3706 Commits

Author SHA1 Message Date
Andreas Klinger
ca90f67ece iio: bmp280: fix compensation of humidity
[ Upstream commit dee2dabc0e4115b80945fe2c91603e634f4b4686 ]

Limit the output of humidity compensation to the range between 0 and 100
percent.

Depending on the calibration parameters of the individual sensor it
happens, that a humidity above 100 percent or below 0 percent is
calculated, which don't make sense in terms of relative humidity.

Add a clamp to the compensation formula as described in the datasheet of
the sensor in chapter 4.2.3.

Although this clamp is documented, it was never in the driver of the
kernel.

It depends on the circumstances (calibration parameters, temperature,
humidity) if one can see a value above 100 percent without the clamp.
The writer of this patch was working with this type of sensor without
noting this error. So it seems to be a rare event when this bug occures.

Signed-off-by: Andreas Klinger <ak@it-klinger.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-24 17:50:12 +02:00
Andy Shevchenko
8bd207bb1a iio: pressure: bmp280: Tolerate IRQ before registering
[ Upstream commit 97b31a6f5fb95b1ec6575b78a7240baddba34384 ]

With DEBUG_SHIRQ enabled we have a kernel crash

[  116.482696] BUG: kernel NULL pointer dereference, address: 0000000000000000

...

[  116.606571] Call Trace:
[  116.609023]  <IRQ>
[  116.611047]  complete+0x34/0x50
[  116.614206]  bmp085_eoc_irq+0x9/0x10 [bmp280]

because DEBUG_SHIRQ mechanism fires an IRQ before registration and drivers
ought to be able to handle an interrupt happening before request_irq() returns.

Fixes: aae953949651 ("iio: pressure: bmp280: add support for BMP085 EOC interrupt")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-24 17:50:08 +02:00
Fabrice Gasnier
8d130bf2fc iio: adc: stm32-adc: fix a wrong error message when probing interrupts
commit 10134ec3f8cefa6a40fe84987f1795e9e0da9715 upstream.

A wrong error message is printed out currently, like on STM32MP15:
- stm32-adc-core 48003000.adc: IRQ index 2 not found.

This is seen since commit 7723f4c5ecdb ("driver core: platform: Add an
error message to platform_get_irq*()").
The STM32 ADC core driver wrongly requests up to 3 interrupt lines. It
should request only the necessary IRQs, based on the compatible:
- stm32f4/h7 ADCs share a common interrupt
- stm32mp1, has one interrupt line per ADC.
So add the number of required interrupts to the compatible data.

Fixes: d58c67d1d851 ("iio: adc: stm32-adc: add support for STM32MP1")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-10 20:24:56 +02:00
Jonathan Cameron
e98b0548b2 iio:chemical:pms7003: Fix timestamp alignment and prevent data leak.
commit 13e945631c2ffb946c0af342812a3cd39227de6e upstream.

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.
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 appart from previous readings.

Fixes: a1d642266c14 ("iio: chemical: add support for Plantower PMS7003 sensor")
Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: <Stable@vger.kernel.org>
Acked-by: Tomasz Duszynski <tomasz.duszynski@octakon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-10 20:24:56 +02:00
Mathieu Othacehe
9b0e734fde iio: vcnl4000: Fix i2c swapped word reading.
commit 18dfb5326370991c81a6d1ed6d1aeee055cb8c05 upstream.

The bytes returned by the i2c reading need to be swapped
unconditionally. Otherwise, on be16 platforms, an incorrect value will be
returned.

Taking the slow path via next merge window as its been around a while
and we have a patch set dependent on this which would be held up.

Fixes: 62a1efb9f868 ("iio: add vcnl4000 combined ALS and proximity sensor")
Signed-off-by: Mathieu Othacehe <m.othacehe@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-10 20:24:56 +02:00
Jonathan Cameron
940530f60c iio:chemical:sps30: Fix timestamp alignment
commit a5bf6fdd19c327bcfd9073a8740fa19ca4525fd4 upstream.

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.

Fixes: 232e0f6ddeae ("iio: chemical: add support for Sensirion SPS30 sensor")
Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: <Stable@vger.kernel.org>
Acked-by: Tomasz Duszynski <tomasz.duszynski@octakon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-10 20:24:56 +02:00
Fabrice Gasnier
f2da8c0dfe iio: adc: stm32-dfsdm: fix device used to request dma
[ Upstream commit b455d06e6fb3c035711e8aab1ca18082ccb15d87 ]

DMA channel request should use device struct from platform device struct.
Currently it's using iio device struct. But at this stage when probing,
device struct isn't yet registered (e.g. device_register is done in
iio_device_register). Since commit 71723a96b8b1 ("dmaengine: Create
symlinks between DMA channels and slaves"), a warning message is printed
as the links in sysfs can't be created, due to device isn't yet registered:
- Cannot create DMA slave symlink
- Cannot create DMA dma:rx symlink

Fix this by using device struct from platform device to request dma chan.

