From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752653AbaLSUI2 (ORCPT ); Fri, 19 Dec 2014 15:08:28 -0500 Received: from arroyo.ext.ti.com ([192.94.94.40]:33938 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751336AbaLSUI0 (ORCPT ); Fri, 19 Dec 2014 15:08:26 -0500 From: Benoit Parrot To: Linus Walleij CC: , , , Alexandre Courbot , Maxime Ripard , Jiri Prchal , Pantelis Antoniou , Benoit Parrot Subject: [Patch v5 2/2] gpio: Document GPIO hogging mechanism Date: Fri, 19 Dec 2014 14:07:51 -0600 Message-ID: <1419019671-25377-3-git-send-email-bparrot@ti.com> X-Mailer: git-send-email 1.8.5.1 In-Reply-To: <1419019671-25377-1-git-send-email-bparrot@ti.com> References: <1419019671-25377-1-git-send-email-bparrot@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add GPIO hogging documentation to gpio.txt Signed-off-by: Benoit Parrot Reviewed-by: Alexandre Courbot --- Documentation/devicetree/bindings/gpio/gpio.txt | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt index b9bd1d6..f5d2717 100644 --- a/Documentation/devicetree/bindings/gpio/gpio.txt +++ b/Documentation/devicetree/bindings/gpio/gpio.txt @@ -115,6 +115,22 @@ 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). +- state: A property specifying the direction/value needed. This property + can take the following values: input, output-high, output-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 { @@ -122,6 +138,13 @@ Example of two SOC GPIO banks defined as gpio-controller nodes: reg = <0x1400 0x18>; gpio-controller; #gpio-cells = <2>; + + line_b { + gpio-hog; + gpios = <6 0>; + state = "output-low"; + line-name = "foo-bar-gpio"; + }; }; qe_pio_e: gpio-controller@1460 { -- 1.8.5.1