usb: typec: Link enumerated USB devices with Type-C partner

Adding functions that USB hub code can use to inform the
Type-C class about connected USB devices.

Once taken into use, it will allow the Type-C port drivers
to power off components that are not needed, for example if
USB2 device is enumerated, everything that is only relevant
for USB3 (retimers, etc.), can be powered off.

This will also create a symlink "typec" for the USB devices
pointing to the USB Type-C partner device.

Suggested-by: Benson Leung <bleung@chromium.org>
Tested-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20231011105825.320062-2-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ACPI: bus: Introduce acpi_bus_for_each_dev()

In order to avoid exposing acpi_bus_type to modules, introduce an
acpi_bus_for_each_dev() helper for iterating over all ACPI device
objects and make typec_link_ports() use it instead of the raw
bus_for_each_dev() along with acpi_bus_type.

Having done that, drop the acpi_bus_type export.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

usb: typec: Don't try to register component master without components

This fixes NULL pointer dereference that happens if
component master is registered with empty component match
list.

Fixes: 730b49aac426 ("usb: typec: port-mapper: Convert to the component framework")
Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Tested-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20220124090228.41396-3-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: typec: Only attempt to link USB ports if there is fwnode

The code that creates the links to the USB ports attached to
a connector inside the system assumed that the ACPI nodes
(fwnodes) always exist for the connectors, but it can not do
that.

There is no guarantee that every USB Type-C connector has
ACPI device node representing it in the ACPI tables, and
even if there are the nodes in the ACPI tables, the _STA
method in those nodes may still return 0 (which means the
device does not exist from ACPI PoW).

This fixes NULL pointer dereference that happens if the
nodes are missing.

Fixes: 730b49aac426 ("usb: typec: port-mapper: Convert to the component framework")
Reported-and-tested-by: Robert Święcki <robert@swiecki.net>
Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Tested-by: Marc Zyngier <maz@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20220124090228.41396-2-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: typec: port-mapper: Convert to the component framework

Instead of trying to keep track of the connections to the
USB Type-C connectors separately, letting the component
framework take care of that.

From now on every USB Type-C connector will register itself
as "aggregate" - component master - and anything that can be
connected to it inside the system can then simply register
itself as a generic component.

The matching of the components and the connector shall rely
on ACPI _PLD initially. Before registering itself as the
aggregate, the connector will find all other ACPI devices
that have matching _PLD crc hash with it (matching value in
the pld_crc member of struct acpi_device), and add a
component match entry for each one of them. Because only
ACPI is supported for now, the driver shall only be build
when ACPI is supported.

This removes the need for the custom API that the driver
exposed. The components and the connector can therefore
exist completely independently of each other. The order in
which they are registered, as well as are they modules or
not, is now irrelevant.

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20211223082422.45637-1-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: typec: silence a static checker warning

Smatch complains about a potential missing error code:

drivers/usb/typec/port-mapper.c:168 typec_link_port()
warn: missing error code 'ret'

This is a false positive and returning zero is intentional. Let's
re-arrange the code to silence the warning and make the intent more
clear.

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/YHadaACH8Mq/10F7@mwanda
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: typec: Link all ports during connector registration

The connectors may be registered after the ports, so the
"connector" links need to be created for the ports also when
ever a new connector gets registered.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20210407065555.88110-5-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: typec: Port mapping utility

Adding functions that can be used to link/unlink ports -
USB ports, TBT3/USB4 ports, DisplayPorts and so on - to
the USB Type-C connectors they are attached to inside a
system. The symlink that is created for the port device is
named "connector".

Initially only ACPI is supported. ACPI port object shares
the _PLD (Physical Location of Device) with the USB Type-C
connector that it's attached to.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20210407065555.88110-2-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>