In preparation for KXTF9 support, make sampling_frequency_avail
attribute dynamic.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Extract reporting of motion event direction from interrupt handler,
as it is not supported by KXTF9.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
'mma8452_read_thresh' and 'mma8452_write_thresh' functions
does more than just read/write threshold values.
They also handle IIO_EV_INFO_HIGH_PASS_FILTER_3DB and
IIO_EV_INFO_PERIOD therefore renaming to generic names.
Improves code readability, no impact on functionality.
Signed-off-by: Harinath Nampally <harinath922@gmail.com>
Acked-by: Martin Kepplinger <martink@posteo.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Replace 'unsigned' with 'unsigned int'
to improve code readability.
Issue found by checkpatch.
Signed-off-by: Harinath Nampally <harinath922@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Replace symbolic permissions with octal permissions
to improve code readability.
Issue found by checkpatch.
Signed-off-by: Harinath Nampally <harinath922@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This driver supports multiple devices like mma8653,
mma8652, mma8452, mma8453 and fxls8471. Almost all
these devices have more than one event.
Current driver design hardcodes the event specific
information, so only one event can be supported by this
driver at any given time.
Also current design doesn't have the flexibility to
add more events.
This patch improves by detaching the event related
information from chip_info struct,and based on channel
type and event direction the corresponding event
configuration registers are picked dynamically.
Hence both transient and freefall events can be
handled in read/write callbacks.
Changes are thoroughly tested on fxls8471 device on imx6UL
Eval board using iio_event_monitor user space program.
After this fix both Freefall and Transient events are
handled by the driver without any conflicts.
Signed-off-by: Harinath Nampally <harinath922@gmail.com>
Reviewed-by: Martin Kepplinger <martink@posteo.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
The equivalent of both of these are now done via macro magic when
the relevant register calls are made. The actual structure
elements will shortly go away.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Jonathan writes:
Second set of IIO new device support, features and cleanup for the 4.14 cycle.
New device support:
* ak8974
- support the AMI306.
* st_magnetometer
- add support for the LIS2MDL with bindings.
* rockchip-saradc
- add binding for rv1108 SoC (no driver change).
* srf08
- add srf02 (i2c only) and srf10 support.
* stm32-timer
- support for the STM32H7 to existing driver.
Features:
* tools
- move over to the tools buildsystem rather than hand rolling.
- add an install section to the build.
* ak8974
- use serial number to add device randomness.
- add AMI306 calibration data output.
* ccs811
- triggered buffer support.
* srf08
- add a device tree table as the old style i2c probing is going away,
- add triggered buffer support
* st32-adc
- add optional st,min-sample-time-nsecs binding to allow control of
sampling against analog circuitry.
* stm32-timer
- add output compare triggers.
* ti-ads1015
- add threshold event support.
* ti-ads7950
- Allow use on ACPI platforms including providing a default reference
voltage as there is no way to obtain this on ACPI currently.
Cleanup and fixes:
* ad7606
- fix an error return code in probe.
* ads1015
- fix incorrect data rate setting update when capture in progress,
- fix wrong scale information for the ADS1115,
- make conversions work when CONFIG_PM is not set,
- make sure we don't get a stale result after a runtime resume by
ensuring we wait long enough,
- avoid returning a false error form the buffer setup callbacks,
- add enough wait time to get the correct conversion,
- remove an unnecessary config register update,
- add a helper to set conversion mode reducing repeated boilerplate,
- use devm_iio_triggered_buffer_setup to simplify error and remove
paths,
- use iio_device_claim_direct_mode instead of opencoding the same.
* ak8974
- mark the INT_CLEAR register as precious to prevent debugfs access.
* apds9300
- constify the i2c_device_id.
* at91-sama5 adc
- add missing Kconfig dependency.
* bma180 accel
- constify the i2c_device_id.
* rockchip_saradc
- explicitly request exclusive reset control as part of the reset rework
on going throughout the kernel.
