From patchwork Tue Jan 18 17:35:04 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Walle X-Patchwork-Id: 532968 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 CFBC0C433EF for ; Tue, 18 Jan 2022 17:35:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347392AbiARRfP (ORCPT ); Tue, 18 Jan 2022 12:35:15 -0500 Received: from ssl.serverraum.org ([176.9.125.105]:36771 "EHLO ssl.serverraum.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346912AbiARRfP (ORCPT ); Tue, 18 Jan 2022 12:35:15 -0500 Received: from mwalle01.kontron.local. (unknown [213.135.10.150]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ssl.serverraum.org (Postfix) with ESMTPSA id AC90B223F6; Tue, 18 Jan 2022 18:35:13 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1642527313; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=E7u3bW2JrZRjIUX82K4eJKjrr9Yp7IpGI/5ky9C3x8w=; b=WfdoMHiDUh24X4gp1I+oyZtPBmatt+zXZn052cVGoQVJjCcoDGUgEjD9jEHfvZDXKUcS3r uJwfyY1THl2BEmA8XRQ0IoLb8GwqtE3iXaMkDiS9GkqtRPq69EiYAQMXn9V7zoLAtEnOCt VySx36gwez+twDu5cazmD0d8AAy9+Bs= From: Michael Walle To: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Rob Herring , Frank Rowand , Michael Walle Subject: [PATCH v3 3/3] of: base: add of_parse_phandle_with_optional_args() Date: Tue, 18 Jan 2022 18:35:04 +0100 Message-Id: <20220118173504.2867523-4-michael@walle.cc> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220118173504.2867523-1-michael@walle.cc> References: <20220118173504.2867523-1-michael@walle.cc> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Add a new variant of the of_parse_phandle_with_args() which treats the cells name as optional. If it's missing, it is assumed that the phandle has no arguments. Up until now, a nvmem node didn't have any arguments, so all the device trees haven't any '#*-cells' property. But there is a need for an additional argument for the phandle, for which we need a '#*-cells' property. Therefore, we need to support nvmem nodes with and without this property. Signed-off-by: Michael Walle Reviewed-by: Rob Herring --- changes since v2: - make index signed - add missing function parameter doc changes since v1: - new patch include/linux/of.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/include/linux/of.h b/include/linux/of.h index c64af2efbc3a..a0880c43d435 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -1028,6 +1028,31 @@ static inline int of_parse_phandle_with_fixed_args(const struct device_node *np, index, out_args); } +/** + * of_parse_phandle_with_optional_args() - Find a node pointed by phandle in a list + * @np: pointer to a device tree node containing a list + * @list_name: property name that contains a list + * @cells_name: property name that specifies phandles' arguments count + * @index: index of a phandle to parse out + * @out_args: optional pointer to output arguments structure (will be filled) + * + * Same as of_parse_phandle_with_args() except that if the cells_name property + * is not found, cell_count of 0 is assumed. + * + * This is used to useful, if you have a phandle which didn't have arguments + * before and thus doesn't have a '#*-cells' property but is now migrated to + * having arguments while retaining backwards compatibility. + */ +static inline int of_parse_phandle_with_optional_args(const struct device_node *np, + const char *list_name, + const char *cells_name, + int index, + struct of_phandle_args *out_args) +{ + return __of_parse_phandle_with_args(np, list_name, cells_name, + 0, index, out_args); +} + /** * of_property_count_u8_elems - Count the number of u8 elements in a property *