From patchwork Mon Feb 13 13:28:12 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Shevchenko X-Patchwork-Id: 653587 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6A213C636D4 for ; Mon, 13 Feb 2023 13:27:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229677AbjBMN1i (ORCPT ); Mon, 13 Feb 2023 08:27:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229489AbjBMN1i (ORCPT ); Mon, 13 Feb 2023 08:27:38 -0500 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5D49D1A4B8; Mon, 13 Feb 2023 05:27:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1676294857; x=1707830857; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=jPQ6x6Tbwh+UqIy3KRlKxbErjK9ePbHRcwUVfTAEYgk=; b=ch3xKtV0RBv57IMykv9Ar+GEnRIqAxgMzfioNHsZR5B8gPQoLaMRElIX dVkKOeGxxFjb6GDU+v7A5lkMxa6QyJYwdZKMhW0WcwklPjDqu4Zrz6shY yeh75nLzAnxAUo9MfV0KSNCFCQy3dcp/3KBbMEEEiHD+xtjH9waukxkeT 9Z74jMzs6ptDjQwP7AWhJ/fr4cQDl0Fz4MHjaIJWFwEuLh3mgtofkd6cI x+tK6s+Hy2Jyd1j6srv8PlQPeSYWy60EGm/BNzmKu0w67aOdnnGxpUuif soYrEM6BLkBKzbmwnCR9eYGLqhhRPUeH8U7U5uCgWI+ES6Uz2jL+37b2J w==; X-IronPort-AV: E=McAfee;i="6500,9779,10620"; a="393286330" X-IronPort-AV: E=Sophos;i="5.97,294,1669104000"; d="scan'208";a="393286330" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Feb 2023 05:27:36 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10620"; a="777842510" X-IronPort-AV: E=Sophos;i="5.97,294,1669104000"; d="scan'208";a="777842510" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga002.fm.intel.com with ESMTP; 13 Feb 2023 05:27:34 -0800 Received: by black.fi.intel.com (Postfix, from userid 1003) id B31781F8; Mon, 13 Feb 2023 15:28:13 +0200 (EET) From: Andy Shevchenko To: Andy Shevchenko , linux-gpio@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Mika Westerberg , "Rafael J. Wysocki" , Len Brown , Linus Walleij , Bartosz Golaszewski Subject: [PATCH v1 1/1] Documentation: firmware-guide: gpio-properties: Clarify Explicit and Implicit Date: Mon, 13 Feb 2023 15:28:12 +0200 Message-Id: <20230213132812.38646-1-andriy.shevchenko@linux.intel.com> X-Mailer: git-send-email 2.39.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Clarify the Explicit and Implicit meanings in the table of Pull Bias. While at it, distinguish pull bias keywords used in ACPI by using bold font in the table of the respective terms. Signed-off-by: Andy Shevchenko --- .../firmware-guide/acpi/gpio-properties.rst | 25 +++++++++++-------- 1 file changed, 14 insertions(+), 11 deletions(-) diff --git a/Documentation/firmware-guide/acpi/gpio-properties.rst b/Documentation/firmware-guide/acpi/gpio-properties.rst index eaec732cc77c..ae87aa64cb7b 100644 --- a/Documentation/firmware-guide/acpi/gpio-properties.rst +++ b/Documentation/firmware-guide/acpi/gpio-properties.rst @@ -67,17 +67,20 @@ state of the output pin which driver should use during its initialization. Linux tries to use common sense here and derives the state from the bias and polarity settings. The table below shows the expectations: -========= ============= ============== -Pull Bias Polarity Requested... -========= ============= ============== -Implicit x AS IS (assumed firmware configured for us) -Explicit x (no _DSD) as Pull Bias (Up == High, Down == Low), - assuming non-active (Polarity = !Pull Bias) -Down Low as low, assuming active -Down High as low, assuming non-active -Up Low as high, assuming non-active -Up High as high, assuming active -========= ============= ============== +========= ============= ============== +Pull Bias Polarity Requested... +========= ============= ============== +Implicit x AS IS (assumed firmware configured it for us) +(**Default**) +Explicit x (no _DSD) as Pull Bias (**Up** == high, **Down** == low), +(**Up**, **Down**, assuming non-active (Polarity = !Pull Bias); + **None**) or AS IS (assumed firmware configured it for us) + with no Pull Bias +**Down** Low as low, assuming active +**Down** High as low, assuming non-active +**Up** Low as high, assuming non-active +**Up** High as high, assuming active +========= ============= ============== That said, for our above example the both GPIOs, since the bias setting is explicit and _DSD is present, will be treated as active with a high