iio: pressure: st_pressure: Add support for LPS22DF

Add support for ST LPS22DF pressure sensor.

Datasheet: https://www.st.com/resource/en/datasheet/lps22df.pdf
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Link: https://lore.kernel.org/r/20220909161611.780720-2-martyn.welch@collabora.co.uk
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: st_sensors: Stop abusing mlock to ensure internal coherency

An odr_lock has been introduced to protect local accesses to the odr
internal cache and ensure the cached value always reflected the actual
value. Using the mlock() for this purpose is no longer needed, so let's
drop these extra mutex_lock/unlock() calls.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Cc: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20220207143840.707510-8-miquel.raynal@bootlin.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:st-sensors: Move exports into IIO_ST_SENSORS namespace

To avoid unnecessary pollution of the global symbol namespace move the
driver core and type specific core exports into their a new namespace
and import that where needed.

For more info see https://lwn.net/Articles/760045/

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Denis Ciocca <denis.ciocca@st.com>
Link: https://lore.kernel.org/r/20220116180535.2367780-14-jic23@kernel.org

iio: st_sensors: remove reference to parent device object on st_sensor_data

The idea behind it, is that all devm_ calls in ST sensors are bound to the
parent device object.

However, the reference to that object is kept on both the st_sensor_data
struct and the IIO object parent (indio_dev->dev.parent).

This change only adds a bit consistency and uses the reference stored on
indio_dev->dev.parent, to enforce the assumption that all ST sensors' devm_
calls are bound to the same reference as the one store on st_sensor_data.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210823112204.243255-6-aardelean@deviqon.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: st_sensors: remove all driver remove functions

At this point all ST driver remove functions do iio_device_unregister().
This change removes them from them and replaces all iio_device_register()
with devm_iio_device_register().

This can be done in a single change relatively easy, since all these remove
functions are define in st_sensors.h.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210823112204.243255-5-aardelean@deviqon.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: st_sensors: remove st_sensors_deallocate_trigger() function

This change converts the st_sensors_allocate_trigger() to use
device-managed functions.

The parent device of the IIO device object is used. This is based on the
assumption that all other devm_ calls in the ST sensors use this reference.

That makes the st_sensors_deallocate_trigger() function un-needed, so it
can be removed.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210823112204.243255-3-aardelean@deviqon.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: pressure: st_pressure: use devm_iio_triggered_buffer_setup() for buffer

The st_press_allocate_ring() function calls iio_triggered_buffer_setup() to
allocate a triggered buffer.

But the same can be done with devm_iio_triggered_buffer_setup() and then
the st_press_common_remove() no longer needs to manually deallocate it.

We know that the parent of the IIO device is used to manage other instances
of the devm unwind, so it can be used in the st_press_allocate_ring() as
well.

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210720074642.223293-1-aardelean@deviqon.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: st-sensors: Remove some unused includes and add some that should be there

The st-sensors drivers have changed in structure over time, and includes
have not always kept up with this. Let's bring them back to nearer
the ideal.

Identified with the include-what-you-use tool and careful checking of
its suggestions.

Note I haven't been particularly aggressive here, so this is just the
cases where the include obviously isn't needed rather than the more
subtle corners.

Note I took the opportunity to add mod_devicetable.h as I generally
prefer to see that when acpi or of match tables are present.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Denis Ciocca <denis.ciocca@st.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210608175149.4019289-1-jic23@kernel.org

iio: st_sensors: Call st_sensors_power_enable() from bus drivers

In case we would initialize two IIO devices from one physical device,
we shouldn't have a clash on regulators. That's why move
st_sensors_power_enable() call from core to bus drivers.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210414195454.84183-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: st_sensors: Drop unneeded explicit castings

In few places the unnecessary explicit castings are being used.
Drop them for good.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: st_sensors: Use dev_get_platdata() to get platform_data

Use dev_get_platdata() to get the platform_data instead of
referencing it directly.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: st: Drop GPIO include

None of the ST sensor drivers use any symbols from
<linux/gpio.h>, just drop the include from all of them.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: remove get_irq_data_ready() function pointer and use IRQ number directly

Not even sure why it was there since the beginning. Just use IRQ
number in the sensor_data struct.

