Merge tag 'topic/mei-hdcp-2019-02-19' of...

Merge tag 'topic/mei-hdcp-2019-02-19' of git://anongit.freedesktop.org/drm/drm-intel into drm-intel-next-queued

Prep patches + headers for the mei-hdcp/i915 component interfaces

Also contains the prep work in the component helpers plus adjustements
for the snd-hda/i915 component interface.

Plus one small static inline in the drm_hdcp.h header that both i915
and mei_hdcp will need.
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190219071619.GA11016@phenom.ffwll.local

Documentation/driver-api/component.rst

+======================================
+Component Helper 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:
+

Documentation/driver-api/device_link.rst

 .. |struct dev_pm_domain| replace:: :c:type:`struct dev_pm_domain <dev_pm_domain>`
 .. |struct generic_pm_domain| replace:: :c:type:`struct generic_pm_domain <generic_pm_domain>`
 
+
+.. _device_link:
+
 ============
 Device links
 ============

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

drivers/base/component.c

@@ -16,11 +16,38 @@
 #include <linux/slab.h>
 #include <linux/debugfs.h>
 
+/**
+ * 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<device_link>`.
+ *
+ * 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 {
 	void *data;
 	int (*compare)(struct device *, void *);
+	int (*compare_typed)(struct device *, int, void *);
 	void (*release)(struct device *, void *);
 	struct component *component;
 	bool duplicate;
@@ -48,6 +75,7 @@ struct component {
 	bool bound;
 
 	const struct component_ops *ops;
+	int subcomponent;
 	struct device *dev;
 };
 
@@ -132,7 +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;
 
@@ -140,7 +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;
 	}
 
@@ -166,7 +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;
@@ -301,15 +333,12 @@ static int component_match_realloc(struct device *dev,
 	return 0;
 }
 
-/*
- * Add a component to be matched, with a release function.
- *
- * The match array is first created or extended if necessary.
- */
-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;
 
@@ -341,13 +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;
@@ -367,6 +452,18 @@ 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 +500,15 @@ 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 +536,15 @@ 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 +618,15 @@ 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;
@@ -537,7 +661,8 @@ int component_bind_all(struct device *master_dev, void *data)
 }
 EXPORT_SYMBOL_GPL(component_bind_all);
 
-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;
@@ -548,6 +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);
 
@@ -566,8 +692,66 @@ 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);
 
+/**
+ * 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;

drivers/gpu/drm/i915/intel_audio.c

@@ -989,7 +989,9 @@ void i915_audio_component_init(struct drm_i915_private *dev_priv)
 {
 	int ret;
 
-	ret = component_add(dev_priv->drm.dev, &i915_audio_component_bind_ops);
+	ret = component_add_typed(dev_priv->drm.dev,
+				  &i915_audio_component_bind_ops,
+				  I915_COMPONENT_AUDIO);
 	if (ret < 0) {
 		DRM_ERROR("failed to add audio component (%d)\n", ret);
 		/* continue with reduced functionality */

drivers/gpu/drm/i915/intel_display.h

@@ -26,6 +26,7 @@
 #define _INTEL_DISPLAY_H_
 
 #include <drm/drm_util.h>
+#include <drm/i915_drm.h>
 
 enum i915_gpio {
 	GPIOA,
@@ -150,21 +151,6 @@ enum plane_id {
 	for ((__p) = PLANE_PRIMARY; (__p) < I915_MAX_PLANES; (__p)++) \
 		for_each_if((__crtc)->plane_ids_mask & BIT(__p))
 
-enum port {
-	PORT_NONE = -1,
-
-	PORT_A = 0,
-	PORT_B,
-	PORT_C,
-	PORT_D,
-	PORT_E,
-	PORT_F,
-
-	I915_MAX_PORTS
-};
-
-#define port_name(p) ((p) + 'A')
-
 /*
  * Ports identifier referenced from other drivers.
  * Expected to remain stable over time

include/drm/drm_audio_component.h

@@ -5,6 +5,7 @@
 #define _DRM_AUDIO_COMPONENT_H_
 
 struct drm_audio_component;
+struct device;
 
