From patchwork Wed Mar 17 17:29:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jaroslav Kysela X-Patchwork-Id: 12146527 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 B3CEFC433E0 for ; Wed, 17 Mar 2021 17:31:13 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 88E0E64EBD for ; Wed, 17 Mar 2021 17:31:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 88E0E64EBD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=perex.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-devel-bounces@alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 6552016B6; Wed, 17 Mar 2021 18:30:20 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 6552016B6 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1616002270; bh=yKNrV5Lq3qBotUK4Fx6OaA9OC+cft2LGeAnpEdCcT5c=; h=From:To:Subject:Date:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=NtIp/Wv73WWgirWKMPmy6oNV+3DJ6EaUdnW6RqbsVDZzfEOlp9pH6PMhHXvQe0bIV TG+nnV4IavfRY1DnjOpj2cpHQri6eeMX4/8WGTMq2FC7S4Krje3lct14Z+UZ7/qUJV +kC5X1bR6+cQib/HIrZmOEbKJGGFiovHw4Gn5Nso= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id BCD0FF8013F; Wed, 17 Mar 2021 18:30:19 +0100 (CET) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 71ED1F80148; Wed, 17 Mar 2021 18:30:12 +0100 (CET) Received: from mail1.perex.cz (mail1.perex.cz [77.48.224.245]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 03A65F80148 for ; Wed, 17 Mar 2021 18:30:03 +0100 (CET) Received: from mail1.perex.cz (localhost [127.0.0.1]) by smtp1.perex.cz (Perex's E-mail Delivery System) with ESMTP id 8E8B3A0042; Wed, 17 Mar 2021 18:30:02 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.perex.cz 8E8B3A0042 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=perex.cz; s=default; t=1616002202; bh=KTqKDX+DCnMNvVisVqYD4DESDUL5FvK+M6H8PBf4PNk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ID9Y0p8mKf0L0WCaBFx6bez+yIed3XqIsUGC0XSfNSHH5ip6mlZSrYEBeX9LxWUmY 3mq+6EDDz+UCY86NfznIaaJg8ffDSB3yyWHLgDL8NcnYRtn4/ddP7UWd2V5XtMC2lY PwF9gY4Cv12CvYO2ZKgPWNbUFMB+sc+Hh7/WTp7M= Received: from p1gen2.perex-int.cz (unknown [192.168.100.98]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: perex) by mail1.perex.cz (Perex's E-mail Delivery System) with ESMTPSA; Wed, 17 Mar 2021 18:29:58 +0100 (CET) From: Jaroslav Kysela To: ALSA development Subject: [PATCH v4 2/6] ALSA: control - add layer registration routines Date: Wed, 17 Mar 2021 18:29:41 +0100 Message-Id: <20210317172945.842280-3-perex@perex.cz> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210317172945.842280-1-perex@perex.cz> References: <20210317172945.842280-1-perex@perex.cz> MIME-Version: 1.0 Cc: Takashi Iwai , Hans de Goede X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" The layer registration allows to handle an extra functionality on top of the control API. It can be used for the audio LED control for example. Signed-off-by: Jaroslav Kysela --- include/sound/control.h | 12 +++++ sound/core/control.c | 110 +++++++++++++++++++++++++++++++++++++++- 2 files changed, 120 insertions(+), 2 deletions(-) diff --git a/include/sound/control.h b/include/sound/control.h index 22f3d48163ff..175610bfa8c8 100644 --- a/include/sound/control.h +++ b/include/sound/control.h @@ -108,6 +108,14 @@ struct snd_ctl_file { struct list_head events; /* waiting events for read */ }; +struct snd_ctl_layer_ops { + struct snd_ctl_layer_ops *next; + const char *module_name; + void (*lregister)(struct snd_card *card); + void (*ldisconnect)(struct snd_card *card); + void (*lnotify)(struct snd_card *card, unsigned int mask, struct snd_kcontrol *kctl, unsigned int ioff); +}; + #define snd_ctl_file(n) list_entry(n, struct snd_ctl_file, list) typedef int (*snd_kctl_ioctl_func_t) (struct snd_card * card, @@ -140,6 +148,10 @@ int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn); #define snd_ctl_unregister_ioctl_compat(fcn) #endif +int snd_ctl_request_layer(const char *module_name); +void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops); +void snd_ctl_disconnect_layer(struct snd_ctl_layer_ops *lops); + int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type); static inline unsigned int snd_ctl_get_ioffnum(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id) diff --git a/sound/core/control.c b/sound/core/control.c index 8a5cedb0a4be..87630021e434 100644 --- a/sound/core/control.c +++ b/sound/core/control.c @@ -28,10 +28,12 @@ struct snd_kctl_ioctl { }; static DECLARE_RWSEM(snd_ioctl_rwsem); +static DECLARE_RWSEM(snd_ctl_layer_rwsem); static LIST_HEAD(snd_control_ioctls); #ifdef CONFIG_COMPAT static LIST_HEAD(snd_control_compat_ioctls); #endif +static struct snd_ctl_layer_ops *snd_ctl_layer; static int snd_ctl_open(struct inode *inode, struct file *file) { @@ -195,10 +197,15 @@ void snd_ctl_notify_one(struct snd_card *card, unsigned int mask, struct snd_kcontrol *kctl, unsigned int ioff) { struct snd_ctl_elem_id id = kctl->id; + struct snd_ctl_layer_ops *lops; id.index += ioff; id.numid += ioff; snd_ctl_notify(card, mask, &id); + down_read(&snd_ctl_layer_rwsem); + for (lops = snd_ctl_layer; lops; lops = lops->next) + lops->lnotify(card, mask, kctl, ioff); + up_read(&snd_ctl_layer_rwsem); } EXPORT_SYMBOL(snd_ctl_notify_one); @@ -1997,6 +2004,86 @@ EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice); #define snd_ctl_ioctl_compat NULL #endif +/* + * control layers (audio LED etc.) + */ + +/** + * snd_ctl_request_layer - request to use the layer + * @module_name: Name of the kernel module (NULL == build-in) + * + * Return an error code when the module cannot be loaded. + */ +int snd_ctl_request_layer(const char *module_name) +{ + struct snd_ctl_layer_ops *lops; + + if (module_name == NULL) + return 0; + down_read(&snd_ctl_layer_rwsem); + for (lops = snd_ctl_layer; lops; lops = lops->next) + if (strcmp(lops->module_name, module_name) == 0) + break; + up_read(&snd_ctl_layer_rwsem); + if (lops) + return 0; + return request_module(module_name); +} +EXPORT_SYMBOL_GPL(snd_ctl_request_layer); + +/** + * snd_ctl_register_layer - register new control layer + * @lops: operation structure + * + * The new layer can track all control elements and do additional + * operations on top (like audio LED handling). + */ +void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops) +{ + struct snd_card *card; + int card_number; + + down_write(&snd_ctl_layer_rwsem); + lops->next = snd_ctl_layer; + snd_ctl_layer = lops; + up_write(&snd_ctl_layer_rwsem); + for (card_number = 0; card_number < SNDRV_CARDS; card_number++) { + card = snd_card_ref(card_number); + if (card) { + down_read(&card->controls_rwsem); + lops->lregister(card); + up_read(&card->controls_rwsem); + snd_card_unref(card); + } + } +} +EXPORT_SYMBOL_GPL(snd_ctl_register_layer); + +/** + * snd_ctl_disconnect_layer - disconnect control layer + * @lops: operation structure + * + * It is expected that the information about tracked cards + * is freed before this call (the disconnect callback is + * not called here). + */ +void snd_ctl_disconnect_layer(struct snd_ctl_layer_ops *lops) +{ + struct snd_ctl_layer_ops *lops2, *prev_lops2; + + down_write(&snd_ctl_layer_rwsem); + for (lops2 = snd_ctl_layer, prev_lops2 = NULL; lops2; lops2 = lops2->next) + if (lops2 == lops) { + if (!prev_lops2) + snd_ctl_layer = lops->next; + else + prev_lops2->next = lops->next; + break; + } + up_write(&snd_ctl_layer_rwsem); +} +EXPORT_SYMBOL_GPL(snd_ctl_disconnect_layer); + /* * INIT PART */ @@ -2020,9 +2107,20 @@ static const struct file_operations snd_ctl_f_ops = static int snd_ctl_dev_register(struct snd_device *device) { struct snd_card *card = device->device_data; + struct snd_ctl_layer_ops *lops; + int err; - return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1, - &snd_ctl_f_ops, card, &card->ctl_dev); + err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1, + &snd_ctl_f_ops, card, &card->ctl_dev); + if (err < 0) + return err; + down_read(&card->controls_rwsem); + down_read(&snd_ctl_layer_rwsem); + for (lops = snd_ctl_layer; lops; lops = lops->next) + lops->lregister(card); + up_read(&snd_ctl_layer_rwsem); + up_read(&card->controls_rwsem); + return 0; } /* @@ -2032,6 +2130,7 @@ static int snd_ctl_dev_disconnect(struct snd_device *device) { struct snd_card *card = device->device_data; struct snd_ctl_file *ctl; + struct snd_ctl_layer_ops *lops; unsigned long flags; read_lock_irqsave(&card->ctl_files_rwlock, flags); @@ -2041,6 +2140,13 @@ static int snd_ctl_dev_disconnect(struct snd_device *device) } read_unlock_irqrestore(&card->ctl_files_rwlock, flags); + down_read(&card->controls_rwsem); + down_read(&snd_ctl_layer_rwsem); + for (lops = snd_ctl_layer; lops; lops = lops->next) + lops->ldisconnect(card); + up_read(&snd_ctl_layer_rwsem); + up_read(&card->controls_rwsem); + return snd_unregister_device(&card->ctl_dev); }