iio: adc: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20230714174628.4057920-1-robh@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ina2xx: avoid NULL pointer dereference on OF device match

The affected lines were resulting in a NULL pointer dereference on our
platform because the device tree contained the following list of
compatible strings:

power-sensor@40 {
compatible = "ti,ina232", "ti,ina231";
...
};

Since the driver doesn't declare a compatible string "ti,ina232", the OF
matching succeeds on "ti,ina231". But the I2C device ID info is
populated via the first compatible string, cf. modalias population in
of_i2c_get_board_info(). Since there is no "ina232" entry in the legacy
I2C device ID table either, the struct i2c_device_id *id pointer in the
probe function is NULL.

Fix this by using the already populated type variable instead, which
points to the proper driver data. Since the name is also wanted, add a
generic one to the ina2xx_config table.

Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Fixes: c43a102e67db ("iio: ina2xx: add support for TI INA2xx Power Monitors")
Link: https://lore.kernel.org/r/20230619141239.2257392-1-alvin@pqrs.dk
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Switch i2c drivers back to use .probe()

After commit b8a1a4cd5a98 ("i2c: Provide a temporary .probe_new()
call-back type"), all drivers being converted to .probe_new() and then
03c835f498b5 ("i2c: Switch .probe() to not take an id parameter") convert
back to (the new) .probe() to be able to eventually drop .probe_new() from
struct i2c_driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230515205048.19561-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ina2xx-adc: Convert to i2c's .probe_new()

.probe_new() doesn't get the i2c_device_id * parameter, so determine
that explicitly in the probe function.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20221118224540.619276-63-uwe@kleine-koenig.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

i2c: Make remove callback return void

The value returned by an i2c driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Reviewed-by: Peter Senna Tschudin <peter.senna@gmail.com>
Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: Benjamin Mugnier <benjamin.mugnier@foss.st.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Crt Mori <cmo@melexis.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Behún <kabel@kernel.org> # for leds-turris-omnia
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Machata <petrm@nvidia.com> # for mlxsw
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> # for surface3_power
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> # for bmc150-accel-i2c + kxcjk-1013
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # for media/* + staging/media/*
Acked-by: Miguel Ojeda <ojeda@kernel.org> # for auxdisplay/ht16k33 + auxdisplay/lcd2s
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # for versaclock5
Reviewed-by: Ajay Gupta <ajayg@nvidia.com> # for ucsi_ccg
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for iio
Acked-by: Peter Rosin <peda@axentia.se> # for i2c-mux-*, max9860
Acked-by: Adrien Grassein <adrien.grassein@gmail.com> # for lontium-lt8912b
Reviewed-by: Jean Delvare <jdelvare@suse.de> # for hwmon, i2c-core and i2c/muxes
Acked-by: Corey Minyard <cminyard@mvista.com> # for IPMI
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> # for drivers/power
Acked-by: Krzysztof Hałasa <khalasa@piap.pl>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

iio:adc:ina2xx: Improve error reporting for problems during .remove()

Returning an error value in an i2c remove callback results in a generic
error message being emitted by the i2c core, but otherwise it doesn't
make a difference. The device goes away anyhow and the devm cleanups are
called.

So instead of triggering the generic i2c error message, emit a more
helpful message if a problem occurs and return 0 to suppress the generic
message.

This patch is a preparation for making i2c remove callbacks return void.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20220515155929.338656-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Replace strtobool() with kstrtobool()

strtobool() is deprecated and just a wrapper around kstrtobool().Replace
it with kstrtobool() so the deprecated function can be removed eventually.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220409105812.2113895-1-lars@metafoo.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core: Simplify the registration of kfifo buffers

Among all the users of the kfifo buffers, no one uses the
INDIO_BUFFER_HARDWARE mode. So let's take this as a general rule and
simplify a little bit the internals - overall the documentation - by
eliminating unused specific cases. Use the INDIO_BUFFER_SOFTWARE mode by
default with kfifo buffers, which will basically mimic what all the "non
direct" modes do.

Cc: Benson Leung <bleung@chromium.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Jyoti Bhayana <jbhayana@google.com>
Cc: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Cc: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Cc: Michael Hennerich <Michael.Hennerich@analog.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20220207143840.707510-13-miquel.raynal@bootlin.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: ina2xx-adc: sysfs_emit()

sysfs_emit() is preferred over raw s*printf() for sysfs attributes since it
knows about the sysfs buffer specifics and has some built-in checks for
size and alignment.