 /**
  * struct drm_audio_component_ops - Ops implemented by DRM driver, called by hda driver

include/drm/drm_hdcp.h

@@ -252,4 +252,22 @@ struct hdcp2_dp_errata_stream_type {
 #define HDCP_2_2_HDMI_RXSTATUS_READY(x)		((x) & BIT(2))
 #define HDCP_2_2_HDMI_RXSTATUS_REAUTH_REQ(x)	((x) & BIT(3))
 
+/*
+ * Helper functions to convert 24bit big endian hdcp sequence number to
+ * host format and back
+ */
+static inline
+u32 drm_hdcp2_seq_num_to_u32(u8 seq_num[HDCP_2_2_SEQ_NUM_LEN])
+{
+	return (u32)(seq_num[2] | seq_num[1] << 8 | seq_num[0] << 16);
+}
+
+static inline
+void drm_hdcp2_u32_to_seq_num(u8 seq_num[HDCP_2_2_SEQ_NUM_LEN], u32 val)
+{
+	seq_num[0] = val >> 16;
+	seq_num[1] = val >> 8;
+	seq_num[2] = val;
+}
+
 #endif

include/drm/i915_component.h

@@ -26,6 +26,11 @@
 
 #include "drm_audio_component.h"
 
+enum i915_component_type {
+	I915_COMPONENT_AUDIO = 1,
+	I915_COMPONENT_HDCP,
+};
+
 /* MAX_PORT is the number of port
  * It must be sync with I915_MAX_PORTS defined i915_drv.h
  */

include/drm/i915_drm.h

@@ -100,4 +100,19 @@ extern struct resource intel_graphics_stolen_res;
 #define INTEL_GEN11_BSM_DW1	0xc4
 #define   INTEL_BSM_MASK	(-(1u << 20))
 
+enum port {
+	PORT_NONE = -1,
+
+	PORT_A = 0,
+	PORT_B,
+	PORT_C,
+	PORT_D,
+	PORT_E,
+	PORT_F,
+
+	I915_MAX_PORTS
+};
+
+#define port_name(p) ((p) + 'A')
+
 #endif				/* _I915_DRM_H_ */

