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

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

As reported by Jean-Francois Dagenais, the wheel algorithm caused a
divide by zero exception due to missing variable pre-initialization.
In fact it turned out that the whole algorithm had several problems.
It is therefore replaced with something that is known working.
Signed-off-by: NMichael Hennerich <michael.hennerich@analog.com>
Tested-by: NJean-Francois Dagenais <jeff.dagenais@gmail.com>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

Add option to specify irqflags in platfrom data.
Also update copyright notice.
Signed-off-by: NMichael Hennerich <michael.hennerich@analog.com>
Tested-by: NJean-Francois Dagenais <jeff.dagenais@gmail.com>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

Fix two issues in the threshold and completion interrupt mask and unmask
functions. According to the AD714x datasheets the highest stage completion
interrupt should be enabled. Fix mask computation.
Signed-off-by: NMichael Hennerich <michael.hennerich@analog.com>
Tested-by: NJean-Francois Dagenais <jeff.dagenais@gmail.com>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

Add missing input name and set up parent devices so input devices will
show in proper places in sysfs tree.
Signed-off-by: NMichael Hennerich <michael.hennerich@analog.com>
Tested-by: NJean-Francois Dagenais <jeff.dagenais@gmail.com>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Signed-off-by: NBarry Song <barry.song@analog.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

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: NBryan Wu <cooloney@kernel.org>
Signed-off-by: NMichael Hennerich <michael.hennerich@analog.com>
Signed-off-by: NBarry Song <21cnbao@gmail.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>