Use sysfs_emit() to format the custom `in_allow_async_readout` device
attribute of the ina2xx-adc driver.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20211216185217.1054495-7-lars@metafoo.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:adc:ina2xx-adc: Suppress clang W=1 warning about pointer to enum conversion.

Cast to a uintptr_t rather than directly to the enum.

As per the discussion in below linked media patch.

Link: https://lore.kernel.org/linux-media/CAK8P3a2ez6nEw4d+Mqa3XXAz0RFTZHunqqRj6sCt7Y_Eqqs0rw@mail.gmail.com/
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20211128172445.2616166-3-jic23@kernel.org

iio: in2xx-adc: Remove unnecessary cast

`buf` is cast to a const char *, but `buf` is already a const char *, so
the case is unnecessary.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ina2xx: Avoid double reference counting from get_task_struct/put_task_struct()

kthread_run() and kthread_stop() already do reference
counting of the task, so remove get_task_struct/put_task_struct()
to avoid double reference counting.

Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Link: https://lore.kernel.org/r/20211021124254.3247-2-caihuoqing@baidu.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ina2xx: Make use of the helper macro kthread_run()

Repalce kthread_create/wake_up_process() with kthread_run()
to simplify the code.

Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Link: https://lore.kernel.org/r/20211021124254.3247-1-caihuoqing@baidu.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core: move @id from struct iio_dev to struct iio_dev_opaque

Continuing from Alexandru Ardelean's introduction of the split between
driver modifiable fields and those that should only be set by the core.

This could have been done in two steps to make the actual move after
introducing iio_device_id() but there seemed limited point to that
given how mechanical the majority of the patch is.

Includes fixup from Alex for missing mxs-lradc-adc conversion.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20210426174911.397061-2-jic23@kernel.org

iio: make use of devm_iio_kfifo_buffer_setup() helper

All drivers that already call devm_iio_kfifo_allocate() &
iio_device_attach_buffer() are simple to convert to
iio_device_attach_kfifo_buffer() in a single go.

This change does that; the unwind order is preserved.
What is important, is that the devm_iio_kfifo_buffer_setup() be called
after the indio_dev->modes is assigned, to make sure that
INDIO_BUFFER_SOFTWARE flag is set and not overridden by the assignment to
indio_dev->modes.

Also, the INDIO_BUFFER_SOFTWARE has been removed from the assignments of
'indio_dev->modes' because it is set by devm_iio_kfifo_buffer_setup().

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Matt Ranostay <matt.ranostay@konsulko.com>x
Link: https://lore.kernel.org/r/20210215104043.91251-4-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:adc:ina2xx Fix timestamp alignment issue.

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 a 32 byte array of smaller elements on the stack.
As Lars also noted this anti pattern can involve a leak of data to
userspace and that indeed can happen here. We close both issues by
moving to a suitable structure in the iio_priv() data with alignment
explicitly requested. This data is allocated with kzalloc so no
data can leak apart from previous readings. The explicit alignment
isn't technically needed here, but it reduced fragility and avoids
cut and paste into drivers where it will be needed.

If we want this in older stables will need manual backport due to
driver reworks.

Fixes: c43a102e67db ("iio: ina2xx: add support for TI INA2xx Power Monitors")
Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Cc: Marc Titinger <mtitinger@baylibre.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: <Stable@vger.kernel.org>

Replace HTTP links with HTTPS ones: drivers/iio

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Remove superfluous of_node assignments

If a driver does not assign an of_node to a IIO device to IIO core will
automatically assign the of_node of the parent device. This automatic
assignment is done in the iio_device_register() function.

There is a fair amount of drivers that currently manually assign the
of_node of the IIO device. All but 4 of them can make use of the automatic
assignment though.

The exceptions are:
* mxs-lradc-adc: Which uses the of_node of the parent of the parent.
* stm32-dfsdm-adc, stm32-adc and stm32-dac: Which reference the of_node
assigned to the IIO device before iio_device_register() is called.

All other drivers are updated to use automatic assignment. This reduces
the amount of boilerplate code involved in setting up the IIO device.

