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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 0BE79C282CB for ; Tue, 5 Feb 2019 16:22:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B790020844 for ; Tue, 5 Feb 2019 16:22:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="OXvXA3FM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730491AbfBEQW1 (ORCPT ); Tue, 5 Feb 2019 11:22:27 -0500 Received: from mail-ed1-f66.google.com ([209.85.208.66]:36959 "EHLO mail-ed1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729844AbfBEQW1 (ORCPT ); Tue, 5 Feb 2019 11:22:27 -0500 Received: by mail-ed1-f66.google.com with SMTP id h15so3352968edb.4 for ; Tue, 05 Feb 2019 08:22:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=gBwblzRMMbCDpRJdW8ie+C2OXqh+J6vMv+GvivGhvRk=; b=OXvXA3FM134y/5GKRaqK2NjQAhmHsVlYeTw73HMTC9TD+mJ3Y+W4jt+k25Rpe40SUc GOkNtov+lJwNPftpDpFFcsPWoYDPM/J/zZX84/++oiUK7X7vfTfGCJQtcYTwGOmOXZZl rtKFiTHTItlS+HSTVZ5KwBmVeLtrLul0oy4+I= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=gBwblzRMMbCDpRJdW8ie+C2OXqh+J6vMv+GvivGhvRk=; b=etb4CWgWL5JOpS88rpGa9vrhSXcDhfCyBSQ2mIj9trg+HgJANYmyYPHMACVrUN0fKP C45yK6Lhis7wLqnUpsjImwQ6yGl9MNo0REjg96to6Sl45SsTkPNIzHAMQxT+y8P+ZfEW xT6qIXSu57Og5j2lFNr2mX+T/LoEpU31wFTvhfi4nJny8WnOFwEGixUNoP/kToRsBpaJ YDSyk30u1YkKr9FfWsXrkCS90tWrVkzlgLUbiWxlmiSSNvpVutFjL47b8sgb/Mjj8X41 acnbUW0bYIfKAMWzW54ppsk4aeF0pdQhDAl5Rk7QpSKz0CRFTYE5EUL7KForE+aGz4EG Ihxg== X-Gm-Message-State: AHQUAuYmCn2Q6GtJ4f+WYQIkMTy2YsSsQpoFXi0gBOUutfGN5f/L8OGe 3ZQq03tP5ycXeJKlJAIt/23FMg== X-Google-Smtp-Source: AHgI3IYp3gV2BXFNMygGp2dHwtj2InCzmvYGDRNGp15bcxjR0vKKtf8SERFBeLZBUsWEOyjGMEcuWQ== X-Received: by 2002:a17:906:5ace:: with SMTP id x14mr4079596ejs.64.1549383743790; Tue, 05 Feb 2019 08:22:23 -0800 (PST) Received: from phenom.ffwll.local ([2a02:168:569e:0:3106:d637:d723:e855]) by smtp.gmail.com with ESMTPSA id e17sm3118644ejb.29.2019.02.05.08.22.22 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 05 Feb 2019 08:22:23 -0800 (PST) From: Daniel Vetter To: DRI Development Cc: LKML , Daniel Vetter , "C, Ramalingam" , Greg Kroah-Hartman , Russell King , "Rafael J . Wysocki" , Jaroslav Kysela , Takashi Iwai , Rodrigo Vivi , Jani Nikula , Daniel Vetter Subject: [PATCH] component: Add documentation Date: Tue, 5 Feb 2019 17:21:07 +0100 Message-Id: <20190205162107.17633-1-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190131144640.17896-1-daniel.vetter@ffwll.ch> References: <20190131144640.17896-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Someone owes me a beer ... While typing these I think doing an s/component_master/aggregate/ would be useful: - it's shorter :-) - I think component/aggregate is much more meaningful naming than component/puppetmaster or something like that. At least to my English ear "aggregate" emphasizes much more the "assemble a pile of things into something bigger" aspect, and there's not really much of a control hierarchy between aggregate and constituing components. But that's way more than a quick doc typing exercise ... Thanks to Ram for commenting on an initial draft of these docs. v2: Review from Rafael: - git add Documenation/driver-api/component.rst - lots of polish to the wording + spelling fixes. Cc: "C, Ramalingam" Cc: Greg Kroah-Hartman Cc: Russell King Cc: Rafael J. Wysocki Cc: Jaroslav Kysela Cc: Takashi Iwai Cc: Rodrigo Vivi Cc: Jani Nikula Signed-off-by: Daniel Vetter --- Documentation/driver-api/component.rst | 17 ++++ Documentation/driver-api/device_link.rst | 3 + Documentation/driver-api/index.rst | 1 + drivers/base/component.c | 107 ++++++++++++++++++++++- include/linux/component.h | 70 +++++++++++++++ 5 files changed, 195 insertions(+), 3 deletions(-) create mode 100644 Documentation/driver-api/component.rst diff --git a/Documentation/driver-api/component.rst b/Documentation/driver-api/component.rst new file mode 100644 index 000000000000..3407ff0424b9 --- /dev/null +++ b/Documentation/driver-api/component.rst @@ -0,0 +1,17 @@ +========================================= +Component Framework for Aggregate Drivers +========================================= + +.. kernel-doc:: drivers/base/component.c + :doc: overview + + +API +=== + +.. kernel-doc:: include/linux/component.h + :internal: + +.. kernel-doc:: drivers/base/component.c + :export: + diff --git a/Documentation/driver-api/device_link.rst b/Documentation/driver-api/device_link.rst index d6763272e747..2d5919b2b337 100644 --- a/Documentation/driver-api/device_link.rst +++ b/Documentation/driver-api/device_link.rst @@ -1,6 +1,9 @@ .. |struct dev_pm_domain| replace:: :c:type:`struct dev_pm_domain ` .. |struct generic_pm_domain| replace:: :c:type:`struct generic_pm_domain ` + +.. _device_link: + ============ Device links ============ diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst index ab38ced66a44..c0b600ed9961 100644 --- a/Documentation/driver-api/index.rst +++ b/Documentation/driver-api/index.rst @@ -22,6 +22,7 @@ available subsections can be seen below. device_connection dma-buf device_link + component message-based sound frame-buffer diff --git a/drivers/base/component.c b/drivers/base/component.c index ddcea8739c12..4851e1006f11 100644 --- a/drivers/base/component.c +++ b/drivers/base/component.c @@ -16,6 +16,33 @@ #include #include +/** + * DOC: overview + * + * The component framework allows drivers to collect a pile of sub-devices, + * including their bound drivers, into an aggregate driver. Various subsystems + * already provide functions to get hold of such components, e.g. + * of_clk_get_by_name(). The component framework can be used when such a + * subsystem-specific way to find a device is not available: The component + * framework fills the niche of aggregate drivers for specific hardware, where + * further standardization into a subsystem would not be practical. The common + * example is when a logical device (e.g. a DRM display driver) is spread around + * the SoC on various component (scanout engines, blending blocks, transcoders + * for various outputs and so on). + * + * The component framework also doesn't solve runtime dependencies, e.g. for + * system suspend and resume operations. See also :ref:`device + * links`. + * + * Components are registered using component_add() and unregistered with + * component_del(), usually from the driver's probe and disconnect functions. + * + * Aggregate drivers first assemble a component match list of what they need + * using component_match_add(). This is then registered as an aggregate driver + * using component_master_add_with_match(), and unregistered using + * component_master_del(). + */ + struct component; struct component_match_array { @@ -301,10 +328,24 @@ static int component_match_realloc(struct device *dev, return 0; } -/* - * Add a component to be matched, with a release function. +/** + * component_match_add_release - add a component match with release callback + * @master: device with the aggregate driver + * @matchptr: pointer to the list of component matches + * @release: release function for @compare_data + * @compare: compare function to match against all components + * @compare_data: opaque pointer passed to the @compare function + * + * This adds a new component match to the list stored in @matchptr, which the + * @master aggregate driver needs to function. @matchptr must be initialized to + * NULL before adding the first match. + * + * The allocated match list in @matchptr is automatically released using devm + * actions. At that point @release will be called, to free any references held + * by @compare_data, e.g. when @compare_data is a &device_node that must be + * released with of_node_put(). * - * The match array is first created or extended if necessary. + * See also component_match_add(). */ void component_match_add_release(struct device *master, struct component_match **matchptr, @@ -367,6 +408,18 @@ static void free_master(struct master *master) kfree(master); } +/** + * component_master_add_with_match - register an aggregate driver + * @dev: device with the aggregate driver + * @ops: callbacks for the aggregate driver + * @match: component match list for the aggregate driver + * + * Registers a new aggregate driver consisting of the components added to @match + * by calling one of the component_match_add() functions. Once all components in + * @match are available, it will be assembled by calling + * &component_master_ops.bind from @ops. Must be unregistered by calling + * component_master_del(). + */ int component_master_add_with_match(struct device *dev, const struct component_master_ops *ops, struct component_match *match) @@ -403,6 +456,15 @@ int component_master_add_with_match(struct device *dev, } EXPORT_SYMBOL_GPL(component_master_add_with_match); +/** + * component_master_del - unregister an aggregate driver + * @dev: device with the aggregate driver + * @ops: callbacks for the aggregate driver + * + * Unregisters an aggregate driver registered with + * component_master_add_with_match(). If necessary the aggregate driver is first + * disassembled by calling &component_master_ops.unbind from @ops. + */ void component_master_del(struct device *dev, const struct component_master_ops *ops) { @@ -430,6 +492,15 @@ static void component_unbind(struct component *component, devres_release_group(component->dev, component); } +/** + * component_unbind_all - unbind all component to an aggregate driver + * @master_dev: device with the aggregate driver + * @data: opaque pointer, passed to all components + * + * Unbinds all components to the aggregate @dev by passing @data to their + * &component_ops.unbind functions. Should be called from + * &component_master_ops.unbind. + */ void component_unbind_all(struct device *master_dev, void *data) { struct master *master; @@ -503,6 +574,15 @@ static int component_bind(struct component *component, struct master *master, return ret; } +/** + * component_bind_all - bind all component to an aggregate driver + * @master_dev: device with the aggregate driver + * @data: opaque pointer, passed to all components + * + * Binds all components to the aggregate @dev by passing @data to their + * &component_ops.bind functions. Should be called from + * &component_master_ops.bind. + */ int component_bind_all(struct device *master_dev, void *data) { struct master *master; @@ -537,6 +617,18 @@ int component_bind_all(struct device *master_dev, void *data) } EXPORT_SYMBOL_GPL(component_bind_all); +/** + * component_add - register a component + * @dev: component device + * @ops: component callbacks + * + * Register a new component for @dev. Functions in @ops will be called when the + * aggregate driver is ready to bind the overall driver by calling + * component_bind_all(). See also &struct component_ops. + * + * The component needs to be unregistered again at driver unload/disconnect by + * calling component_del(). + */ int component_add(struct device *dev, const struct component_ops *ops) { struct component *component; @@ -568,6 +660,15 @@ int component_add(struct device *dev, const struct component_ops *ops) } EXPORT_SYMBOL_GPL(component_add); +/** + * component_del - unregister a component + * @dev: component device + * @ops: component callbacks + * + * Unregister a component added with component_add(). If the component is bound + * into an aggregate driver, this will force the entire aggregate driver, including + * all its components, to be unbound. + */ void component_del(struct device *dev, const struct component_ops *ops) { struct component *c, *component = NULL; diff --git a/include/linux/component.h b/include/linux/component.h index e71fbbbc74e2..b5a989e3871e 100644 --- a/include/linux/component.h +++ b/include/linux/component.h @@ -4,11 +4,31 @@ #include + struct device; +/** + * struct component_ops - callbacks for component drivers + * + * Components are registered with component_add() and unregistered with + * component_del(). + */ struct component_ops { + /** + * @bind: + * + * Called through component_bind_all() when the aggregate driver is + * ready to bind the overall driver. + */ int (*bind)(struct device *comp, struct device *master, void *master_data); + /** + * @unbind: + * + * Called through component_unbind_all() when the aggregate driver is + * ready to bind the overall driver, or when component_bind_all() fails + * part-ways through and needs to unbind some already bound components. + */ void (*unbind)(struct device *comp, struct device *master, void *master_data); }; @@ -21,8 +41,42 @@ void component_unbind_all(struct device *master, void *master_data); struct master; +/** + * struct component_master_ops - callback for the aggregate driver + * + * Aggregate drivers are registered with component_master_add_with_match() and + * unregistered with component_master_del(). + */ struct component_master_ops { + /** + * @bind: + * + * Called when all components or the aggregate driver, as specified in + * the match list passed to component_master_add_with_match(), are + * ready. Usually there are 3 steps to bind an aggregate driver: + * + * 1. Allocate a structure for the aggregate driver. + * + * 2. Bind all components to the aggregate driver by calling + * component_bind_all() with the aggregate driver structure as opaque + * pointer data. + * + * 3. Register the aggregate driver with the subsystem to publish its + * interfaces. + * + * Note that the lifetime of the aggregate driver does not align with + * any of the underlying &struct device instances. Therefore devm cannot + * be used and all resources acquired or allocated in this callback must + * be explicitly released in the @unbind callback. + */ int (*bind)(struct device *master); + /** + * @unbind: + * + * Called when either the aggregate driver, using + * component_master_del(), or one of its components, using + * component_del(), is unregistered. + */ void (*unbind)(struct device *master); }; @@ -38,6 +92,22 @@ void component_match_add_release(struct device *master, void (*release)(struct device *, void *), int (*compare)(struct device *, void *), void *compare_data); +/** + * component_match_add - add a compent match + * @master: device with the aggregate driver + * @matchptr: pointer to the list of component matches + * @compare: compare function to match against all components + * @compare_data: opaque pointer passed to the @compare function + * + * Adds a new component match to the list stored in @matchptr, which the + * @master aggregate driver needs to function. @matchptr must be initialized to + * NULL before adding the first match. + * + * The allocated match list in @matchptr is automatically released using devm + * actions. + * + * See also component_match_add_release(). + */ static inline void component_match_add(struct device *master, struct component_match **matchptr, int (*compare)(struct device *, void *), void *compare_data) -- 2.20.1