* st_accel
- fix drdy configuration for a load of accelerometers that only have
the int1 line. Fix is unimportant as presumably no deviec tree actually
used the non existent hardware line.
* st_pressure
- fix drdy configuration for LPS22HB and LPS25H by dropping int2 support
as they don't have this. Fix is unimportant as presumably no device tree
actually used the non existent hardware line.
* stm32-dac
- explicitly request exclusive reset control (part of reset being reworked).
* tsl2583
- constify the i2c_device_id.
* xadc
- coding style fixes.
i2c_device_id are not supposed to change at runtime. All functions
working with i2c_device_id provided by <linux/i2c.h> work with
const i2c_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Remove int2 configuration parameter for LIS3DH, LSM303DLHC, LSM330D,
LSM330DL, LSM330DLC, LSM303AGR, LIS2DH12 and LNG2DM since these devices
export just int1 as data-ready line
Fixes: 23cde4d65c (iio: Added platform data to select the DRDY pin)
Fixes: dcdb0a78ca (iio: accel: st_accel: add support to lng2dm)
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Jonathan writes:
First set of IIO fixes for the 4.13 cycle.
* ad2s1210
- Fix negative angular velocity reads (identified by a gcc 7 warning)
* aspeed-adc
- Wait for initialization sequence to finish before enabling channels.
Without it no channels work.
* axp288
- Revert a patch that dropped some bogus register mods. No one is entirely
sure why but it breaks charging on some devices.
- Fix GPADC pin read returning 0. Turns out a small sleep is needed.
* bmc150
- Make sure device is restored to normal state after suspend / resume
cycle. Otherwise, simple sysfs reads are broken.
* tsl2563
- fix wrong event code.
* st-accel
- add spi 3-wire support. Needed to fix the lsm303agr accelerometer
which only had 3 wires in all cases. Side effect is to enable optional
3-wire support for other devices.
* st-pressure
- disable multiread by default for LPS22HB (only effects SPI)
* sun4i-gpadc-iio
- fix unbalanced irq enable / disable
* vf610
- Fix VALT slection for REFSEL bits - ensures we are using the
right reference pins.
After probe we would put the device in normal mode, after a runtime
suspend-resume we would put it back in normal mode. But for a regular
suspend-resume we would only put it back in normal mode if triggers
or events have been requested. This is not consistent and breaks
reading raw values after a suspend-resume.
This commit changes the regular resume path to also unconditionally put
the device back in normal mode, fixing reading of raw values not working
after a regular suspend-resume cycle.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
In order to use the standard name convention rename H3LIS331DL_DRIVER_NAME
macro in H3LIS331DL_ACCEL_DEV_NAME
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Add H3LIS331DL, LIS331DL and LIS3LV02DL entries in st_accel_id_table
Fixes: 1e52fefc9b (iio: accel: Add support for the h3lis331dl accel)
Fixes: bbf5f037fa (iio: st_accel: support the LIS331DL sensor)
Fixes: 3acddf74f8 (iio: st-sensors: add support for lis3lv02d accel)
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Making the const array init_data static rather having it on the
stack saves us a couple hundreds of bytes:
Before:
text data bss dec hex filename
3175 848 0 4023 fb7 drivers/iio/accel/da311.o
After:
text data bss dec hex filename
2860 936 0 3796 ed4 drivers/iio/accel/da311.o
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Add SPI Serial Interface Mode (SIM) register information
in st_sensor_settings look up table to support devices
(like LSM303AGR accel sensor) that allow just SPI-3wire
communication mode. SIM mode has to be configured before any
other operation since it is not enabled by default and the driver
is not able to read without that configuration
Whilst a fairly substantial patch, the actual logic is simple and it
is better to have the generic fix than a band aid.