The patch has mostly been auto-generated with the following semantic patch

// <smpl>
@exists@
expression indio_dev;
expression parent;
@@
indio_dev = \(devm_iio_device_alloc\|iio_device_alloc\)(&parent, ...)
...
-indio_dev->dev.of_node = parent.of_node;

@exists@
expression indio_dev;
expression parent;
@@
indio_dev = \(devm_iio_device_alloc\|iio_device_alloc\)(parent, ...)
...
-indio_dev->dev.of_node = parent->of_node;
// </smpl>

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: remove explicit IIO device parent assignment

This patch applies the semantic patch:
@@
expression I, P, SP;
@@
I = devm_iio_device_alloc(P, SP);
...
- I->dev.parent = P;

It updates 302 files and does 307 deletions.
This semantic patch also removes some comments like
'/* Establish that the iio_dev is a child of the i2c device */'

But this is is only done in case where the block is left empty.

The patch does not seem to cover all cases. It looks like in some cases a
different variable is used in some cases to assign the parent, but it
points to the same reference.
In other cases, the block covered by ... may be just too big to be covered
by the semantic patch.

However, this looks pretty good as well, as it does cover a big bulk of the
drivers that should remove the parent assignment.

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

iio: adc: ina2xx: add in early -EINVAL returns in case statements

Static analysis with CoverityScan is throwing warnings that specific
case statements are missing breaks. Rather than adding breaks, add
return -EINVAL to the specific case statements to clarify the
error return paths. Fix also saves 50 bytes.

Before:
text data bss dec hex filename
21418 4936 128 26482 6772 drivers/iio/adc/ina2xx-adc.o

After:
dec hex filename
21370 4936 128 26434 6742 drivers/iio/adc/ina2xx-adc.o

(gcc 8.2, x86-64)

Detected by CoverityScan, CID#1462408 ("Missing break in switch")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ina2xx: avoid kthread_stop() with stale task_struct

When the buffer is enabled for ina2xx driver, a dedicated kthread is
invoked to capture mesurement data. When the buffer is disabled, the
kthread is stopped.

However if the kthread gets register access errors, it immediately exits
and when the malfunctional buffer is disabled, the stale task_struct
pointer is accessed as there is no kthread to be stopped.

A similar issue in the usbip driver is prevented by kthread_get_run and
kthread_stop_put helpers by increasing usage count of the task_struct.
This change applies the same solution.

Cc: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Cc: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Fixes: c43a102e67db ("iio: ina2xx: add support for TI INA2xx Power Monitors")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ina2xx: Actually align the loop with the conversion ready flag

Currently, the registers are read out once per conversion interval. If
the reading is delayed as the conversion has not yet finished, this extra
time is treated as being part of the readout, although it should delay
the start of the poll interval. This results in the interval starting
slightly earlier in each iteration, until all time between reads is
spent polling the status registers instead of sleeping.

To fix this, the delay has to account for the state of the conversion
ready flag. Whenever the conversion is already finished, schedule the next
read on the regular interval, otherwise schedule it one interval after the
flag bit has been set.

Split the work function in two functions, one for the status poll and one
for reading the values, to be able to note down the time when the flag
bit is raised.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio: adc: ina2xx: Align timestamp with conversion ready flag

As the timestamp is no longer (ab-)used to measure the function run time,
it can be taken at the correct time, i.e. when the conversion has finished.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio: adc: ina2xx: Use a monotonic clock for delay calculation

The iio timestamp clock is user selectable and may be non-monotonic. Also,
only part of the acquisition time is measured, thus the delay was longer
than intended.

Use a monotonic timestamp to track the time for the next poll iteration.
The timestamp is advanced by the sampling interval each iteration. In case
the conversion overrruns the register readout (i.e. fast sampling combined
with a slow bus), one or multiple samples will be dropped.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio: adc: ina2xx: Make calibration register value fixed

Calibration register is used for calculating current register in
hardware according to datasheet:
current = shunt_volt * calib_register / 2048 (ina 226)
current = shunt_volt * calib_register / 4096 (ina 219)

Fix calib_register value to 2048 for ina226 and 4096 for ina 219 in
order to avoid truncation error and provide best precision allowed
by shunt_voltage measurement. Make current scale value follow changes
of shunt_resistor from sysfs as calib_register value is now fixed.

