If the platform device creation fails for whichever reason the driver
prints out something like:
[ 0.978837] ACPI: watchdog: Failed to create platform device
However, that is quite confusing and does not include any information
why it failed. To make it more understandable, reword it like:
[ 0.978837] ACPI: watchdog: Device creation failed: -16
Which tells that we failed to create the watchdog device because some of
the resources were already reserved (-EBUSY).
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Starting from Intel Skylake the iTCO watchdog timer registers were moved to
reside in the same register space with SMBus host controller. Not all
needed registers are available though and we need to unhide P2SB (Primary
to Sideband) device briefly to be able to read status of required NO_REBOOT
bit. The i2c-i801.c SMBus driver used to handle this and creation of the
iTCO watchdog platform device.
Windows, on the other hand, does not use the iTCO watchdog hardware
directly even if it is available. Instead it relies on ACPI Watchdog Action
Table (WDAT) table to describe the watchdog hardware to the OS. This table
contains necessary information about the the hardware and also set of
actions which are executed by a driver as needed.
This patch implements a new watchdog driver that takes advantage of the
ACPI WDAT table. We split the functionality into two parts: first part
enumerates the WDAT table and if found, populates resources and creates
platform device for the actual driver. The second part is the driver
itself.
The reason for the split is that this way we can make the driver itself to
be a module and loaded automatically if the WDAT table is found. Otherwise
the module is not loaded.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