Fixes: ddc05fa286 (iio: st-accel: add support for lsm303agr accel)
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
In order to add proper device tree support give a more general name
to of_device_id table
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Move st_sensors_of_i2c_probe() in st_sensors_core and rename it in
st_sensors_of_name_probe(). That change is necessary to add device-tree
support in spi code otherwise the rest of the autodetection will fail
since spi->modalias (and indio_dev->name) will be set using compatible
string value that differs from standard sensor name
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Add support for the BOSC0200 ACPI device id used on some x86 tablets.
note driver_data is not set to a specific model, driver_data is not
used anyways (instead detection is done on the chip_id reg) and the
2 tablets with a BOSC0200 ACPI device id I've have 2 different chips,
one has a BMA250E, the other a BMA222E.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
While using GPIO library API we might get into troubles in the future,
because we can't rely on label name in the driver since vendor firmware
might provide any GPIO pin there, e.g. "reset", and even mark it in _DSD
(in which case the request will fail).
To avoid inconsistency and potential issues we have two options:
a) generate GPIO ACPI mapping table and supply it via
acpi_dev_add_driver_gpios(), or
b) just pass NULL as connection ID.
The b) approach is much simpler and would work since the driver relies
on GPIO indices only. Moreover, the _CRS fallback mechanism, when
requesting GPIO, is going to be stricter, and supplying non-NULL
connection ID when neither _DSD, nor GPIO ACPI mapping is present, will
make request fail.
See
https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio.git/commit/?h=for-next&id=ed7fcf1ed5ea4ea01243995ae085757a77cf0f3e for more background.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This reverts commit f1320b0951.
The BMA250E is already handled by the bmc150-accel-i2c driver, which
supports the "E" variants of the BMA??? accelerometers better then the
bma180 driver.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This reverts commit 5333e88661.
The BMA250E is already handled by the bmc150-accel-i2c driver, which
supports the "E" variants of the BMA??? accelerometers better then the
bma180 driver.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Remove LSM303DL, LSM303DLM, LSM303DLH, LSM303DLHC from st_accel_id_table
since LSM303DL series does not support spi interface
Fixes: d62511689d (iio: accel: Add STMicroelectronics accel driver)
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Some x86 tablets use the BMA250E accelerometer, add support for this.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
The BMA250E adds a new fifo mode and is fully backwards compatible
with the BMA250, but with a different chip-id.
This commit adds support for it by adjusting the chip-id check and
otherwise treating it as a regular BMA250.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Drop static on a local variable, when the variable is initialized before
use, on every possible execution path through the function. The static has
no benefit, and dropping it reduces the code size.
The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@bad exists@
position p;
identifier x;
type T;
@@
static T x@p;
...
x = <+...x...+>
@@
identifier x;
expression e;
type T;
position p != bad.p;
@@
-static
T x@p;
... when != x
when strict
?x = e;
// </smpl>
The change in code size is indicates by the following output from the size
command.
before:
text data bss dec hex filename
3879 512 8 4399 112f drivers/iio/accel/hid-sensor-accel-3d.o
after:
text data bss dec hex filename
3863 512 0 4375 1117 drivers/iio/accel/hid-sensor-accel-3d.o
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This patch fixes the sensor platform data initialisation for st_pressure
and st_accel device drivers. Without this patch, the driver fails to
register the sensors when the user removes and re-loads the driver.
1. Unload the kernel modules for st_pressure
$ sudo rmmod st_pressure_i2c
$ sudo rmmod st_pressure
2. Re-load the driver
$ sudo insmod st_pressure
$ sudo insmod st_pressure_i2c
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
When both accel_3d and gravity sensor are present, iio_device_register()
fails with "Duplicate scan index" error.
The reason for this is setting of indio_dev->num_channels based on
accel_3d channel for both gravity and accel-3d sensor. But number of
channels are not same, so for gravity it is pointing to some invalid
memory and getting scan_index to compare which may match.
To fix this issue, set the indio_dev->num_channels correctly based on
the sensor type.
Fixes: 0e377f3b9a ('iio: Add gravity sensor support')
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
The driver doesn't have a struct of_device_id table but supported devices
are registered via Device Trees. This is working on the assumption that a
I2C device registered via OF will always match a legacy I2C device ID and
that the MODALIAS reported will always be of the form i2c:<device>.
