linux-stable.git/include/linux/iio/iio.h, branch linux-4.7.y

iio:core: mounting matrix support

2016-04-23T21:13:05+00:00

Expose a rotation matrix to indicate userspace the chip placement with
respect to the overall hardware system. This is needed to adjust
coordinates sampled from a sensor chip when its position deviates from the
main hardware system.

Final coordinates computation is delegated to userspace since:
* computation may involve floating point arithmetics ;
* it allows an application to combine adjustments with arbitrary
  transformations.

This 3 dimentional space rotation matrix is expressed as 3x3 array of
strings to support floating point numbers. It may be retrieved from a
"[_][_]mount_matrix" sysfs attribute file. It is declared into a
device / driver specific DTS property or platform data.

Signed-off-by: Gregor Boirie 
Signed-off-by: Jonathan Cameron

iio: core: implement iio_device_{claim|release}_direct_mode()

2016-03-12T11:17:19+00:00

It is often the case that the driver wants to be sure a device stays
in direct mode while it is executing a task or series of tasks.  To
accomplish this today, the driver performs this sequence: 1) take the
device state lock, 2) verify it is not in a buffered mode, 3) execute
some tasks, and 4) release that lock.

This patch introduces a pair of helper functions that simplify these
steps and make it more semantically expressive.

iio_device_claim_direct_mode()
        If the device is not in any buffered mode it is guaranteed
        to stay that way until iio_release_direct_mode() is called.

iio_device_release_direct_mode()
        Release the claim. Device is no longer guaranteed to stay
        in direct mode.

Signed-off-by: Alison Schofield 
Signed-off-by: Jonathan Cameron

iio: Fix typos in the struct iio_event_spec documentation comments

2016-02-17T21:11:08+00:00

This patch fixes a few minor typos in the documentation comments for the
scan_type member of the iio_event_spec structure. The sign member name
was improperly capitalized as "Sign" in the comments. The storagebits
member name was improperly listed as "storage_bits" in the comments. The
endianness member entry in the comments was moved after the repeat
member entry in order to maintain consistency with the actual struct
iio_event_spec layout.

Signed-off-by: William Breathitt Gray 
Signed-off-by: Jonathan Cameron

iio: Fix documentation for iio_dev mlock

2016-02-08T18:34:32+00:00

mlock *must* be used by core and drivers to protect access
to devices state changes.

Signed-off-by: Daniel Baluta 
Signed-off-by: Jonathan Cameron

iio: Make IIO value formating function globally available.

2015-12-22T17:04:56+00:00

Make IIO value formating function globally available to allow IIO drivers
to output values as the core does.

Signed-off-by: Andrew F. Davis 
Signed-off-by: Jonathan Cameron

iio: Support triggered events

2015-08-27T19:47:09+00:00

Support triggered events.

This is useful for chips that don't have their own interrupt sources.
It allows to use generic/standalone iio triggers for those drivers.

Signed-off-by: Vladimir Barinov 
Signed-off-by: Jonathan Cameron

iio: Add inverse unit conversion macros

2015-08-08T11:50:40+00:00

Add inverse unit conversion macro to convert from standard IIO units to
units that might be used by some devices.

Those are useful in combination with scale factors that are specified as
IIO_VAL_FRACTIONAL. Typically the denominator for those specifications will
contain the maximum raw value the sensor will generate and the numerator
the value it maps to in a specific unit. Sometimes datasheets specify those
in different units than the standard IIO units (e.g. degree/s instead of
rad/s) and so we need to do a unit conversion.

From a mathematical point of view it does not make a difference whether we
apply the unit conversion to the numerator or the inverse unit conversion
to the denominator since (x / y) / z = x / (y * z). But as the denominator
is typically a larger value and we are rounding both the numerator and
denominator to integer values using the later method gives us a better
precision (E.g. the relative error is smaller if we round 8000.3 to 8000
rather than rounding 8.3 to 8).

This is where in inverse unit conversion macros will be used.

Marked for stable as used by some upcoming fixes.

Signed-off-by: Lars-Peter Clausen 
Cc: 
Signed-off-by: Jonathan Cameron

iio: core: add high pass filter attributes

2015-05-17T09:32:35+00:00

Add a high pass filter attribute for measurements
(like the existing low pass)

Also add both high and low pass attributes for events.

Signed-off-by: Martin Fuzzey 
Signed-off-by: Jonathan Cameron

iio: core: Introduce IIO_CHAN_INFO_OVERSAMPLING_RATIO

2015-05-10T19:31:44+00:00

Some magnetometers can perform a number of repetitions in HW
for each measurement to increase accuracy. One example is
Bosch BMC150:
http://ae-bst.resource.bosch.com/media/products/dokumente/bmc150/BST-BMC150-DS000-04.pdf.

Introduce an interface to set the oversampling ratio
for these devices.

Signed-off-by: Irina Tirdea 
Signed-off-by: Jonathan Cameron

iio: core: Introduce IIO_CHAN_INFO_CALIBEMISSIVITY

2015-04-09T14:03:05+00:00

Contact-less IR temperature sensors measure the temperature of an object
by using its thermal radiation.  Surfaces with different emissivity
ratios emit different amounts of energy at the same temperature.

IIO_CHAN_INFO_CALIBEMISSIVITY allows the user to inform the sensor of the
emissivity of the object in front of it, in order to effectively measure
its temperature.

A device providing such setting is Melexis's MLX90614:
http://melexis.com/Assets/IR-sensor-thermometer-MLX90614-Datasheet-5152.aspx.

Signed-off-by: Vianney le Clément de Saint-Marcq 
Cc: Arnout Vandecappelle (Essensium/Mind) 
Signed-off-by: Jonathan Cameron