From 4d69c80e0d0fd8cf12d985841eb0fce5c29819ad Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Fri, 8 Feb 2019 00:27:56 +0100 Subject: component: Add documentation 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. v3: Review from Russell: - s/framework/helper - clarify the documentation for component_match_add functions. v4: Remove a few superflous "This". Reviewed-by: Rafael J. Wysocki 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 Reviewed-by: Greg Kroah-Hartman Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20190207232759.14553-1-daniel.vetter@ffwll.ch --- include/linux/component.h | 70 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) (limited to 'include/linux/component.h') diff --git a/include/linux/component.h b/include/linux/component.h index e71fbbbc74e2..83da25bdf59c 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. The list of component matches pointed to + * by @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) -- cgit v1.2.3 From 3521ee994bca90c57b539e106ff7e12a839aa8ea Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Fri, 8 Feb 2019 00:27:57 +0100 Subject: components: multiple components for a device Component framework is extended to support multiple components for a struct device. These will be matched with different masters based on its sub component value. We are introducing this, as I915 needs two different components with different subcomponent value, which will be matched to two different component masters(Audio and HDCP) based on the subcomponent values. v2: Add documenation. v3: Rebase on top of updated documenation. v4: Review from Rafael: - Remove redundant "This" from kerneldoc (also in the previous patch) - Streamline the logic in find_component() a bit. Signed-off-by: Daniel Vetter (v1 code) Signed-off-by: Ramalingam C (v1 commit message) Cc: Ramalingam C Cc: Greg Kroah-Hartman Cc: Russell King Cc: Rafael J. Wysocki Cc: Jaroslav Kysela Cc: Takashi Iwai Cc: Rodrigo Vivi Cc: Jani Nikula Reviewed-by: Greg Kroah-Hartman Reviewed-by: Rafael J. Wysocki Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20190207232759.14553-2-daniel.vetter@ffwll.ch --- include/linux/component.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'include/linux/component.h') diff --git a/include/linux/component.h b/include/linux/component.h index 83da25bdf59c..30bcc7e590eb 100644 --- a/include/linux/component.h +++ b/include/linux/component.h @@ -34,6 +34,8 @@ struct component_ops { }; int component_add(struct device *, const struct component_ops *); +int component_add_typed(struct device *dev, const struct component_ops *ops, + int subcomponent); void component_del(struct device *, const struct component_ops *); int component_bind_all(struct device *master, void *master_data); @@ -91,6 +93,9 @@ void component_match_add_release(struct device *master, struct component_match **matchptr, void (*release)(struct device *, void *), int (*compare)(struct device *, void *), void *compare_data); +void component_match_add_typed(struct device *master, + struct component_match **matchptr, + int (*compare_typed)(struct device *, int, void *), void *compare_data); /** * component_match_add - add a compent match @@ -101,12 +106,13 @@ void component_match_add_release(struct device *master, * * Adds a new component match to the list stored in @matchptr, which the @master * aggregate driver needs to function. The list of component matches pointed to - * by @matchptr must be initialized to NULL before adding the first match. + * by @matchptr must be initialized to NULL before adding the first match. This + * only matches against components added with component_add(). * * The allocated match list in @matchptr is automatically released using devm * actions. * - * See also component_match_add_release(). + * See also component_match_add_release() and component_match_add_typed(). */ static inline void component_match_add(struct device *master, struct component_match **matchptr, -- cgit v1.2.3