Input: iqs269a - add support for OTP variants

This patch adds support for each available OTP variant of the device.
The OTP configuration cannot be read over I2C, so it is derived from
a compatible string instead.

Early revisions of the D0 order code require their OTP-enabled func-
tionality to be manually restored following a soft reset; this patch
accommodates this erratum as well.

Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/ZZMaZbdk6iAKUjlm@nixie71
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: iqs269a - add support for slider gestures

This patch adds support for slider gestures that can be expressed
by the device. Each gesture (e.g. tap or hold) can be mapped to a
unique keycode for either slider 0 or 1.

With this change, raw slider coordinates are reported only if the
slider has no keycodes defined. This prevents unwanted mouse cur-
sor movement when expressing axial gestures (e.g. swipe) and also
eliminates some unnecessary I2C traffic.

Different revisions of silicon use different tap and swipe timeout
step sizes. Apply an appropriate scaling factor depending on which
revision is found.

To facilitate this change, store the iqs269_ver_info struct in the
driver's private data so that other functions can use it after the
driver has probed.

Last but not least, a former reserved field in iqs269_ver_info now
contains useful information; give it a name (fw_num).

Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/ZZMaT46WQq1/Nrsb@nixie71
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: iqs269a - use sysfs_emit() instead of scnprintf()

Replace calls to scnprintf() in the methods showing device attributes
with sysfs_emit() to simplify the code.

Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn>
Link: https://lore.kernel.org/r/202212011548387254492@zte.com.cn
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: iqs269a - use device core to create driver-specific device attributes

Instead of creating driver-specific device attributes with
devm_device_add_group() have device core do this by setting up dev_groups
pointer in the driver structure.

Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Reviewed-by: Jeff LaBundy <jeff@labundy.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230729005133.1095051-3-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230714174633.4058096-1-robh@kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: Switch i2c drivers back to use .probe()

After commit b8a1a4cd5a98 ("i2c: Provide a temporary .probe_new()
call-back type"), all drivers being converted to .probe_new() and then
03c835f498b5 ("i2c: Switch .probe() to not take an id parameter") convert
back to (the new) .probe() to be able to eventually drop .probe_new() from
struct i2c_driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230517164645.162294-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: iqs269a - do not poll during ATI

After initial start-up, the driver triggers ATI (calibration) with
the newly loaded register configuration in place. Next, the driver
polls a register field to ensure ATI completed in a timely fashion
and that the device is ready to sense.

However, communicating with the device over I2C while ATI is under-
way may induce noise in the device and cause ATI to fail. As such,
the vendor recommends not to poll the device during ATI.

To solve this problem, let the device naturally signal to the host
that ATI is complete by way of an interrupt. A completion prevents
the device from successfully probing until this happens.

As an added benefit, initial switch states are now reported in the
interrupt handler at the same time ATI status is checked. As such,
duplicate code that reports initial switch states has been removed
from iqs269_input_init().

The former logic that scaled ATI timeout and filter settling delay
is not carried forward with the new implementation, as it produces
overly conservative delays at the lower clock rate.

Rather, a single timeout that covers both clock rates is used. The
filter settling delay does not happen to be necessary and has been
removed as well.

Fixes: 04e49867fad1 ("Input: add support for Azoteq IQS269A")
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/Y7RtB2T7AF9rYMjK@nixie71
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: iqs269a - do not poll during suspend or resume

Polling the device while it transitions from automatic to manual
power mode switching may keep the device from actually finishing
the transition. The process appears to time out depending on the
polling rate and the device's core clock frequency.

This is ultimately unnecessary in the first place; instead it is
sufficient to write the desired mode during initialization, then
disable automatic switching at suspend. This eliminates the need
to ensure the device is prepared for a manual change and removes
the 'suspend_mode' variable.

Similarly, polling the device while it transitions from one mode
to another under manual control may time out as well. This added
step does not appear to be necessary either, so drop it.

Fixes: 04e49867fad1 ("Input: add support for Azoteq IQS269A")
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/Y7Rs+eEXlRw4Vq57@nixie71
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: iqs269a - configure device with a single block write

Unless it is being done as part of servicing a soft reset interrupt,
configuring channels on-the-fly (as is the case when writing to the
ati_trigger attribute) may cause GPIO3 (which reflects the state of
touch for a selected channel) to be inadvertently asserted.

To solve this problem, follow the vendor's recommendation and write
all channel configuration as well as the REDO_ATI register field as
part of a single block write. This ensures the device has been told
to re-calibrate itself following an I2C stop condition, after which
sensing resumes and GPIO3 may be asserted.

Fixes: 04e49867fad1 ("Input: add support for Azoteq IQS269A")
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/Y7Rs8GyV7g0nF5Yy@nixie71
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: iqs269a - increase interrupt handler return delay

The time the device takes to deassert its RDY output following an
I2C stop condition scales with the core clock frequency.

To prevent level-triggered interrupts from being reasserted after
the interrupt handler returns, increase the time before returning
to account for the worst-case delay (~140 us) plus margin.

Fixes: 04e49867fad1 ("Input: add support for Azoteq IQS269A")
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/Y7Rs484ypy4dab5G@nixie71
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: iqs269a - drop unused device node references

Each call to device/fwnode_get_named_child_node() must be matched
with a call to fwnode_handle_put() once the corresponding node is
no longer in use. This ensures a reference count remains balanced
in the case of dynamic device tree support.

Currently, the driver does not call fwnode_handle_put() on nested
event nodes. This patch solves this problem by adding the missing
instances of fwnode_handle_put().

As part of this change, the logic which parses each channel's key
code is gently refactored in order to reduce the number of places
from which fwnode_handle_put() is called.

Fixes: 04e49867fad1 ("Input: add support for Azoteq IQS269A")
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/Y7Rsx68k/gvDVXAt@nixie71
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: iqs269a - switch to DEFINE_SIMPLE_DEV_PM_OPS() and pm_sleep_ptr()

SIMPLE_DEV_PM_OPS() is deprecated as it requires explicit protection
against unused function warnings. The new combination of pm_sleep_ptr()
and DEFINE_SIMPLE_DEV_PM_OPS() allows the compiler to see the functions,
thus suppressing the warning, but still allowing the unused code to be
removed. Thus also drop the __maybe_unused markings.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jeff LaBundy <jeff@labundy.com>
Reviewed-by: Jeff LaBundy <jeff@labundy.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230102181842.718010-9-jic23@kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20200707180857.GA30600@embeddedor
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: add support for Azoteq IQS269A

This patch adds support for the Azoteq IQS269A capacitive touch
controller.

Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/1588352982-5117-2-git-send-email-jeff@labundy.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>