Fixes: eca949800d2d ("IIO: ADC: add stm32 DFSDM support for PDM microphone")

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-27 17:46:51 +02:00
Peter Ujfalusi
7b5af65ca2 iio: adc: stm32-dfsdm: Use dma_request_chan() instead dma_request_slave_channel()
[ Upstream commit a9ab624edd9186fbad734cfe5d606a6da3ca34db ]

dma_request_slave_channel() is a wrapper on top of dma_request_chan()
eating up the error code.

By using dma_request_chan() directly the driver can support deferred
probing against DMA.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Olivier Moysan <olivier.moysan@st.com>
Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-27 17:46:50 +02:00
Fabrice Gasnier
692001a867 iio: adc: stm32-adc: fix device used to request dma
[ Upstream commit 52cd91c27f3908b88e8b25aed4a4d20660abcc45 ]

DMA channel request should use device struct from platform device struct.
Currently it's using iio device struct. But at this stage when probing,
device struct isn't yet registered (e.g. device_register is done in
iio_device_register). Since commit 71723a96b8b1 ("dmaengine: Create
symlinks between DMA channels and slaves"), a warning message is printed
as the links in sysfs can't be created, due to device isn't yet registered:
- Cannot create DMA slave symlink
- Cannot create DMA dma:rx symlink

Fix this by using device struct from platform device to request dma chan.

Fixes: 2763ea0585c99 ("iio: adc: stm32: add optional dma support")

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-27 17:46:50 +02:00
Peter Ujfalusi
8e8836b2b7 iio: adc: stm32-adc: Use dma_request_chan() instead dma_request_slave_channel()
[ Upstream commit 735404b846dffcb320264f62b76e6f70012214dd ]

dma_request_slave_channel() is a wrapper on top of dma_request_chan()
eating up the error code.

By using dma_request_chan() directly the driver can support deferred
probing against DMA.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-27 17:46:50 +02:00
Gregory CLEMENT
e64b205035 iio: adc: ti-ads8344: Fix channel selection
commit bcfa1e253d2e329e1ebab5c89f3c73f6dd17606c upstream.

During initial submission the selection of the channel was done using
the scan_index member of the iio_chan_spec structure. It was an abuse
because this member is supposed to be used with a buffer so it was
removed.

However there was still the need to be able to known how to select a
channel, the correct member to store this information is address.

Thanks to this it is possible to select any other channel than the
channel 0.

Fixes: 8dd2d7c0fed7 ("iio: adc: Add driver for the TI ADS8344 A/DC chips")
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27 17:46:46 +02:00
Christophe JAILLET
9af65dc54b iio: dac: vf610: Fix an error handling path in 'vf610_dac_probe()'
commit aad4742fbf0a560c25827adb58695a4497ffc204 upstream.

A call to 'vf610_dac_exit()' is missing in an error handling path.

Fixes: 1b983bf42fad ("iio: dac: vf610_dac: Add IIO DAC driver for Vybrid SoC")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27 17:46:45 +02:00
Christophe JAILLET
d54e5a4ff0 iio: sca3000: Remove an erroneous 'get_device()'
commit 928edefbc18cd8433f7df235c6e09a9306e7d580 upstream.

This looks really unusual to have a 'get_device()' hidden in a 'dev_err()'
call.
Remove it.

While at it add a missing \n at the end of the message.

Fixes: 574fb258d636 ("Staging: IIO: VTI sca3000 series accelerometer driver (spi)")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27 17:46:45 +02:00
YueHaibing
f9e41e4bbe iio:ad7797: Use correct attribute_group
commit 28535877ac5b2b84f0d394fd67a5ec71c0c48b10 upstream.

It should use ad7797_attribute_group in ad7797_info,
according to commit ("iio:ad7793: Add support for the ad7796 and ad7797").

Scale is fixed for the ad7796 and not programmable, hence
should not have the scale_available attribute.

Fixes: fd1a8b912841 ("iio:ad7793: Add support for the ad7796 and ad7797")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 08:48:44 +02:00
Lars-Peter Clausen
557f3f5492 iio: xilinx-xadc: Make sure not exceed maximum samplerate
commit 3b7f9dbb827ce8680b98490215e698b6079a9ec5 upstream.

The XADC supports a samplerate of up to 1MSPS. Unfortunately the hardware
does not have a FIFO, which means it generates an interrupt for each
conversion sequence. At one 1MSPS this creates an interrupt storm that
causes the system to soft-lock.

