From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C410BC83009 for ; Wed, 29 Apr 2020 12:57:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AD114208FE for ; Wed, 29 Apr 2020 12:57:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727061AbgD2M57 (ORCPT ); Wed, 29 Apr 2020 08:57:59 -0400 Received: from asav21.altibox.net ([109.247.116.8]:58740 "EHLO asav21.altibox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727030AbgD2M56 (ORCPT ); Wed, 29 Apr 2020 08:57:58 -0400 Received: from localhost.localdomain (unknown [81.166.168.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: noralf.tronnes@ebnett.no) by asav21.altibox.net (Postfix) with ESMTPSA id D5C058014B; Wed, 29 Apr 2020 14:48:49 +0200 (CEST) From: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= To: dri-devel@lists.freedesktop.org, linux-usb@vger.kernel.org Cc: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= , Lee Jones , Daniel Thompson , Jingoo Han Subject: [PATCH 01/10] backlight: Add backlight_device_get_by_name() Date: Wed, 29 Apr 2020 14:48:21 +0200 Message-Id: <20200429124830.27475-2-noralf@tronnes.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20200429124830.27475-1-noralf@tronnes.org> References: <20200429124830.27475-1-noralf@tronnes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-CMAE-Score: 0 X-CMAE-Analysis: v=2.3 cv=AvXAIt1P c=1 sm=1 tr=0 a=OYZzhG0JTxDrWp/F2OJbnw==:117 a=OYZzhG0JTxDrWp/F2OJbnw==:17 a=IkcTkHD0fZMA:10 a=M51BFTxLslgA:10 a=KKAkSRfTAAAA:8 a=pGLkceISAAAA:8 a=SJz97ENfAAAA:8 a=vKVk4XFhGoKKoRoBPQAA:9 a=QEXdDO2ut3YA:10 a=cvBusfyB2V15izCimMoJ:22 a=vFet0B0WnEQeilDPIY6i:22 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Add a way to lookup a backlight device based on its name. Will be used by a USB display gadget getting the name from configfs. Cc: Lee Jones Cc: Daniel Thompson Cc: Jingoo Han Signed-off-by: Noralf Trønnes --- drivers/video/backlight/backlight.c | 21 +++++++++++++++++++++ include/linux/backlight.h | 1 + 2 files changed, 22 insertions(+) diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index cac3e35d7630..92d80aa0c0ef 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -432,6 +432,27 @@ struct backlight_device *backlight_device_get_by_type(enum backlight_type type) } EXPORT_SYMBOL(backlight_device_get_by_type); +/** + * backlight_device_get_by_name - Get backlight device by name + * @name: Device name + * + * This function looks up a backlight device by its name. It obtains a reference + * on the backlight device and it is the caller's responsibility to drop the + * reference by calling backlight_put(). + * + * Returns: + * A pointer to the backlight device if found, otherwise NULL. + */ +struct backlight_device *backlight_device_get_by_name(const char *name) +{ + struct device *dev; + + dev = class_find_device_by_name(backlight_class, name); + + return dev ? to_backlight_device(dev) : NULL; +} +EXPORT_SYMBOL(backlight_device_get_by_name); + /** * backlight_device_unregister - unregisters a backlight device object. * @bd: the backlight device object to be unregistered and freed. diff --git a/include/linux/backlight.h b/include/linux/backlight.h index c7d6b2e8c3b5..56e4580d4f55 100644 --- a/include/linux/backlight.h +++ b/include/linux/backlight.h @@ -190,6 +190,7 @@ extern void backlight_force_update(struct backlight_device *bd, extern int backlight_register_notifier(struct notifier_block *nb); extern int backlight_unregister_notifier(struct notifier_block *nb); extern struct backlight_device *backlight_device_get_by_type(enum backlight_type type); +struct backlight_device *backlight_device_get_by_name(const char *name); extern int backlight_device_set_brightness(struct backlight_device *bd, unsigned long brightness); #define to_backlight_device(obj) container_of(obj, struct backlight_device, dev) -- 2.23.0