Add oversampling support for STM32H7, STM32MP15 & STM32MP13.
STM32F4 ADC has no oversampling feature.
The current support of the oversampling feature aims at increasing the
data SNR, without changing the data resolution.
As the oversampling by itself increases data resolution, a right shift
is applied to keep the initial resolution.
Only the oversampling ratio corresponding to a power of two are
supported here, to get a direct link between right shift and
oversampling ratio. (2^n ratio <=> n right shift)
The oversampling ratio is shared by all channels, whatever channel type.
(e.g. single ended or differential).
Oversampling can be configured using IIO ABI:
- oversampling_ratio_available
- oversampling_ratio
Co-developed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Signed-off-by: Olivier Moysan <olivier.moysan@foss.st.com>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Link: https://patch.msgid.link/20250424151604.626758-1-olivier.moysan@foss.st.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Set the suppress bit feature to the double tap detection, whenever
double tap is enabled. This impedes the suppress bit dangling in any
state, and thus varying in sensitivity for double tap detection.
Any tap event is defined by a rising signal edge above threshold, i.e.
duration time starts counting; and the falling edge under threshold
within duration time, i.e. then the tap event is issued. This means
duration is used individually for each tap event.
For double tap detection after a single tap, a latency time needs to be
specified. Usually tap events, i.e. spikes above and returning below
threshold will be ignored within latency. After latency, the window
time starts counting for a second tap detection which has to happen
within a duration time.
If the suppress bit is not set, spikes within latency time are ignored.
Setting the suppress bit will invalidate the double tap function. The
sensor will thus be able to save the window time for double tap
detection, and follow a more strict definition of what signal qualifies
for a double tap.
In a summary having the suppress bit set, fewer signal spikes will be
considered as double taps. This is an optional add on to double tap,
thus a separate patch.
Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
Link: https://patch.msgid.link/20250414184245.100280-5-l.rubusch@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Add the double tap feature of the sensor. The interrupt handler needs
to catch and forward the event to the IIO channel. The single tap
implementation now is extended to deal with double tap as well.
Doubletap introduces window and latency times, both in us. Since both
times are scaled, the 8-bit register value is stored in hardware,
where the scaled value in [us] is stored as member variable.
Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
Link: https://patch.msgid.link/20250414184245.100280-4-l.rubusch@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Add the single tap feature with a threshold in 62.5mg/LSB points and a
scaled duration in us. Keep singletap threshold in regmap cache but
the scaled value of duration in us as member variable.
Both use IIO channels for individual enable of the x/y/z axis. Initializes
threshold and duration with reasonable content. When an interrupt is
caught it will be pushed to the according IIO channel.
Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
Link: https://patch.msgid.link/20250414184245.100280-3-l.rubusch@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Move the fifo handling into a separate function. This is a preparation
for a generic handling of the interrupt status register results. The
function is supposed to handle particular sensor events, and later to
forward them to the iio channel. This is needed to read out the interrupt
status register.
The function shall return occurring errors, if any, or 0 in case of
handled events or read fifo content. Thus migrate fifo read-out and push
fifo content to iio channels into this function to be built up with
additional event handling.
Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
Link: https://patch.msgid.link/20250414184245.100280-2-l.rubusch@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Follow the pattern of other drivers and use aligned_s64 for the
timestamp. Technically there was no issue here since
AD74413R_FRAME_SIZE * AD74413R_CHANNEL_MAX == 16 and IIO_DMA_MINALIGN
is always a multiple of 8. But best to conform in case someone copies
this to new code and then tweaks something.
Also move the unaligned.h header while touching this since it was the
only one not in alphabetical order.
Signed-off-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://patch.msgid.link/20250417-iio-more-timestamp-alignment-v1-3-eafac1e22318@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
The driver previously used an array of two s64, then type cast the
pointer to write an s16 to the start. The code is made more readable
using a structure. At the same time switch to the new
iio_push_to_buffers_with_ts() helper to enable runtime checking of the
size of the source buffer.
Note that this approach uses a structure with holes, so use memset()
to ensure those do not contain old kernel data as this data is passed
to userspace.
Reviewed-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20250413103443.2420727-17-jic23@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
By providing the size of the buffer used, runtime checks can be performed
to ensure not overrun.
Also change the pushed data pointer to be that of the structure that also
contains the timestamp. Not an actual bug but semantically incorrect to
push the channel data when we want the storage with the timestamp as well.
Reviewed-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20250413103443.2420727-9-jic23@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
It has long been discouraged for drivers to make use of iio_dev->scan_bytes
directly as that is an implementation detail of the core. As such our
example driver should definitely not be doing so.
In order to illustrate the more complex case, where a DMA safe buffer is
needed, continue to kzalloc() the storage (but with a structure definition
to provide an explicit data layout). Also add comments on when a DMA safe
buffer is necessary and the two common ways of obtaining one.
