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>

Some hid sensor feature report can contain more than one reports.
This API can now support receiving multiple values from the feature
report.
Also update the parameters in the users of this API.

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

Add additional flag to read in async mode. In this mode the caller will get
reply via registered callback for capture_sample. Callbacks can be registered
using sensor_hub_register_callback function. The usage id parameter of the
capture_sample can be matched with the usage id of the requested attribute.

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

Current implementation only allows one outstanding synchronous read.
This is a performance hit when user mode is requesting raw reads
of sensor attributes on multiple sensors together.
This change changes the mutex lock to per hid sensor hub device instead
of global lock. Although request to hid sensor hub is serialized, there
can be multiple outstanding read requests pending for responses via
hid reports.

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

During changes to the interface, some documentation field comments
were missed. Added missing comments.

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

Added an API to allow client drivers to turn ON and OFF sensors for
quick read. Added data_read as counting varaible instead of boolean,
so that sensor is powered off only when last user released it.

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

Added interface to get poll value in milli-seconds. This value is
changed by changing sampling frequency. This API allows clients
to wait for at least some poll milli seconds before reading a new sample.

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

HID sensor hub specify a default unit and alternative units. This
along with unit exponent can be used adjust scale. This change
change HID sensor data units to IIO defined units for each
sensor type. So in this way user space can use a simply use:
"(data + offset) * scale" to get final result.

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

In HID sensor hub, HID physical ids are used to represent different sensors.
For example physical id of 0x73 in usage page = 0x20, represents an
accelerometer. The HID sensor hub driver uses this physical ids to create
platform devices using MFD. There is 1:1 correspondence between an phy id and a
client driver.

But in some cases these physical ids are reused. There is a phy id 0xe1, which
specifies a custom sensor, which can exist multiple times to represent various
custom sensors. In this case there can be multiple instances of client MFD
drivers, processing specific custom sensor. In this case when client driver
looks for report id or a field index, it should still get the report id
specific to its own type. This is also true for reports, they should be
directed towards correct instance.  This change introduce a way to parse and
tie physical devices to their correct instance.

Summary of changes:
- To get physical ids, use collections. If a collection of type=physical
  exist then use usage id as in the name of platform device name
- As part of the platform data, we assign a hdsev instance, which has
  start and end of collection indexes. Using these indexes attributes
  can be tied to correct MFD client instances
- When a report is received, call callback with correct hsdev instance.
  In this way using its private data stored as part of its registry, it
  can distinguish different sensors even when they have same physical and
  logical ids.

  This patch is co-authored with Archana Patni <archna.patni@intel.com>.

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