iio: cros: Register FIFO callback after sensor is registered

Instead of registering callback to process sensor events right at
initialization time, wait for the sensor to be register in the iio
subsystem.

Events can come at probe time (in case the kernel rebooted abruptly
without switching the sensor off for instance), and be sent to IIO core
before the sensor is fully registered.

Fixes: aa984f1ba4a4 ("iio: cros_ec: Register to cros_ec_sensorhub when EC supports FIFO")
Reported-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20220711144716.642617-1-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: common: cros_ec_sensors: Add label attribute

When sensor location is known, populate iio sysfs "label" attribute:

* "accel-base" : the sensor is in the base of the convertible (2-1)
device.
* "accel-display" : the sensor is in the lid/display plane of the
device.
* "accel-camera" : the sensor is in the swivel camera subassembly.

The non-standard |location| attribute is removed, the field |loc| in
cros_ec_sensors_core_state is removed.

It apply to standalone accelerometer as well as IMU (accelerometer +
gyroscope) and sensors where the location is known (light).

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Link: https://lore.kernel.org/r/20220427190804.961697-3-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: cros: unify hw fifo attributes without API changes

Commit 2e2366c2d141 ("iio: cros_ec: unify hw fifo attributes into the core file")
should be reverted as it set buffer extended attributes at
the wrong place. However, to revert it will requires to revert more
commits:
commit 165aea80e2e2 ("iio: cros_ec: use devm_iio_triggered_buffer_setup_ext()")
commit 21232b4456ba ("iio: buffer: remove iio_buffer_set_attrs() helper")).
and we would still have conflict with more recent development.
commit ee708e6baacd ("iio: buffer: introduce support for attaching more IIO buffers")

Instead, this commit reverts the first 2 commits without re-adding
iio_buffer_set_attrs() and set the buffer extended attributes at the
right place:

1. Instead of adding has_fw_fifo, deduct it from the configuration:
- EC must support FIFO (EC_FEATURE_MOTION_SENSE_FIFO) set.
- sensors send data a regular interval (accelerometer, gyro,
magnetomer, barometer, light sensor).
- "Legacy accelerometer" is only present on EC without FIFO, so we don't
need to set buffer attributes.

2. devm_iio_triggered_buffer_setup_ext() does not need to be called when
EC does not support FIFO, as there is no FIFO to manage.

3. Use devm_iio_triggered_buffer_setup_ext() when EC has a FIFO to
specify the buffer extended attributes.

Fixes: 2e2366c2d141 ("iio: cros_ec: unify hw fifo attributes into the core file")
Fixes: 165aea80e2e2 ("iio: cros_ec: use devm_iio_triggered_buffer_setup_ext()")
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210318184857.2679181-1-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: cros_ec: unify hw fifo attributes into the core file

The intent here is to minimize the use of iio_buffer_set_attrs(). Since we
are planning to add support for multiple IIO buffers per IIO device, the
issue has to do with:
1. Accessing 'indio_dev->buffer' directly (as is done with
'iio_buffer_set_attrs(indio_dev->buffer, <attrs>)').
2. The way that the buffer attributes would get handled or expanded when
there are more buffers per IIO device. Current a sysfs kobj_type expands
into a 'device' object that expands into an 'iio_dev' object.
We will need to change this, so that the sysfs attributes for IIO
buffers expand into IIO buffers at some point.

Right now, the current IIO framework works fine for the
'1 IIO device == 1 IIO buffer' case (that is now).

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Link: https://lore.kernel.org/r/20200923130339.997902-1-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: cros_ec_accel_legacy: Add Read Only frequency entries

Report to user space that 10Hz is the sampling frequency of
the accelerometers in legacy mode, and it can not be changed.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: cros_ec: Register to cros_ec_sensorhub when EC supports FIFO

When EC supports FIFO, each IIO device registers a callback, to put
samples in the buffer when they arrives from the FIFO.

When no FIFO, the user space app needs to call trigger_new, or better
register a high precision timer.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

cros_ec: treewide: Remove 'include/linux/mfd/cros_ec.h'

This header file now only includes the cros_ec_dev struct, however, is the
'include/linux/platform_data/cros_ec_proto.h' who contains the definition of
all the Chrome OS EC related structs. There is no reason to have a
separate include for this struct so move to the place where other
structs are defined. That way, we can remove the include itself, but also
simplify the common pattern

#include <linux/mfd/cros_ec.h>
#include <linux/platform_data/cros_ec_proto.h>

for a single include

#include <linux/platform_data/cros_ec_proto.h>

The changes to remove the cros_ec.h include were generated with the
following shell script:

git grep -l "<linux/mfd/cros_ec.h>" | xargs sed -i '/<linux\/mfd\/cros_ec.h>/d'

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

mfd / platform / iio: cros_ec: Register sensor through sensorhub

Remove the duplicated code in MFD, since MFD just registers cros-ec-sensorhub
if at least one sensor is present.

