iio: pressure: ms5611: ms5611_prom_is_valid false negative bug

The ms5611 driver falsely rejects lots of MS5607-02BA03-50 chips
with "PROM integrity check failed" because it doesn't accept a prom crc
value of zero as legitimate.

According to the datasheet for this chip (and the manufacturer's
application note about the PROM CRC), none of the possible values for the
CRC are excluded - but the current code in ms5611_prom_is_valid() ends with

return crc_orig != 0x0000 && crc == crc_orig

Discussed with the driver author (Tomasz Duszynski) and he indicated that
at that time (2015) he was dealing with some faulty chip samples which
returned blank data under some circumstances and/or followed example code
which indicated CRC zero being bad.

As far as I can tell this exception should not be applied anymore; We've
got a few hundred custom boards here with this chip where large numbers
of the prom have a legitimate CRC value 0, and do work fine, but which the
current driver code wrongly rejects.

Signed-off-by: Alexander Zangerl <az@breathe-safe.com>
Fixes: c0644160a8b5 ("iio: pressure: add support for MS5611 pressure and temperature sensor")
Link: https://lore.kernel.org/r/2535-1695168070.831792@Ze3y.dhYT.s3fx
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: pressure: ms5611: Switch to fully devm_ managed registration.

All the remaining calls in probe() have devm_ equivalents so
switching to those allows the remove() callbacks to be deleted.
No functional change.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Tomasz Duszynski <tduszyns@gmail.com>
Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>
Link: https://lore.kernel.org/r/20221016163409.320197-15-jic23@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: pressure: ms5611: Use devm_regulator_get_enable()

This driver only turns the power on at probe and off at remove.
The new devm_regulator_get_enable() replaces this boilerplate code.
Some additional refactoring to drop now unnecessary unwinding after
this change.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Tomasz Duszynski <tduszyns@gmail.com>
Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>
Link: https://lore.kernel.org/r/20221016163409.320197-14-jic23@kernel.org

iio: pressure: ms5611: fixed value compensation bug

When using multiple instances of this driver the compensation PROM was
overwritten by the last initialized sensor. Now each sensor has own PROM
storage.

Signed-off-by: Mitja Spes <mitja@lxnav.com>
Fixes: 9690d81a02dc ("iio: pressure: ms5611: add support for MS5607 temperature and pressure sensor")
Link: https://lore.kernel.org/r/20221021135827.1444793-2-mitja@lxnav.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:pressure:ms5611: Move exports into IIO_MS5611 namespace

In order to avoid unnecessary pollution of the global symbol namespace
move the common/library functions into a specific namespace and import
that into the bus specific device drivers that use them.

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

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Tomasz Duszynski <tduszyns@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220130205701.334592-11-jic23@kernel.org

iio: ms5611: Simplify IO callback parameters

The ms5611 passes &indio_dev->dev as a parameter to all its IO callbacks
only to directly cast the struct device back to struct iio_dev. And the
struct iio_dev is then only used to get the drivers state struct.

Simplify this a bit by passing the state struct directly. This makes it a
bit easier to follow what the code is doing.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20211020142110.7060-1-lars@metafoo.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: pressure: ms5611: Make ms5611_remove() return void

Up to now ms5611_remove() returns zero unconditionally. Make it return
void instead which makes it easier to see in the callers that there is
no error to handle.

Also the return value of i2c and spi remove callbacks is ignored anyway.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20211013203223.2694577-16-u.kleine-koenig@pengutronix.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:pressure:ms5611 Fix buffer element alignment

One of a class of bugs pointed out by Lars in a recent review.
iio_push_to_buffers_with_timestamp assumes the buffer used is aligned
to the size of the timestamp (8 bytes). This is not guaranteed in
this driver which uses an array of smaller elements on the stack.
Here there is no data leak possibility so use an explicit structure
on the stack to ensure alignment and nice readable fashion.

The forced alignment of ts isn't strictly necessary in this driver
as the padding will be correct anyway (there isn't any). However
it is probably less fragile to have it there and it acts as
documentation of the requirement.

Fixes: 713bbb4efb9dc ("iio: pressure: ms5611: Add triggered buffer support")
Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Tomasz Duszynski <tomasz.duszynski@octakon.com>
Cc: <Stable@vger.kernel.org>

iio: remove left-over parent assignments

These were found by doing some shell magic:
------------
for file in $(git grep -w devm_iio_device_alloc | cut -d: -f1 | sort | uniq) ; do
if grep 'parent =' $file | grep -v trig | grep -vq devm_; then
echo "$file -> $(grep "parent =" $file)"
fi
done
-----------

The output is bearable [after the semantic patch is applied].
There is a mix of trigger assignments with some iio device parent
assignments that are removed via this patch.

