commit 0c1f91b98552da49d9d8eed32b3132a58d2f4598 upstream.

These two spi_w8r8() calls return a value with is used by the code
following the error check. The dubious use was caused by a cleanup
patch.

Fixes: d34dbee8ac8e ("staging:iio:accel:kxsd9 cleanup and conversion to iio_chan_spec.")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

For big endian platforms, reading the axes will return
invalid values.

The device stores each axis value in a 16 bit little
endian register. The driver uses regmap_read_bulk to get
the axis value, resulting in a 16 bit little endian value.
This needs to be converted to cpu endianness to work
on big endian platforms.

Fix endianness for big endian platforms by converting
the values for the axes read from little endian to
cpu.

This is also partially fixed in commit b6fb9b6d6552 ("iio:
accel: bmc150: optimize transfers in trigger handler").

Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

We want the upstream staging fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Jonathan writes:

First set of IIO fixes for the 4.5 cycle.

This set comprises those not dependent on patches in the 4.5 merge cycle.
A second set will follow shortly with ones that are.

* core in kernel interfaces
  - fix a possible NULL dereference that is a theoretical possibility
    via odd usage of iio_channel_release. Pretty much a hardening of
    the interface, but observed in the wild with the twl4030_charger
    driver.
* acpi-als
  - report the data as processed as it is in lux.  This fixes a wrong
    use of the IIO ABI.  However, old _raw version retained to avoid
    breaking any userspace in the wild that is relying on that (none
    known but it doesn't hurt us much to retain it)
* ade7753
  - fix some error handling to avoid use of unitialized data.
* ltr501
  - use a signed return type for ltr501_match_samp_freq so as to allow
    returning of an error code.
* mcp4725
  - set name field of struct iio_dev to ensure the sysfs name attribute
    doesn't give NULL.
* mpl115
  - temperature offset sign is wrong.
* stk8ba50
  - IIO_TRIGGER dependency added
* ti_am335x_adc
  - Label buffer as a software buffer. It's actually a hybrid of a
    true hardware buffer feeding a kfifo, but the meaning of these fields
    has changed a little recently and in this case it should be labeled
    a software buffer ensure it is allowed to use the kfifo.
* vf610_adc
  - HAS_IOMEM dependency

This adds support for this series' 14 bit accelerometer chip, MMA8451Q.
It's datasheet is available at the vendor's website:

https://cache.freescale.com/files/sensors/doc/data_sheet/MMA8451Q.pdf

Signed-off-by: Martin Kepplinger <martin.kepplinger@theobroma-systems.com>
Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Signed-off-by: Martin Kepplinger <martin.kepplinger@theobroma-systems.com>
Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

This adds freefall event detection to the supported devices. It adds
the in_accel_x&y&z_mag_falling_en iio event attribute, which activates
freefall mode.

In freefall mode, the current acceleration magnitude (AND combination
of all axis values) is compared to the specified threshold.
If it falls under the threshold (in_accel_mag_falling_value),
the appropriate IIO event code is generated.

This is what the sysfs "events" directory for these devices looks
like after this change:

-rw-r--r--    4096 Oct 23 08:45 in_accel_mag_falling_period
-rw-r--r--    4096 Oct 23 08:45 in_accel_mag_falling_value
-rw-r--r--    4096 Oct 23 08:45 in_accel_mag_rising_period
-rw-r--r--    4096 Oct 23 08:45 in_accel_mag_rising_value
-r--r--r--    4096 Oct 23 08:45 in_accel_scale
-rw-r--r--    4096 Oct 23 08:45 in_accel_x&y&z_mag_falling_en
-rw-r--r--    4096 Oct 23 08:45 in_accel_x_mag_rising_en
-rw-r--r--    4096 Oct 23 08:45 in_accel_y_mag_rising_en
-rw-r--r--    4096 Oct 23 08:45 in_accel_z_mag_rising_en

Signed-off-by: Martin Kepplinger <martin.kepplinger@theobroma-systems.com>
Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Most ST MEMS Sensors that support interrupts can also handle sending
an active low interrupt, i.e. going from high to low on data ready
(or other interrupt) and thus triggering on a falling edge to the
interrupt controller.

Set up logic to inspect the interrupt line we get for a sensor: if
it is triggering on rising edge, leave everything alone, but if it
triggers on falling edges, set up active low, and if unsupported
configurations appear: warn with errors and reconfigure the interrupt
to a rising edge, which all interrupt generating sensors support.

Create a local header for st_sensors_core.h to share functions
between the sensor core and the trigger setup code.

Cc: Giuseppe Barba <giuseppe.barba@st.com>
Cc: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Ran into this on UML:

drivers/iio/accel/stk8ba50.c: In function ‘stk8ba50_data_rdy_trigger_set_state’:
drivers/iio/accel/stk8ba50.c:163:9: error: implicit declaration of function ‘iio_trigger_get_drvdata’ [-Werror=implicit-function-declaration]

iio_trigger_get_drvdata() is defined only when IIO_TRIGGER is selected.

Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

This gets rid of some magic numbers by adding an enum.

Signed-off-by: Martin Kepplinger <martin.kepplinger@theobroma-systems.com>
Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>