From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: [PATCH 3/5] mfd: ti_am335x_tscadc: Don't read back REG_SE Date: Mon, 6 Jan 2014 10:10:43 -0800 Message-ID: <20140106181043.GC2754@core.coreip.homeip.net> References: <1387466911-3732-1-git-send-email-bigeasy@linutronix.de> <1387466911-3732-4-git-send-email-bigeasy@linutronix.de> <20140106093525.GE23772@lee--X1> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pa0-f50.google.com ([209.85.220.50]:60464 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755320AbaAFSKr (ORCPT ); Mon, 6 Jan 2014 13:10:47 -0500 Content-Disposition: inline In-Reply-To: <20140106093525.GE23772@lee--X1> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Lee Jones Cc: Sebastian Andrzej Siewior , Samuel Ortiz , Jonathan Cameron , Zubair Lutfullah , Felipe Balbi , linux-iio@vger.kernel.org, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org On Mon, Jan 06, 2014 at 09:35:25AM +0000, Lee Jones wrote: > On Thu, 19 Dec 2013, Sebastian Andrzej Siewior wrote: > > > The purpose of reg_se_cache has been defeated. It should avoid the > > read-back of the register to avoid the latency and the fact that the > > bits are reset to 0 after the individual conversation took place. > > > > The reason why this is required like this to work, is that read-back of > > the register removes the bits of the ADC so they do not start another > > conversation after the register is re-written from the TSC side for the > > update. > > To avoid the not required read-back I introduce a "set once" variant which > > does not update the cache mask. After the conversation completes, the > > bit is removed from the SE register anyway and we don't plan a new > > conversation "any time soon". The current set function is renamed to > > set_cache to distinguish the two operations. > > This is a small preparation for a larger sync-rework. > > > > Acked-by: Lee Jones > > Signed-off-by: Sebastian Andrzej Siewior > > --- > > drivers/iio/adc/ti_am335x_adc.c | 4 ++-- > > drivers/input/touchscreen/ti_am335x_tsc.c | 4 ++-- > > Just need Dmitry's Ack now. Well, that has nothing to do with input per se but rather inner workings of the device. But yes, FWIW: Acked-by: Dmitry Torokhov Thanks. -- Dmitry