From mboxrd@z Thu Jan 1 00:00:00 1970 From: wg@grandegger.com (Wolfgang Grandegger) Date: Tue, 18 Dec 2012 07:51:02 +0100 Subject: [PATCH RESEND 0/6 v10] gpio: Add block GPIO In-Reply-To: <50CF8FA9.8050609@antcom.de> 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> <50CF5E45.5030104@antcom.de> <50CF76D3.9030708@grandegger.com> <50CF8FA9.8050609@antcom.de> Message-ID: <50D01256.1020105@grandegger.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 12/17/2012 10:33 PM, Roland Stigge wrote: > On 17/12/12 20:47, Wolfgang Grandegger wrote: >> On 12/17/2012 07:02 PM, Roland Stigge wrote: >>> 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. >> >> OK, what do you think about the following untested patch: > > Looks good! > > Why "untested"? ;-) Because I didn't have a chance to test it yet. Will do tomorrow. Wolfgang. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752477Ab2LRGvP (ORCPT ); Tue, 18 Dec 2012 01:51:15 -0500 Received: from ngcobalt02.manitu.net ([217.11.48.102]:46179 "EHLO ngcobalt02.manitu.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751233Ab2LRGvO (ORCPT ); Tue, 18 Dec 2012 01:51:14 -0500 X-manitu-Original-Sender-IP: 79.230.55.182 X-manitu-Original-Receiver-Name: ngcobalt02.manitu.net Message-ID: <50D01256.1020105@grandegger.com> Date: Tue, 18 Dec 2012 07:51:02 +0100 From: Wolfgang Grandegger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Roland Stigge 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> <50CF5E45.5030104@antcom.de> <50CF76D3.9030708@grandegger.com> <50CF8FA9.8050609@antcom.de> In-Reply-To: <50CF8FA9.8050609@antcom.de> X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset=ISO-8859-1 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 10:33 PM, Roland Stigge wrote: > On 17/12/12 20:47, Wolfgang Grandegger wrote: >> On 12/17/2012 07:02 PM, Roland Stigge wrote: >>> 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. >> >> OK, what do you think about the following untested patch: > > Looks good! > > Why "untested"? ;-) Because I didn't have a chance to test it yet. Will do tomorrow. Wolfgang.