JC: A few more added via inspection of all parent =
statements in drivers/iio. Some of these may just have crossed with this
series, others were less obvious to scripting due to some cross
file / module boundary calls.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: pressure: ms5611: switch to SPDX identifier

Drop boilerplate license text and use SPDX identifier instead.

Signed-off-by: Tomasz Duszynski <tduszyns@gmail.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: ms5611: claim direct mode during oversampling changes

Driver was checking for direct mode before changing oversampling
ratios, but was not locking it. Use the claim/release helper
functions to guarantee the device stays in direct mode while the
oversampling ratios are being updated. Continue to use the drivers
private state lock to protect against conflicting direct mode access
of the state data.

Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: ms65611_core: Fixes dereferencing regulator pointer

Change in handling of the regulator description means that static
checkers correctly assume we could be using dereferenced pointer to the
regulator. In reality we will never get the -ENODEV error, as current
behavior flow does not predict it, because:
If the device tree or board file does not define suitable regulators for
the component, it will be substituted by a dummy regulator, or, if
regulators are disabled altogether, by stubs.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Suggested-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Crt Mori <cmo@melexis.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: fetch and enable regulators unconditionally

This patch is inspired by a comment of Jonathan Cameron on patch of
Linus Walleij commit aeb55fff3891834e07a3144159a7298a19696af8 ("iio: st_sensors: fetch and enable regulators unconditionally").

The explanation for this change is same as in that patch:
"Supplies are *not* optional (optional means that the supply is
optional in the electrical sense, not the software sense) so we need to
get the and enable them at all times.

If the device tree or board file does not define suitable regulators for
the component, it will be substituted by a dummy regulator, or, if
regulators are disabled altogether, by stubs. There is no need to use the
IS_ERR_OR_NULL() check that is considered harmful.

Reported-by: Linus Wallerij <linus.walleij@linaro.org>
Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Crt Mori <cmo@melexis.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:core: timestamping clock selection support

Adds a new per-device sysfs attribute "current_timestamp_clock" to allow
userspace to select a particular POSIX clock for buffered samples and
events timestamping.

Following clocks, as listed in clock_gettime(2), are supported:
CLOCK_REALTIME, CLOCK_MONOTONIC, CLOCK_MONOTONIC_RAW,
CLOCK_REALTIME_COARSE, CLOCK_MONOTONIC_COARSE, CLOCK_BOOTTIME and
CLOCK_TAI.

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

iio: pressure: ms5611: use tab for indention

This fixes the errors reported by checkpatch.pl:

ERROR: code indent should use tabs where possible

Signed-off-by: Slawomir Stepien <sst@poczta.fm>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:pressure:ms5611: fix missing regulator_disable

Ensure optional regulator is properly disabled when present.

Fixes: 3145229f9191 ("iio:pressure:ms5611: power regulator support")
Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:pressure:ms5611: oversampling rate support

Add support for setting and retrieving OverSampling Rate independently for
each of the temperature and pressure channels. This allows userspace to
fine tune hardware sampling process according to the following tradeoffs :
* the higher the OSR, the finer the resolution ;
* the higher the OSR, the lower the noise ;
BUT:
* the higher the OSR, the larger the drift ;
* the higher the OSR, the longer the response time, i.e. less samples per
unit of time.

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

iio:pressure:ms5611: power regulator support

Add support for an optional regulator which, if found into device-tree,
will power on device at probing time.
The regulator is declared into ms5611 DTS entry as a "vdd-supply" property.

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

iio:pressure:ms5611: use probed device name

Use name of probed device instead of driver's one when registering device.

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

iio:pressure:ms5611: fix ms5607 temp compensation

Computation of sens2 was wrong and is fixed by this patch, sens2 should be:
2 * (t - 2000)^2
See page 8 of ms5607 datasheet here:
http://www.meas-spec.com/product/pressure/MS5607-02BA03.aspx

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Acked-by: Lucas De Marchi <lucas.demarchi@intel.com>
Acked-by: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: pressure: ms5611: Add triggered buffer support

This will be used together with an external trigger (e.g hrtimer
based software trigger).

Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: pressure: ms5611: Add IIO_CHAN_INFO_SCALE to mask

This allows data exported via buffer interface to be converted
to standard units in userspace.

Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: pressure: ms5611: add support for MS5607 temperature and pressure sensor

MS5607 is temperature and pressure sensor which hardware is similar to MS5611.
Both sensors share command protocol and support both I2C and SPI serial
protocols. They only differ in compensation algorithms.

Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: pressure: ms5611: remove IIO_CHAN_INFO_SCALE from mask

IIO_CHAN_INFO_SCALE is useful whenever conversion to standard units is done
in userspace. In this case conversion is handled by driver so this bit
is unnecessary.

Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: pressure: add support for MS5611 pressure and temperature sensor

Add support for Measurement Specialities MS5611 pressure
and temperature sensor.

Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>