Input: ad714x - unify dev_pm_ops using EXPORT_SIMPLE_DEV_PM_OPS()

The I2C and SPI PM callbacks were identical (though wrapped in some
bouncing out to the bus specific container of the struct device and
then back again to get the drvdata). As such rather than just moving
these to SIMPLE_DEV_PM_OPS() and pm_sleep_ptr() take the opportunity
to unify the struct dev_pm_ops and use the new EXPORT_SIMPLE_DEV_PM_OPS()
macro so that we can drop the unused suspend and resume callbacks as well
as the structure if !CONFIG_PM_SLEEP without needing to mark the callbacks
__maybe_unused.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Michael Hennerich <michael.hennerich@analog.com>
Link: https://lore.kernel.org/r/20230114171620.42891-8-jic23@kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 149

Based on 1 normalized pattern(s):

licensed under the gpl 2 or later

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 82 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190524100845.150836982@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Input: ad714x - convert to using managed resources

Use managed resource functions devm_request_threaded_irq,
devm_inpute_allocate_device and devm_kzalloc to simplify error handling.
Also, remove use of input_unregister_device as input_register_device itself
handles it and works as resource managed function.

To be compatible with the change, various gotos are replaced with direct
returns, and unneeded labels are dropped. With these changes remove
ad714x_remove and corresponding calls of it as they are now redundant.

Signed-off-by: Vaishali Thakkar <vthakkar1994@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: ad714x - read the interrupt status registers in a row

The interrupt status registers should be read in row to avoid invalid data.

Alter "read" method for both bus options to allow reading several registers
in a row and make sure we read interrupt status registers properly.

Read sequence saves 50% of bus transactions compared to single register
reads. So use it also for the result registers, which are also located
in a row.

Also update copyright notice.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: ad714x - use DMA-safe buffers for spi_write()

spi_write() requires use of DMA-safe (cacheline aligned) buffers.
Also use the same buffers when reading data since to avoid extra
locking and potential memory allocation in spi_write_then_read().

Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Input: add Analog Devices AD714x captouch input driver

AD7142 and AD7147 are integrated capacitance-to-digital converters
(CDCs) with on-chip environmental calibration for use in systems
requiring a novel user input method. The AD7142 and AD7147 can interface
to external capacitance sensors implementing functions such as buttons,
scrollwheels, sliders, touchpads and so on.

The chips don't restrict the specific usage. Depending on the hardware
connection, one special target board can include one or several these
components. The platform_data for the device's "struct device" holds
these information. The data-struct defined in head file descript the
hardware feature of button/scrollwheel/slider/touchpad components on
target boards, which need be filled in the arch/mach-/.

As the result, the driver is independent of boards. It gets the
components layout from the platform_data, registers related devices,
fullfills the algorithms and state machines for these components and
report related input events to up level.

Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>