iio: commom: st_sensors: ensure proper DMA alignment

Aligning the buffer to the L1 cache is not sufficient in some platforms
as they might have larger cacheline sizes for caches after L1 and thus,
we can't guarantee DMA safety.

That was the whole reason to introduce IIO_DMA_MINALIGN in [1]. Do the same
for st_sensors common buffer.

While at it, moved the odr_lock before buffer_data as we definitely
don't want any other data to share a cacheline with the buffer.

[1]: https://lore.kernel.org/linux-iio/20220508175712.647246-2-jic23@kernel.org/

Fixes: e031d5f558f1 ("iio:st_sensors: remove buffer allocation at each buffer enable")
Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20240131-dev_dma_safety_stm-v2-1-580c07fae51b@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: accel: st_accel: Add LSM303D

The lsm303d has the same register mapping as the lsm9ds0,
thus we can just re-use that.

Tested on a Lenovo Yoga Tablet 2 1051-F.

Signed-off-by: Marius Hoch <mail@mariushoch.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Hans de Goede <hansg@kernel.org>
Link: https://lore.kernel.org/r/20230415231130.115094-2-mail@mariushoch.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: st_sensors: core and lsm9ds0 switch to devm_regulator_bulk_get_enable()

These drivers only turns the power on at probe and off via a custom
devm_add_action_or_reset() callback. The two regulators were handled
separately so also switch to bulk registration.
The new devm_regulator_bulk_get_enable() replaces all this boilerplate
code.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20221016163409.320197-8-jic23@kernel.org

iio: st_sensors: Add a local lock for protecting odr

Right now the (framework) mlock lock is (ab)used for multiple purposes:
1- protecting concurrent accesses over the odr local cache
2- avoid changing samplig frequency whilst buffer is running

Let's start by handling situation #1 with a local lock.

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/20220207143840.707510-7-miquel.raynal@bootlin.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

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_power_disable() function

This change converts the st_sensors_power_enable() function to use
devm_add_action_or_reset() handlers to register regulator_disable hooks for
when the drivers get unloaded.

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.

This makes the st_sensors_power_disable() un-needed.
Removing this also changes unload order a bit, as all ST drivers would call
st_sensors_power_disable() first and iio_device_unregister() after that.

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/20210823112204.243255-4-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: accel: st_sensors: Support generic mounting matrix

The ST accelerators support a special type of quirky mounting matrix found
in ACPI systems, but not a generic mounting matrix such as from the device
tree.

Augment the ACPI hack to be a bit more generic and accept a mounting
matrix from device properties.

This makes it possible to fix orientation on the Ux500 HREF device.

Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Denis Ciocca <denis.ciocca@st.com>
Cc: Daniel Drake <drake@endlessm.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210518230722.522446-2-linus.walleij@linaro.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: st_sensors: Create extended attr macro

Extend ST_SENSORS_LSM_CHANNELS() to a version that will accept extended
attributes named ST_SENSORS_LSM_CHANNELS_EXT() and wrap the former as a
specialized version of the former.

Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Denis Ciocca <denis.ciocca@st.com>
Cc: Daniel Drake <drake@endlessm.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210518230722.522446-1-linus.walleij@linaro.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: st_sensors: Add lsm9ds0 IMU support

We can utilize separate drivers for accelerometer and magnetometer,
so here is the glue driver to enable LSM9DS0 IMU support.

The idea was suggested by Crestez Dan Leonard in [1]. The proposed change
was sent as RFC due to race condition concerns, which are indeed possible.

In order to amend the initial change, I went further by providing a specific
multi-instantiate probe driver that reuses existing accelerometer and
magnetometer.

[1]: https://lore.kernel.org/patchwork/patch/670353/

Suggested-by: Crestez Dan Leonard <leonard.crestez@intel.com>
Cc: mr.lahorde@laposte.net
Cc: Matija Podravec <matija_podravec@fastmail.fm>
Cc: Sergey Borishchenko <borischenko.sergey@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210414195454.84183-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: st_sensors: Make accel, gyro, magn and pressure probe shared

Some IMUs may utilize existing library code for STMicro accelerometer,
gyroscope, magnetometer and pressure. Let's share them via st_sensors.h.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210414195454.84183-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: st_sensors: Drop redundant parameter from st_sensors_of_name_probe()

Since we have access to the struct device_driver and thus to the ID table,
there is no need to supply special parameters to st_sensors_of_name_probe().