But this could change in the future so the correct approach is to have an
OF device ID table if the devices are registered via OF.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
The driver doesn't have a struct of_device_id table but supported devices
are registered via Device Trees. This is working on the assumption that a
I2C device registered via OF will always match a legacy I2C device ID and
that the MODALIAS reported will always be of the form i2c:<device>.
But this could change in the future so the correct approach is to have an
OF device ID table if the devices are registered via OF.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
The driver doesn't have a struct of_device_id table but supported devices
are registered via Device Trees. This is working on the assumption that a
I2C device registered via OF will always match a legacy I2C device ID and
that the MODALIAS reported will always be of the form i2c:<device>.
But this could change in the future so the correct approach is to have an
OF device ID table if the devices are registered via OF.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Fix checkpatch warnings:
WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
Signed-off-by: Miguel Robles <miguel.robles@farole.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Add SPI driver that initializes SPI regmap for the adxl345 core driver.
The driver supports the same functionality as I2C namely the x, y, z and
scale readings.
Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Move I2C-specific code into its own file and rely on regmap to access
registers. The core code provides access to x, y, z and scale readings.
Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Convert the driver to use regmap instead of I2C-specific functions. This
is done in preparation for splitting this driver into core and
I2C-specific code as well as introduction of SPI driver.
Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Use devm_iio_device_register() for IIO subsystem device
registration and delete the remove function since there
is no need after this change.
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
commit 762227721f
"iio: accel: st_accel: handle deprecated bindings"
attempted to be smart and let users use the old I2C
driver and the new SPI driver, or the old SPI driver and
the new I2C driver in combination for the LIS3LV02,
and put the restrictions on the I2C and SPI subdrivers
not not be combined with the old subdrivers.
This doesn't work since the IIO ST accel top-level
component selects the I2C and SPI subdrivers, resulting
in the following Kconfig noise:
warning: (IIO_ST_ACCEL_3AXIS) selects IIO_ST_ACCEL_I2C_3AXIS
which has unmet direct dependencies (IIO && !SENSORS_LIS3_I2C
&& IIO_ST_ACCEL_3AXIS && IIO_ST_SENSORS_I2C)
warning: (IIO_ST_ACCEL_3AXIS) selects IIO_ST_ACCEL_SPI_3AXIS
which has unmet direct dependencies (IIO && !SENSORS_LIS3_SPI
&& IIO_ST_ACCEL_3AXIS && IIO_ST_SENSORS_SPI)
(...)
This fixes the issue by putting the dependencies directly
in the top-level component instead, so that it never gets
to select its unselectable subcomponent.
Fixes: 762227721f ("iio: accel: st_accel: handle deprecated bindings")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jonathan writes:
First round of new device support, features and cleanups for IIO in the 4.11 cycle.
It's shaping to be another fairly busy cycle. Lots more on the way!
New device support
* ads7950
- new driver supporting ads7950, ads7951, ads7952, ads7953, ads7954,
ads7955, ads7956, ads7957, ads7958, ads7959, ads7960, and ads7961 ADCs.
* cm3605
- New driver for this light sensor and proximity sensor which is an
analog part with some additional digital controls.
* hx711
- New driver.
Core new stuff
* Gravity sensor type. This is a processed datastream in which the device
will try to work out which way is down.
* Split the buffer.h file into two parts. One provides the interface to 'use'
a buffer, the second provides the internals of the buffer functionality as
needed by implementations of buffers.
- Move documentation inline so as to allow use of private: tag when
generating documentation.
- Add some utility functions for the few things that are directly done
with the buffers.
- Stop exporting functions that no-one uses outside of the core code.
- Push docs down by the code in the c file where they should have always
been.
- Fix typo in kernel-doc for buffer.
- push down some includes that were previously happening implicitly.
- stop enabling the timestamp of the dummy device.
Features and cleanups
* ad5592r
- ACPI support
* ad5593r
-ACPI support.