Change IIO cros-ec driver to get the pointer to the cros-ec-dev through
cros-ec-sensorhub.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

mfd / platform: cros_ec: Reorganize platform and mfd includes

There is a bit of mess between cros-ec mfd includes and platform
includes. For example, we have a linux/mfd/cros_ec.h include that
exports the interface implemented in platform/chrome/cros_ec_proto.c. Or
we have a linux/mfd/cros_ec_commands.h file that is non related to the
multifunction device (in the sense that is not exporting any function of
the mfd device). This causes crossed includes between mfd and
platform/chrome subsystems and makes the code difficult to read, apart
from creating 'curious' situations where a platform/chrome driver includes
a linux/mfd/cros_ec.h file just to get the exported functions that are
implemented in another platform/chrome driver.

In order to have a better separation on what the cros-ec multifunction
driver does and what the cros-ec core provides move and rework the
affected includes doing:

- Move cros_ec_commands.h to include/linux/platform_data/cros_ec_commands.h
- Get rid of the parts that are implemented in the platform/chrome/cros_ec_proto.c
driver from include/linux/mfd/cros_ec.h to a new file
include/linux/platform_data/cros_ec_proto.h
- Update all the drivers with the new includes, so
- Drivers that only need to know about the protocol include
- linux/platform_data/cros_ec_proto.h
- linux/platform_data/cros_ec_commands.h
- Drivers that need to know about the cros-ec mfd device also include
- linux/mfd/cros_ec.h

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Tested-by: Gwendal Grignou <gwendal@chromium.org>
Series changes: 3
- Fix dereferencing pointer to incomplete type 'struct cros_ec_dev' (lkp)
Signed-off-by: Lee Jones <lee.jones@linaro.org>

iio: cros_ec_accel_legacy: Add support for veyron-minnie

Veyron minnie embedded controller presents 2 accelerometers using an
older interface. Add function to query the data in cros_ec_accel.

Verify accelerometers on veyron-minnie are presented and working.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: cros_ec_accel_legacy: Use cros_ec_sensors_core

Remove duplicate code in cros-ec-accel-legacy,
use cros-ec-sensors-core functions and structures when possible.

On glimmer, check the 2 accelerometers are presented and working.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: cros_ec_accel_legacy: Fix incorrect channel setting

INFO_SCALE is set both for each channel and all channels.
iio is using all channel setting, so the error was not user visible.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: cros_ec_accel_legacy: Fix incorrect channel setting

INFO_SCALE is set both for each channel and all channels.
iio is using all channel setting, so the error was not user visible.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: cros_ec: Switch to SPDX identifier.

Adopt the SPDX license identifier headers to ease license compliance
management. Also fix MODULE_LICENSE for cros_ec_accel_legacy to match
the SPDX and boiler plate license.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: cros_ec: Drop unnecessary include files

The cros_ec sensors drivers do not call any sysfs functions
or use any sysfs defines, and thus do not need to include
linux/sysfs.h. Also, some cros_ec drivers include linux/delay.h
and is not used.

Signed-off-by: Guenter Roeck <groeck@chromium.org>
[remove linux/delay.h]
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: cros_ec_accel_legacy: Refactor code in cros_ec_accel_legacy_probe

Refactor some code in order to fix both the technical implementation
and the following warnings:

drivers/iio/accel/cros_ec_accel_legacy.c: In function ‘cros_ec_accel_legacy_probe’:
drivers/iio/accel/cros_ec_accel_legacy.c:387:36: warning: this statement may fall through [-Wimplicit-fallthrough=]
ec_accel_channels[X].scan_index = Y;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
drivers/iio/accel/cros_ec_accel_legacy.c:388:3: note: here
case Y:
^~~~
drivers/iio/accel/cros_ec_accel_legacy.c:389:36: warning: this statement may fall through [-Wimplicit-fallthrough=]
ec_accel_channels[Y].scan_index = X;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
drivers/iio/accel/cros_ec_accel_legacy.c:390:3: note: here
case Z:
^~~~

Notice that neither the for loop nor the switch statement is needed.
Also, "state->sign[Y] = 1" should be unconditional.

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

platform/chrome: Add cros_ec_accel_legacy driver

Add driver to support older EC firmware that only support deprecated
ec command. Rely on ACPI memory map register to access sensor
information.
Present same interface as the regular cros_ec sensor stack:
- one iio device per accelerometer
- use HTML5 axis definition
- use iio abi units
- accept calibration calls, but do nothing
Chrome can use the same code than regular cros_ec sensor stack to
calculate orientation and lid angle.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>