From patchwork Sat Jul 11 05:46:02 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dirk Behme X-Patchwork-Id: 493972 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id B464B140321 for ; Sat, 11 Jul 2015 16:16:58 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b=CU+pNii4; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752008AbbGKGQ5 (ORCPT ); Sat, 11 Jul 2015 02:16:57 -0400 Received: from mail-wg0-f42.google.com ([74.125.82.42]:36072 "EHLO mail-wg0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751649AbbGKGQ5 (ORCPT ); Sat, 11 Jul 2015 02:16:57 -0400 Received: by wgxm20 with SMTP id m20so80015124wgx.3 for ; Fri, 10 Jul 2015 23:16:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id; bh=Vy57+74PUWlYiv/U/zDUdihxnWlIiS+nwOBFMbdoEZQ=; b=CU+pNii4fYCG1d68F9d07q6wdmX+UzBujmPO8RYeiidfSeE1jiOVCeTgbmg3tTvOVu cUd3UOtXm9Y0IsXGFcwD5A7L4afk/4C6iYCjqluuOtg0eO1Y5NSisWn9HHxXh7lGKki4 57UL9RJygdJ/tIwx9X+2QTsX1SbFVOrCAjHhyRYdluFT1xKECdM4ZI0pzUow+3wFrA6i wkUDda949E+kPou3pGpPeNS4l/wWaMj8YNVNPnYbuE3d91PbOCh5Brh/DULKtCfhH6WT DC+MlxoU3yRdPd/X4Pfp0jWCtXw3RHPCslAlFAVRgRMRIe8d+H7g9JWq2LC92toeZl+j IkbQ== X-Received: by 10.194.5.103 with SMTP id r7mr46403275wjr.47.1436593566042; Fri, 10 Jul 2015 22:46:06 -0700 (PDT) Received: from localhost.localdomain (p4FEE0A39.dip0.t-ipconnect.de. [79.238.10.57]) by smtp.gmail.com with ESMTPSA id ib9sm16611872wjb.2.2015.07.10.22.46.05 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 10 Jul 2015 22:46:05 -0700 (PDT) From: Dirk Behme To: linux-gpio@vger.kernel.org Cc: Dirk Behme Subject: [PATCH] Documentation: gpio: consumer: describe the con_id parameter Date: Sat, 11 Jul 2015 07:46:02 +0200 Message-Id: <1436593562-5119-1-git-send-email-dirk.behme@gmail.com> X-Mailer: git-send-email 2.4.5 Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org The con_id parameter has to match the GPIO description and is automatically extended by the GPIO suffix if not NULL. I had to look into the code to understand this and properly find the GPIO I've been looking for, so document this. Signed-off-by: Dirk Behme Acked-by: Alexandre Courbot --- Documentation/gpio/consumer.txt | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt index 75542b9..d0d1e47 100644 --- a/Documentation/gpio/consumer.txt +++ b/Documentation/gpio/consumer.txt @@ -39,6 +39,18 @@ device that displays digits), an additional index argument can be specified: const char *con_id, unsigned int idx, enum gpiod_flags flags) +The con_id string parameter has to be either NULL or the prefix of the GPIO +suffixes ("gpios" or "gpio"): + +* If the GPIO description is just named with one of the GPIO suffixes + ("gpios" or "gpio") use NULL. +* If the GPIO description is prefixed with anything, e.g. "reset-gpios", use the + prefix without the "-" as con_id parameter (in this example "reset"). + +In case con_id is not NULL, the gpiod subsystem prefixes the GPIO suffix +("gpios" or "gpio") with the string passed in con_id to get the resulting string +(snprintf(... "%s-%s", con_id, gpio_suffixes[]). + The flags parameter is used to optionally specify a direction and initial value for the GPIO. Values can be: