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 <daniel.vetter@ffwll.ch> (v1 code)
Signed-off-by: Ramalingam C <ramalingam.c@intel.com> (v1 commit message)
Cc: Ramalingam C <ramalingam.c@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190207232759.14553-2-daniel.vetter@ffwll.ch

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);
 
 /**

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,