include/drm/i915_mei_hdcp_interface.h

+/* SPDX-License-Identifier: (GPL-2.0+) */
+/*
+ * Copyright © 2017-2018 Intel Corporation
+ *
+ * Authors:
+ * Ramalingam C <ramalingam.c@intel.com>
+ */
+
+#ifndef _I915_MEI_HDCP_INTERFACE_H_
+#define _I915_MEI_HDCP_INTERFACE_H_
+
+#include <linux/mutex.h>
+#include <linux/device.h>
+#include <drm/drm_hdcp.h>
+#include <drm/i915_drm.h>
+
+/**
+ * enum hdcp_port_type - HDCP port implementation type defined by ME FW
+ * @HDCP_PORT_TYPE_INVALID: Invalid hdcp port type
+ * @HDCP_PORT_TYPE_INTEGRATED: In-Host HDCP2.x port
+ * @HDCP_PORT_TYPE_LSPCON: HDCP2.2 discrete wired Tx port with LSPCON
+ *			   (HDMI 2.0) solution
+ * @HDCP_PORT_TYPE_CPDP: HDCP2.2 discrete wired Tx port using the CPDP (DP 1.3)
+ *			 solution
+ */
+enum hdcp_port_type {
+	HDCP_PORT_TYPE_INVALID,
+	HDCP_PORT_TYPE_INTEGRATED,
+	HDCP_PORT_TYPE_LSPCON,
+	HDCP_PORT_TYPE_CPDP
+};
+
+/**
+ * enum hdcp_wired_protocol - HDCP adaptation used on the port
+ * @HDCP_PROTOCOL_INVALID: Invalid HDCP adaptation protocol
+ * @HDCP_PROTOCOL_HDMI: HDMI adaptation of HDCP used on the port
+ * @HDCP_PROTOCOL_DP: DP adaptation of HDCP used on the port
+ */
+enum hdcp_wired_protocol {
+	HDCP_PROTOCOL_INVALID,
+	HDCP_PROTOCOL_HDMI,
+	HDCP_PROTOCOL_DP
+};
+
+/**
+ * struct hdcp_port_data - intel specific HDCP port data
+ * @port: port index as per I915
+ * @port_type: HDCP port type as per ME FW classification
+ * @protocol: HDCP adaptation as per ME FW
+ * @k: No of streams transmitted on a port. Only on DP MST this is != 1
+ * @seq_num_m: Count of RepeaterAuth_Stream_Manage msg propagated.
+ *	       Initialized to 0 on AKE_INIT. Incremented after every successful
+ *	       transmission of RepeaterAuth_Stream_Manage message. When it rolls
+ *	       over re-Auth has to be triggered.
+ * @streams: struct hdcp2_streamid_type[k]. Defines the type and id for the
+ *	     streams
+ */
+struct hdcp_port_data {
+	enum port port;
+	u8 port_type;
+	u8 protocol;
+	u16 k;
+	u32 seq_num_m;
+	struct hdcp2_streamid_type *streams;
+};
+
+/**
+ * struct i915_hdcp_component_ops- ops for HDCP2.2 services.
+ * @owner: Module providing the ops
+ * @initiate_hdcp2_session: Initiate a Wired HDCP2.2 Tx Session.
+ *			    And Prepare AKE_Init.
+ * @verify_receiver_cert_prepare_km: Verify the Receiver Certificate
+ *				     AKE_Send_Cert and prepare
+				     AKE_Stored_Km/AKE_No_Stored_Km
+ * @verify_hprime: Verify AKE_Send_H_prime
+ * @store_pairing_info: Store pairing info received
+ * @initiate_locality_check: Prepare LC_Init
+ * @verify_lprime: Verify lprime
+ * @get_session_key: Prepare SKE_Send_Eks
+ * @repeater_check_flow_prepare_ack: Validate the Downstream topology
+ *				     and prepare rep_ack
+ * @verify_mprime: Verify mprime
+ * @enable_hdcp_authentication:  Mark a port as authenticated.
+ * @close_hdcp_session: Close the Wired HDCP Tx session per port.
+ *			This also disables the authenticated state of the port.
+ */
+struct i915_hdcp_component_ops {
+	/**
+	 * @owner: mei_hdcp module
+	 */
+	struct module *owner;
+
+	int (*initiate_hdcp2_session)(struct device *dev,
+				      struct hdcp_port_data *data,
+				      struct hdcp2_ake_init *ake_data);
+	int (*verify_receiver_cert_prepare_km)(struct device *dev,
+					       struct hdcp_port_data *data,
+					       struct hdcp2_ake_send_cert
+								*rx_cert,
+					       bool *km_stored,
+					       struct hdcp2_ake_no_stored_km
+								*ek_pub_km,
+					       size_t *msg_sz);
+	int (*verify_hprime)(struct device *dev,
+			     struct hdcp_port_data *data,
+			     struct hdcp2_ake_send_hprime *rx_hprime);
+	int (*store_pairing_info)(struct device *dev,
+				  struct hdcp_port_data *data,
+				  struct hdcp2_ake_send_pairing_info
+								*pairing_info);
+	int (*initiate_locality_check)(struct device *dev,
+				       struct hdcp_port_data *data,
+				       struct hdcp2_lc_init *lc_init_data);
+	int (*verify_lprime)(struct device *dev,
+			     struct hdcp_port_data *data,
+			     struct hdcp2_lc_send_lprime *rx_lprime);
+	int (*get_session_key)(struct device *dev,
+			       struct hdcp_port_data *data,
+			       struct hdcp2_ske_send_eks *ske_data);
+	int (*repeater_check_flow_prepare_ack)(struct device *dev,
+					       struct hdcp_port_data *data,
+					       struct hdcp2_rep_send_receiverid_list
+								*rep_topology,
+					       struct hdcp2_rep_send_ack
+								*rep_send_ack);
+	int (*verify_mprime)(struct device *dev,
+			     struct hdcp_port_data *data,
+			     struct hdcp2_rep_stream_ready *stream_ready);
+	int (*enable_hdcp_authentication)(struct device *dev,
+					  struct hdcp_port_data *data);
+	int (*close_hdcp_session)(struct device *dev,
+				  struct hdcp_port_data *data);
+};
+
+/**
+ * struct i915_hdcp_component_master - Used for communication between i915
+ * and mei_hdcp drivers for the HDCP2.2 services
+ * @mei_dev: device that provide the HDCP2.2 service from MEI Bus.
+ * @hdcp_ops: Ops implemented by mei_hdcp driver, used by i915 driver.
+ */
+struct i915_hdcp_comp_master {
+	struct device *mei_dev;
+	const struct i915_hdcp_component_ops *ops;
+
+	/* To protect the above members. */
+	struct mutex mutex;
+};
+
+#endif /* _I915_MEI_HDCP_INTERFACE_H_ */