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: make st_sensors drivers use regmap

This patch is meant to replace the i2c/spi transfer functions with
regmap. SPI framework requires DMA safe buffers so let's add GFP_DMA
flag for memory allocation used by bulk_read functions.

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: move 3-wire spi initialization to st_sensors_spi

Some devices need to be configured with special bit in order to
use spi 3-wire. This was done during device identification phase.
Instead, let's move this part as spi specific.
Doing this the check_device_support function becomes a simple
device id check, so let's rename it.

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:pressure: introduce st_press_get_settings() function

The function is introduced to retrieve press device settings. It will be
used by probe in order to configure regmap.

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 177

Based on 1 normalized pattern(s):

licensed under the gpl 2

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 135 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528170026.071193225@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio:st_pressure:initial lps22hh sensor support

Initial support for ST LPS22HH pressure sensor. Datasheet:
http://www2.st.com/resource/en/datasheet/lps22hh.pdf

Features:
* pressure, temperature data and timestamping channels
* sampling frequency selection [1..200] Hz
* interrupt based trigger
* over I2C or SPI interface

Signed-off-by: mario tesi <mario.tesi@st.com>
Acked-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: st_pressure: st_accel: pass correct platform data to init

Commit 7383d44b added a pointer pdata which get set to the default
platform_data when non was defined in the device. But it did not
pass this pointer to the st_sensors_init_sensor call but still
used the maybe uninitialized platform_data from dev.

This breaks initialization when no platform_data is given and
the optional st,drdy-int-pin devicetree option is not set.

This commit fixes this.

Cc: stable@vger.kernel.org
Fixes: 7383d44b ("iio: st_pressure: st_accel: Initialise sensor platform data properly")
Signed-off-by: Michael Nosthoff <committed@heine.so>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: st_sensors: split open-drain parameters for irq1 and irq2

Define st_sensor_int_drdy structure in st_sensor_data_ready_irq in order
to contain irq line parameters of the device.
Moreover separate data-ready open-drain configuration parameters for INT1
and INT2 pins in st_sensor_data_ready_irq data structure.
That change will be used to properly support LIS3DHH accel sensor.

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: pressure: st_pressure: add SPI-3wire support to st_pressure framework

Add SPI Serial Interface Mode (SIM) register information
to STM pressure framework

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: st_sensors: decouple irq1 configuration parameters from the irq2 ones

Separate data-ready configuration parameters for INT1 and INT2 pins in
st_sensor_data_ready_irq data structure. That change will be use to
properly support LIS2DW12 accel sensor.

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: st_sensors: add register mask for status register

Introduce register mask for data-ready status register since
pressure sensors (e.g. LPS22HB) export just two channels
(BIT(0) and BIT(1)) and BIT(2) is marked reserved while in
st_sensors_new_samples_available() value read from status register
is masked using 0x7.
Moreover do not mask status register using active_scan_mask since
now status value is properly masked and if the result is not zero the
interrupt has to be consumed by the driver. This fix an issue on LPS25H
and LPS331AP where channel definition is swapped respect to status
register.
Furthermore that change allows to properly support new devices
(e.g LIS2DW12) that report just ZYXDA (data-ready) field in status register
to figure out if the interrupt has been generated by the device.

Fixes: 97865fe41322 (iio: st_sensors: verify interrupt event to status)
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: pressure: add support to LPS33HW and LPS35HW

add support to STMicroelectronics LPS33HW and LPS35HW pressure sensors
to st_pressure framework

http://www.st.com/resource/en/datasheet/lps33hw.pdf
http://www.st.com/resource/en/datasheet/lps35hw.pdf
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:pressure: drop assign iio_info.driver_module and iio_trigger_ops.owner

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>

iio: pressure: st_pressure: fix drdy configuration for LPS22HB and LPS25H

Remove int2 configuration parameter for LPS22HB and LPS25H since
these devices export just int1 as data-ready line

Fixes: 931878405b86 (iio:pressure: Add support for LPS25H pressure sensor)
Fixes: e039e2f5b4da (iio:st_pressure:initial lps22hb sensor support)
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: pressure: st_pressure_core: disable multiread by default for LPS22HB

Set multiread variable to false for LPS22HB pressure sensor since
it is already enabled in CTRL_REG2. Previous configuration does not
cause any issue in I2C communication since SUB Msb has no meaning
whereas it breaks register address in SPI communication

Fixes: e039e2f5b4da (iio:st_pressure:initial lps22hb sensor support)
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: st_pressure: st_accel: Initialise sensor platform data properly

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>

iio: st_pressure: initialize lps22hb bootime

This patch initializes the bootime in struct st_sensor_settings for
lps22hb sensor. Without this, sensor channels read from sysfs always
report stale values.