For this reason the driver limits the maximum samplerate to 150kSPS.
Currently this check is only done when setting a new samplerate. But it is
also possible that the initial samplerate configured in the FPGA bitstream
exceeds the limit.

In this case when starting to capture data without first changing the
samplerate the system can overload.

To prevent this check the currently configured samplerate in the probe
function and reduce it to the maximum if necessary.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Fixes: bdc8cda1d010 ("iio:adc: Add Xilinx XADC driver")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-29 16:33:13 +02:00
Lars-Peter Clausen
b3e365a070 iio: xilinx-xadc: Fix sequencer configuration for aux channels in simultaneous mode
commit 8bef455c8b1694547ee59e8b1939205ed9d901a6 upstream.

The XADC has two internal ADCs. Depending on the mode it is operating in
either one or both of them are used. The device manual calls this
continuous (one ADC) and simultaneous (both ADCs) mode.

The meaning of the sequencing register for the aux channels changes
depending on the mode.

In continuous mode each bit corresponds to one of the 16 aux channels. And
the single ADC will convert them one by one in order.

In simultaneous mode the aux channels are split into two groups the first 8
channels are assigned to the first ADC and the other 8 channels to the
second ADC. The upper 8 bits of the sequencing register are unused and the
lower 8 bits control both ADCs. This means a bit needs to be set if either
the corresponding channel from the first group or the second group (or
both) are set.

Currently the driver does not have the special handling required for
simultaneous mode. Add it.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Fixes: bdc8cda1d010 ("iio:adc: Add Xilinx XADC driver")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-29 16:33:13 +02:00
Lars-Peter Clausen
cf2849c9ef iio: xilinx-xadc: Fix clearing interrupt when enabling trigger
commit f954b098fbac4d183219ce5b42d76d6df2aed50a upstream.

When enabling the trigger and unmasking the end-of-sequence (EOS) interrupt
the EOS interrupt should be cleared from the status register. Otherwise it
is possible that it was still set from a previous capture. If that is the
case the interrupt would fire immediately even though no conversion has
been done yet and stale data is being read from the device.

The old code only clears the interrupt if the interrupt was previously
unmasked. Which does not make much sense since the interrupt is always
masked at this point and in addition masking the interrupt does not clear
the interrupt from the status register. So the clearing needs to be done
unconditionally.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Fixes: bdc8cda1d010 ("iio:adc: Add Xilinx XADC driver")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-29 16:33:13 +02:00
Lars-Peter Clausen
6a956eb2e1 iio: xilinx-xadc: Fix ADC-B powerdown
commit e44ec7794d88f918805d700240211a9ec05ed89d upstream.

The check for shutting down the second ADC is inverted. This causes it to
be powered down when it should be enabled. As a result channels that are
supposed to be handled by the second ADC return invalid conversion results.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Fixes: bdc8cda1d010 ("iio:adc: Add Xilinx XADC driver")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-29 16:33:12 +02:00
Alexandre Belloni
f83a969fcb iio: adc: ti-ads8344: properly byte swap value
commit dd7de4c0023e7564cabe39d64b2822a522890792 upstream.

The first received byte is the MSB, followed by the LSB so the value needs
to be byte swapped.

Also, the ADC actually has a delay of one clock on the SPI bus. Read three
bytes to get the last bit.

Fixes: 8dd2d7c0fed7 ("iio: adc: Add driver for the TI ADS8344 A/DC chips")
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-29 16:33:12 +02:00
Olivier Moysan
db168069b0 iio: adc: stm32-adc: fix sleep in atomic context
commit e2042d2936dfc84e9c600fe9b9d0039ca0e54b7d upstream.

This commit fixes the following error:
"BUG: sleeping function called from invalid context at kernel/irq/chip.c"

In DMA mode suppress the trigger irq handler, and make the buffer
transfers directly in DMA callback, instead.

Fixes: 2763ea0585c9 ("iio: adc: stm32: add optional dma support")
Signed-off-by: Olivier Moysan <olivier.moysan@st.com>
Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-29 16:33:12 +02:00
Lary Gibaud
02311bc133 iio: st_sensors: rely on odr mask to know if odr can be set
commit e450e07c14abae563ad13b064cbce9fdccc6bc8d upstream.

Indeed, relying on addr being not 0 cannot work because some device have
their register to set odr at address 0. As a matter of fact, if the odr
can be set, then there is a mask.

Sensors with ODR register at address 0 are: lsm303dlh, lsm303dlhc, lsm303dlm

Fixes: 7d245172675a ("iio: common: st_sensors: check odr address value in st_sensors_set_odr()")
Signed-off-by: Lary Gibaud <yarl-baudig@mailoo.org>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-29 16:33:12 +02:00
Maxime Roussin-Bélanger
47e4d791d5 iio: si1133: read 24-bit signed integer for measurement
commit 328b50e9a0ad1fe8accdf8c19923deebab5e0c01 upstream.

