The component helper treats the void match data pointer as an opaque
object which needs no further management. When device nodes being
passed, this is not true: the caller should pass its refcount to the
component helper, and there should be a way to drop the refcount when
the matching information is destroyed.
This patch provides a per-match release method in addition to the match
method to solve this issue. Rather than using component_match_add(),
users should use component_match_add_release() which takes an additional
function pointer for releasing this reference.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Now that drivers create an array of component matches at probe time, we
can retire the old methods. This involves removing the add_components
master method, and removing component_master_add_child() from public
view. We also remove component_add_master() as that interface is no
longer useful.
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add support for generating a set of component matches at master probe
time, and submitting them to the component layer. This allows the
component layer to perform the matches internally without needing to
call into the master driver, and allows for further restructuring of
the component helper.
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Subsystems such as ALSA, DRM and others require a single card-level
device structure to represent a subsystem. However, firmware tends to
describe the individual devices and the connections between them.
Therefore, we need a way to gather up the individual component devices
together, and indicate when we have all the component devices.
We do this in DT by providing a "superdevice" node which specifies
the components, eg:
imx-drm {
compatible = "fsl,drm";
crtcs = <&ipu1>;
connectors = <&hdmi>;
};
The superdevice is declared into the component support, along with the
subcomponents. The superdevice receives callbacks to locate the
subcomponents, and identify when all components are present. At this
point, we bind the superdevice, which causes the appropriate subsystem
to be initialised in the conventional way.
When any of the components or superdevice are removed from the system,
we unbind the superdevice, thereby taking the subsystem down.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Russell King