Signed-off-by: Shrirang Bagul <shrirang.bagul@canonical.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: st_pressure: Export sampling frequency for lps25h and lps331ap

Both devices are using the same iio_chan_spec to define which settings
are exported with sysfs. Both are properly configured to set/get
sampling frequency for pressure and temperature. They also properly
export available sampling frequencies. The only missing thing is
sampling_frequency sysfs file, which allows to set/get this property
from userspace.

Add sampling frequency to iio channel info mask, so sampling_frequency
file is properly exported using sysfs.

Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: st_pressure: Fix data sign

Datasheet of each device (lps331ap, lps25h, lps001wp, lps22hb) says that
the pressure and temperature data is a 2's complement.

I'm sending this the slow way, as negative pressures on these are pretty
unusual and the nature of the fixing of multiple device introduction patches
will make it hard to apply to older kernels - Jonathan.

Fixes: 217494e5b780 ("iio:pressure: Add STMicroelectronics pressures driver")
Fixes: 2f5effcbd097 ("iio: pressure-core: st: Expand and rename LPS331AP's channel descriptor")
Fixes: 7885a8ce6800 ("iio: pressure: st: Add support for new LPS001WP pressure sensor")
Fixes: e039e2f5b4da ("iio:st_pressure:initial lps22hb sensor support")
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: pressure: st_pressure: inline per-sensor data

We have #defines for all the individual sensor registers and
value/mask pairs #defined at the top of the file and used at
exactly one spot.

This is usually good if the #defines give a meaning to the
opaque magic numbers.

However in this case, the semantic meaning is inherent in the
name of the C99-addressable fields, and that means duplication
of information, and only makes the code hard to maintain since
you every time have to add a new #define AND update the site
where it is to be used.

Get rid of the #defines and just open code the values into the
appropriate struct elements. Make sure to explicitly address
the .hz and .value fields in the st_sensor_odr_avl struct
so that the meaning of all values is clear.

This patch is purely syntactic should have no semantic effect.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:st_pressure: clean useless static channel initializers

Some static channels are explicitly initialized with default values.
Remove them to enhance readability.

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:st_pressure:lps22hb: temperature support

Implement lps22hb temperature sampling channel.

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:st_pressure:lps22hb: open drain support

Add support for open drain interrupt line.

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:st_pressure: temperature triggered buffering

Enable support for triggered buffering of temperature samples.

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:st_pressure: document sampling gains

Details scaling factors and offsets applied to raw temperature and pressure
samples.

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:st_pressure: align storagebits on power of 2

Sampled pressure data are 24 bits long and should be stored in a 32 bits
word.

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: st_sensors: switch to a threaded interrupt

commit 98ad8b41f58dff6b30713d7f09ae3834b8df7ded
("iio: st_sensors: verify interrupt event to status") caused
a regression when reading ST sensors from a HRTimer trigger
rather than the intrinsic interrupts: the HRTimer may
trigger faster than the sensor provides new values, and
as the check against new values available as a cause of
the interrupt trigger was done in the poll function,
this would bail out of the HRTimer interrupt with
IRQ_NONE.

So clearly we need to only check the new values available
from the proper interrupt handler and not from the poll
function, which should rather just read the raw values
from the registers, put them into the buffer and be happy.

To achieve this: switch the ST Sensors over to using a true
threaded interrupt handler.

In the interrupt thread, check if new values are available,
else yield to the (potential) next device on the same
interrupt line to check the registers. If the interrupt
was ours, proceed to poll the values.

Instead of relying on iio_trigger_generic_data_rdy_poll() as
a top half to wake up the thread that polls the sensor for
new data, have the thread call iio_trigger_poll_chained()
after determining that is is the proper source of the
interrupt. This is modelled on drivers/iio/accel/mma8452.c
which is already using a properly threaded interrupt handler.

In order to get the same precision in timestamps as
previously, where samples would be timestamped in the
poll function pf->timestamp when calling
iio_trigger_generic_data_rdy_poll() we introduce a
local timestamp in the sensor data, set it in the top half
(fastpath) of the interrupt handler and provide that to the
core when calling iio_push_to_buffers_with_timestamp().

