platform/surface: aggregator: make ssam_bus_type constant and static

Now that the driver core can properly handle constant struct bus_type,
move the ssam_bus_type variable to be a constant structure

platform/surface: aggregator: make ssam_bus_type constant and static

Now that the driver core can properly handle constant struct bus_type,
move the ssam_bus_type variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.

It's also never used outside of
drivers/platform/surface/aggregator/bus.c so make it static and don't
export it as no one is using it.

Cc: Maximilian Luz <[email protected]>
Cc: Hans de Goede <[email protected]>
Cc: Ilpo Järvinen <[email protected]>
Cc: <[email protected]>
Reviewed-by: Maximilian Luz <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Link: https://lore.kernel.org/r/2023121957-tapered-upswing-8326@gregkh
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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platform/surface: aggregator: Make to_ssam_device_driver() respect constness

Make to_ssam_device_driver() a bit safer by replacing container_of()
with container_of_const() to respect the constness o

platform/surface: aggregator: Make to_ssam_device_driver() respect constness

Make to_ssam_device_driver() a bit safer by replacing container_of()
with container_of_const() to respect the constness of the passed in
pointer, instead of silently discarding any const specifications. This
change also makes it more similar to to_ssam_device(), which already
uses container_of_const().

Signed-off-by: Maximilian Luz <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Hans de Goede <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>

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platform/surface: aggregator: Rename top-level request functions to avoid ambiguities

We currently have a struct ssam_request_sync and a function
ssam_request_sync(). While this is valid C, there ar

platform/surface: aggregator: Rename top-level request functions to avoid ambiguities

We currently have a struct ssam_request_sync and a function
ssam_request_sync(). While this is valid C, there are some downsides to
it.

One of these is that current Sphinx versions (>= 3.0) cannot
disambiguate between the two (see disucssion and pull request linked
below). It instead emits a "WARNING: Duplicate C declaration" and links
for the struct and function in the resulting documentation link to the
same entry (i.e. both to either function or struct documentation)
instead of their respective own entries.

While we could just ignore that and wait for a fix, there's also a point
to be made that the current naming can be somewhat confusing when
searching (e.g. via grep) or trying to understand the levels of
abstraction at play:

We currently have struct ssam_request_sync and associated functions
ssam_request_sync_[alloc|free|init|wait|...]() operating on this struct.
However, function ssam_request_sync() is one abstraction level above
this. Similarly, ssam_request_sync_with_buffer() is not a function
operating on struct ssam_request_sync, but rather a sibling to
ssam_request_sync(), both using the struct under the hood.

Therefore, rename the top level request functions:

ssam_request_sync() -> ssam_request_do_sync()
ssam_request_sync_with_buffer() -> ssam_request_do_sync_with_buffer()
ssam_request_sync_onstack() -> ssam_request_do_sync_onstack()

Link: https://lore.kernel.org/all/085e0ada65c11da9303d07e70c510dc45f21315b.1656756450.git.mchehab@kernel.org/
Link: https://github.com/sphinx-doc/sphinx/pull/8313
Signed-off-by: Maximilian Luz <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Hans de Goede <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>

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platform/surface: aggregator: Enforce use of target-ID enum in device ID macros

Similar to the target category (TC), the target ID (TID) can be one
value out of a small number of choices, given in e

platform/surface: aggregator: Enforce use of target-ID enum in device ID macros

Similar to the target category (TC), the target ID (TID) can be one
value out of a small number of choices, given in enum ssam_ssh_tid.

In the device ID macros, SSAM_SDEV() and SSAM_VDEV() we already use text
expansion to, both, remove some textual clutter for the target category
values and enforce that the value belongs to the known set. Now that we
know the names for the target IDs, use the same trick for them as well.

Also rename the SSAM_ANY_x macros to SSAM_SSH_x_ANY to better fit in.

Signed-off-by: Maximilian Luz <[email protected]>
Acked-by: Sebastian Reichel <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Hans de Goede <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>

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platform/surface: aggregator: move to_ssam_device() to use container_of_const()

The driver core is changing to pass some pointers as const, so move
to_ssam_device() to use container_of_const() to ha

platform/surface: aggregator: move to_ssam_device() to use container_of_const()

The driver core is changing to pass some pointers as const, so move
to_ssam_device() to use container_of_const() to handle this change.
to_ssam_device() now properly keeps the const-ness of the pointer passed
into it, while as before it could be lost.

Reviewed-by: Maximilian Luz <[email protected]>
Acked-by: Hans de Goede <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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platform/surface: aggregator: Move device registry helper functions to core module

Move helper functions for client device registration to the core module.
This simplifies addition of future DT/OF s

platform/surface: aggregator: Move device registry helper functions to core module

Move helper functions for client device registration to the core module.
This simplifies addition of future DT/OF support and also allows us to
split out the device hub drivers into their own module.