include/linux/component.h

@@ -4,16 +4,38 @@
 
 #include <linux/stddef.h>
 
+
 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);
 };
 
 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);
@@ -21,8 +43,42 @@ 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);
 };
 
@@ -37,7 +93,27 @@ 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
+ * @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. 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() and component_match_add_typed().
+ */
 static inline void component_match_add(struct device *master,
 	struct component_match **matchptr,
 	int (*compare)(struct device *, void *), void *compare_data)

include/sound/hda_component.h

@@ -20,7 +20,7 @@ int snd_hdac_acomp_get_eld(struct hdac_device *codec, hda_nid_t nid, int dev_id,
 			   bool *audio_enabled, char *buffer, int max_bytes);
 int snd_hdac_acomp_init(struct hdac_bus *bus,
 			const struct drm_audio_component_audio_ops *aops,
-			int (*match_master)(struct device *, void *),
+			int (*match_master)(struct device *, int, void *),
 			size_t extra_size);
 int snd_hdac_acomp_exit(struct hdac_bus *bus);
 int snd_hdac_acomp_register_notifier(struct hdac_bus *bus,
@@ -47,7 +47,8 @@ static inline int snd_hdac_acomp_get_eld(struct hdac_device *codec, hda_nid_t ni
 }
 static inline int snd_hdac_acomp_init(struct hdac_bus *bus,
 				      const struct drm_audio_component_audio_ops *aops,
-				      int (*match_master)(struct device *, void *),
+				      int (*match_master)(struct device *,
+							  int, void *),
 				      size_t extra_size)
 {
 	return -ENODEV;

sound/hda/hdac_component.c

@@ -275,7 +275,7 @@ EXPORT_SYMBOL_GPL(snd_hdac_acomp_register_notifier);
  */
 int snd_hdac_acomp_init(struct hdac_bus *bus,
 			const struct drm_audio_component_audio_ops *aops,
-			int (*match_master)(struct device *, void *),
+			int (*match_master)(struct device *, int, void *),
 			size_t extra_size)
 {
 	struct component_match *match = NULL;
@@ -294,7 +294,7 @@ int snd_hdac_acomp_init(struct hdac_bus *bus,
 	bus->audio_component = acomp;
 	devres_add(dev, acomp);
 
-	component_match_add(dev, &match, match_master, bus);
+	component_match_add_typed(dev, &match, match_master, bus);
 	ret = component_master_add_with_match(dev, &hdac_component_master_ops,
 					      match);
 	if (ret < 0)

sound/hda/hdac_i915.c

@@ -82,9 +82,11 @@ void snd_hdac_i915_set_bclk(struct hdac_bus *bus)
 }
 EXPORT_SYMBOL_GPL(snd_hdac_i915_set_bclk);
 
-static int i915_component_master_match(struct device *dev, void *data)
+static int i915_component_master_match(struct device *dev, int subcomponent,
+				       void *data)
 {
-	return !strcmp(dev->driver->name, "i915");
+	return !strcmp(dev->driver->name, "i915") &&
+	       subcomponent == I915_COMPONENT_AUDIO;
 }
 
 /* check whether intel graphics is present */