-owner@vger.kernel.org > >[mailto:linux-omap-owner@vger.kernel.org] On Behalf Of ext > >Tony Lindgren > >Sent: 20 August, 2008 14:37 > >To: Hogander Jouni (Nokia-D/Tampere) > >Cc: linux-omap@vger.kernel.org > >Subject: Re: [PATCH 2/4] PM: Workaround for taking care of gpio clocks > > > >* Jouni Hogander [080815 10:47]: > >> In omap3 gpios 2-6 are in per domain. Functional clocks for these > >> should be disabled. This patch is needed until gpio driver disables > >> gpio clocks. > >> > >> GPIO modules in PER domain are not able to act as a wake up > >source if > >> PER domain is in retention. PER domain sleep transition > >before MPU is > >> prevented by leaving icks active. PER domain still enters retention > >> together with MPU. When this happens IOPAD wake up mechanism is used > >> for gpios. > > > >As we talked offline.. Should we pass the GPIO wake-up > >configuration from board-*.c files? Or can we always > >automatically do this safely on 34xx? > > After some investigation it seems that we can configure wake-up events > for almost every GPIO from the padconfigs. There are only 2 pins that do > not seem to have this functionality, however I am not sure if this is a > documentation bug or what because it is strange that only 2 pins lack > this capability. GPIOs 32 and 187 are missing wake-up capability from > padconfig. > > Because of this, our proposal would be to make GPIO clock switching > global, but this would be enabled from a sysfs entry pretty much like > how it is in the patches now. However, this would be separated from UART > clock switching. So, we would introduce two new sysfs files: > uart_clocks_off_while_idle and gpio_clocks_off_while_idle. This would > avoid introducing new complexity in to the idle loop. > > How does this sound like? Sounds good to me. Then we may be able to remove both sysfs files eventually. Regards, Tony