Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932766AbaLAW6H (ORCPT ); Mon, 1 Dec 2014 17:58:07 -0500 Received: from arroyo.ext.ti.com ([192.94.94.40]:41888 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932458AbaLAW6D (ORCPT ); Mon, 1 Dec 2014 17:58:03 -0500 Date: Mon, 1 Dec 2014 16:57:47 -0600 From: Benoit Parrot To: Alexandre Courbot CC: Linus Walleij , "linux-gpio@vger.kernel.org" , Linux Kernel Mailing List , "devicetree@vger.kernel.org" , Pantelis Antoniou , Jiri Prchal , Maxime Ripard Subject: Re: [Patch v2 2/2] gpio: Document GPIO hogging mechanism Message-ID: <20141201225747.GA24551@ti.com> References: <1416527684-19017-1-git-send-email-bparrot@ti.com> <1416527684-19017-3-git-send-email-bparrot@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alexandre Courbot wrote on Fri [2014-Nov-28 16:31:19 +0900]: > On Fri, Nov 21, 2014 at 8:54 AM, Benoit Parrot wrote: > > Add GPIO hogging documentation to gpio.txt > > > > Signed-off-by: Benoit Parrot > > --- > > Changes since v1: > > * Split the devicetree bindings documentation in its own patch. > > > > Documentation/devicetree/bindings/gpio/gpio.txt | 25 +++++++++++++++++++++++++ > > 1 file changed, 25 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt > > index 3fb8f53..82755e2 100644 > > --- a/Documentation/devicetree/bindings/gpio/gpio.txt > > +++ b/Documentation/devicetree/bindings/gpio/gpio.txt > > @@ -103,6 +103,24 @@ Every GPIO controller node must contain both an empty "gpio-controller" > > property, and a #gpio-cells integer property, which indicates the number of > > cells in a gpio-specifier. > > > > +The GPIO chip may contain GPIO hog definitions. GPIO hogging is a mechanism > > +providing automatic GPIO request and configuration as part of the > > +gpio-controller's driver probe function. > > + > > +Each GPIO hog definition is represented as a child node of the GPIO controller. > > +Required properties: > > +- gpio-hog: a property specifying that this child node represent a gpio-hog. > > +- gpios: store the gpio information (id, flags, ...). Shall contain the > > + number of cells specified in its parent node (GPIO controller node). > > +- input: a property specifying to set the GPIO direction as input. > > +- output-high: a property specifying to set the GPIO direction to output with > > + the value high. > > +- output-low: a property specifying to set the GPIO direction to output with > > + the value low. > > + > > +Optional properties: > > +- line-name: the GPIO label name. If not present the node name is used. > > + > > Example of two SOC GPIO banks defined as gpio-controller nodes: > > > > qe_pio_a: gpio-controller@1400 { > > @@ -110,6 +128,13 @@ Example of two SOC GPIO banks defined as gpio-controller nodes: > > reg = <0x1400 0x18>; > > gpio-controller; > > #gpio-cells = <2>; > > + > > + line_b: line_b { > > Mmm what is the label used for? Can this node ever be referenced from > somewhere else? It's not used for anything else as far as I know other than as the line-name to be assigned to the gpio being hogged. I guess you agree with Linus and should make the line-name mandatory and remove the label altogether? I was trying to keep the verbosity to a minimum so as to have the possibilty to keep everything on a single line when possible. Benoit -- 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/