Some bus types don't support power management natively, but generally
there may be device nodes in ACPI tables corresponding to the devices
whose bus types they are (under ACPI 5 those bus types may be SPI,
I2C and platform). If that is the case, standard ACPI power
management may be applied to those devices, although currently the
kernel has no means for that.
For this reason, provide a set of routines that may be used as power
management callbacks for such devices. This may be done in three
different ways.
(1) Device drivers handling the devices in question may run
acpi_dev_pm_attach() in their .probe() routines, which (on
success) will cause the devices to be added to the general ACPI
PM domain and ACPI power management will be used for them going
forward. Then, acpi_dev_pm_detach() may be used to remove the
devices from the general ACPI PM domain if ACPI power management
is not necessary for them any more.
(2) The devices' subsystems may use acpi_subsys_runtime_suspend(),
acpi_subsys_runtime_resume(), acpi_subsys_prepare(),
acpi_subsys_suspend_late(), acpi_subsys_resume_early() as their
power management callbacks in the same way as the general ACPI
PM domain does that.
(3) The devices' drivers may execute acpi_dev_suspend_late(),
acpi_dev_resume_early(), acpi_dev_runtime_suspend(),
acpi_dev_runtime_resume() from their power management callbacks
as appropriate, if that's absolutely necessary, but it is not
recommended to do that, because such drivers may not work
without ACPI support as a result.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Introduce helper function returning the target sleep state of the
system and use it to move the remaining device power management
functions from sleep.c to device_pm.c.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Two device wakeup management routines in device_pm.c and sleep.c,
acpi_pm_device_run_wake() and acpi_pm_device_sleep_wake(), take a
device pointer argument and use it to obtain the ACPI handle of the
corresponding ACPI namespace node. That handle is then used to get
the address of the struct acpi_device object corresponding to the
struct device passed as the argument.
Unfortunately, that last operation may be costly, because it involves
taking the global ACPI namespace mutex, so it shouldn't be carried
out too often. However, the callers of those routines usually call
them in a row with acpi_pm_device_sleep_state() which also takes that
mutex for the same reason, so it would be more efficient if they ran
acpi_bus_get_device() themselves to obtain a pointer to the struct
acpi_device object in question and then passed that pointer to the
appropriate PM routines.
To make that possible, split each of the PM routines mentioned above
in two parts, one taking a struct acpi_device pointer argument and
the other implementing the current interface for compatibility.
Additionally, change acpi_pm_device_run_wake() to actually return
an error code if there is an error while setting up runtime remote
wakeup for the device.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The ACPI function for setting up devices to do runtime remote
wakeup is now located in drivers/acpi/sleep.c, but
drivers/acpi/device_pm.c is a more logical place for it, so move it
there.
No functional changes should result from this modification.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The ACPI function for choosing device power state is now located
in drivers/acpi/sleep.c, but drivers/acpi/device_pm.c is a more
logical place for it, so move it there.
However, instead of moving the function entirely, move its core only
under a different name and with a different list of arguments, so
that it is more flexible, and leave a wrapper around it in the
original location.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI routines for adding and removing device wakeup notifiers are
currently defined in a PCI-specific file, but they will be necessary
for non-PCI devices too, so move them to a separate file under
drivers/acpi and rename them to indicate their ACPI origins.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Rafael J. Wysocki