From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935244Ab3FSWDH (ORCPT ); Wed, 19 Jun 2013 18:03:07 -0400 Received: from avon.wwwdotorg.org ([70.85.31.133]:35550 "EHLO avon.wwwdotorg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934979Ab3FSWDF (ORCPT ); Wed, 19 Jun 2013 18:03:05 -0400 Message-ID: <51C22A95.4050703@wwwdotorg.org> Date: Wed, 19 Jun 2013 16:03:01 -0600 From: Stephen Warren User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130510 Thunderbird/17.0.6 MIME-Version: 1.0 To: Linus Walleij CC: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, James Hogan , Stephen Warren , =?UTF-8?B?77+9?= , Linus Walleij , Anmar Oueja , Laurent Pinchart Subject: Re: [PATCH] pinctrl: establish pull-up/pull-down terminology References: <1371379548-6482-1-git-send-email-linus.walleij@stericsson.com> In-Reply-To: <1371379548-6482-1-git-send-email-linus.walleij@stericsson.com> X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/16/2013 04:45 AM, Linus Walleij wrote: > From: Linus Walleij > > It is counter-intuitive to have "0" mean disable in a boolean > manner for electronic properties of pins such as pull-up and > pull-down. Therefore, define that a pull-up/pull-down argument > of 0 to such a generic option means that the pin is > short-circuited to VDD or GROUND. Pull disablement shall be > done using PIN_CONFIG_BIAS_DISABLE. > > Cc: Heiko St�bner > Cc: James Hogan > Cc: Laurent Pinchart > Signed-off-by: Linus Walleij > --- > include/linux/pinctrl/pinconf-generic.h | 13 +++++++------ > 1 file changed, 7 insertions(+), 6 deletions(-) > > diff --git a/include/linux/pinctrl/pinconf-generic.h b/include/linux/pinctrl/pinconf-generic.h > index d414a77..67780f5 100644 > --- a/include/linux/pinctrl/pinconf-generic.h > +++ b/include/linux/pinctrl/pinconf-generic.h > @@ -36,14 +36,15 @@ > * tristate. The argument is ignored. > * @PIN_CONFIG_BIAS_PULL_UP: the pin will be pulled up (usually with high > * impedance to VDD). If the argument is != 0 pull-up is enabled, > - * if it is 0, pull-up is disabled. > + * if it is 0, pull-up it total, i.e. the pin is connected to VDD. > * @PIN_CONFIG_BIAS_PULL_DOWN: the pin will be pulled down (usually with high > * impedance to GROUND). If the argument is != 0 pull-down is enabled, > - * if it is 0, pull-down is disabled. > + * if it is 0, pull-down is total, i.e. the pin is connected to GROUND. > * @PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: the pin will be pulled up or down based > * on embedded knowledge of the controller, like current mux function. > - * If the argument is != 0 pull up/down is enabled, if it is 0, > - * the pull is disabled. > + * If the argument is != 0 pull up/down is enabled, if it is 0, the > + * configuration is ignored. The proper way to disable it is to use > + * @PIN_CONFIG_BIAS_DISABLE. Why treat PULL_UP/PULL_DOWN differently from PULL_PIN_DEFAULT? PULL_PIN_DEFAULT is logically simply a macro that selects PULL_UP/DOWN based on what's "normal" for the pin's expected usage, so surely the value associated with that option should behave identically?