Whilst we have a mixture of signed and unsigned channels, the unsigned
channels have ranges that can be stored in a signed value - hence
use signed storage for all channels, simplifying the structure definition.
Reviewed-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20250413103443.2420727-7-jic23@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Use `\t(\{ ?\},|\{\}|\{\s*/\*.*\*/\s*\},?)$` regex to find and replace
the array sentinel in all IIO drivers to the same style.
For some time, we've been trying to consistently use `{ }` (no trailing
comma, no comment, one space between braces) for array sentinels in the
IIO subsystem. Still nearly 50% of existing code uses a different style.
To save reviewers from having to request this trivial change as
frequently, let's normalize the style in all existing IIO drivers.
At least when code is copy/pasted to new drivers, the style will be
consistent.
Signed-off-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Link: https://patch.msgid.link/20250411-iio-sentinel-normalization-v1-1-d293de3e3d93@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Fix Smatch-detected issue:
drivers/iio/adc/ad_sigma_delta.c:604 ad_sd_trigger_handler() error:
uninitialized symbol 'status_pos'.
The variable `status_pos` was only initialized in specific switch cases
(1, 2, 3, 4), which could leave it uninitialized if `reg_size` had an
unexpected value.
Fix by adding a default case to the switch block to catch unexpected
values of `reg_size`. Use `dev_err_ratelimited()` for error logging and
`goto irq_handled` instead of returning early.
Signed-off-by: Purva Yeshi <purvayeshi550@gmail.com>
Link: https://patch.msgid.link/20250410170408.8585-1-purvayeshi550@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
The ROHM BD79104 ADC has identical SPI communication logic as the
ti-adc128s052. Eg, SPI transfer should be 16 clk cycles, conversion is
started when the CS is pulled low, and channel selection is done by
writing the channel ID after two zero bits. Data is contained in
big-endian format in the last 12 bits.
The BD79104 has two input voltage pins. Data sheet uses terms "vdd" and
"iovdd". The "vdd" is used also as an analog reference voltage. Hence
the driver expects finding these from the device-tree, instead of having
the "vref" only as TI's driver.
NOTE: The TI's data sheet[1] does show that the TI's IC does actually
have two voltage inputs as well. Pins are called Va (analog reference)
and Vd (digital supply pin) - but I keep the existing driver behaviour
for the TI's IC "as is", because I have no HW to test changes, and
because I have no real need to touch it.
NOTE II: The BD79104 requires SPI MODE 3.
NOTE III: I used evaluation board "BD79104FV-EVK-001" made by ROHM. With
this board I had to drop the SPI speed below the 20M which is mentioned
in the data-sheet [2]. This, however, may be a limitation of the EVK
board, not the component itself.
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Datasheet: https://www.ti.com/lit/ds/symlink/adc128s052.pdf # [1]
Datasheet: https://fscdn.rohm.com/en/products/databook/datasheet/ic/data_converter/dac/bd79104fv-la-e.pdf # [2]
Link: https://patch.msgid.link/36ffa72cbdf8dbbdf1e612040db82ebcdf73fa24.1744022065.git.mazziesaccount@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
The ti-adc128s052 driver has NULL terminated ID arrays for the
of_device_id, spi_device_id and acpi_device_id. All of these are
terminated by having an empty string as the last member of an array.
Only the of_device_id array uses the /* sentinel */ comment.
It's better to be consistent.
This /* sentinel */ comment serves no real purpose these days as people
are used to seeing these ID lists terminated with an empty array
element.
Drop the /* sentinel */ from the of_device_id.
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Link: https://patch.msgid.link/bb58002accc696bd4a8fbbab37100c6fa0c29941.1744022065.git.mazziesaccount@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
The ROHM BD79104 is a 12-bit, 8-channel ADC with two power supply pins,
connected to SPI. It's worth noting the IC requires SPI MODE 3, (CPHA =
1, CPOL = 1).
I used an evaluation board "BD79104FV-EVK-001" from ROHM. With this
board I had problems to have things working correctly with higher SPI
clock frequencies. I didn't do thorough testing for maximum frequency
though. First attempt was 40M, then 20M and finally 4M. With 20M it
seemed as if the read values were shifted by 1 bit. With 4M it worked
fine.
The component data-sheet is not exact what comes to the maximum SPI
frequency. It says SPI frequency is 20M - "unless othervice specified".
Additionally, it says that maximum sampling rate is 1Mhz, and since
reading a sample requires writing the channel (16 bits) and reading
data (16 bits) - we get some upper limit from this.
>From the "frequency is 20M, unless othervice specified" I picked the
maximum frequency 20M - and did assumption that my problems with 20M
weren't related to the BD79104 - but to the evaluation board
"BD79104FV-EVK-001".
Add bindings for the ROHM BD79104 ADC.
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/2a4c65ee35cb79c6b29dbc59cfd9bc7d615a08ac.1744022065.git.mazziesaccount@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
