The null check on st->chip_info->convst_channel is redundant because
convst_channel is a 2 element array of struct iio_chan_spec objects
and this can never be null. Fix this by removing the null check.

Addresses-Coverity: ("Array compared against 0")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This change is both cosmetic and a prequel to adding support for attaching
multiple buffers per IIO device.

The IIO buffer sysfs attrs are mostly designed to support only one attached
buffer, and in order to support more, we need to centralize [in each attr
function] the buffer which is being accessed.

This also makes it a bit more uniform, as in some functions there is a
short-hand 'buffer' variable and at the same time the 'indio_dev->buffer'
is still access directly.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This module is related to AD5592R, not AD5593R, so be consistent in naming.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This module is related to AD5593R, not AD5592R.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Use these functions instead of open-coding them.

Cc: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This makes the driver code slightly easier to read.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This makes the driver code slightly easier to read.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This makes the driver code slightly easier to read.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Tomasz Duszynski <tduszyns@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This makes the driver code slightly easier to read.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This makes the driver code slightly easier to read.

Cc: Song Qiang <songqiang1304521@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This makes the driver code slightly easier to read.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This makes the driver code slightly easier to read.

Cc: Maxime Roussin-Bélanger <maxime.roussinbelanger@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This makes the driver code slightly easier to read.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This makes the driver code slightly easier to read.

Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Michael Hennerich <Michael.Hennerich@analog.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This makes the driver code slightly easier to read.

Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Michael Hennerich <Michael.Hennerich@analog.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This makes the driver code slightly easier to read.

Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Michael Hennerich <Michael.Hennerich@analog.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This makes the driver code slightly easier to read.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This makes the driver code slightly easier to read.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This makes the driver code slightly easier to read.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This makes the driver code slightly easier to read.

Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Michael Hennerich <Michael.Hennerich@analog.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Noticed whilst reviewing Alexandru's patch to the same function.
If we simply flip the logic and return NULL immediately after memory
allocation failure we reduce the indent of the following block and
end up with more 'idiomatic' kernel code.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>

Add devicetree OF match table support for CCS811 VOC sensor.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

CCS811 VOC sensor exposes nRESET and nWAKE pins which can be connected
to GPIO pins of the host controller. These pins can be used to externally
release the device from reset and also to wake it up before any I2C
transaction. The initial driver support assumed that the nRESET pin is not
connected and the nWAKE pin is tied to ground.

This commit improves it by adding support for controlling those two pins
externally using a host controller. For the case of reset, if the hardware
reset is not available, the mechanism to do software reset is also added.

As a side effect of doing this, the IIO device allocation needs to be
slightly moved to top of probe to make use of priv data early.
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This commit adds devicetree binding for AMS CCS811 VOC sensor.
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Document the ADIS16475 device devicetree bindings
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Support ADIS16475 and similar IMU devices. These devices are
a precision, miniature MEMS inertial measurement unit (IMU) that
includes a triaxial gyroscope and a triaxial accelerometer. Each
inertial sensor combines with signal conditioning that optimizes
dynamic performance.

The driver adds support for the following devices:
* adis16470, adis16475, adis16477, adis16465, adis16467, adis16500,
  adis16505, adis16507.
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Add burst_max_len to `adis_burst`. This is useful for devices which
support different burst modes with different sizes. The buffer to be
used in the spi transfer is allocated with this variable making sure
that has space for all burst modes. The spi transfer length should hold
the "real" burst length depending on the current burst mode configured
in the device.

Moreover, `extra_len` in `adis_burst` is made const and it should
contain the smallest extra length necessary for a burst transfer. In
`struct adis` was added a new `burst_extra_len` that should hold the
extra bytes needed depending on the device instance being used.
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This patch adds a `regmap_update_bits()` like API to the ADIS library.
It provides locked and unlocked variant.
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

There are some ADIS devices that can configure the data ready pin
polarity. Hence, we cannot hardcode our IRQ mask as IRQF_TRIGGER_RISING
since we might want to have it as IRQF_TRIGGER_FALLING.
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This patch adds support for a managed device version of
adis_setup_buffer_and_trigger. It works exactly as the original
one but it calls all the devm_iio_* functions to setup an iio
buffer and trigger. Hence we do not need to care about cleaning those
and we do not need to support a remove() callback for every driver using
the adis library.
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

The iio_triggered_buffer_{predisable,postenable} functions attach/detach
poll functions.

