From mboxrd@z Thu Jan 1 00:00:00 1970 From: stigge@antcom.de (Roland Stigge) Date: Mon, 17 Dec 2012 19:02:45 +0100 Subject: [PATCH RESEND 0/6 v10] gpio: Add block GPIO In-Reply-To: <50CF584E.1040601@grandegger.com> References: <1355495185-24220-1-git-send-email-stigge@antcom.de> <50CB68AB.5070806@grandegger.com> <50CBBB25.20002@antcom.de> <50CF03FB.2030100@grandegger.com> <50CF0744.7040404@grandegger.com> <50CF1EF1.2070601@antcom.de> <50CF237E.5020409@antcom.de> <50CF4838.9000401@grandegger.com> <50CF5327.6070205@antcom.de> <50CF584E.1040601@grandegger.com> Message-ID: <50CF5E45.5030104@antcom.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 12/17/2012 06:37 PM, Wolfgang Grandegger wrote: > /* Do synchronous data output with a single write access */ > __raw_writel(~mask, pio + PIO_OWDR); > __raw_writel(mask, pio + PIO_OWER); > __raw_writel(val, pio + PIO_ODSR); > > For caching we would need a storage. Not sure if it's worth compared to > a context switch into the kernel. Block GPIO is not only for you in userspace. ;-) You can also implement efficient n-bit bus I/O in kernel drivers, n-bit-banging. :-) So not always context switches involved. Roland From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753360Ab2LQSCs (ORCPT ); Mon, 17 Dec 2012 13:02:48 -0500 Received: from antcom.de ([188.40.178.216]:55293 "EHLO chuck.antcom.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752478Ab2LQSCr (ORCPT ); Mon, 17 Dec 2012 13:02:47 -0500 Message-ID: <50CF5E45.5030104@antcom.de> Date: Mon, 17 Dec 2012 19:02:45 +0100 From: Roland Stigge Organization: ANTCOM IT Research & Development User-Agent: Mozilla/5.0 (X11; Linux i686; rv:10.0.11) Gecko/20121123 Icedove/10.0.11 MIME-Version: 1.0 To: Wolfgang Grandegger CC: rmallon@gmail.com, gregkh@linuxfoundation.org, linus.walleij@linaro.org, broonie@opensource.wolfsonmicro.com, w.sang@pengutronix.de, linux-kernel@vger.kernel.org, grant.likely@secretlab.ca, daniel-gl@gmx.net, sr@denx.de, plagnioj@jcrosoft.com, linux-arm-kernel@lists.infradead.org, highguy@gmail.com Subject: Re: [PATCH RESEND 0/6 v10] gpio: Add block GPIO References: <1355495185-24220-1-git-send-email-stigge@antcom.de> <50CB68AB.5070806@grandegger.com> <50CBBB25.20002@antcom.de> <50CF03FB.2030100@grandegger.com> <50CF0744.7040404@grandegger.com> <50CF1EF1.2070601@antcom.de> <50CF237E.5020409@antcom.de> <50CF4838.9000401@grandegger.com> <50CF5327.6070205@antcom.de> <50CF584E.1040601@grandegger.com> In-Reply-To: <50CF584E.1040601@grandegger.com> X-Enigmail-Version: 1.4 OpenPGP: url=subkeys.pgp.net Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/17/2012 06:37 PM, Wolfgang Grandegger wrote: > /* Do synchronous data output with a single write access */ > __raw_writel(~mask, pio + PIO_OWDR); > __raw_writel(mask, pio + PIO_OWER); > __raw_writel(val, pio + PIO_ODSR); > > For caching we would need a storage. Not sure if it's worth compared to > a context switch into the kernel. Block GPIO is not only for you in userspace. ;-) You can also implement efficient n-bit bus I/O in kernel drivers, n-bit-banging. :-) So not always context switches involved. Roland