Additionally: if the active scanmask is not set for the
sensor no IRQs should be enabled and we need to bail out
with IRQ_NONE. This can happen if spurious IRQs fire when
installing the threaded interrupt handler.

Tested with hard interrupt triggers on LIS331DL, then also
tested with hrtimers on the same sensor by creating a 75Hz
HRTimer and using it to poll the sensor.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Giuseppe Barba <giuseppe.barba@st.com>
Cc: Denis Ciocca <denis.ciocca@st.com>
Reported-by: Crestez Dan Leonard <cdleonard@gmail.com>
Tested-by: Crestez Dan Leonard <cdleonard@gmail.com>
Tested-by: Jonathan Cameron <jic23@kernel.org>
Fixes: 97865fe41322 ("iio: st_sensors: verify interrupt event to status")
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:st_sensors: fix power regulator usage

Ensure failure to enable power regulators is properly handled.

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:st_pressure: fix sampling gains (bring inline with ABI)

Temperature channels report scaled samples in Celsius although expected as
milli degree Celsius in Documentation/ABI/testing/sysfs-bus-iio.
Gains are not implemented at all for LPS001WP pressure and temperature
channels.

This patch ensures that proper offsets and scales are exposed to userpace
for both pressure and temperature channels.
Also fix a NULL pointer exception when userspace reads content of sysfs
scale attribute when gains are not defined.

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:st_pressure:initial lps22hb sensor support

Initial support for ST LPS22HB pressure sensor. Datasheet:
http://www2.st.com/resource/en/datasheet/lps22hb.pdf

Features:
* pressure data and timestamping channels
* sampling frequency selection
* interrupt based trigger
* over I2C or SPI

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: st_sensors: support open drain mode

Some types of ST Sensors can be connected to the same IRQ line
as other peripherals using open drain. Add a device tree binding
and a sensor data property to flip the right bit in the interrupt
control register to enable open drain mode on the INT line.

If the line is set to be open drain, also tag on IRQF_SHARED
to the IRQ flags when requesting the interrupt, as the whole
point of using open drain interrupt lines is to share them with
more than one peripheral (wire-or).

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

iio: st_sensors: verify interrupt event to status

This makes all ST sensor drivers check that they actually have
new data available for the requested channel(s) before claiming
an IRQ, by reading the status register (which is conveniently
the same for all ST sensors) and check that the channel has new
data before proceeding to read it and fill the buffer.

This way sensors can share an interrupt line: it can be flaged
as shared and then the sensor that did not fire will return
NO_IRQ, and the sensor that fired will handle the IRQ and
return IRQ_HANDLED.

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>

iio: st_sensors: support active-low interrupts

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>

iio: st_sensors: add debugfs register read hook

This adds a debugfs hook to read/write registers in the ST
sensors using debugfs. Proved to be awesome help when trying
to debug why IRQs do not arrive.

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

iio: st-sensors: add configuration for WhoAmI address

This patch permits to configure the WhoAmI register address
because some device could have not a standard address for
this register.

Signed-off-by: Giuseppe Barba <giuseppe.barba@st.com>
Reviewed-by: Denis Ciocca <denis.ciocca@st.com>
Acked-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:st_sensors: Fix oops when probing SPI devices

In SPI mode the transfer buffer is locked with a mutex. However this
mutex is only initilized after the probe, but some transfer needs to
be done in the probe.

To fix this bug we move the mutex initialization at the beginning of
the device probe.

Signed-off-by: Alban Bedel <alban.bedel@avionic-design.de>
Acked-by: Denis Ciocca <denis.ciocca@st.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:pressure: Changed pressure data variable name to press_data

This patch fix pressure data variable name. Usually pdata name
it is used for platform data.

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:pressure: Removed unnecessary parameter on common_probe function

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:imu: changed structure name from st_sensors to st_sensor_settings

This patch change structure name and related variables names.

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:st sensors: remove custom sampling frequence attribute in favour of core support.