In most cases the iio_triggered_buffer_postenable() should be called first
to attach the poll function, and then the driver can init the data to be
triggered.
In this case it's the other way around: the DMA code should be initialized
before the attaching the poll function and the reverse should be done when
un-initializing.

To make things easier when removing the iio_triggered_buffer_postenable() &
iio_triggered_buffer_predisable() functions from the IIO core API, the DMA
code has been moved into preenable() for init, and postdisable() for
uninit.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Reviewed-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Reviewed-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This change moves the logic to check if the current channel is the
touchscreen channel to a separate helper.
This reduces some code duplication, but the main intent is to re-use this
in the next patches.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Reviewed-by: Eugen Hristev <eugen.hristev@microchip.com>
Reviewed-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This change will allow the at91-sama5d2_adc driver to use other triggers
than it's own.
In particular, tested with the sysfs trigger.
To be able to achieve this functionality, some changes were required:
1) Do not enable/disable channels when enabling/disabling the trigger.
This is because the trigger is enabled/disabled only for our trigger
(obviously). We need channels enabled/disabled regardless of what trigger is
being used.
2) Cope with DMA : DMA cannot be used when using another type of trigger.
Other triggers work through pollfunc, so we get polled anyway on every trigger.
Thus we have to obtain data at every trigger.
3) When to start conversion? The usual pollfunc (store time from subsystem)
would be in hard irq and this would be a good way, but current iio subsystem
recommends to have it in the threaded irq. Thus adding software start
code in this handler.
4) Buffer config: we need to setup buffer regardless of our own device's
trigger. We may get one attached later.
5) IRQ handling: we use our own device IRQ only if it's our own trigger
and we do not use DMA . If we use DMA, we use the DMA controller's IRQ.
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

It can happen that on IRQ trigger, not all conversions are done if
we are enabling multiple channels.
The IRQ is triggered on first EOC (end of channel), but it can happen
that not all channels are done. This leads into erroneous reports to
userspace (zero values or previous values).
To solve this, in trigger handler, check if the mask of done channels
is the same as the mask of active scan channels.
If it's the same, proceed and push to buffers. Otherwise, use usleep
to sleep until the conversion is done or we timeout.
Normally, it should happen that in a short time fashion, all channels are
ready, since the first IRQ triggered.
If a hardware fault happens (for example the clock suddently dissappears),
the handler will not be completed, in which case we do not report anything to
userspace anymore.
Also, change from using the EOC interrupts to DRDY interrupt.
This helps with the fact that not 'n' interrupt statuses are enabled,
each being able to trigger an interrupt, and instead only data ready
interrupt can wake up the CPU. Like this, when data is ready, check in
handler which and how many channels are done. While the DRDY is raised,
other IRQs cannot occur. Once the channel data is being read, we ack the
IRQ and finish the conversion.
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Enables probing via ACPI PRP0001 route and removes an example of
an approach we no longer want people to copy.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>

Enables probing via ACPI PRP0001 and removes an example that we don't
want people to cut and paste into new drivers.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>

Enables probing via ACPI PRP0001 but mostly about removing examples
that might be copied to new drivers.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>

Also drops ifdef protections for CONFIG_OF.

Enables probing via ACPI PRP0001 and removes an example that might be
cut and paste into new drivers.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>

Enables ACPI probing via PRP0001 and removes an example that might
be cut and paste to a new driver.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>

Enables probing via the ACPI PRP0001 route but more is mosty about
removing examples of this that might get copied into new drivers.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>