At the same time, also improve device node validation a bit by not
silently skipping devices with invalid device UID specifiers. Further,
ensure proper lifetime management for the firmware/software nodes
associated with the added devices.

Signed-off-by: Maximilian Luz <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Hans de Goede <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>

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platform/surface: aggregator: Add helper macros for requests with argument and return value

Add helper macros for synchronous stack-allocated Surface Aggregator
request with both argument and return

platform/surface: aggregator: Add helper macros for requests with argument and return value

Add helper macros for synchronous stack-allocated Surface Aggregator
request with both argument and return value, similar to the current
argument-only and return-value-only ones.

Signed-off-by: Maximilian Luz <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Hans de Goede <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>

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platform/surface: aggregator: Allow notifiers to avoid communication on unregistering

When SSAM client devices have been (physically) hot-removed,
communication attempts with those devices may fail

platform/surface: aggregator: Allow notifiers to avoid communication on unregistering

When SSAM client devices have been (physically) hot-removed,
communication attempts with those devices may fail and time out. This
can even extend to event notifiers, due to which timeouts may occur
during device removal, slowing down that process.

Add a parameter to the notifier unregister function that allows skipping
communication with the EC to prevent this. Furthermore, add wrappers for
registering and unregistering notifiers belonging to SSAM client devices
that automatically check if the device has been marked as hot-removed
and communication should be avoided.

Note that non-SSAM client devices can generally not be hot-removed, so
also add a convenience wrapper for those, defaulting to allow
communication.

Signed-off-by: Maximilian Luz <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Hans de Goede <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>

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platform/surface: aggregator: Allow devices to be marked as hot-removed

Some SSAM devices, notably the keyboard cover (keyboard and touchpad) on
the Surface Pro 8, can be hot-removed. When this occu

platform/surface: aggregator: Allow devices to be marked as hot-removed

Some SSAM devices, notably the keyboard cover (keyboard and touchpad) on
the Surface Pro 8, can be hot-removed. When this occurs, communication
with the device may fail and time out. This timeout can unnecessarily
block and slow down device removal and even cause issues when the
devices are detached and re-attached quickly. Thus, communication should
generally be avoided once hot-removal is detected.

While we already remove a device as soon as we detect its (hot-)removal,
the corresponding device driver may still attempt to communicate with
the device during teardown. This is especially critical as communication
failure may also extend to disabling of events, which is typically done
at that stage.

Add a flag to allow marking devices as hot-removed. This can then be
used during client driver teardown to check if any communication
attempts should be avoided.

Signed-off-by: Maximilian Luz <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Hans de Goede <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>

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platform/surface: aggregator: Allow is_ssam_device() to be used when CONFIG_SURFACE_AGGREGATOR_BUS is disabled

In SSAM subsystem drivers that handle both ACPI and SSAM-native client
devices, we may

platform/surface: aggregator: Allow is_ssam_device() to be used when CONFIG_SURFACE_AGGREGATOR_BUS is disabled

In SSAM subsystem drivers that handle both ACPI and SSAM-native client
devices, we may want to check whether we have a SSAM (native) client
device. Further, we may want to do this even when instantiation thereof
cannot happen due to CONFIG_SURFACE_AGGREGATOR_BUS=n. Currently, doing
so causes an error due to an undefined reference error due to
ssam_device_type being placed in the bus source unit.

Therefore, if CONFIG_SURFACE_AGGREGATOR_BUS is not defined, simply let
is_ssam_device() return false to prevent this error.

Signed-off-by: Maximilian Luz <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Hans de Goede <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>

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platform/surface: aggregator: Make client device removal more generic

Currently, there are similar functions defined in the Aggregator
Registry and the controller core.

Make client device removal m

platform/surface: aggregator: Make client device removal more generic

Currently, there are similar functions defined in the Aggregator
Registry and the controller core.

Make client device removal more generic and export it. We can then use
this function later on to remove client devices from device hubs as well
as the controller and avoid re-defining similar things.

Signed-off-by: Maximilian Luz <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Hans de Goede <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>

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platform/surface: aggregator: Update copyright

It's 2021, update the copyright accordingly.

Signed-off-by: Maximilian Luz <[email protected]>
Reviewed-by: Hans de Goede <[email protected]>

platform/surface: aggregator: Update copyright

It's 2021, update the copyright accordingly.

