From patchwork Thu Sep 24 22:09:15 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Linus Walleij X-Patchwork-Id: 522596 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 381FE140775 for ; Fri, 25 Sep 2015 08:09:36 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753468AbbIXWJf (ORCPT ); Thu, 24 Sep 2015 18:09:35 -0400 Received: from mail-pa0-f46.google.com ([209.85.220.46]:33090 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753301AbbIXWJe (ORCPT ); Thu, 24 Sep 2015 18:09:34 -0400 Received: by pacex6 with SMTP id ex6so84558245pac.0 for ; Thu, 24 Sep 2015 15:09:34 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=itSNBx1evWEYZhKlKLyLy6TIHT6onn5CE5ig3dwKAn0=; b=Qx+swIa1Ht+se7yKlkJ4/K6yZSMTLqbVq1sJ6kJ0TM59Lh/XReIi8XUEOIEG9cqbCZ Do5ASyFrcdIG/9BKJ3Qw1x1HhRPDo9RR+V80r+EJAFgZ5Fh1NI6sXZOLMHjvoA6c/O4z 69nSUeRD5HDVeH/uywDoqoq7p3TwqMPGDJtgAQEPp6O5OM1t7h3mRWHNwn0tqEF9Sjfp +TCm5L1YSSR/jSKkNnCemcyOn+IUiSnIed5mOVVBnwo9qaDcf1Y3YZ2hYom9mKmSMdzQ d0MkZoZdJiwehmu1SDKn6C75P0Tv061NHzvlhjEui7lu9tAJBq2YoWZkHzragidxJ2TW iOtA== X-Gm-Message-State: ALoCoQlTSXJH3fBbgLA2PeBMrK+t3Q0lUWmB6lDelEHYknZH1PpPv1smCxpb+jPGrYf4W3rqOTin X-Received: by 10.67.30.74 with SMTP id kc10mr2390588pad.147.1443132573952; Thu, 24 Sep 2015 15:09:33 -0700 (PDT) Received: from localhost.localdomain.localdomain ([70.35.39.2]) by smtp.gmail.com with ESMTPSA id fu4sm270001pbb.59.2015.09.24.15.09.31 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 24 Sep 2015 15:09:33 -0700 (PDT) From: Linus Walleij To: linux-gpio@vger.kernel.org Cc: Alexandre Courbot , Linus Walleij , Tony Lindgren , Grygorii Strashko , "H. Nikolaus Schaller" Subject: [PATCH] gpio: add DT bindings for existing consumer flags Date: Thu, 24 Sep 2015 15:09:15 -0700 Message-Id: <1443132555-8244-1-git-send-email-linus.walleij@linaro.org> X-Mailer: git-send-email 2.4.3 Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org It is customary for GPIO controllers to support open drain/collector and open source/emitter configurations. Add standard GPIO line flags to account for this and augment the documentation to say that these are the most generic bindings. Several people approached me to add new flags to the lines, and this makes sense, but let's first bind up the most common cases before we start to add exotic stuff. Cc: Tony Lindgren Cc: Grygorii Strashko Cc: H. Nikolaus Schaller Signed-off-by: Linus Walleij --- Documentation/devicetree/bindings/gpio/gpio.txt | 15 +++++++++++++-- include/dt-bindings/gpio/gpio.h | 2 ++ 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt index 5788d5cf1252..7b1c8bc24e2d 100644 --- a/Documentation/devicetree/bindings/gpio/gpio.txt +++ b/Documentation/devicetree/bindings/gpio/gpio.txt @@ -52,9 +52,13 @@ only uses one. gpio-specifier may encode: bank, pin position inside the bank, whether pin is open-drain and whether pin is logically inverted. + Exact meaning of each specifier cell is controller specific, and must -be documented in the device tree binding for the device. Use the macros -defined in include/dt-bindings/gpio/gpio.h whenever possible: +be documented in the device tree binding for the device. + +Most controllers are however specifying a generic flag bitfield +in the last cell, so for these, use the macros defined in +include/dt-bindings/gpio/gpio.h whenever possible: Example of a node using GPIOs: @@ -65,6 +69,13 @@ Example of a node using GPIOs: GPIO_ACTIVE_HIGH is 0, so in this example gpio-specifier is "18 0" and encodes GPIO pin number, and GPIO flags as accepted by the "qe_pio_e" gpio-controller. +Optional standard bitfield specifiers for the last cell: + +- Bit 0: 0 means active high, 1 means active low +- Bit 1: 1 means open drain/open collector, see: + https://en.wikipedia.org/wiki/Open_collector +- Bit 2: 1 means open source/open emitter + 1.1) GPIO specifier best practices ---------------------------------- diff --git a/include/dt-bindings/gpio/gpio.h b/include/dt-bindings/gpio/gpio.h index e6b1e0a808ae..f5ed02e81bf7 100644 --- a/include/dt-bindings/gpio/gpio.h +++ b/include/dt-bindings/gpio/gpio.h @@ -11,5 +11,7 @@ #define GPIO_ACTIVE_HIGH 0 #define GPIO_ACTIVE_LOW 1 +#define GPIO_OPEN_DRAIN 2 +#define GPIO_OPEN_SOURCE 4 #endif