ACPI: TAD: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: TAD: Install SystemCMOS address space handler for ACPI000E

Currently, the SystemCMOS address space handler is installed for the
ACPI RTC devices (PNP0B00/PNP0B01/PNP0B02) only. But there are platforms
with SystemCMOS Operetion Region defined under the ACPI Time and Alarm
Device (ACPI000E), which is used by the ACPI pre-defined control methods
like _GRT (Get the Real time) and _SRT (Set the Real time).

When accessing these control methods via the acpi_tad sysfs interface,
missing SystemCMOS address space handler causes errors like below
[ 478.255453] ACPI Error: No handler for Region [RTCM] (00000000a8d2dd39) [SystemCMOS] (20230331/evregion-130)
[ 478.255458] ACPI Error: Region SystemCMOS (ID=5) has no handler (20230331/exfldio-261)
[ 478.255461] Initialized Local Variables for Method [_GRT]:
[ 478.255461] Local1: 00000000f182542c <Obj> Integer 0000000000000000
[ 478.255464] No Arguments are initialized for method [_GRT]
[ 478.255465] ACPI Error: Aborting method \_SB.AWAC._GRT due to previous error (AE_NOT_EXIST) (20230331/psparse-529)

Export two APIs for SystemCMOS address space handler from acpi_cmos_rtc
scan handler and install the handler for the ACPI Time and Alarm Device
from the ACPI TAD driver.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217714
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
[ rjw: Subject and changelog edits, whitespace adjustment ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: Use DEVICE_ATTR_<RW|RO|WO> macros

Instead of open coding DEVICE_ATTR(), use the
DEVICE_ATTR_RW(), DEVICE_ATTR_RO() and DEVICE_ATTR_WO()
macros wherever possible.

This required a few functions to be renamed but the
functionality itself is unchanged.

Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM: sleep: core: Rename DPM_FLAG_LEAVE_SUSPENDED

Rename DPM_FLAG_LEAVE_SUSPENDED to DPM_FLAG_MAY_SKIP_RESUME which
matches its purpose more closely.

No functional impact.

Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de> # for I2C
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

ACPI: TAD: Add low-level support for real time capability

Add low-level support for the (optional) real time capability of the
ACPI Time and Alarm Device (TAD) to the ACPI TAD driver.

This allows the real time to be acquired or set via sysfs with the
help of the _GRT and _SRT methods of the TAD, respectively.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>

ACPI: Add Time and Alarm Device (TAD) driver

Introduce a driver for the ACPI Time and Alarm Device (TAD) based on
Section 9.18 of ACPI 6.2.

This driver only supports the system wakeup capabilities of the TAD
which are mandatory. Support for the RTC capabilities of the TAD
will be added to it in the future.

This driver is entirely sysfs-based. It provides attributes (under
the TAD platform device) to allow user space to manage the AC and DC
wakeup timers of the TAD: set and read their values, set and check
their expire timer wake policies, check and clear their status and
check the capabilities of the TAD reported by AML. The DC timer
attributes are only present if the TAD supports a separate DC alarm
timer.

The wakeup events handling and power management of the TAD is
expected to be taken care of by the ACPI PM domain attached to its
platform device.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>