Signed-off-by: Maximilian Luz <[email protected]>
Reviewed-by: Hans de Goede <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Hans de Goede <[email protected]>

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platform/surface: aggregator: avoid clang -Wconstant-conversion warning

Clang complains about the assignment of SSAM_ANY_IID to
ssam_device_uid->instance:

drivers/platform/surface/surface_aggregato

platform/surface: aggregator: avoid clang -Wconstant-conversion warning

Clang complains about the assignment of SSAM_ANY_IID to
ssam_device_uid->instance:

drivers/platform/surface/surface_aggregator_registry.c:478:25: error: implicit conversion from 'int' to '__u8' (aka 'unsigned char') changes value from 65535 to 255 [-Werror,-Wconstant-conversion]
{ SSAM_VDEV(HUB, 0x02, SSAM_ANY_IID, 0x00) },
~ ^~~~~~~~~~~~
include/linux/surface_aggregator/device.h:71:23: note: expanded from macro 'SSAM_ANY_IID'
#define SSAM_ANY_IID 0xffff
^~~~~~
include/linux/surface_aggregator/device.h:126:63: note: expanded from macro 'SSAM_VDEV'
SSAM_DEVICE(SSAM_DOMAIN_VIRTUAL, SSAM_VIRTUAL_TC_##cat, tid, iid, fun)
^~~
include/linux/surface_aggregator/device.h:102:41: note: expanded from macro 'SSAM_DEVICE'
.instance = ((iid) != SSAM_ANY_IID) ? (iid) : 0, \
^~~

The assignment doesn't actually happen, but clang checks the type limits
before checking whether this assignment is reached. Replace the ?:
operator with a __builtin_choose_expr() invocation that avoids the
warning for the untaken part.

Fixes: eb0e90a82098 ("platform/surface: aggregator: Add dedicated bus and device type")
Cc: [email protected]
Signed-off-by: Arnd Bergmann <[email protected]>
Reviewed-by: Nathan Chancellor <[email protected]>
Reviewed-by: Maximilian Luz <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Hans de Goede <[email protected]>

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platform/surface: aggregator: Make SSAM_DEFINE_SYNC_REQUEST_x define static functions

The SSAM_DEFINE_SYNC_REQUEST_x() macros are intended to reduce
boiler-plate code for SSAM request definitions by

platform/surface: aggregator: Make SSAM_DEFINE_SYNC_REQUEST_x define static functions

The SSAM_DEFINE_SYNC_REQUEST_x() macros are intended to reduce
boiler-plate code for SSAM request definitions by defining a wrapper
function for the specified request. The client device variants of those
macros, i.e. SSAM_DEFINE_SYNC_REQUEST_CL_x() in particular rely on the
multi-device (MD) variants, e.g.:

#define SSAM_DEFINE_SYNC_REQUEST_CL_R(name, rtype, spec...) \
SSAM_DEFINE_SYNC_REQUEST_MD_R(__raw_##name, rtype, spec) \
int name(struct ssam_device *sdev, rtype *ret) \
{ \
return __raw_##name(sdev->ctrl, sdev->uid.target, \
sdev->uid.instance, ret); \
}

This now creates the problem that it is not possible to declare the
generated functions static via

static SSAM_DEFINE_SYNC_REQUEST_CL_R(...)

as this will only apply to the function defined by the multi-device
macro, i.e. SSAM_DEFINE_SYNC_REQUEST_MD_R(). Thus compiling with
`-Wmissing-prototypes' rightfully complains that there is a 'static'
keyword missing.

To solve this, make all SSAM_DEFINE_SYNC_REQUEST_x() macros define
static functions. Non-client-device macros are also changed for
consistency. In general, we expect those functions to be only used
locally in the respective drivers for the corresponding interfaces, so
having to define a wrapper function to be able to export this should be
the odd case out.

Reported-by: kernel test robot <[email protected]>
Fixes: b78b4982d763 ("platform/surface: Add platform profile driver")
Signed-off-by: Maximilian Luz <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Hans de Goede <[email protected]>

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platform/surface: aggregator: Add dedicated bus and device type

The Surface Aggregator EC provides varying functionality, depending on
the Surface device. To manage this functionality, we use dedica

platform/surface: aggregator: Add dedicated bus and device type

The Surface Aggregator EC provides varying functionality, depending on
the Surface device. To manage this functionality, we use dedicated
client devices for each subsystem or virtual device of the EC. While
some of these clients are described as standard devices in ACPI and the
corresponding client drivers can be implemented as platform drivers in
the kernel (making use of the controller API already present), many
devices, especially on newer Surface models, cannot be found there.

To simplify management of these devices, we introduce a new bus and
client device type for the Surface Aggregator subsystem. The new device
type takes care of managing the controller reference, essentially
guaranteeing its validity for as long as the client device exists, thus
alleviating the need to manually establish device links for that purpose
in the client driver (as has to be done with the platform devices).

Signed-off-by: Maximilian Luz <[email protected]>
Reviewed-by: Hans de Goede <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Hans de Goede <[email protected]>

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