Besides that we have a common API to get driver match data, there is
no need to do matching separately for OF and ACPI.

Taking into consideration above, simplify the ST sensors code.

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

iio:st_sensors: remove buffer allocation at each buffer enable

This patch is removing the buffer allocation at each buffer enable.
We just allocate enough memory in the main structure during probe
to cover maximum size needed (that anyway is pretty small) [16bytes].

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
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:common:st_sensors: add st_sensors_get_settings_index() helper function

Extract from st_sensors_check_device_support() function the code that
is used to get the specific settings for a device. This will be used
as generic extractor by each ST driver.

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_accel: use ACPI orientation data

Platform-specific ST accelerometer mount matrix information can be
provided by returning a package of 6 integers from the ACPI _ONT
method. This has been seen on Acer products such as Veriton Z4860G,
Z6860G and A890, which include a ST SMO8840 sensor. We have also
confirmed experimentally that the Windows driver uses such information.

The _ONT data format was explained by a ST vendor contact. However,
strangely enough, the _ONT transformations must be applied after first
applying another mount matrix which we determined experimentally. ST
have not commented on why this is the case, but we imagine that perhaps
earlier devices (before _ONT was introduced) required this translation
and hence it became 'standard.'

Interpret the _ONT data and export the equivalent mount matrix to
userspace.

If no _ONT data is present, no mount matrix is exported.

Signed-off-by: Daniel Drake <drake@endlessm.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: st-accel: add support for lis3de

This commit add support for STMicroelectronics lis3de accelerometer.
Datasheet for this device can be found here:

https://www.st.com/resource/en/datasheet/lis3de.pdf

Signed-off-by: Heiko Stuebner <heiko.stuebner@bq.com>
Acked-by: Rob Herring <robh@kernel.org>
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: 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: accel: st_accel: add SPI-3wire support

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: ddc05fa28606 (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>

iio: common: st_sensors: move st_sensors_of_i2c_probe() in common code

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>

iio: accel: st_accel: fix LIS3LV02 reading and scaling

The LIS3LV02 has a special bit that need to be set to get the
read values left aligned. Before this patch we get gibberish
like this:

iio_generic_buffer -a -c10 -n lis3lv02dl_accel
(...)
0.000000 -0.010042 -0.642688 19155832931907
0.000000 -0.010042 -0.642688 19155858751073

Which is because we read a raw value for 1g as 64 which is
the nominal 1024 for 1g shifted 4 bits to the left by being
right-aligned rather than left aligned.

Since all other sensors are left aligned, add some code to
set the special DAS (data alignment setting) bit to 1 so that
the right value is now read like this:

iio_generic_buffer -a -c10 -n lis3lv02dl_accel
(...)
0.000000 -0.147095 -10.120135 24761614364956
-0.029419 -0.176514 -10.120135 24761631624540

The scaling was weird as well: we have a gain of 1000 for 1g
and 3000 for 6g. I don't even remember how I came up with the
old values but they are wrong.

Fixes: 3acddf74f807 ("iio: st-sensors: add support for lis3lv02d accelerometer")
Cc: Lorenzo Bianconi <lorenzo.bianconi@st.com>
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: harden interrupt handling

Leonard Crestez observed the following phenomenon: when using
hard interrupt triggers (the DRDY line coming out of an ST
sensor) sometimes a new value would arrive while reading the
previous value, due to latencies in the system.

We discovered that the ST hardware as far as can be observed
is designed for level interrupts: the DRDY line will be held
asserted as long as there are new values coming. The interrupt
handler should be re-entered until we're out of values to
handle from the sensor.

If interrupts were handled as occurring on the edges (usually
low-to-high) new values could appear and the line be held
asserted after that, and these values would be missed, the
interrupt handler would also lock up as new data was
available, but as no new edges occurs on the DRDY signal,
nothing happens: the edge detector only detects edges.

To counter this, do the following:

- Accept interrupt lines to be flagged as level interrupts
using IRQF_TRIGGER_HIGH and IRQF_TRIGGER_LOW. If the line
is marked like this (in the device tree node or ACPI
table or similar) it will be utilized as a level IRQ.
We mark the line with IRQF_ONESHOT and mask the IRQ
while processing a sample, then the top half will be
entered again if new values are available.