Power_lsb value should also follow shunt_resistor changes as stated in
datasheet:
power_lsb = 25 * current_lsb (ina 226)
power_lsb = 20 * current_lsb (ina 219)

This is a part of the patchset: https://lkml.org/lkml/2017/11/22/394

Signed-off-by: Maciej Purski <m.purski@samsung.com>
Reviewed-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio: adc: ina2xx: Do not udelay for several seconds

The conversion time can be up to 16 seconds (8 ms per channel, 2 channels,
1024 times averaging).

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio: adc: ina2xx: Remove unneeded dummy read to clear CNVR flag

Although the datasheet states the CNVR flag is cleared by reading the
BUS_VOLTAGE register, it is actually cleared by reading any of the
voltage/current/power registers.

The behaviour has been confirmed by TI support:
http://e2e.ti.com/support/amplifiers/current-shunt-monitors/f/931/p/647053/2378282

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio: adc: ina2xx: Clarify size requirement for data buffer

The timestamp is inserted into the buffer after the sample data by
iio_push_to_buffers_with_timestamp, document the space requirement for
the timestamp.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio: adc: ina2xx: Remove bogus cast for data argument

iio_push_to_buffers_with_timestamp expects a void pointer, so the cast
is both unnecessary and misleading.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio: adc: ina2xx: Allow setting Shunt Voltage PGA gain and Bus Voltage range

Reducing shunt and bus voltage range improves the accuracy, so allow
altering the default settings.

Both settings are exposed as gain values. While for the shunt voltage
this is straightforward, the bus range settings of 32V (default) and 16V
are mapped to gain values of 1 resp. 2, to provide a uniform API to
userspace.

As the gain settings are incorporated into the raw values by the sensor
itself, adjusting of the scale attributes is not necessary.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ina2xx: Use LSB specifier instead of divider in config

While the config uses the physical value corresponding to the LSB
for both the power and the bus voltage register, the shunt voltage is
specified as parts of 1 mV. Use the LSB physical value for all registers.

No functional change.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ina2xx: Shift bus voltage register to mask flag bits

Lower bits of the INA219/220 bus voltage register are conversion
status flags, properly shift the value.

When reading via IIO buffer, the value is passed on unaltered,
shifting is the responsibility of the user.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ina2xx: Adhere to documented ABI, use Ohm instead of uOhm

According to the ABI documentation, the shunt resistor value should be
specificied in Ohm. As this is also used/documented for the MAX9611,
use the same for the INA2xx driver.

This poses an ABI break for anyone actually altering the shunt value
through the sysfs interface, it does not alter the default value nor
a value set from the devicetree.

Minor change: Fix comment, 1mA is 10^-3A.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:adc: 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: adc: ina219: Avoid underflow for sleeping time

Proper support for the INA219 lowered the minimum sampling period from
2*140us to 2*84us. Subtracting 200us later leads to an underflow and
an almost infinite udelay later.

Using a signed int for the sampling period provides sufficient range
(at most 2*8640*1024us), but catches the underflow when comparing with
buffer_us.

Fixes: 18edac2e22f4 ("iio: adc: Fix integration time/averaging for INA219/220")
Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: Fix polling of INA219 conversion ready flag

While the INA226 has a conversion ready flag (CVRF) in the R/W Mask/Enable
register with read-to-clear semantics, the corresponding bit of the INA219
(CNVR) is part of the bus voltage register. The flag is cleared by reading
the power register.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: adc: Fix integration time/averaging for INA219/220

INA226/230/231 has integration times per voltage channel and common
averaging setting for both channels, while the INA219/220 only has a
combined integration time/averaging setting per channel.
Only expose the averaging attribute for the INA226, and expose the correct
integration times for the INA219.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: adc: ina2xx: Make use of attribute flags consistent on all channels

Flags for shared channel attributes should be set on all channels of a
channel set. I.e. SAMP_FREQUENCY and OVERSAMPLING_RATIO are set on the
in_voltage{0,1} channels, thus should be set on in_power, in_current.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: adc: Fix bad GENMASK use, typos, whitespace

Commit 7906dd52c5a0 ("iio: ina2xx: Fix whitespace and re-order code")
changed the register number of the MASK_ENABLE register from 0x06 to the
value equivalent GENMASK(2,1), although its no mask.
Also fix a typo (INA2_6_6 instead of INA2_2_6), and use the datasheet
name ("Mask/Enable") for the register number define.
Fix bad indentation for channel attributes.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Acked-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: adc: ina2xx: Add OF device ID table

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>

iio:kfifo_buf header include push down.

