linux.git/drivers/platform/surface/aggregator/core.c, branch v6.7

platform/surface: aggregator: fix recv_buf() return value

2023-11-29T09:07:02+00:00

Serdev recv_buf() callback is supposed to return the amount of bytes
consumed, therefore an int in between 0 and count.

Do not return negative number in case of issue, when
ssam_controller_receive_buf() returns ESHUTDOWN just returns 0, e.g. no
bytes consumed, this keep the exact same behavior as it was before.

This fixes a potential WARN in serdev-ttyport.c:ttyport_receive_buf().

Fixes: c167b9c7e3d6 ("platform/surface: Add Surface Aggregator subsystem")
Cc: stable@vger.kernel.org
Signed-off-by: Francesco Dolcini 
Reviewed-by: Maximilian Luz 
Link: https://lore.kernel.org/r/20231128194935.11350-1-francesco@dolcini.it
Reviewed-by: Ilpo Järvinen 
Signed-off-by: Ilpo Järvinen

platform/surface: Update copyright year of various drivers

2022-07-02T09:23:30+00:00

Update the copyright of various Surface drivers to the current year.

Signed-off-by: Maximilian Luz 
Link: https://lore.kernel.org/r/20220624205800.1355621-4-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede 
Signed-off-by: Hans de Goede

platform/surface: aggregator: Fix initialization order when compiling as builtin module

2022-05-06T11:05:57+00:00

When building the Surface Aggregator Module (SAM) core, registry, and
other SAM client drivers as builtin modules (=y), proper initialization
order is not guaranteed. Due to this, client driver registration
(triggered by device registration in the registry) races against bus
initialization in the core.

If any attempt is made at registering the device driver before the bus
has been initialized (i.e. if bus initialization fails this race) driver
registration will fail with a message similar to:

    Driver surface_battery was unable to register with bus_type surface_aggregator because the bus was not initialized

Switch from module_init() to subsys_initcall() to resolve this issue.
Note that the serdev subsystem uses postcore_initcall() so we are still
able to safely register the serdev device driver for the core.

Fixes: c167b9c7e3d6 ("platform/surface: Add Surface Aggregator subsystem")
Reported-by: Blaž Hrastnik 
Signed-off-by: Maximilian Luz 
Link: https://lore.kernel.org/r/20220429195738.535751-1-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede 
Signed-off-by: Hans de Goede

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

2021-11-16T09:56:54+00:00

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 
Link: https://lore.kernel.org/r/20211028002243.1586083-2-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede 
Signed-off-by: Hans de Goede

platform/surface: aggregator: Use serdev_acpi_get_uart_resource() helper

2021-08-13T07:13:19+00:00

serdev provides a generic helper to get UART Serial Bus resources.
Use it instead of an open coded variant.

Reviewed-by: Maximilian Luz 
Acked-by: Hans de Goede 
Signed-off-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20210806111736.66591-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

Merge remote-tracking branch 'linux-pm/acpi-scan' into review-hans

2021-06-16T15:48:22+00:00

platform/surface: aggregator: Update copyright

2021-06-16T15:47:53+00:00

It's 2021, update the copyright accordingly.

Signed-off-by: Maximilian Luz 
Reviewed-by: Hans de Goede 
Link: https://lore.kernel.org/r/20210604134755.535590-4-luzmaximilian@gmail.com
Signed-off-by: Hans de Goede

ACPI: scan: Extend acpi_walk_dep_device_list()

2021-06-07T14:45:05+00:00

The acpi_walk_dep_device_list() function is not as generic as its
name implies, serving only to decrement the dependency count for each
dependent device of the input.

Extend it to accept a callback which can be applied to all the
dependencies in acpi_dep_list.

Replace all existing calls to the function with calls to a wrapper,
passing a callback that applies the same dependency reduction.

Reviewed-by: Andy Shevchenko 
Acked-by: Maximilian Luz   # for platform/surface parts
Signed-off-by: Daniel Scally 
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki

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

2021-01-06T23:06:39+00:00

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 
Reviewed-by: Hans de Goede 
Link: https://lore.kernel.org/r/20201221183959.1186143-7-luzmaximilian@gmail.com
Signed-off-by: Hans de Goede

platform/surface: aggregator: Add trace points

2021-01-06T23:06:17+00:00

Add trace points to the Surface Aggregator subsystem core. These trace
points can be used to track packets, requests, and allocations. They are
further intended for debugging and testing/validation, specifically in
combination with the error injection capabilities introduced in the
subsequent commit.

Signed-off-by: Maximilian Luz 
Reviewed-by: Hans de Goede 
Acked-by: Steven Rostedt (VMware) 
Link: https://lore.kernel.org/r/20201221183959.1186143-5-luzmaximilian@gmail.com
Signed-off-by: Hans de Goede