kernel/linux.git/drivers/acpi/tiny-power-button.c, branch v7.0.11

ACPI: driver: Check ACPI_COMPANION() against NULL during probe

2026-06-01T15:54:24+00:00

[ Upstream commit e4865a56d013e86e46ea6acea15bb6eae01898ff ] Since every platform driver can be forced to match a device that doesn't match its list of device IDs because of device_match_driver_override(), platform drivers that rely on the existence of a device's ACPI companion object should verify its presence. Accordingly, add requisite ACPI_COMPANION() or ACPI_HANDLE() checks against NULL to 13 platform drivers handling core ACPI devices. Also change the value returned by the ACPI thermal zone driver when the device's ACPI companion is not present to -ENODEV for consistency with the other drivers. Signed-off-by: Rafael J. Wysocki Reviewed-by: Hans de Goede Reviewed-by: Andy Shevchenko Link: https://patch.msgid.link/4516068.ejJDZkT8p0@rafael.j.wysocki Cc: 7.0+ # 7.0+ [ reordered variable declaration to add NULL check before pre-existing stable-only code that dereferences the pointer ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ACPI: tiny-power-button: Convert the driver to a platform one

2025-12-26T14:08:57+00:00

While binding drivers directly to struct acpi_device objects allows basic functionality to be provided, at least in the majority of cases, there are some problems with it, related to general consistency, sysfs layout, power management operation ordering, and code cleanliness. Overall, it is better to bind drivers to platform devices than to their ACPI companions, so convert the ACPI tiny-power-button driver to a platform one. While this is not expected to alter functionality, it changes sysfs layout and so it will be visible to user space. Signed-off-by: Rafael J. Wysocki [ rjw: White space fixup ] Link: https://patch.msgid.link/5629403.Sb9uPGUboI@rafael.j.wysocki Signed-off-by: Rafael J. Wysocki

ACPI: tiny-power-button: Eliminate the driver notify callback

2023-06-16T17:48:09+00:00

Rework the ACPI tiny-power-button driver to install a notify handler or a fixed event handler for the device it binds to by itself and drop its notify callback. This will allow acpi_device_install_notify_handler() and acpi_device_remove_notify_handler() to be simplified going forward. Signed-off-by: Rafael J. Wysocki

ACPI: make remove callback of ACPI driver void

2022-11-23T18:11:22+00:00

For bus-based driver, device removal is implemented as: 1 device_remove()-> 2 bus->remove()-> 3 driver->remove() Driver core needs no inform from callee(bus driver) about the result of remove callback. In that case, commit fc7a6209d571 ("bus: Make remove callback return void") forces bus_type::remove be void-returned. Now we have the situation that both 1 & 2 of calling chain are void-returned, so it does not make much sense for 3(driver->remove) to return non-void to its caller. So the basic idea behind this change is making remove() callback of any bus-based driver to be void-returned. This change, for itself, is for device drivers based on acpi-bus. Acked-by: Uwe Kleine-König Acked-by: Lee Jones Acked-by: Dmitry Torokhov Reviewed-by: Hans de Goede Signed-off-by: Dawei Li Reviewed-by: Maximilian Luz # for drivers/platform/surface/* Signed-off-by: Rafael J. Wysocki

ACPI: tiny-power-button: Simplify the code using module_acpi_driver()

2020-11-17T17:12:34+00:00

Using module_acpi_driver() to simplify the code. Signed-off-by: Hanjun Guo Signed-off-by: Rafael J. Wysocki

ACPI: tiny-power-button: Remove dead ACPICA debug code

2020-09-25T16:25:51+00:00

The ACPICA debug code is not used, can be removed. Signed-off-by: Hanjun Guo [ rjw: Subject edit ] Signed-off-by: Rafael J. Wysocki

ACPI: Add new tiny-power-button driver to directly signal init

2020-02-13T22:36:23+00:00

Virtual machines often use an ACPI power button event to tell the machine to shut down gracefully. Provide an extremely lightweight "tiny power button" driver to handle this event by signaling init directly, rather than running a separate daemon (such as acpid or systemd-logind) that adds to startup time and VM image complexity. The kernel configuration defines the default signal to send init, and userspace can change this signal via a module parameter. Suggested-by: "Rafael J. Wysocki" Signed-off-by: Josh Triplett Signed-off-by: Rafael J. Wysocki