Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752349Ab2BTHks (ORCPT ); Mon, 20 Feb 2012 02:40:48 -0500 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:44205 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751501Ab2BTHkr (ORCPT ); Mon, 20 Feb 2012 02:40:47 -0500 Date: Mon, 20 Feb 2012 07:39:41 +0000 From: Russell King - ARM Linux To: Stephen Warren Cc: Grant Likely , Linus Walleij , Randy Dunlap , Olof Johansson , Colin Cross , linux-doc@vger.kernel.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org, Chris Ball , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 1/2] Documentation/gpio.txt: Explain expected pinctrl interaction Message-ID: <20120220073941.GC22562@n2100.arm.linux.org.uk> References: <1329719263-18971-1-git-send-email-swarren@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1329719263-18971-1-git-send-email-swarren@nvidia.com> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1021 Lines: 20 On Sun, Feb 19, 2012 at 11:27:42PM -0700, Stephen Warren wrote: > Update gpio.txt based on recent discussions regarding interaction with the > pinctrl subsystem. > > Previously, gpio_request() was described as explicitly not performing any > required mux setup operations etc. > > Now, gpio_request() is explicitly as explicitly performing any required mux > setup operations where possible. In the case it isn't, platform code is > required to have set up any required muxing or other configuration prior to > gpio_request() being called, in order to maintain the same semantics. So what if you need to have the pin as a GPIO, manipulate it as a GPIO, and then hand it off to a special function, and then take it back as a GPIO before you shut the special function down ? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/