From patchwork Wed Apr 10 15:24:58 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Heikki Krogerus X-Patchwork-Id: 10894253 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8973313B5 for ; Wed, 10 Apr 2019 15:26:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7A4A828AE6 for ; Wed, 10 Apr 2019 15:26:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 78BC628BAE; Wed, 10 Apr 2019 15:26:19 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2B88628AE6 for ; Wed, 10 Apr 2019 15:26:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733171AbfDJPZW (ORCPT ); Wed, 10 Apr 2019 11:25:22 -0400 Received: from mga06.intel.com ([134.134.136.31]:15566 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733170AbfDJPZV (ORCPT ); Wed, 10 Apr 2019 11:25:21 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Apr 2019 08:25:21 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,332,1549958400"; d="scan'208";a="163102943" Received: from black.fi.intel.com (HELO black.fi.intel.com.) ([10.237.72.28]) by fmsmga001.fm.intel.com with ESMTP; 10 Apr 2019 08:25:19 -0700 From: Heikki Krogerus To: "Rafael J. Wysocki" Cc: Greg Kroah-Hartman , Hans de Goede , Darren Hart , Andy Shevchenko , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, platform-driver-x86@vger.kernel.org Subject: [PATCH v2 05/12] driver core: Add helper device_find_child_by_name() Date: Wed, 10 Apr 2019 18:24:58 +0300 Message-Id: <20190410152505.87041-6-heikki.krogerus@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190410152505.87041-1-heikki.krogerus@linux.intel.com> References: <20190410152505.87041-1-heikki.krogerus@linux.intel.com> MIME-Version: 1.0 Sender: platform-driver-x86-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: platform-driver-x86@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP It looks like the child device is often matched with a name. This introduces a helper that does it automatically. Signed-off-by: Heikki Krogerus --- drivers/base/core.c | 31 +++++++++++++++++++++++++++++++ include/linux/device.h | 2 ++ 2 files changed, 33 insertions(+) diff --git a/drivers/base/core.c b/drivers/base/core.c index 4aeaa0c92bda..5819ba4c9d4c 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -2469,6 +2469,37 @@ struct device *device_find_child(struct device *parent, void *data, } EXPORT_SYMBOL_GPL(device_find_child); +/** + * device_find_child_by_name - device iterator for locating a child device. + * @parent: parent struct device + * @name: name of the child device + * + * This is similar to the device_find_child() function above, but it + * returns a reference to a device that has the name @name. + * + * The callback should return NULL if the child is not found and a reference to + * the child device if it is found. + * + * NOTE: you will need to drop the reference with put_device() after use. + */ +struct device *device_find_child_by_name(struct device *parent, + const char *name) +{ + struct klist_iter i; + struct device *child; + + if (!parent) + return NULL; + + klist_iter_init(&parent->p->klist_children, &i); + while ((child = next_device(&i))) + if (!strcmp(dev_name(child), name) && get_device(child)) + break; + klist_iter_exit(&i); + return child; +} +EXPORT_SYMBOL_GPL(device_find_child_by_name); + int __init devices_init(void) { devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL); diff --git a/include/linux/device.h b/include/linux/device.h index 4457e560bc2b..fadb84dd07f9 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1250,6 +1250,8 @@ extern int device_for_each_child_reverse(struct device *dev, void *data, int (*fn)(struct device *dev, void *data)); extern struct device *device_find_child(struct device *dev, void *data, int (*match)(struct device *dev, void *data)); +extern struct device *device_find_child_by_name(struct device *parent, + const char *name); extern int device_rename(struct device *dev, const char *new_name); extern int device_move(struct device *dev, struct device *new_parent, enum dpm_order dpm_order);