Add SPI offload support to the ad_sigma_delta module.
When the SPI controller has SPI offload capabilities, the module will
now use that for buffered reads instead of the RDY interrupt trigger.
Drivers that use the ad_sigma_delta module will have to opt into this
by setting supports_spi_offload since each driver will likely need
additional changes before SPI offload can be used. This will allow us
to gradually enable SPI offload support for each driver.
Signed-off-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://patch.msgid.link/20250701-iio-adc-ad7173-add-spi-offload-support-v3-11-42abb83e3dac@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Use spi_optimize_message() to improve the performance of buffered reads.
By setting up the SPI message and pre-optimizing it in the buffer
postenable callback, we can reduce overhead during each sample read.
A rough estimate shows that this reduced the CPU usage of the interrupt
handler thread from 22% to 16% using an EVAL-AD4112ARDZ board on a
DE10-Nano (measuring a single channel at the default 6.2 kHz sample
rate).
Signed-off-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://patch.msgid.link/20250701-iio-adc-ad7173-add-spi-offload-support-v3-8-42abb83e3dac@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Replace uint8_t with u8 in the ad_sigma_delta driver.
Technically, uint8_t comes from the C standard library, while u8 is a
Linux kernel type. Since we don't use the C standard library in the
kernel, we should use the kernel types instead.
There is also one instance where int64_t is replaced with s64.
Signed-off-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://patch.msgid.link/20250701-iio-adc-ad7173-add-spi-offload-support-v3-3-42abb83e3dac@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Move the call to fwnode_irq_get_byname() from the driver-specific
ad7173_fw_parse_device_config() to the shared ad_sd_init() function.
The main reason for this is that we want struct ad_sigma_delta_info to
be static const data that describes the actual ADC chip, not the
application-specific configuration or any runtime state.
Previously, this struct was being used to pass the IRQ number to the
shared ad_sd_init() function. Now, this is replaced by a boolean flag
that is set at compile time and the ad_sd_init() function handles
looking up the IRQ number instead. This also has the added benefit that
if any other drivers need to make use of this in the future, they just
have to set the flag and the shared code will take care of the rest
rather than duplicating the code in each driver.
Signed-off-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20250113-iio-adc-ad7313-fix-non-const-info-struct-v4-1-b63be3ecac4a@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
The various chips can be reset using a sequence of SPI transfers with
MOSI = 1. The length of such a sequence varies from chip to chip. Store
that length in struct ad_sigma_delta_info and replace the respective
parameter to ad_sd_reset() with it.
Note the ad7192 used to pass 48 as length but the documentation
specifies 40 as the required length. Assuming the latter is right.
(Using a too long sequence doesn't hurt apart from using a longer spi
transfer than necessary, so this is no relevant fix.)
The motivation for storing this information is that this is useful to
clear a pending R̅D̅Y̅ signal in the next change.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/9750db62fce638bf140ff48172c23bff7f785e5b.1733504533.git.u.kleine-koenig@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
The ad_sigma_delta driver helper uses irq_disable_nosync(). With that
one it is possible that the irq handler still runs after the
irq_disable_nosync() function call returns. Also to properly synchronize
irq disabling in the different threads proper locking is needed and
because it's unclear if the irq handler's irq_disable_nosync() call
comes first or the one in the enabler's error path, all code locations
that disable the irq must check for .irq_dis first to ensure there is
exactly one disable call per enable call.
So add a spinlock to the struct ad_sigma_delta and use it to synchronize
irq enabling and disabling. Also only act in the irq handler if the irq
is still enabled.
Fixes: af3008485e ("iio:adc: Add common code for ADI Sigma Delta devices")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/9e6def47e2e773e0e15b7a2c29d22629b53d91b1.1733504533.git.u.kleine-koenig@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Some of the ADCs by Analog signal their irq condition on the MISO line.
So typically that line is connected to an SPI controller and a GPIO. The
GPIO is used as input and the respective interrupt is enabled when the
last SPI transfer is completed.
Depending on the GPIO controller the toggling MISO line might make the
interrupt pending even while it's masked. In that case the irq handler
is called immediately after irq_enable() and so before the device
actually pulls that line low which results in non-sense values being
reported to the upper layers.
The only way to find out if the line was actually pulled low is to read
the GPIO. (There is a flag in AD7124's status register that also signals
if an interrupt was asserted, but reading that register toggles the MISO
line and so might trigger another spurious interrupt.)
Add the possibility to specify an interrupt GPIO in the machine
description in addition to the plain interrupt. This GPIO is used then
to check if the irq line is actually active in the irq handler.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/5be9a4cc4dc600ec384c88db01dd661a21506b9c.1733504533.git.u.kleine-koenig@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Sigma delta ADCs with a sequencer need to disable the previously enabled
channel when reading using ad_sigma_delta_single_conversion(). This was
done manually in drivers for devices with sequencers.
This patch implements handling of single channel disabling after a
single conversion.
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Signed-off-by: Dumitru Ceclan <dumitru.ceclan@analog.com>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20240607-ad4111-v7-3-97e3855900a0@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Add optional irq_num attribute to ad_sigma_delta_info structure for
selecting the used interrupt line for ADC's conversion completion.
Signed-off-by: Dumitru Ceclan <mitrutzceclan@gmail.com>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20240228110622.25114-2-mitrutzceclan@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Some sigma-delta chips support sampling of multiple
channels in continuous mode.
When the operating with more than one channel enabled,
the channel sequencer cycles through the enabled channels
in sequential order, from first channel to the last one.
If a channel is disabled, it is skipped by the sequencer.
If more than one channel is used in continuous mode,
instruct the device to append the status to the SPI transfer
(1 extra byte) every time we receive a sample.
All sigma-delta chips possessing a sampling sequencer have
this ability. Inside the status register there will be
the number of the converted channel. In this way, even
if the CPU won't keep up with the sampling rate, it won't
send to userspace wrong channel samples.
When multiple channels are enabled in continuous mode,
the device needs to perform a measurement on all slots
before we can push to userspace the sample.
If, during sequencing and data reading, a channel measurement
is lost, a desync occurred. In this case, ad_sigma_delta drops
the incomplete sample and waits for the device to send the
measurement on the first active slot.
Co-developed-by: Alexandru Tachici <alexandru.tachici@analog.com>
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20220322105029.86389-5-alexandru.tachici@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Since all AD Sigma-Delta drivers now use the
devm_ad_sd_setup_buffer_and_trigger() function, we can remove the old
ad_sd_{setup,cleanup}_buffer_and_trigger() functions.
This way we can discourage new drivers that use the ad_sigma_delta
lib-driver to use these (older functions).
Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210513120752.90074-13-aardelean@deviqon.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This is a version of ad_sd_setup_buffer_and_trigger() with all underlying
functions (that are used) being replaced with their device-managed
variants.
One thing to take care here is with {devm_}iio_trigger_alloc(), where both
functions take a parent-device object as the first parameter.
To make sure nothing quirky is happening, the devm_ad_sd_probe_trigger()
function is checking that the provided 'dev' reference is the same as the
one stored on the 'struct ad_sigma_delta' driver data.
Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210513120752.90074-6-aardelean@deviqon.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Use a heap allocated memory for the SPI transfer buffer. Using stack memory
can corrupt stack memory when using DMA on some systems.
This change moves the buffer from the stack of the trigger handler call to
the heap of the buffer of the state struct. The size increases takes into
account the alignment for the timestamp, which is 8 bytes.
The 'data' buffer is split into 'tx_buf' and 'rx_buf', to make a clearer
separation of which part of the buffer should be used for TX & RX.
Fixes: af3008485e ("iio:adc: Add common code for ADI Sigma Delta devices")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20201124123807.19717-1-alexandru.ardelean@analog.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Now that all channel SigmaDelta IIO channel macros have been localized,
remove the generic ones.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Before this patch the ad_sigma_delta implementation hardcoded
the irq trigger type to low, assuming that all Sigma-Delta ADCs
have the same interrupt-type.
This patch allows all drivers using the ad_sigma_delta layer to set the
irq trigger type to the one specified in the datasheet.
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This patch exports the ad_sd_calibrate function in order to be able to
call it from outside ad_sigma_delta.
There are cases where the option to calibrate one channel at a time is
necessary (ex. system calibration for zero scale and full scale).
Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
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>
For devices from the SigmaDelta family we need to keep CS low when doing a
conversion, since the device will use the MISO line as a interrupt to
indicate that the conversion is complete.
This is why the driver locks the SPI bus and when the SPI bus is locked
keeps as long as a conversion is going on. The current implementation gets
one small detail wrong though. CS is only de-asserted after the SPI bus is
unlocked. This means it is possible for a different SPI device on the same
bus to send a message which would be wrongfully be addressed to the
SigmaDelta device as well. Make sure that the last SPI transfer that is
done while holding the SPI bus lock de-asserts the CS signal.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <Alexandru.Ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Some newer devices from the Sigma-Delta ADC family do have their data
register at a different address than the current default address. Add a
parameter to the ad_sigma_delta_info struct which allows to override the
default address.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
The `ad7780` driver does not implement setting/getting the sampling
frequency.
For the ad7780/ad7781 devices, the control is done via an external pin,
and the ad7170/ad7171 devices have a fixed sampling rate (so, no control).
For these devices, and similar other that may be added later on,
a AD_SD_CHANNEL_NO_SAMPLE_FREQ() macro has been added, which doesn't set
the IIO_CHAN_INFO_SAMP_FREQ flag.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Since most of the SD ADCs have the option of reseting the serial
interface by sending a number of SCLKs with CS = 0 and DIN = 1,
a dedicated function that can do this is usefull.
Needed for the patch: iio: ad7793: Fix the serial interface reset
Signed-off-by: Dragos Bogdan <dragos.bogdan@analog.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This driver predates the availability of IIO_CHAN_INFO_SAMP_FREQ
attribute wherein usage has some advantages like it can be accessed by
in-kernel consumers as well as reduces the code size.
Therefore, use IIO_CHAN_INFO_SAMP_FREQ to implement the
sampling_frequency attribute instead of using IIO_DEV_ATTR_SAMP_FREQ()
macro.
Move code from the functions associated with IIO_DEV_ATTR_SAMP_FREQ()
into respective read and write hooks with the mask set to
IIO_CHAN_INFO_SAMP_FREQ.
Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
The original info_mask is going away in favour of the broken out versions.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Most devices from the Analog Devices Sigma Delta family use a similar scheme for
communication with the device. This includes register access, as well as trigger
handling. But each device sub-family has different features and different
register layouts (some even have no registers at all) and thus it is impractical
to try to support all of the devices by the same driver. This patch adds a
common base library for Sigma Delta converter devices. It will be used by
individual drivers.
This code is mostly based on the three existing Sigma Delta drivers the AD7192,
AD7780 and AD7793, but has been improved for more robustness and flexibility.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
