linux-toradex.git/include/linux/surface_aggregator/device.h, branch v6.14-rc2

platform/surface: aggregator: make ssam_bus_type constant and static

2024-01-04T16:01:14+00:00

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

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

2023-05-30T09:20:02+00:00

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 
Link: https://lore.kernel.org/r/20230525205041.2774947-1-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede 
Signed-off-by: Hans de Goede

Merge tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2023-02-24T20:58:55+00:00

Pull driver core updates from Greg KH:
 "Here is the large set of driver core changes for 6.3-rc1.

  There's a lot of changes this development cycle, most of the work
  falls into two different categories:

   - fw_devlink fixes and updates. This has gone through numerous review
     cycles and lots of review and testing by lots of different devices.
     Hopefully all should be good now, and Saravana will be keeping a
     watch for any potential regression on odd embedded systems.

   - driver core changes to work to make struct bus_type able to be
     moved into read-only memory (i.e. const) The recent work with Rust
     has pointed out a number of areas in the driver core where we are
     passing around and working with structures that really do not have
     to be dynamic at all, and they should be able to be read-only
     making things safer overall. This is the contuation of that work
     (started last release with kobject changes) in moving struct
     bus_type to be constant. We didn't quite make it for this release,
     but the remaining patches will be finished up for the release after
     this one, but the groundwork has been laid for this effort.

  Other than that we have in here:

   - debugfs memory leak fixes in some subsystems

   - error path cleanups and fixes for some never-able-to-be-hit
     codepaths.

   - cacheinfo rework and fixes

   - Other tiny fixes, full details are in the shortlog

  All of these have been in linux-next for a while with no reported
  problems"

[ Geert Uytterhoeven points out that that last sentence isn't true, and
  that there's a pending report that has a fix that is queued up - Linus ]

* tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (124 commits)
  debugfs: drop inline constant formatting for ERR_PTR(-ERROR)
  OPP: fix error checking in opp_migrate_dentry()
  debugfs: update comment of debugfs_rename()
  i3c: fix device.h kernel-doc warnings
  dma-mapping: no need to pass a bus_type into get_arch_dma_ops()
  driver core: class: move EXPORT_SYMBOL_GPL() lines to the correct place
  Revert "driver core: add error handling for devtmpfs_create_node()"
  Revert "devtmpfs: add debug info to handle()"
  Revert "devtmpfs: remove return value of devtmpfs_delete_node()"
  driver core: cpu: don't hand-override the uevent bus_type callback.
  devtmpfs: remove return value of devtmpfs_delete_node()
  devtmpfs: add debug info to handle()
  driver core: add error handling for devtmpfs_create_node()
  driver core: bus: update my copyright notice
  driver core: bus: add bus_get_dev_root() function
  driver core: bus: constify bus_unregister()
  driver core: bus: constify some internal functions
  driver core: bus: constify bus_get_kset()
  driver core: bus: constify bus_register/unregister_notifier()
  driver core: remove private pointer from struct bus_type
  ...

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

2023-02-02T21:48:20+00:00

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 
Link: https://lore.kernel.org/r/20221220175608.1436273-2-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede 
Signed-off-by: Hans de Goede

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

2023-02-02T21:48:20+00:00

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 
Acked-by: Sebastian Reichel 
Link: https://lore.kernel.org/r/20221202223327.690880-9-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede 
Signed-off-by: Hans de Goede

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

2023-01-27T12:45:34+00:00

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 
Acked-by: Hans de Goede 
Link: https://lore.kernel.org/r/20230111113018.459199-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman

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

2022-07-02T09:23:14+00:00

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 
Link: https://lore.kernel.org/r/20220624205800.1355621-2-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede 
Signed-off-by: Hans de Goede

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

2022-07-02T09:11:07+00:00

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 
Link: https://lore.kernel.org/r/20220624183642.910893-2-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede 
Signed-off-by: Hans de Goede

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

2022-06-13T15:25:07+00:00

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 
Link: https://lore.kernel.org/r/20220527023447.2460025-4-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede 
Signed-off-by: Hans de Goede

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

2022-06-13T15:25:07+00:00

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 
Link: https://lore.kernel.org/r/20220527023447.2460025-3-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede 
Signed-off-by: Hans de Goede