* ad5933
- Fix a false comment about size of a particular register.
* ad7150
- replace S_IRUGO | S_IWUSR with 0644. I'm not that keen on these patches
in general, but as it was nicely presented I took this one anyway. As a
general rule will only take these as part of a larger driver cleanup.
- don't eat an error but rather reutnr it in the write_event_config callback.
* ad7606
- replace non standard range attibute with _scale
* ade7753
- use usleep_range for short sleeps
* ade7754
- use usleep_range for short sleeps
* ade7758
- use usleep_range for short sleeps
* ade7759
- use usleep_range for short sleeps
* ade7854
- use usleep_range for short sleeps
* adis16201
- fix description
* adis16203
- fix description
- fix copyright year
* adis16209
- fix description
* adt7316
- Add braces to arms of if else statement (for consistency)
- Alignment fixes.
* axp288
- Fix up an issue with accidental overwrites of data.
* bmi160
- add deivce tables for i2c and spi to support correctly identifying the
full dt name (including manufacturer).
- device tree binding.
* bmp280
- use usleep_range for short sleeps.
* cm3232
- return error from cm3232_reg_init rather than eating it if the last write
fails.
* dummy driver
- remove a semicolor found at end of a function defintition.
* exynos-adc
- use usleep_range for short sleeps.
* hid-sensor (accel)
- Add timestamp support. The hardware can provide timestamps so lets support
them. If not fall back to timestamps estimated in kernel.
* hid-sensor (light)
- Add a duplicate ID for the light channels so as to keep existing interface
whilst also using the more standard IIO interface.
* hts221
- acpi probing
* imx25-gcq
- Add a macro call to allow this driver to be automatically loaded.
* isl29028
- reorganise code to avoid deep nesting of if statements.
- move chip test and default regs into a function suitable or sharing with
power management code.
- tidy up some code alignment.
* lidar-lite-v3
- introduce compatible strings that make it clear Garmin have consideral
friends.
* mma8452
- avoid returning signed value when unsigned is appropriate
* spmi-vadc
- Update function for generic voltage conversion to take into account that
different channels on this device should be handled differently.
- Rework code to allow per channel voltage scaling and support the standard
options for this hardware.
- Fixup three minor issues with the above patches for this part. These all
effect test builds rather than the native builds for the part, but good to
clean them up anyway.
* st_sensors
- support device matching from the ACPI DST tables.
- acpi based probing for accelerometers
- acpi based probing for pressure sensors
- Allow pressure sensors to read negative values.
- Export sampling frequency for lps25h and lps331ap.
- Add support for the old DT bindings from the period when these deivces
were often supported through windows.
Docs fixup:
* typo in sysfs-bus-iio
As a precursor to splitting buffer.h, lets make sure all drivers
include the relevant headers rather than relying on picking them
up from kfifo_buf.h.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
This is a necessary step in taking the buffer implementation
opaque.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
The earlier deployed LIS3LV02DL driver had already defined a few
DT bindings that need to be supported by the new more generic
driver and listed as compatible but deprecated bindings in the
documentation.
After this we can start to activate the new driver with the old
systems where applicable.
As part of this enablement: make us depend on the old drivers
not being in use so we don't get a kernel with two competing
drivers.
Cc: devicetree@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Gravity sensor is a soft sensor, which derives value from
standard accelerometer device by filtering out the acceleration
which is not caused by gravity.
Gravity sensor provides a three dimensional vector indicating
the direction and magnitude of gravity. Typically, this sensor
is used to determine the device's relative orientation in space.
The units and the coordinate system is the same as the one used by
the acceleration sensor.
When a device is at rest, the output of the gravity sensor should
be identical to that of the accelerometer.
More information can be found in:
http://www.usb.org/developers/hidpage/HUTRR59_-_Usages_for_Wearables.pdf
Gravity sensor and accelerometer have similar channels and
share channel usage ids. So the most of the code for accel_3d
can be reused.
Signed-off-by: Song Hongyan <hongyan.song@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