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>

iio: adc: ina2xx: remove unused debug field from chip global data

commit 1961bce76452 "iio: ina2xx: Remove trace_printk debug
statements" removed the code that used the chip->prev_ns field.
This patch cleans it up further by removing the unused field
and assignments.

Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Cc: Daniel Baluta <daniel.baluta@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: adc: add missing of_node references to iio_dev

Adding missing indio_dev->dev.of_node references to allow iio consumers
to access the device channels.

Signed-off-by: Matt Ranostay <mranostay@gmail.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: ina2xx-adc: fix scale for VShunt

The scale would result in uV instead of expected mV.
Mostly cosmetic, since the value of 'Power' was computed OK.

Signed-off-by: Marc Titinger <marc.titinger@baylibre.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: ina2xx-adc: update the CALIB. register when RShunt changes

The user (or an init script) may setup RShunt via sysfs after the
driver was initialized, for instance based on the EEPROM contents
of a modular probe. The calibration register must be set accordingly.

Signed-off-by: Marc Titinger <marc.titinger@baylibre.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: ina2xx: Remove trace_printk debug statments

These are generally for devlopment use only, remove these
from performance-critical code, convert to dev_dbg elswhere.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: ina2xx: Fix whitespace and re-order code

Group of probably overly rigorous whitespace and code cleanups.
- Alphabetize includes
- Assign to variables in the order they are defined
- Alignment issues
- Group alike statements together
- Use helper macros

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: adc: ina2xx: Fix incorrect report of data endianness to userspace.

This was extracted from a reposting of the driver after it had been applied
to the IIO tree. I have fast tracked it as the driver will be in 4.5 and
it would be nice to fix this trivial issue before it is.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: ina2xx: fix channel order in software buffer

POWER and CURRENT were swapped out in the buffer:
was current2 and power3, correct order is power2 and current3.

Signed-off-by: Marc Titinger <mtitinger@baylibre.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: ina2xx: give the capture kthread a more useful name string.

PID PPID USER STAT VSZ %VSZ %CPU COMMAND
144 2 root DW 0 0% 33% [ina226:1-8800us]
141 2 root DW 0 0% 25% [ina226:0-8800us]
40 2 root SW 0 0% 15% [irq/156-4802a00]
147 2 root DW 0 0% 7% [ina226:2-8800us]
145 1 root S 1236 0% 6% dd if /dev/iio:device1 of /dev/null
148 1 root S 1236 0% 4% dd if /dev/iio:device2 of /dev/null
149 137 root R 1244 0% 3% top -d 1
142 1 root S 1236 0% 2% dd if /dev/iio:device0 of /dev/null

Signed-off-by: Marc Titinger <mtitinger@baylibre.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: ina2xx: re-instate a sysfs show/store for the shunt resistor value

Different probe modules use different resistor values. The front-end
application may read a probe ID (from eeprom) and set the shunt value
accordingly.

Signed-off-by: Marc Titinger <mtitinger@baylibre.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: ina2xx: provide a sysfs parameter to allow async readout of the ADCs

This can lead to repeated or skipped samples depending on the clock beat
between the capture thread and the chip sampling clock, but will also spare
reading/waiting for the Capture Ready Flag and improve the available i2c
bandwidth for reading measurements.

Output of iio_info:
...snip...
4 device-specific attributes found:
attr 0: in_oversampling_ratio value: 4
attr 1: in_allow_async_readout value: 0
attr 2: integration_time_available value: 140 204 332 588 1100 2116...
attr 3: in_sampling_frequency value: 114

Signed-off-by: Marc Titinger <mtitinger@baylibre.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: ina2xx: add support for TI INA2xx Power Monitors

in SOFTWARE buffer mode, a kthread will capture the active scan_elements
into a kfifo, then compute the remaining time until the next capture tick
and do an active wait (udelay).

This will produce a stream of up to fours channels plus a 64bits
timestamps (ns).

Tested with ina226, on BeagleBoneBlack.

Datasheet: http://www.ti.com/lit/gpn/ina226

Signed-off-by: Marc Titinger <mtitinger@baylibre.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>