- If we are flagged as using edge interrupts with
IRQF_TRIGGER_RISING or IRQF_TRIGGER_FALLING: remove
IRQF_ONESHOT so that the interrupt line is not
masked while running the thread part of the interrupt.
This way we will never miss an interrupt, then introduce
a loop that polls the data ready registers repeatedly
until no new samples are available, then exit the
interrupt handler. This way we know no new values are
available when the interrupt handler exits and
new (edge) interrupts will be triggered when data arrives.
Take some extra care to update the timestamp in the poll
loop if this happens. The timestamp will not be 100%
perfect, but it will at least be closer to the actual
events. Usually the extra poll loop will handle the new
samples, but once in a blue moon, we get a new IRQ
while exiting the loop, before returning from the
thread IRQ bottom half with IRQ_HANDLED. On these rare
occasions, the removal of IRQF_ONESHOT means the
interrupt will immediately fire again.

- If no interrupt type is indicated from the DT/ACPI,
choose IRQF_TRIGGER_RISING as default, as this is necessary
for legacy boards.

Tested successfully on the LIS331DL and L3G4200D by setting
sampling frequency to 400Hz/800Hz and stressing the system:
extra reads in the threaded interrupt handler occurs.

Cc: Giuseppe Barba <giuseppe.barba@st.com>
Cc: Denis Ciocca <denis.ciocca@st.com>
Tested-by: Crestez Dan Leonard <cdleonard@gmail.com>
Reported-by: Crestez Dan Leonard <cdleonard@gmail.com>
Signed-off-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_sensors: unexport st_sensors_get_buffer_element

Remove st_sensors_get_buffer_element symbol export since not explicitly
used outside of st_sensors driver.

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: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: 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: 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: 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:common: Removed stuff macros, added num_data_channels on st_sensors struct and added support on one-shot sysfs reads to 3 byte channel

This patch introduce num_data_channels variable on st_sensors struct
to manage different type of channels (size or number) in
st_sensors_get_buffer_element function.
Removed ST_SENSORS_NUMBER_DATA_CHANNELS and ST_SENSORS_BYTE_FOR_CHANNEL
and used struct iio_chan_spec const *ch to catch data.
Added 3 byte channel data support on one-shot reads.

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

iio:common: ST_SENSORS_LSM_CHANNELS macro changed

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

iio:st_sensors move to info_mask_(shared_by_type/separate)

The original info_mask is going away in favour of the broken out versions.

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

iio: Fix build error seen if IIO_TRIGGER is defined but IIO_BUFFER is not

If CONFIG_IIO_TRIGGER is defined but CONFIG_IIO_BUFFER is not, the following
build error is seen.

drivers/iio/common/st_sensors/st_sensors_trigger.c:21:5: error:
redefinition of ‘st_sensors_allocate_trigger’
In file included from
drivers/iio/common/st_sensors/st_sensors_trigger.c:18:0:
include/linux/iio/common/st_sensors.h:239:19: note: previous
definition of ‘st_sensors_allocate_trigger’ was here
drivers/iio/common/st_sensors/st_sensors_trigger.c:65:6: error:
redefinition of ‘st_sensors_deallocate_trigger’
In file included from
drivers/iio/common/st_sensors/st_sensors_trigger.c:18:0:
include/linux/iio/common/st_sensors.h:244:20: note: previous
definition of ‘st_sensors_deallocate_trigger’ was here

This occurs because st_sensors_deallocate_trigger is built if CONFIG_IIO_TRIGGER
is defined, but the dummy function is compiled if CONFIG_IIO_BUFFER is defined.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:common: added allocate and deallocate trigger functions when trigger is disabled.

This patch resolve a bugfix when driver is compiled without trigger.

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

iio:common: removed unused functions outside st_sensors library

This patch remove st_sensors_get_sampling_frequency_avl and
st_sensors_get_scale_avl functions used only in
st_sensors_sysfs_sampling_frequency_avail and st_sensors_sysfs_scale_avail
sysfs functions.

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

iio:common: Add STMicroelectronics common library

This patch add a generic library for STMicroelectronics 3-axis sensors.

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>