This allows in kernel client drivers to access this

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Cc: Denis Ciocca <denis.ciocca@st.com>
Reviewed-by: Hartmut Knaack <knaack.h@gmx.de>

iio: st_sensors: move regulator retrieveal to core

Currently the pressure sensor has code to retrieve and enable two
regulators for Vdd and Vdd IO, but actually these voltage inputs
are found on all of these ST sensors, so move the regulator
handling to the core and make sure all the ST sensors call these
functions on probe() and remove() to enable/disable power.

Here also mover over to obtaining the regulator from the *parent*
device of the IIO device, as the IIO device is created on-the-fly
in this very subsystem it very unlikely evert have any regulators
attached to it whatsoever. It is much more likely that the parent
is a platform device, possibly instantiated from a device tree,
which in turn have Vdd and Vdd IO supplied assigned to it.

Cc: Lee Jones <lee.jones@linaro.org>
Cc: Denis CIOCCA <denis.ciocca@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: st_sensors: announce registered sensors

It is pretty helpful to know already from dmesg that a certain
device is successfully registered, instead of having to browse
sysfs to see if it's actually there.

Cc: Lee Jones <lee.jones@linaro.org>
Cc: Denis CIOCCA <denis.ciocca@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:pressure: Add support for LPS25H pressure sensor

This patch adds support for the new barometer sensor: LPS25H.

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: pressure-core: st: Provide support for the Vdd_IO power supply

The power to some of the sensors are controlled by regulators. In most
cases these are 'always on', but if not they will fail to work until
the regulator is enabled using the relevant APIs. This patch allows for
the Vdd_IO power supply to be specified by either platform data or
Device Tree.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: pressure-core: st: Provide support for the Vdd power supply

The power to some of the sensors are controlled by regulators. In most
cases these are 'always on', but if not they will fail to work until
the regulator is enabled using the relevant APIs. This patch allows for
the Vdd power supply to be specified by either platform data or Device
Tree.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:press: Register buffer also without specific trigger

This patch fix buffer registration that allows to use generic IIO trigger.

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: pressure: st: Add support for new LPS001WP pressure sensor

Here we use existing practices to introduce support for another
pressure/temperature sensor, the LPS001WP.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: pressure-core: st: Clean-up probe() function

This patch contains some pretty basic clean-ups in probe() pertaining to
the simplification of error handling and a couple of readability adaptions.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: sensors-core: st: Support sensors which don't have a Data Ready pin

Not all ST's sensors support data ready, so let's make the declaration
of one conditional.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: pressure-core: st: Allow for number of channels to vary

At the moment the number of channels specified is dictated by the first
sensor supported by the driver. As we add support for more sensors this
is likely to vary. Instead of using the ARRAY_SIZE() of the LPS331AP's
channel specifier we'll use a new adaptable 'struct st_sensors' element
instead.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: pressure-core: st: Expand and rename LPS331AP's channel descriptor

Due to the MACRO used, the task of reading, understanding and maintaining
the LPS331AP's channel descriptor is substantially difficult. This patch
is based on the view that it's better to have easy to read, maintainable
code than to save a few lines here and there. For that reason we're
expanding the array so initialisation is completed in full.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: pressure-core: st: Describe LPS331AP defines by name

They're currently named *_1_*, for 'Sensor 1', but the code will be much
more readable if we use the naming convention *_LPS331AP_* instead.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: sensors-core: st: Allow full-scale to be an optional feature

Some chips either don't support it or fail to provide adequate documentation,
so sometimes it's impossible to enable the feature even if it is supported.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: pressure: st_pressure: Use devm_iio_device_alloc

Using devm_iio_device_alloc makes code simpler.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: lps331ap: Modify in_temp_scale calculation way

This patch modifies the way how the in_temp_scale output value is
calculated. With this implementation it is more clear how the value
is obtained.

Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: Added ST-sensors platform data to select the DRDY interrupt pin

This patch add support to redirect the DRDY interrupt on INT1 or INT2
on accelerometer and pressure sensors.

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: lps331ap: Fix wrong in_pressure_scale output value

This patch fixes improper in_pressure_scale output that is
returned by the lps331ap barometer sensor driver. According
to the documentation the pressure after applying the scale has to
be expressed in kilopascal units. With erroneous implementation
the scale value larger by two orders of magnitude is returned -
2441410 instead of 24414.

Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:pressure: Add STMicroelectronics pressures driver

This patch adds a generic pressure driver for STMicroelectronics
pressure sensors, currently it supports: LPS331AP.

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>