The chip is configured in 24 bit mode. The values read from
it must always be treated as is. This fixes the issue by
replacing the previous 16 bits value by a 24 bits buffer.

This changes affects the value output by previous version of
the driver, since the least significant byte was missing.
The upper half of 16 bit values previously output are now
the upper half of a 24 bit value.

Fixes: e01e7eaf37d8 ("iio: light: introduce si1133")

Reported-by: Simon Goyette <simon.goyette@gmail.com>
Co-authored-by: Guillaume Champagne <champagne.guillaume.c@gmail.com>
Signed-off-by: Maxime Roussin-Bélanger <maxime.roussinbelanger@gmail.com>
Signed-off-by: Guillaume Champagne <champagne.guillaume.c@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-23 10:36:43 +02:00
Tomas Novotny
dbb328d1a8 iio: light: vcnl4000: update sampling periods for vcnl4040
commit 2ca5a8792d617b4035aacd0a8be527f667fbf912 upstream.

Vishay has published a new version of "Designing the VCNL4200 Into an
Application" application note in October 2019. The new version specifies
that there is +-20% of part to part tolerance. Although the application
note is related to vcnl4200, according to support the vcnl4040's "ASIC
is quite similar to that one for the VCNL4200".

So update the sampling periods (and comment), including the correct
sampling period for proximity. Both sampling periods are lower. Users
relying on the blocking behaviour of reading will get proximity
measurements much earlier.

Fixes: 5a441aade5b3 ("iio: light: vcnl4000 add support for the VCNL4040 proximity and light sensor")
Reviewed-by: Guido Günther <agx@sigxcpu.org>
Tested-by: Guido Günther <agx@sigxcpu.org>
Signed-off-by: Tomas Novotny <tomas@novotny.cz>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25 08:25:54 +01:00
Tomas Novotny
c3540b094e iio: light: vcnl4000: update sampling periods for vcnl4200
commit b42aa97ed5f1169cfd37175ef388ea62ff2dcf43 upstream.

Vishay has published a new version of "Designing the VCNL4200 Into an
Application" application note in October 2019. The new version specifies
that there is +-20% of part to part tolerance. This explains the drift
seen during experiments. The proximity pulse width is also changed from
32us to 30us. According to the support, the tolerance also applies to
ambient light.

So update the sampling periods. As the reading is blocking, current
users may notice slightly longer response time.

Fixes: be38866fbb97 ("iio: vcnl4000: add support for VCNL4200")
Reviewed-by: Guido Günther <agx@sigxcpu.org>
Signed-off-by: Tomas Novotny <tomas@novotny.cz>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25 08:25:54 +01:00
Eugen Hristev
7ad22950ca iio: adc: at91-sama5d2_adc: fix differential channels in triggered mode
commit a500f3bd787f8224341e44b238f318c407b10897 upstream.

The differential channels require writing the channel offset register (COR).
Otherwise they do not work in differential mode.
The configuration of COR is missing in triggered mode.

Fixes: 5e1a1da0f8c9 ("iio: adc: at91-sama5d2_adc: add hw trigger and buffer support")
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25 08:25:53 +01:00
Olivier Moysan
4d71a4f761 iio: adc: stm32-dfsdm: fix sleep in atomic context
commit e19ac9d9a978f8238a85a28ed624094a497d5ae6 upstream.

This commit fixes the error message:
"BUG: sleeping function called from invalid context at kernel/irq/chip.c"
Suppress the trigger irq handler. Make the buffer transfers directly
in DMA callback, instead.
Push buffers without timestamps, as timestamps are not supported
in DFSDM driver.

Fixes: 11646e81d775 ("iio: adc: stm32-dfsdm: add support for buffer modes")

Signed-off-by: Olivier Moysan <olivier.moysan@st.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25 08:25:53 +01:00
Stephan Gerhold
a79f53a2f5 iio: magnetometer: ak8974: Fix negative raw values in sysfs
commit b500c086e4110829a308c23e83a7cdc65b26228a upstream.

At the moment, reading from in_magn_*_raw in sysfs tends to return
large values around 65000, even though the output of ak8974 is actually
limited to ±32768. This happens because the value is never converted
to the signed 16-bit integer variant.

Add an explicit cast to s16 to fix this.

Fixes: 7c94a8b2ee8c ("iio: magn: add a driver for AK8974")
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Reviewed-by: Linus Waleij <linus.walleij@linaro.org>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25 08:25:53 +01:00
Alexandru Tachici
6387b40023 iio: accel: adxl372: Set iio_chan BE
commit cb2116ff97859d34fda6cb561ac654415f4c6230 upstream.

