From patchwork Thu Oct 3 12:32:11 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 11172657 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2B4D4112B for ; Thu, 3 Oct 2019 12:32:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 13D2320862 for ; Thu, 3 Oct 2019 12:32:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729592AbfJCMc0 (ORCPT ); Thu, 3 Oct 2019 08:32:26 -0400 Received: from mga01.intel.com ([192.55.52.88]:21657 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729193AbfJCMcX (ORCPT ); Thu, 3 Oct 2019 08:32:23 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Oct 2019 05:32:22 -0700 X-IronPort-AV: E=Sophos;i="5.67,252,1566889200"; d="scan'208";a="185899631" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Oct 2019 05:32:19 -0700 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTP id 0CA3120F9B; Thu, 3 Oct 2019 15:32:17 +0300 (EEST) Received: from sailus by punajuuri.localdomain with local (Exim 4.92) (envelope-from ) id 1iG0HL-0002wK-OB; Thu, 03 Oct 2019 15:32:19 +0300 From: Sakari Ailus To: Petr Mladek , linux-kernel@vger.kernel.org, rafael@kernel.org Cc: Andy Shevchenko , linux-acpi@vger.kernel.org, devicetree@vger.kernel.org, Rob Herring , Heikki Krogerus , Joe Perches Subject: [PATCH v9 04/12] device property: Add functions for accessing node's parents Date: Thu, 3 Oct 2019 15:32:11 +0300 Message-Id: <20191003123219.11237-5-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191003123219.11237-1-sakari.ailus@linux.intel.com> References: <20191003123219.11237-1-sakari.ailus@linux.intel.com> MIME-Version: 1.0 Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Add two convenience functions for accessing node's parents: fwnode_count_parents() returns the number of parent nodes a given node has. fwnode_get_nth_parent() returns node's parent at a given distance from the node itself. Signed-off-by: Sakari Ailus Reviewed-by: Andy Shevchenko --- drivers/base/property.c | 46 ++++++++++++++++++++++++++++++++++++++++ include/linux/property.h | 3 +++ 2 files changed, 49 insertions(+) diff --git a/drivers/base/property.c b/drivers/base/property.c index 3d9dffbe96378..f2e555e68b56a 100644 --- a/drivers/base/property.c +++ b/drivers/base/property.c @@ -590,6 +590,52 @@ struct fwnode_handle *fwnode_get_next_parent(struct fwnode_handle *fwnode) } EXPORT_SYMBOL_GPL(fwnode_get_next_parent); +/** + * fwnode_count_parents - Return the number of parents a node has + * @fwnode: The node the parents of which are to be counted + * + * Returns the number of parents a node has. + */ +unsigned int fwnode_count_parents(const struct fwnode_handle *fwnode) +{ + struct fwnode_handle *__fwnode; + unsigned int count; + + __fwnode = fwnode_get_parent(fwnode); + + for (count = 0; __fwnode; count++) + __fwnode = fwnode_get_next_parent(__fwnode); + + return count; +} +EXPORT_SYMBOL_GPL(fwnode_count_parents); + +/** + * fwnode_get_nth_parent - Return an nth parent of a node + * @fwnode: The node the parent of which is requested + * @depth: Distance of the parent from the node + * + * Returns the nth parent of a node. If there is no parent at the requested + * @depth, %NULL is returned. If @depth is 0, the functionality is equivalent to + * fwnode_handle_get(). For @depth == 1, it is fwnode_get_parent() and so on. + * + * The caller is responsible for calling fwnode_handle_put() for the returned + * node. + */ +struct fwnode_handle *fwnode_get_nth_parent(struct fwnode_handle *fwnode, + unsigned int depth) +{ + unsigned int i; + + fwnode_handle_get(fwnode); + + for (i = 0; i < depth && fwnode; i++) + fwnode = fwnode_get_next_parent(fwnode); + + return fwnode; +} +EXPORT_SYMBOL_GPL(fwnode_get_nth_parent); + /** * fwnode_get_next_child_node - Return the next child node handle for a node * @fwnode: Firmware node to find the next child node for. diff --git a/include/linux/property.h b/include/linux/property.h index 421c76e53708d..5450e7ec219ac 100644 --- a/include/linux/property.h +++ b/include/linux/property.h @@ -83,6 +83,9 @@ struct fwnode_handle *fwnode_find_reference(const struct fwnode_handle *fwnode, struct fwnode_handle *fwnode_get_parent(const struct fwnode_handle *fwnode); struct fwnode_handle *fwnode_get_next_parent( struct fwnode_handle *fwnode); +unsigned int fwnode_count_parents(const struct fwnode_handle *fwn); +struct fwnode_handle *fwnode_get_nth_parent(struct fwnode_handle *fwn, + unsigned int depth); struct fwnode_handle *fwnode_get_next_child_node( const struct fwnode_handle *fwnode, struct fwnode_handle *child); struct fwnode_handle *fwnode_get_next_available_child_node(