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 --- drivers/base/component.c | 106 +++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 103 insertions(+), 3 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/component.c b/drivers/base/component.c index ddcea8739c12..1624c2a892a5 100644 --- a/drivers/base/component.c +++ b/drivers/base/component.c @@ -16,6 +16,32 @@ #include #include +/** + * DOC: overview + * + * The component helper 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 helper can be used when such a + * subsystem-specific way to find a device is not available: The component + * helper 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 helper 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 +327,24 @@ 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 + * + * 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, where upon @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 +407,18 @@ 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 +455,15 @@ 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 +491,15 @@ 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 +573,15 @@ 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 +616,18 @@ 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 at driver unload/disconnect by calling + * component_del(). + */ int component_add(struct device *dev, const struct component_ops *ops) { struct component *component; @@ -568,6 +659,15 @@ 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; -- 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 --- drivers/base/component.c | 158 ++++++++++++++++++++++++++++++++++++----------- 1 file changed, 121 insertions(+), 37 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/component.c b/drivers/base/component.c index 1624c2a892a5..7dbc41cccd58 100644 --- a/drivers/base/component.c +++ b/drivers/base/component.c @@ -47,6 +47,7 @@ struct component; struct component_match_array { void *data; int (*compare)(struct device *, void *); + int (*compare_typed)(struct device *, int, void *); void (*release)(struct device *, void *); struct component *component; bool duplicate; @@ -74,6 +75,7 @@ struct component { bool bound; const struct component_ops *ops; + int subcomponent; struct device *dev; }; @@ -158,7 +160,7 @@ static struct master *__master_find(struct device *dev, } static struct component *find_component(struct master *master, - int (*compare)(struct device *, void *), void *compare_data) + struct component_match_array *mc) { struct component *c; @@ -166,7 +168,11 @@ static struct component *find_component(struct master *master, if (c->master && c->master != master) continue; - if (compare(c->dev, compare_data)) + if (mc->compare && mc->compare(c->dev, mc->data)) + return c; + + if (mc->compare_typed && + mc->compare_typed(c->dev, c->subcomponent, mc->data)) return c; } @@ -192,7 +198,7 @@ static int find_components(struct master *master) if (match->compare[i].component) continue; - c = find_component(master, mc->compare, mc->data); + c = find_component(master, mc); if (!c) { ret = -ENXIO; break; @@ -327,29 +333,12 @@ static int component_match_realloc(struct device *dev, return 0; } -/** - * 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 - * - * 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, where upon @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(). - * - * See also component_match_add(). - */ -void component_match_add_release(struct device *master, +static void __component_match_add(struct device *master, struct component_match **matchptr, void (*release)(struct device *, void *), - int (*compare)(struct device *, void *), void *compare_data) + int (*compare)(struct device *, void *), + int (*compare_typed)(struct device *, int, void *), + void *compare_data) { struct component_match *match = *matchptr; @@ -381,13 +370,69 @@ void component_match_add_release(struct device *master, } match->compare[match->num].compare = compare; + match->compare[match->num].compare_typed = compare_typed; match->compare[match->num].release = release; match->compare[match->num].data = compare_data; match->compare[match->num].component = NULL; match->num++; } + +/** + * 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 + * + * 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. This + * only matches against components added with component_add(). + * + * The allocated match list in @matchptr is automatically released using devm + * actions, where upon @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(). + * + * See also component_match_add() and component_match_add_typed(). + */ +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) +{ + __component_match_add(master, matchptr, release, compare, NULL, + compare_data); +} EXPORT_SYMBOL(component_match_add_release); +/** + * component_match_add_typed - add a compent match for a typed component + * @master: device with the aggregate driver + * @matchptr: pointer to the list of component matches + * @compare_typed: compare function to match against all typed 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. This + * only matches against components added with component_add_typed(). + * + * The allocated match list in @matchptr is automatically released using devm + * actions. + * + * See also component_match_add_release() and component_match_add_typed(). + */ +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(master, matchptr, NULL, NULL, compare_typed, + compare_data); +} +EXPORT_SYMBOL(component_match_add_typed); + static void free_master(struct master *master) { struct component_match *match = master->match; @@ -616,19 +661,8 @@ 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 at driver unload/disconnect by calling - * component_del(). - */ -int component_add(struct device *dev, const struct component_ops *ops) +static int __component_add(struct device *dev, const struct component_ops *ops, + int subcomponent) { struct component *component; int ret; @@ -639,6 +673,7 @@ int component_add(struct device *dev, const struct component_ops *ops) component->ops = ops; component->dev = dev; + component->subcomponent = subcomponent; dev_dbg(dev, "adding component (ops %ps)\n", ops); @@ -657,6 +692,55 @@ int component_add(struct device *dev, const struct component_ops *ops) return ret < 0 ? ret : 0; } + +/** + * component_add_typed - register a component + * @dev: component device + * @ops: component callbacks + * @subcomponent: nonzero identifier for subcomponents + * + * Register a new component for @dev. Functions in @ops will be call when the + * aggregate driver is ready to bind the overall driver by calling + * component_bind_all(). See also &struct component_ops. + * + * @subcomponent must be nonzero and is used to differentiate between multiple + * components registerd on the same device @dev. These components are match + * using component_match_add_typed(). + * + * The component needs to be unregistered at driver unload/disconnect by + * calling component_del(). + * + * See also component_add(). + */ +int component_add_typed(struct device *dev, const struct component_ops *ops, + int subcomponent) +{ + if (WARN_ON(subcomponent == 0)) + return -EINVAL; + + return __component_add(dev, ops, subcomponent); +} +EXPORT_SYMBOL_GPL(component_add_typed); + +/** + * 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 at driver unload/disconnect by + * calling component_del(). + * + * See also component_add_typed() for a variant that allows multipled different + * components on the same device. + */ +int component_add(struct device *dev, const struct component_ops *ops) +{ + return __component_add(dev, ops, 0); +} EXPORT_SYMBOL_GPL(component_add); /** -- cgit v1.2.3