Data stored in the iio-buffer is BE and this
should be specified in the iio_chan_spec struct.

Fixes: f4f55ce38e5f8 ("iio:adxl372: Add FIFO and interrupts support")
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25 08:25:53 +01:00
Fabrice Gasnier
3c69b794f9 iio: trigger: stm32-timer: disable master mode when stopping
commit 29e8c8253d7d5265f58122c0a7902e26df6c6f61 upstream.

Master mode should be disabled when stopping. This mainly impacts
possible other use-case after timer has been stopped. Currently,
master mode remains set (from start routine).

Fixes: 6fb34812c2a2 ("iio: stm32 trigger: Add support for TRGO2 triggers")

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25 08:25:53 +01:00
Wen-chien Jesse Sung
eb5f46b0cc iio: st_sensors: remap SMO8840 to LIS2DH12
commit e43d110cdc206b6df4dd438cd10c81d1da910aad upstream.

According to ST, the HID is for LIS2DH12.

Fixes: 3d56e19815b3 ("iio: accel: st_accel: Add support for the SMO8840 ACPI id")
Signed-off-by: Wen-chien Jesse Sung <jesse.sung@canonical.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25 08:25:53 +01:00
Petr Štetiar
69399842e4 iio: chemical: sps30: fix missing triggered buffer dependency
commit 016a8845f6da65b2203f102f192046fbb624e250 upstream.

SPS30 uses triggered buffer, but the dependency is not specified in the
Kconfig file.  Fix this by selecting IIO_BUFFER and IIO_TRIGGERED_BUFFER
config symbols.

Cc: stable@vger.kernel.org
Fixes: 232e0f6ddeae ("iio: chemical: add support for Sensirion SPS30 sensor")
Signed-off-by: Petr Štetiar <ynezz@true.cz>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25 08:25:53 +01:00
Andy Shevchenko
3811bd2b93 iio: st_gyro: Correct data for LSM9DS0 gyro
commit e825070f697abddf3b9b0a675ed0ff1884114818 upstream.

The commit 41c128cb25ce ("iio: st_gyro: Add lsm9ds0-gyro support")
assumes that gyro in LSM9DS0 is the same as others with 0xd4 WAI ID,
but datasheet tells slight different story, i.e. the first scale factor
for the chip is 245 dps, and not 250 dps.

Correct this by introducing a separate settings for LSM9DS0.

Fixes: 41c128cb25ce ("iio: st_gyro: Add lsm9ds0-gyro support")
Depends-on: 45a4e4220bf4 ("iio: gyro: st_gyro: fix L3GD20H support")
Cc: Leonard Crestez <leonard.crestez@nxp.com>
Cc: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-01 09:34:36 +00:00
Olivier Moysan
a6d19450c3 iio: adc: stm32-dfsdm: fix single conversion
commit dc26935fb60e8da8d59655dd2ec0de47b20d7d8f upstream.

Apply data formatting to single conversion,
as this is already done in continuous and trigger modes.

Fixes: 102afde62937 ("iio: adc: stm32-dfsdm: manage data resolution in trigger mode")

Signed-off-by: Olivier Moysan <olivier.moysan@st.com>
Cc: <Stable@vger.kernel.org>
Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-01 09:34:36 +00:00
Lars Möllendorf
2d44f11a4c iio: buffer: align the size of scan bytes to size of the largest element
commit 883f616530692d81cb70f8a32d85c0d2afc05f69 upstream.

Previous versions of `iio_compute_scan_bytes` only aligned each element
to its own length (i.e. its own natural alignment). Because multiple
consecutive sets of scan elements are buffered this does not work in
case the computed scan bytes do not align with the natural alignment of
the first scan element in the set.

This commit fixes this by aligning the scan bytes to the natural
alignment of the largest scan element in the set.

Fixes: 959d2952d124 ("staging:iio: make iio_sw_buffer_preenable much more general.")
Signed-off-by: Lars Möllendorf <lars.moellendorf@plating.de>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-23 08:22:33 +01:00
Tomasz Duszynski
6786d6a4f3 iio: chemical: pms7003: fix unmet triggered buffer dependency
commit 217afe63ccf445fc220e5ef480683607b05c0aa5 upstream.

IIO triggered buffer depends on IIO buffer which is missing from Kconfig
file. This should go unnoticed most of the time because there's a
chance something else has already enabled buffers. In some rare cases
though one might experience kbuild warnings about unmet direct
dependencies and build failures due to missing symbols.

Fix this by selecting IIO_BUFFER explicitly.

Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
Fixes: a1d642266c14 ("iio: chemical: add support for Plantower PMS7003 sensor")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-23 08:22:33 +01:00
Guido Günther
70814a4b2a iio: light: vcnl4000: Fix scale for vcnl4040
commit bc80573ea25bb033a58da81b3ce27205b97c088e upstream.

According to the data sheet the ambient sensor's scale is 0.12 lux/step
(not 0.024 lux/step as used by vcnl4200) when the integration time is
80ms. The integration time is currently hardcoded in the driver to that
value.

See p. 8 in https://www.vishay.com/docs/84307/designingvcnl4040.pdf

Fixes: 5a441aade5b3 ("iio: light: vcnl4000 add support for the VCNL4040 proximity and light sensor")
Signed-off-by: Guido Günther <agx@sigxcpu.org>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-23 08:22:33 +01:00
Stephan Gerhold
8e5164949a iio: imu: st_lsm6dsx: Fix selection of ST_LSM6DS3_ID
commit fb4fbc8904e786537e29329d791147389e1465a2 upstream.

At the moment, attempting to probe a device with ST_LSM6DS3_ID
(e.g. using the st,lsm6ds3 compatible) fails with:

    st_lsm6dsx_i2c 1-006b: unsupported whoami [69]

... even though 0x69 is the whoami listed for ST_LSM6DS3_ID.

This happens because st_lsm6dsx_check_whoami() also attempts
to match unspecified (zero-initialized) entries in the "id" array.
ST_LSM6DS3_ID = 0 will therefore match any entry in
st_lsm6dsx_sensor_settings (here: the first), because none of them
actually have all 12 entries listed in the "id" array.

Avoid this by additionally checking if "name" is set,
which is only set for valid entries in the "id" array.

Note: Although the problem was introduced earlier it did not surface until
commit 52f4b1f19679 ("iio: imu: st_lsm6dsx: add support for accel/gyro unit of lsm9ds1")
because ST_LSM6DS3_ID was the first entry in st_lsm6dsx_sensor_settings.

Fixes: d068e4a0f921 ("iio: imu: st_lsm6dsx: add support to multiple devices with the same settings")
Cc: <stable@vger.kernel.org> # 5.4
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-23 08:22:33 +01:00
Alexandru Tachici
5408cbc633 iio: adc: ad7124: Fix DT channel configuration
commit d7857e4ee1ba69732b16c73b2f2dde83ecd78ee4 upstream.

This patch fixes device tree channel configuration.

ad7124 driver reads channels configuration from the device tree.
It expects to find channel specifications as child nodes.
Before this patch ad7124 driver assumed that the child nodes are parsed
by for_each_available_child_of_node in the order 0,1,2,3...

This is wrong and the real order of the children can be seen by running:
dtc -I fs /sys/firmware/devicetree/base on the machine.

For example, running this on an rpi 3B+ yields the real
children order: 4,2,0,7,5,3,1,6

Before this patch the driver assigned the channel configuration
like this:
        - 0 <- 4
        - 1 <- 2
        - 2 <- 0
        ........
For example, the symptoms can be observed by connecting the 4th channel
to a 1V tension and then reading the in_voltage0-voltage19_raw sysfs
(multiplied of course by the scale) one would see that channel 0
measures 1V and channel 4 measures only noise.

Now the driver uses the reg property of each child in order to
correctly identify to which channel the parsed configuration
belongs to.

Fixes b3af341bbd966: ("iio: adc: Add ad7124 support")
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-23 08:22:33 +01:00
Alexandru Ardelean
c2fa84aca8 iio: imu: adis16480: assign bias value only if operation succeeded
commit 9b742763d9d4195e823ae6ece760c9ed0500c1dc upstream.

This was found only after the whole thing with the inline functions, but
the compiler actually found something. The value of the `bias` (in
adis16480_get_calibbias()) should only be set if the read operation was
successful.

No actual known problem occurs as users of this function all
ultimately check the return value.  Hence probably not stable material.

Fixes: 2f3abe6cbb6c9 ("iio:imu: Add support for the ADIS16480 and similar IMUs")
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-17 19:48:48 +01:00
Lorenzo Bianconi
62d701a130 iio: imu: st_lsm6dsx: fix gyro gain definitions for LSM9DS1
commit 1b3751017e09f0857bc38f9b1be08dce38f3d92c upstream.

