iio: cros_ec: fix an use-after-free in cros_ec_sensors_push_data()

cros_ec_sensors_push_data() reads `indio_dev->active_scan_mask` and
calls iio_push_to_buffers_with_timestamp() without making sure the
`indio_dev` stays in buffer mode. There is a race if `indio_dev` exits
buffer mode right before cros_ec_sensors_push_data() accesses them.

An use-after-free on `indio_dev->active_scan_mask` was observed. The
call trace:
[...]
_find_next_bit
cros_ec_sensors_push_data
cros_ec_sensorhub_event
blocking_notifier_call_chain
cros_ec_irq_thread

It was caused by a race condition: one thread just freed
`active_scan_mask` at [1]; while another thread tried to access the
memory at [2].

Fix it by calling iio_device_claim_buffer_mode() to ensure the
`indio_dev` can't exit buffer mode during cros_ec_sensors_push_data().

[1]: https://elixir.bootlin.com/linux/v6.5/source/drivers/iio/industrialio-buffer.c#L1189
[2]: https://elixir.bootlin.com/linux/v6.5/source/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c#L198

Cc: stable@vger.kernel.org
Fixes: aa984f1ba4a4 ("iio: cros_ec: Register to cros_ec_sensorhub when EC supports FIFO")
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20230829030622.1571852-1-tzungbi@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: cros_ec: Fix the allocation size for cros_ec_command

The struct cros_ec_command contains several integer fields and a
trailing array. An allocation size neglecting the integer fields can
lead to buffer overrun.

Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Signed-off-by: Yiyuan Guo <yguoaz@gmail.com>
Fixes: 974e6f02e27e ("iio: cros_ec_sensors_core: Add common functions for the ChromeOS EC Sensor Hub.")
Link: https://lore.kernel.org/r/20230630143719.1513906-1-yguoaz@gmail.com
Cc: <Stable@vger.kerenl.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Don't silently expect attribute types

The iio_triggered_buffer_setup_ext() and the
devm_iio_kfifo_buffer_setup_ext() were changed by
commit 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr")
to silently expect that all attributes given in buffer_attrs array are
device-attributes. This expectation was not forced by the API - and some
drivers did register attributes created by IIO_CONST_ATTR().

When using IIO_CONST_ATTRs the added attribute "wrapping" does not copy
the pointer to stored string constant and when the sysfs file is read the
kernel will access to invalid location.

Change the function signatures to expect an array of iio_dev_attrs to
avoid similar errors in the future.

Merge conflict resolved whilst applying due to patch crossing with
two new drivers (kx022a accelerometer and ad4130 ADC).

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Tested-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/63f54787a684eb1232f1c5d275a09c786987fe4a.1664782676.git.mazziesaccount@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

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: Replace strtobool() with kstrtobool()

strtobool() is deprecated and just a wrapper around kstrtobool().Replace
it with kstrtobool() so the deprecated function can be removed eventually.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220409105812.2113895-1-lars@metafoo.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core: Simplify the registration of kfifo buffers

Among all the users of the kfifo buffers, no one uses the
INDIO_BUFFER_HARDWARE mode. So let's take this as a general rule and
simplify a little bit the internals - overall the documentation - by
eliminating unused specific cases. Use the INDIO_BUFFER_SOFTWARE mode by
default with kfifo buffers, which will basically mimic what all the "non
direct" modes do.

Cc: Benson Leung <bleung@chromium.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Jyoti Bhayana <jbhayana@google.com>
Cc: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Cc: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Cc: Michael Hennerich <Michael.Hennerich@analog.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20220207143840.707510-13-miquel.raynal@bootlin.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: common: cros_ec_sensors: simplify getting .driver_data

We should get 'driver_data' from 'struct device' directly. Going via
platform_device is an unneeded step back and forth.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Link: https://lore.kernel.org/r/20210920090522.23784-7-wsa+renesas@sang-engineering.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_sensors: Fix a wrong function name in kernel doc.

cros_ec_sensors_read_data_unsafe() had wrong function name in kernel-doc
This shows up with W=1 builds.

No fixes tag because I don't want to waste time on this being
backported.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Gwendal Grignou <gwendal@chromium.org>
Cc: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Link: https://lore.kernel.org/r/20210313145341.116088-1-jic23@kernel.org

iio: make use of devm_iio_kfifo_buffer_setup() helper

All drivers that already call devm_iio_kfifo_allocate() &
iio_device_attach_buffer() are simple to convert to
iio_device_attach_kfifo_buffer() in a single go.

This change does that; the unwind order is preserved.
What is important, is that the devm_iio_kfifo_buffer_setup() be called
after the indio_dev->modes is assigned, to make sure that
INDIO_BUFFER_SOFTWARE flag is set and not overridden by the assignment to
indio_dev->modes.

Also, the INDIO_BUFFER_SOFTWARE has been removed from the assignments of
'indio_dev->modes' because it is set by devm_iio_kfifo_buffer_setup().

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Matt Ranostay <matt.ranostay@konsulko.com>x
Link: https://lore.kernel.org/r/20210215104043.91251-4-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: cros_ec: use devm_iio_triggered_buffer_setup_ext()

This change switches to the new devm_iio_triggered_buffer_setup_ext()
function and removes the iio_buffer_set_attrs() call, for assigning the
HW FIFO attributes to the buffer.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20200929125949.69934-8-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: cros_ec: Use default frequencies when EC returns invalid information

Minimal and maximal frequencies supported by a sensor is queried.
On some older machines, these frequencies are not returned properly and
the EC returns 0 instead.
When returned maximal frequency is 0, ignore the information and use
default frequencies instead.

Fixes: ae7b02ad2f32 ("iio: common: cros_ec_sensors: Expose cros_ec_sensors frequency range via iio sysfs")
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Link: https://lore.kernel.org/r/20200630153730.3302889-1-gwendal@chromium.org
CC: <Stable@vger.kernel.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: Set Gyroscope default frequency to 25Hz

BMI160 Minimium gyroscope frequency in normal mode is 25Hz.
When older EC firmware do not report their sensors frequencies,
use 25Hz as the minimum for gyroscope to be sure it works on BMI160.

Fixes: ae7b02ad2f32d ("iio: common: cros_ec_sensors: Expose cros_ec_sensors frequency range via iio sysfs")
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: cros_ec: fix spelling mistake

Fix typo: "tigger" --> "trigger"

Signed-off-by: Keyur Patel <iamkeyur96@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: remove left-over parent assignments

These were found by doing some shell magic:
------------
for file in $(git grep -w devm_iio_device_alloc | cut -d: -f1 | sort | uniq) ; do
if grep 'parent =' $file | grep -v trig | grep -vq devm_; then
echo "$file -> $(grep "parent =" $file)"
fi
done
-----------

The output is bearable [after the semantic patch is applied].
There is a mix of trigger assignments with some iio device parent
assignments that are removed via this patch.

JC: A few more added via inspection of all parent =
statements in drivers/iio. Some of these may just have crossed with this
series, others were less obvious to scripting due to some cross
file / module boundary calls.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: cros_ec: Reapply range at resume

EC does not currently preserve range across sensor reinit.
If sensor is powered down at suspend, it will default to the EC default
range at resume, not the range set by the host.

Save range if modified, and apply at resume.

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

iio: cros_ec: Use Hertz as unit for sampling frequency

To be compliant with other sensors, set and get sensor sampling
frequency in Hz, not mHz.

Fixes: ae7b02ad2f32 ("iio: common: cros_ec_sensors: Expose cros_ec_sensors frequency range via iio sysfs")
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

iio: cros_ec: Report hwfifo_watermark_max

Report the maximum amount of sample the EC can hold.
This is not tunable, but can be useful for application to find out the
maximum amount of time it can sleep when hwfifo_timeout is set to a
large number.

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>

iio: cros_ec: Expose hwfifo_timeout

Expose EC minimal interrupt period through buffer/hwfifo_timeout:
- Maximal timeout is limited to 65s.
- When timeout for all sensors is set to 0, EC will not send events,
even if the sensor sampling rate is greater than 0.

Rename frequency to sampling_frequency to match IIO ABI.

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>

iio: cros_ec: Remove pm function

Since cros_ec_sensorhub is shutting down the FIFO when the device
suspends, no need to slow down the EC sampling period rate.

It was necesseary to do that before command CMD_FIFO_INT_ENABLE was
introduced, but now all supported chromebooks have it.

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>

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>

iio: cros_ec: Move function description to .c file

To prevent comment rot, move function description to
cros_ec_sensors_core.c.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Acked-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>

iio: cros_ec: set calibscale for 3d MEMS to unit vector

By default, set the calibscale vector to unit vector.
When calibrating one axis, the other axis calibrations are sent as well.
If left to 0, sensor data from uncalibrated axis are zero'ed out until
all axis are calibrated.

Fixes: ed1f2e85da79 ("iio: cros_ec: Add calibscale for 3d MEMS ")
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.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: common: cros_ec_sensors: Expose cros_ec_sensors frequency range via iio sysfs

Embedded controller return minimum and maximum frequencies, unfortunately
we have no way to know the step for all available frequencies.
Even if not complete, we can return a list of known values using the
standard read_avail callback (IIO_CHAN_INFO_SAMP_FREQ) to provide them to
userland.

Now cros_ec_* sensors provides frequencies values in sysfs like this:
"0 min max". 0 is always true to disable the sensor.

Default frequencies are provided for earlier protocol.

Signed-off-by: Nick Vaccaro <nvaccaro@chromium.org>
Signed-off-by: Fabien Lahoudere <fabien.lahoudere@collabora.com>
[rebased on top of iio/testing and solved conflicts]
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: cros_ec: Add sign vector in core for backward compatibility

To allow cros_ec iio core library to be used with legacy device, add a
vector to rotate sensor data if necessary: legacy devices are not
reporting data in HTML5/Android sensor referential.

Check the data is not rotated on recent chromebooks that use the HTML5
standard to present sensor data.

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

iio: common: cros_ec_sensors: determine protocol version

This patch adds a function to determine which version of the
protocol is used to communicate with EC.

Signed-off-by: Nick Vaccaro <nvaccaro@chromium.org>
Signed-off-by: Fabien Lahoudere <fabien.lahoudere@collabora.com>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Tested-by: Gwendal Grignou <gwendal@chromium.org>
[rebased on top of iio/testing and solved conflicts]
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: cros_ec: Remove replacing error code with -EIO

Due to an API misread, error code can be different for -EIO when reading
a sysfs entry. Return the error reported by the cros_ec stack.

Check the proper error message (protocol error, not supported) is
reported when there is an error returned by the EC stack.

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

iio: cros_ec: Add calibscale for 3d MEMS

Add calibration scale support to accel, gyro and magnetometer.

Check on eve with current firmware, check reading calibscale returns 1.0,
check with newer firmware values are applied.

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

iio: cros_ec: add 'id' sysfs entry

This new sysfs entry is used to interpret ring buffer information,
mainly by Android sensor HAL.
It expand to all sensors, the documentation about 'id' we can found
in Documentation/ABI/testing/sysfs-bus-iio-cros-ec.

Also fix typo in docs, I replace 'Septembre' by 'September'.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Fabien Lahoudere <fabien.lahoudere@collabora.com>
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: Add kernel-doc for cros_ec_sensors_read_lpc

Document cros_ec_sensors_read_lpc, adding an additional note to explain
that this is the safe function for reading the EC data.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
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: common: cros_ec_sensors: simplify getting .drvdata

We should get drvdata from struct device directly. Going via
platform_device is an unneeded step back and forth.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: cros_ec: Move cros_ec_sensors_core.h in /include

Similar to other common iio frameworks, move cros_ec_sensors_core.h from
drivers/iio/common/cros_ec_sensors/ to include/linux/iio/common.

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

iio: cros_ec: Relax sampling frequency before suspending

If an application set a tight sampling frequency, given the interrupt
use is a wakeup source, suspend will not happen: the kernel will receive
a wake up interrupt and will cancel the suspend process.

Given cros_ec sensors type is non wake up, this patch adds prepare and
complete callbacks to set 1s sampling period just before suspend. This
ensures the sensor hub will not be a source of interrupt during the
suspend process.

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

iio: cros_ec_sensors_core: fix unsigned compared less than zero on status

status is a u8 hence the check if status is less than zero has no effect.
Fix this by replacing status with int ret so the less than zero compare
will correctly detect errors.

Issue found with static analysis with CoverityScan, CID 1375919

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Fixes: 974e6f02e27e ("iio: cros_ec_sensors_core: Add common functions for the ChromeOS EC Sensor Hub")
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: cros_ec_sensors_core: Add common functions for the ChromeOS EC Sensor Hub.

Add the core functions to be able to support the sensors attached behind
the ChromeOS Embedded Controller and used by other IIO cros-ec sensor
drivers.

The cros_ec_sensor_core driver matches with current driver in ChromeOS
4.4 tree, so it includes all the fixes at the moment. The support for
this driver was made by Gwendal Grignou. The original patch and all the
fixes has been squashed and rebased on top of mainline.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Guenter Roeck <groeck@chromium.org>
[eballetbo: split, squash and rebase on top of mainline the patches
found in ChromeOS tree]
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>