One of the user complained that on his system Thinkpad Yoga S1, with
commit f1664eaacec3 ("iio: hid-sensor-trigger: Fix the race with user
space powering up sensors") causes the system to resume immediately
on suspend (S3 operation). On this system the sensor hub is on USB
and is a wake up device from S3. So if any sensor sends data on
motion, the system will wake up. This can be a legitimate use case
to wake up device motion, but that needs proper user space support
to set right thresholds.

In fact the above commit didn't cause this regression, but any operation
which cause sensors to wake up would have caused the same issue. So if
user reads the raw sensor data, same issue occurs, with or without this
commit. Only difference is that the above commit by default will trigger
a power up and power down of sensors as part of runtime pm enable
(runtime enable will cause a runtime resume callback followed by
runtime_suspend callback). Previously user has to do some action on
sensors.

On investigation it was observed that the current driver correctly
changing the state of all sensors to power off but then also some sensor
will still send some data. Only option is to never power up any sensor.

Only good option is to:
- Using sysfs interface disable USB as a wakeup device (This will not
need any driver change)

Since some user don't care about sensors. So for those users this change
brings back old functionality. As long as they don't cause any operation
to power up sensors (like raw read or start iio-sensor-proxy service),
the sensors will not be to touched. This is done by delaying run time
enable till user space does some operation with sensors.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=196853
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

HID sensor hubs using Integrated Senor Hub (ISH) has added capability to
support batch mode. This allows host processor to go to sleep for extended
duration, while the sensor hub is storing samples in its internal buffers.

'Commit f4f4673b7535 ("iio: add support for hardware fifo")' implements
feature in IIO core to implement such feature. This feature is used in
bmc150-accel-core.c to implement batch mode. This implementation allows
software device buffer watermark to be used as a hint to adjust hardware
FIFO.

But HID sensor hubs don't allow to change internal buffer size of FIFOs.
Instead an additional usage id to set "maximum report latency" is defined.
This allows host to go to sleep upto this latency period without getting
any report. Since there is no ABI to set this latency, a new attribute
"hwfifo_timeout" is added so that user mode can specify a latency.

This change checks presence of usage id to get/set maximum report latency
and if present, it will expose hwfifo_timeout.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

This change undo the change done by 'commit 3bec24747446
("iio: hid-sensor-trigger: Change get poll value function order to avoid
sensor properties losing after resume from S3")' as this breaks some
USB/i2c sensor hubs.

Instead of relying on HW for restoring poll and hysteresis, driver stores
and restores on resume (S3). In this way user space modified settings are
not lost for any kind of sensor hub behavior.

In this change, whenever user space modifies sampling frequency or
hysteresis driver will get the feature value from the hub and store in the
per device hid_sensor_common data structure. On resume callback from S3,
system will set the feature to sensor hub, if user space ever modified the
feature value.

Fixes: 3bec24747446 ("iio: hid-sensor-trigger: Change get poll value function order to avoid sensor properties losing after resume from S3")
Reported-by: Ritesh Raj Sarraf <rrs@researchut.com>
Tested-by: Ritesh Raj Sarraf <rrs@researchut.com>
Tested-by: Song, Hongyan <hongyan.song@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Added timestamp channel. With this change, each sample has a timestamp.
This timestamp can be from the sensor hub when present or local kernel
timestamp. HID sensors can send timestamp with input data using usage id
HID_USAGE_SENSOR_TIME_TIMESTAMP. This timestamp value is converted to
nano seconds before pushing this sample to the iio core.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Some platforms power off sensor hubs during S3 suspend, which will require
longer time to resume. This hurts system resume time, so resume
asynchronously.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Jonathan writes:

First set of IIO fixes for the 4.2 cycle.

* Fix a regression in hid sensors suspend time as a result of adding runtime
  pm.  The normal flow of waking up devices in order to go into suspend
  (given the devices are normally suspended when not reading) to a regression
  in suspend time on some laptops (reports of an additional 8 seconds).
  Fix this by checking to see if a user action resulting in the wake up, and
  make it a null operation if it didn't.  Note that for hid sensors, there is
  nothing useful to be done when moving into a full suspend from a runtime
  suspend so they might as well be left alone.
* rochip_saradc: fix some missing MODULE_* data including the licence so that
  the driver does not taint the kernel incorrectly and can build as a module.
* twl4030 - mark irq as oneshot as it always should have been.
* inv-mpu - write formats for attributes not specified, leading to miss
  interpretation of the gyro scale channel when written.
* Proximity ABI clarification.  This had snuck through as a mess.  Some
  drivers thought proximity went in one direction, some the other.  We went
  with the most common option, documented it and fixed up the drivers going
  the other way.  Fix for sx9500 included in this set.
* ad624r - fix a wrong shift in the output data.
* at91_adc - remove a false limit on the value of the STARTUP register
  applied by too small a type for the device tree parameter.
* cm3323 - clear the bits when setting the integration time (otherwise
  we can only ever set more bits in the relevant field).
* bmc150-accel - multiple triggers are registered, but on error were not being
  unwound in the opposite order leading to removal of triggers that had not
  yet successfully been registered (count down instead of up when unwinding).
* tcs3414 - ensure right part of val / val2 pair read so that the integration
  time is not always 0.
* cc10001_adc - bug in kconfig dependency. Use of OR when AND was intended.

By default all the sensors are runtime suspended state (lowest power
state). During Linux suspend process, all the run time suspended
devices are resumed and then suspended. This caused all sensors to
power up and introduced delay in suspend time, when we introduced
runtime PM for HID sensors. The opposite process happens during resume
process.

To fix this, we do powerup process of the sensors only when the request
is issued from user (raw or tiggerred). In this way when runtime,
resume calls for powerup it will simply return as this will not match
user requested state.

Note this is a regression fix as the increase in suspend / resume
times can be substantial (report of 8 seconds on Len's laptop!)

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Tested-by: Len Brown <len.brown@intel.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

When CONFIG_DEBUG_LOCK_ALLOC is defined, mutex magic is compared and
warned for (l->magic != l), here l is the address of mutex pointer.
In hid-sensor-hub as part of hsdev creation, a per hsdev mutex is
initialized during MFD cell creation. This hsdev, which contains, mutex
is part of platform data for the a cell. But platform_data is copied
in platform_device_add_data() in platform.c. This copy will copy the
whole hsdev structure including mutex. But once copied the magic
will no longer match. So when client driver call
sensor_hub_input_attr_get_raw_value, this will trigger mutex warning.
So to avoid this allocate mutex dynamically. This will be same even
after copy.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Conflicts:
	drivers/iio/common/hid-sensors/hid-sensor-trigger.c
	include/linux/hid-sensor-hub.h

Current API only allows setting one offset in the field. This API
is extended to set multiple offsets in the field report.
Also update parameters in the users of this API.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>