Fix typos in gyro gain definitions for LSM9DS1 sensor

Fixes: 52f4b1f19679 ("iio: imu: st_lsm6dsx: add support for accel/gyro unit of lsm9ds1")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-17 19:48:48 +01:00
Geert Uytterhoeven
8db2bb9681 iio: adc: max9611: Fix too short conversion time delay
[ Upstream commit 9fd229c478fbf77c41c8528aa757ef14210365f6 ]

As of commit b9ddd5091160793e ("iio: adc: max9611: Fix temperature
reading in probe"), max9611 initialization sometimes fails on the
Salvator-X(S) development board with:

    max9611 4-007f: Invalid value received from ADC 0x8000: aborting
    max9611: probe of 4-007f failed with error -5

The max9611 driver tests communications with the chip by reading the die
temperature during the probe function, which returns an invalid value.

According to the datasheet, the typical ADC conversion time is 2 ms, but
no minimum or maximum values are provided.  Maxim Technical Support
confirmed this was tested with temperature Ta=25 degreeC, and promised
to inform me if a maximum/minimum value is available (they didn't get
back to me, so I assume it is not).

However, the driver assumes a 1 ms conversion time.  Usually the
usleep_range() call returns after more than 1.8 ms, hence it succeeds.
When it returns earlier, the data register may be read too early, and
the previous measurement value will be returned.  After boot, this is
the temperature POR (power-on reset) value, causing the failure above.

Fix this by increasing the delay from 1000-2000 µs to 3000-3300 µs.

Note that this issue has always been present, but it was exposed by the
aformentioned commit.

Fixes: 69780a3bbc0b1e7e ("iio: adc: Add Maxim max9611 ADC driver")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-09 10:19:43 +01:00
YueHaibing
f7a667db91 iio: st_accel: Fix unused variable warning
[ Upstream commit 0163c1c521ff8b09cd8ca395003cc00178161d77 ]

drivers/iio/accel/st_accel_core.c:1005:44: warning:
 mount_matrix_ext_info defined but not used [-Wunused-const-variable=]

Using stub helper while CONFIG_ACPI is disabled to fix it.

Suggested-by: Ladislav Michl <ladis@linux-mips.org>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-09 10:19:43 +01:00
Stefan Popa
8714dfa436 iio: dac: ad5446: Add support for new AD5600 DAC
[ Upstream commit 6376cbe549fffb378403cee78efd26b8a2c8e450 ]

The AD5600 is a single channel, 16-bit resolution, voltage output digital
to analog converter (DAC). The AD5600 uses a 3-wire SPI interface. It is
part of the AD5541 family of DACs.

The ad5446 IIO driver implements support for some of these DACs (in the
AD5441 family), so the change is a simple entry in this driver.

Link: https://www.analog.com/media/en/technical-documentation/data-sheets/AD5600.pdf

Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31 16:45:19 +01:00
Gwendal Grignou
dd20c1122e iio: cros_ec_baro: set info_mask_shared_by_all_available field
[ Upstream commit e9a4cbcaaa391ef44d623d548ee715e77265030c ]

Field was already set for light/proximity and
accelerometer/gyroscope/magnetometer sensors.

Fixes: ae7b02ad2f32 ("iio: common: cros_ec_sensors: Expose cros_ec_sensors frequency range via iio sysfs")
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31 16:45:15 +01:00
Alexandru Ardelean
8679dce8c6 iio: dln2-adc: fix iio_triggered_buffer_postenable() position
[ Upstream commit a7bddfe2dfce1d8859422124abe1964e0ecd386e ]

The iio_triggered_buffer_postenable() hook should be called first to
attach the poll function. The iio_triggered_buffer_predisable() hook is
called last (as is it should).

This change moves iio_triggered_buffer_postenable() to be called first. It
adds iio_triggered_buffer_predisable() on the error paths of the postenable
hook.
For the predisable hook, some code-paths have been changed to make sure
that the iio_triggered_buffer_predisable() hook gets called in case there
is an error before it.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31 16:44:32 +01:00
Miquel Raynal
e57ff9fb69 iio: adc: max1027: Reset the device at probe time
[ Upstream commit db033831b4f5589f9fcbadb837614a7c4eac0308 ]

All the registers are configured by the driver, let's reset the chip
at probe time, avoiding any conflict with a possible earlier
configuration.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31 16:44:07 +01:00
Krzysztof Wilczynski
240e9c97ba iio: light: bh1750: Resolve compiler warning and make code more readable
[ Upstream commit f552fde983d378e7339f9ea74a25f918563bf0d3 ]

Separate the declaration of struct bh1750_chip_info from definition
of bh1750_chip_info_tbl[] in a single statement as it makes the code
hard to read, and with the extra newline it makes it look as if the
bh1750_chip_info_tbl[] had no explicit type.

This change also resolves the following compiler warning about the
unusual position of the static keyword that can be seen when building
with warnings enabled (W=1):

drivers/iio/light/bh1750.c:64:1: warning:
  ‘static’ is not at beginning of declaration [-Wold-style-declaration]

Related to commit 3a11fbb037a1 ("iio: light: add support for ROHM
BH1710/BH1715/BH1721/BH1750/BH1751 ambient light sensors").

Signed-off-by: Krzysztof Wilczynski <kw@linux.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31 16:42:48 +01:00
Andrea Merello
2eea454289 iio: max31856: add missing of_node and parent references to iio_dev
[ Upstream commit 505ea3ada665c466d0064b11b6e611b7f995517d ]

Adding missing indio_dev->dev.of_node references so that, in case multiple
max31856 are present, users can get some clues to being able to distinguish
each of them. While at it, add also the missing parent reference.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31 16:42:46 +01:00
Andrea Merello
af5b2e18ae iio: ad7949: fix channels mixups
[ Upstream commit 3b71f6b59508b1c9befcb43de434866aafc76520 ]

Each time we need to read a sample (from the sysfs interface, since the
driver supports only it) the driver writes the configuration register
with the proper settings needed to perform the said read, then it runs
another xfer to actually read the resulting value. Most notably the
configuration register is updated to set the ADC internal MUX depending by
which channel the read targets.

Unfortunately this seems not enough to ensure correct operation because
the ADC works in a pipelined-like fashion and the new configuration isn't
applied in time.

The ADC alternates two phases: acquisition and conversion. During the
acquisition phase the ADC samples the analog signal in an internal
capacitor; in the conversion phase the ADC performs the actual analog to
digital conversion of the stored voltage. Note that of course the MUX
needs to be set to the proper channel when the acquisition phase is
performed.

Once the conversion phase has been completed, the device automatically
switches back to a new acquisition; on the other hand the device switches
from acquisition to conversion on the rising edge of SPI cs signal (that
is when the xfer finishes).

Only after both two phases have been completed (with the proper settings
already written in the configuration register since the beginning) it is
possible to read the outcome from SPI bus.

With the current driver implementation, we end up in the following
situation:

        _______  1st xfer ____________  2nd xfer ___________________
SPI cs..       \_________/            \_________/
SPI rd.. idle  |(val N-2)+    idle    | val N-1 +   idle ...
SPI wr.. idle  |  cfg N  +    idle    |   (X)   +   idle ...
------------------------ + -------------------- + ------------------
  AD  ..   acq  N-1      + cnv N-1 |  acq N     +  cnv N  | acq N+1

As shown in the diagram above, the value we read in the Nth read belongs
to configuration setting N-1.

In case the configuration is not changed (config[N] == config[N-1]), then
we still get correct data, but in case the configuration changes (i.e.
switching the MUX on another channel), we get wrong data (data from the
previously selected channel).

This patch fixes this by performing one more "dummy" transfer in order to
ending up in reading the data when it's really ready, as per the following
timing diagram.

        _______  1st xfer ____________  2nd xfer ___________  3rd xfer ___
SPI cs..       \_________/            \_________/           \_________/
SPI rd.. idle  |(val N-2)+    idle    |(val N-1)+    idle   |  val N  + ..
SPI wr.. idle  |  cfg N  +    idle    |   (X)   +    idle   |   (X)   + ..
------------------------ + -------------------- + ------------------- + --
  AD  ..   acq  N-1      + cnv N-1 |  acq N     +  cnv N  | acq N+1   | ..

NOTE: in the latter case (cfg changes), the acquisition phase for the
value to be read begins after the 1st xfer, that is after the read request
has been issued on sysfs. On the other hand, if the cfg doesn't change,
then we can refer to the fist diagram assuming N == (N - 1); the
acquisition phase _begins_ before the 1st xfer (potentially a lot of time
before the read has been issued via sysfs, but it _ends_ after the 1st
xfer, that is _after_ the read has started. This should guarantee a
reasonably fresh data, which value represents the voltage that the sampled
signal has after the read start or maybe just around it.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Reviewed-by: Charles-Antoine Couret <charles-antoine.couret@essensium.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-17 19:56:45 +01:00
Andrea Merello
a4160d9f57 iio: ad7949: kill pointless "readback"-handling code
[ Upstream commit c270bbf7bb9ddc4e2a51b3c56557c377c9ac79bc ]

The device could be configured to spit out also the configuration word
while reading the AD result value (in the same SPI xfer) - this is called
"readback" in the device datasheet.

The driver checks if readback is enabled and it eventually adjusts the SPI
xfer length and it applies proper shifts to still get the data, discarding
the configuration word.

The readback option is actually never enabled (the driver disables it), so
the said checks do not serve for any purpose.

Since enabling the readback option seems not to provide any advantage (the
driver entirely sets the configuration word without relying on any default
value), just kill the said, unused, code.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-17 19:56:45 +01:00