From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753842AbaAFJfc (ORCPT ); Mon, 6 Jan 2014 04:35:32 -0500 Received: from mail-wg0-f53.google.com ([74.125.82.53]:42164 "EHLO mail-wg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753441AbaAFJfa (ORCPT ); Mon, 6 Jan 2014 04:35:30 -0500 Date: Mon, 6 Jan 2014 09:35:25 +0000 From: Lee Jones To: Sebastian Andrzej Siewior Cc: Samuel Ortiz , Jonathan Cameron , Dmitry Torokhov , Zubair Lutfullah , Felipe Balbi , linux-iio@vger.kernel.org, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/5] mfd: ti_am335x_tscadc: Don't read back REG_SE Message-ID: <20140106093525.GE23772@lee--X1> References: <1387466911-3732-1-git-send-email-bigeasy@linutronix.de> <1387466911-3732-4-git-send-email-bigeasy@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1387466911-3732-4-git-send-email-bigeasy@linutronix.de> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog