Commit graph

1659 commits

Author SHA1 Message Date
Marcus Folkesson
cca358eaa4 iio: dac: mcp4922: fix error handling in mcp4922_write_raw
[ Upstream commit 0833627fc3f757a0dca11e2a9c46c96335a900ee ]

Do not try to write negative values and make sure that the write goes well.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-25 15:53:44 +01:00
Alexandru Ardelean
c1bbd9808c iio: imu: adis16480: make sure provided frequency is positive
commit 24e1eb5c0d78cfb9750b690bbe997d4d59170258 upstream.

It could happen that either `val` or `val2` [provided from userspace] is
negative. In that case the computed frequency could get a weird value.

Fix this by checking that neither of the 2 variables is negative, and check
that the computed result is not-zero.

Fixes: e4f9593901 ("iio: imu: adis16480 switch sampling frequency attr to core support")
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@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>
2019-11-12 19:13:20 +01:00
Pascal Bouwmann
74ebfbc9ec iio: fix center temperature of bmc150-accel-core
[ Upstream commit 6c59a962e081df6d8fe43325bbfabec57e0d4751 ]

The center temperature of the supported devices stored in the constant
BMC150_ACCEL_TEMP_CENTER_VAL is not 24 degrees but 23 degrees.

It seems that some datasheets were inconsistent on this value leading
to the error.  For most usecases will only make minor difference so
not queued for stable.

Signed-off-by: Pascal Bouwmann <bouwmann@tau-tec.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-06 12:09:13 +01:00
David Frey
07bc13c09b iio: light: opt3001: fix mutex unlock race
commit 82f3015635249a8c8c45bac303fd84905066f04f upstream.

When an end-of-conversion interrupt is received after performing a
single-shot reading of the light sensor, the driver was waking up the
result ready queue before checking opt->ok_to_ignore_lock to determine
if it should unlock the mutex. The problem occurred in the case where
the other thread woke up and changed the value of opt->ok_to_ignore_lock
to false prior to the interrupt thread performing its read of the
variable. In this case, the mutex would be unlocked twice.

Signed-off-by: David Frey <dpfrey@gmail.com>
Reviewed-by: Andreas Dannenberg <dannenberg@ti.com>
Fixes: 94a9b7b180 ("iio: light: add support for TI's opt3001 light sensor")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-17 13:41:03 -07:00
Marco Felsch
2a736f3547 iio: adc: ad799x: fix probe error handling
commit c62dd44901cfff12acc5792bf3d2dec20bcaf392 upstream.

Since commit 0f7ddcc1bf ("iio:adc:ad799x: Write default config on probe
and reset alert status on probe") the error path is wrong since it
leaves the vref regulator on. Fix this by disabling both regulators.

Fixes: 0f7ddcc1bf ("iio:adc:ad799x: Write default config on probe and reset alert status on probe")
Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@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>
2019-10-17 13:41:03 -07:00
Nathan Chancellor
6d7b052d84 iio: common: ssp_sensors: Initialize calculated_time in ssp_common_process_data
[ Upstream commit 6f9ca1d3eb74b81f811a87002de2d51640d135b1 ]

When building with -Wsometimes-uninitialized, Clang warns:

drivers/iio/common/ssp_sensors/ssp_iio.c:95:6: warning: variable
'calculated_time' is used uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]

While it isn't wrong, this will never be a problem because
iio_push_to_buffers_with_timestamp only uses calculated_time
on the same condition that it is assigned (when scan_timestamp
is not zero). While iio_push_to_buffers_with_timestamp is marked
as inline, Clang does inlining in the optimization stage, which
happens after the semantic analysis phase (plus inline is merely
a hint to the compiler).

Fix this by just zero initializing calculated_time.

Link: https://github.com/ClangBuiltLinux/linux/issues/394
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-11 12:24:02 +02:00
Lars-Peter Clausen
a86d061794 iio: ad_sigma_delta: Properly handle SPI bus locking vs CS assertion
[ Upstream commit df1d80aee963480c5c2938c64ec0ac3e4a0df2e0 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-11 12:24:02 +02:00
Sven Van Asbroeck
45679938dc iio: adc: xilinx: fix potential use-after-free on remove
[ Upstream commit 62039b6aef63380ba7a37c113bbaeee8a55c5342 ]

When cancel_delayed_work() returns, the delayed work may still
be running. This means that the core could potentially free
the private structure (struct xadc) while the delayed work
is still using it. This is a potential use-after-free.

Fix by calling cancel_delayed_work_sync(), which waits for
any residual work to finish before returning.

Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-16 19:45:05 +02:00
he, bo
dc4f96499d io: accel: kxcjk1013: restore the range after resume.
commit fe2d3df639a7940a125a33d6460529b9689c5406 upstream.

On some laptops, kxcjk1013 is powered off when system enters S3. We need
restore the range regiter during resume. Otherwise, the sensor doesn't
work properly after S3.

Signed-off-by: he, bo <bo.he@intel.com>
Signed-off-by: Chen, Hu <hu1.chen@intel.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>
2019-04-27 09:34:01 +02:00
Georg Ottinger
07921e3cb1 iio: adc: at91: disable adc channel interrupt in timeout case
commit 09c6bdee51183a575bf7546890c8c137a75a2b44 upstream.

Having a brief look at at91_adc_read_raw() it is obvious that in the case
of a timeout the setting of AT91_ADC_CHDR and AT91_ADC_IDR registers is
omitted. If 2 different channels are queried we can end up with a
situation where two interrupts are enabled, but only one interrupt is
cleared in the interrupt handler. Resulting in a interrupt loop and a
system hang.

Signed-off-by: Georg Ottinger <g.ottinger@abatec.at>
Acked-by: Ludovic Desroches <ludovic.desroches@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>
2019-04-27 09:34:01 +02:00
Dragos Bogdan
c69e21be54 iio: ad_sigma_delta: select channel when reading register
commit fccfb9ce70ed4ea7a145f77b86de62e38178517f upstream.

The desired channel has to be selected in order to correctly fill the
buffer with the corresponding data.
The `ad_sd_write_reg()` already does this, but for the
`ad_sd_read_reg_raw()` this was omitted.

Fixes: af3008485e ("iio:adc: Add common code for ADI Sigma Delta devices")
Signed-off-by: Dragos Bogdan <dragos.bogdan@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@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>
2019-04-27 09:34:01 +02:00
Mike Looijmans
e20204c43c iio/gyro/bmg160: Use millidegrees for temperature scale
commit 40a7198a4a01037003c7ca714f0d048a61e729ac upstream.

Standard unit for temperature is millidegrees Celcius, whereas this driver
was reporting in degrees. Fix the scale factor in the driver.

Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-27 09:34:01 +02:00
Eugen Hristev
cc8e1ff726 iio: adc: at91: fix wrong channel number in triggered buffer mode
commit aea835f2dc8a682942b859179c49ad1841a6c8b9 upstream.

When channels are registered, the hardware channel number is not the
actual iio channel number.
This is because the driver is probed with a certain number of accessible
channels. Some pins are routed and some not, depending on the description of
the board in the DT.
Because of that, channels 0,1,2,3 can correspond to hardware channels
2,3,4,5 for example.
In the buffered triggered case, we need to do the translation accordingly.
Fixed the channel number to stop reading the wrong channel.

Fixes: 0e589d5fb ("ARM: AT91: IIO: Add AT91 ADC driver.")
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@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>
2018-11-21 09:27:35 +01:00
Eugen Hristev
6b2aa089c9 iio: adc: at91: fix acking DRDY irq on simple conversions
commit bc1b45326223e7e890053cf6266357adfa61942d upstream.

When doing simple conversions, the driver did not acknowledge the DRDY irq.
If this irq status is not acked, it will be left pending, and as soon as a
trigger is enabled, the irq handler will be called, it doesn't know why
this status has occurred because no channel is pending, and then it will go
int a irq loop and board will hang.
To avoid this situation, read the LCDR after a raw conversion is done.

Fixes: 0e589d5fb ("ARM: AT91: IIO: Add AT91 ADC driver.")
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@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>
2018-11-21 09:27:35 +01:00
Lars-Peter Clausen
0785d7aedf iio: ad9523: Fix return value for ad952x_store()
commit 9a5094ca29ea9b1da301b31fd377c0c0c4c23034 upstream.

A sysfs write callback function needs to either return the number of
consumed characters or an error.

The ad952x_store() function currently returns 0 if the input value was "0",
this will signal that no characters have been consumed and the function
will be called repeatedly in a loop indefinitely. Fix this by returning
number of supplied characters to indicate that the whole input string has
been consumed.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Fixes: cd1678f963 ("iio: frequency: New driver for AD9523 SPI Low Jitter Clock Generator")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-09 20:04:33 +02:00
Lars-Peter Clausen
ac14c5d1a5 iio: ad9523: Fix displayed phase
commit 5a4e33c1c53ae7d4425f7d94e60e4458a37b349e upstream.

Fix the displayed phase for the ad9523 driver. Currently the most
significant decimal place is dropped and all other digits are shifted one
to the left. This is due to a multiplication by 10, which is not necessary,
so remove it.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Fixes: cd1678f963 ("iio: frequency: New driver for AD9523 SPI Low Jitter Clock Generator")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-09 20:04:33 +02:00
Martin Kelly
5c39f9f374 iio:buffer: make length types match kfifo types
commit c043ec1ca5baae63726aae32abbe003192bc6eec upstream.

Currently, we use int for buffer length and bytes_per_datum. However,
kfifo uses unsigned int for length and size_t for element size. We need
to make sure these matches or we will have bugs related to overflow (in
the range between INT_MAX and UINT_MAX for length, for example).

In addition, set_bytes_per_datum uses size_t while bytes_per_datum is an
int, which would cause bugs for large values of bytes_per_datum.

Change buffer length to use unsigned int and bytes_per_datum to use
size_t.

Signed-off-by: Martin Kelly <mkelly@xevo.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
[bwh: Backported to 4.4:
 - Drop change to iio_dma_buffer_set_length()
 - Adjust filename, context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-03 11:21:30 +02:00
Martin Kelly
a6b686a290 iio:kfifo_buf: check for uint overflow
commit 3d13de4b027d5f6276c0f9d3a264f518747d83f2 upstream.

Currently, the following causes a kernel OOPS in memcpy:

echo 1073741825 > buffer/length
echo 1 > buffer/enable

Note that using 1073741824 instead of 1073741825 causes "write error:
Cannot allocate memory" but no OOPS.

This is because 1073741824 == 2^30 and 1073741825 == 2^30+1. Since kfifo
rounds up to the nearest power of 2, it will actually call kmalloc with
roundup_pow_of_two(length) * bytes_per_datum.

Using length == 1073741825 and bytes_per_datum == 2, we get:

kmalloc(roundup_pow_of_two(1073741825) * 2
or kmalloc(2147483648 * 2)
or kmalloc(4294967296)
or kmalloc(UINT_MAX + 1)

so this overflows to 0, causing kmalloc to return ZERO_SIZE_PTR and
subsequent memcpy to fail once the device is enabled.

Fix this by checking for overflow prior to allocating a kfifo. With this
check added, the above code returns -EINVAL when enabling the buffer,
rather than causing an OOPS.

Signed-off-by: Martin Kelly <mkelly@xevo.com>
cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-06 16:46:22 +02:00
Lorenzo Bianconi
857fb4eb56 iio: magnetometer: st_magn_spi: fix spi_device_id table
[ Upstream commit c83761ff0aac954aa368c623bb0f0d1a3214e834 ]

Remove LSM303DLHC, LSM303DLM from st_magn_id_table since LSM303DL series
does not support spi interface

Fixes: 872e79add7 (iio: magn: Add STMicroelectronics magn driver)
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-13 19:50:21 +02:00
Nikita Yushchenko
a091f8aba5 iio: hi8435: cleanup reset gpio
[ Upstream commit 61305664a542f874283f74bf0b27ddb31f5045d7 ]

Reset GPIO is active low.

Currently driver uses gpiod_set_value(1) to clean reset, which depends
on device tree to contain GPIO_ACTIVE_HIGH - that does not match reality.

This fixes driver to use _raw version of gpiod_set_value() to enforce
active-low semantics despite of what's written in device tree. Allowing
device tree to override that only opens possibility for errors and does
not add any value.

Additionally, use _cansleep version to make things work with i2c-gpio
and other sleeping gpio drivers.

Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-13 19:50:08 +02:00
Nikita Yushchenko
ce839ed818 iio: hi8435: avoid garbage event at first enable
[ Upstream commit ee19ac340c5fdfd89c6348be4563453c61ab54a9 ]

Currently, driver generates events for channels if new reading differs
from previous one. This "previous value" is initialized to zero, which
results into event if value is constant-one.

Fix that by initializing "previous value" by reading at event enable
time.

This provides reliable sequence for userspace:
- enable event,
- AFTER THAT read current value,
- AFTER THAT each event will correspond to change.

Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-13 19:50:08 +02:00
Michael Nosthoff
8e1f1062d9 iio: st_pressure: st_accel: pass correct platform data to init
commit 8b438686a001db64c21782d04ef68111e53c45d9 upstream.

Commit 7383d44b added a pointer pdata which get set to the default
platform_data when non was defined in the device. But it did not
pass this pointer to the st_sensors_init_sensor call but still
used the maybe uninitialized platform_data from dev.

This breaks initialization when no platform_data is given and
the optional st,drdy-int-pin devicetree option is not set.

This commit fixes this.

Cc: stable@vger.kernel.org
Fixes: 7383d44b ("iio: st_pressure: st_accel: Initialise sensor platform data properly")
Signed-off-by: Michael Nosthoff <committed@heine.so>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-28 18:40:12 +02:00
Shrirang Bagul
50f7d70a3f iio: st_pressure: st_accel: Initialise sensor platform data properly
[ Upstream commit 7383d44b84c94aaca4bf695a6bd8a69f2295ef1a ]

This patch fixes the sensor platform data initialisation for st_pressure
and st_accel device drivers. Without this patch, the driver fails to
register the sensors when the user removes and re-loads the driver.

1. Unload the kernel modules for st_pressure
$ sudo rmmod st_pressure_i2c
$ sudo rmmod st_pressure

2. Re-load the driver
$ sudo insmod st_pressure
$ sudo insmod st_pressure_i2c

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-24 10:58:44 +01:00
Lars-Peter Clausen
b19f9c4311 iio: adis_lib: Initialize trigger before requesting interrupt
commit f027e0b3a774e10302207e91d304bbf99e3a8b36 upstream.

The adis_probe_trigger() creates a new IIO trigger and requests an
interrupt associated with the trigger. The interrupt uses the generic
iio_trigger_generic_data_rdy_poll() function as its interrupt handler.

Currently the driver initializes some fields of the trigger structure after
the interrupt has been requested. But an interrupt can fire as soon as it
has been requested. This opens up a race condition.

iio_trigger_generic_data_rdy_poll() will access the trigger data structure
and dereference the ops field. If the ops field is not yet initialized this
will result in a NULL pointer deref.

It is not expected that the device generates an interrupt at this point, so
typically this issue did not surface unless e.g. due to a hardware
misconfiguration (wrong interrupt number, wrong polarity, etc.).

But some newer devices from the ADIS family start to generate periodic
interrupts in their power-on reset configuration and unfortunately the
interrupt can not be masked in the device.  This makes the race condition
much more visible and the following crash has been observed occasionally
when booting a system using the ADIS16460.

	Unable to handle kernel NULL pointer dereference at virtual address 00000008
	pgd = c0004000
	[00000008] *pgd=00000000
	Internal error: Oops: 5 [#1] PREEMPT SMP ARM
	Modules linked in:
	CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.9.0-04126-gf9739f0-dirty #257
	Hardware name: Xilinx Zynq Platform
	task: ef04f640 task.stack: ef050000
	PC is at iio_trigger_notify_done+0x30/0x68
	LR is at iio_trigger_generic_data_rdy_poll+0x18/0x20
	pc : [<c042d868>]    lr : [<c042d924>]    psr: 60000193
	sp : ef051bb8  ip : 00000000  fp : ef106400
	r10: c081d80a  r9 : ef3bfa00  r8 : 00000087
	r7 : ef051bec  r6 : 00000000  r5 : ef3bfa00  r4 : ee92ab00
	r3 : 00000000  r2 : 00000000  r1 : 00000000  r0 : ee97e400
	Flags: nZCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment none
	Control: 18c5387d  Table: 0000404a  DAC: 00000051
	Process swapper/0 (pid: 1, stack limit = 0xef050210)
	[<c042d868>] (iio_trigger_notify_done) from [<c0065b10>] (__handle_irq_event_percpu+0x88/0x118)
	[<c0065b10>] (__handle_irq_event_percpu) from [<c0065bbc>] (handle_irq_event_percpu+0x1c/0x58)
	[<c0065bbc>] (handle_irq_event_percpu) from [<c0065c30>] (handle_irq_event+0x38/0x5c)
	[<c0065c30>] (handle_irq_event) from [<c0068e28>] (handle_level_irq+0xa4/0x130)
	[<c0068e28>] (handle_level_irq) from [<c0064e74>] (generic_handle_irq+0x24/0x34)
	[<c0064e74>] (generic_handle_irq) from [<c021ab7c>] (zynq_gpio_irqhandler+0xb8/0x13c)
	[<c021ab7c>] (zynq_gpio_irqhandler) from [<c0064e74>] (generic_handle_irq+0x24/0x34)
	[<c0064e74>] (generic_handle_irq) from [<c0065370>] (__handle_domain_irq+0x5c/0xb4)
	[<c0065370>] (__handle_domain_irq) from [<c000940c>] (gic_handle_irq+0x48/0x8c)
	[<c000940c>] (gic_handle_irq) from [<c0013e8c>] (__irq_svc+0x6c/0xa8)

To fix this make sure that the trigger is fully initialized before
requesting the interrupt.

Fixes: ccd2b52f4a ("staging:iio: Add common ADIS library")
Reported-by: Robin Getz <Robin.Getz@analog.com>
Signed-off-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>
2018-02-28 10:17:22 +01:00
Stefan Windfeldt-Prytz
f4e23b4343 iio: buffer: check if a buffer has been set up when poll is called
commit 4cd140bda6494543f1c1b0ccceceaa44b676eef6 upstream.

If no iio buffer has been set up and poll is called return 0.
Without this check there will be a null pointer dereference when
calling poll on a iio driver without an iio buffer.

Cc: stable@vger.kernel.org
Signed-off-by: Stefan Windfeldt-Prytz <stefan.windfeldt@axis.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-28 10:17:22 +01:00
Colin Ian King
4f4762381f iio: adc: axp288: remove redundant duplicate const on axp288_adc_channels
commit 7ca6574a7afb669b0b4b30dd63adeb310e97e250 upstream.

duplicate const can be removed, it is redundant. Found by static
analysis using smatch.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-25 11:03:48 +01:00
Pan Bian
266913b390 iio: light: fix improper return value
[ Upstream commit db4e5376d058af8924fafd0520a0942d92538d0e ]

In function cm3232_reg_init(), it returns 0 even if the last call to
i2c_smbus_write_byte_data() returns a negative value (indicates error).
As a result, the return value may be inconsistent with the execution
status, and the caller of cm3232_reg_init() will not be able to detect
the error. This patch fixes the bug.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=188641

Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30 08:37:27 +00:00
Alison Schofield
079822da0a iio: trigger: free trigger resource correctly
[ Upstream commit 10e840dfb0b7fc345082dd9e5fff3c1c02e7690e ]

These stand-alone trigger drivers were using iio_trigger_put()
where they should have been using iio_trigger_free().  The
iio_trigger_put() adds a module_put which is bad since they
never did a module_get.

In the sysfs driver, module_get/put's are used as triggers are
added & removed. This extra module_put() occurs on an error path
in the probe routine (probably rare).

In the bfin-timer & interrupt trigger drivers, the module resources
are not explicitly managed, so it's doing a put on something that
was never get'd.  It occurs on the probe error path and on the
remove path (not so rare).

Tested with the sysfs trigger driver.
The bfin & interrupt drivers were build tested & inspected only.

Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-15 17:13:10 +01:00
Christophe JAILLET
4d134d830e iio: adc: xilinx: Fix error handling
[ Upstream commit ca1c39ef76376b67303d01f94fe98bb68bb3861a ]

Reorder error handling labels in order to match the way resources have
been allocated.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-21 17:09:04 +02:00
Lukas Wunner
8b4196420d iio: adc: mcp320x: Fix oops on module unload
commit 0964e40947a630a2a6f724e968246992f97bcf1c upstream.

The driver calls spi_get_drvdata() in its ->remove hook even though it
has never called spi_set_drvdata().  Stack trace for posterity:

Unable to handle kernel NULL pointer dereference at virtual address 00000220
Internal error: Oops: 5 [#1] SMP ARM
[<8072f564>] (mutex_lock) from [<7f1400d0>] (iio_device_unregister+0x24/0x7c [industrialio])
[<7f1400d0>] (iio_device_unregister [industrialio]) from [<7f15e020>] (mcp320x_remove+0x20/0x30 [mcp320x])
[<7f15e020>] (mcp320x_remove [mcp320x]) from [<8055a8cc>] (spi_drv_remove+0x2c/0x44)
[<8055a8cc>] (spi_drv_remove) from [<805087bc>] (__device_release_driver+0x98/0x134)
[<805087bc>] (__device_release_driver) from [<80509180>] (driver_detach+0xdc/0xe0)
[<80509180>] (driver_detach) from [<8050823c>] (bus_remove_driver+0x5c/0xb0)
[<8050823c>] (bus_remove_driver) from [<80509ab0>] (driver_unregister+0x38/0x58)
[<80509ab0>] (driver_unregister) from [<7f15e69c>] (mcp320x_driver_exit+0x14/0x1c [mcp320x])
[<7f15e69c>] (mcp320x_driver_exit [mcp320x]) from [<801a78d0>] (SyS_delete_module+0x184/0x1d0)
[<801a78d0>] (SyS_delete_module) from [<80108100>] (ret_fast_syscall+0x0/0x1c)

Fixes: f5ce4a7a92 ("iio: adc: add driver for MCP3204/08 12-bit ADC")
Cc: Oskar Andero <oskar.andero@gmail.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-12 11:27:34 +02:00
Lukas Wunner
18215da0c2 iio: adc: mcp320x: Fix readout of negative voltages
commit e6f4794371ee7cce1339e7ca9542f1e703c5f84a upstream.

Commit f686a36b4b ("iio: adc: mcp320x: Add support for mcp3301")
returns a signed voltage from mcp320x_adc_conversion() but neglects that
the caller interprets a negative return value as failure.  Only mcp3301
(and the upcoming mcp3550/1/3) is affected as the other chips are
incapable of measuring negative voltages.

Fix and while at it, add mcp3301 to the list of supported chips at the
top of the file.

Fixes: f686a36b4b ("iio: adc: mcp320x: Add support for mcp3301")
Cc: Andrea Galbusera <gizero@gmail.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-12 11:27:34 +02:00
Dragos Bogdan
f2f68ec0b2 iio: ad7793: Fix the serial interface reset
commit 7ee3b7ebcb74714df6d94c8f500f307e1ee5dda5 upstream.

The serial interface can be reset by writing 32 consecutive 1s to the device.
'ret' was initialized correctly but its value was overwritten when
ad7793_check_platform_data() was called. Since a dedicated reset function
is present now, it should be used instead.

Fixes: 2edb769d24 ("iio:ad7793: Add support for the ad7798 and ad7799")
Signed-off-by: Dragos Bogdan <dragos.bogdan@analog.com>
Acked-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>
2017-10-12 11:27:34 +02:00
Matt Fornero
2c29a38680 iio: core: Return error for failed read_reg
commit 3d62c78a6eb9a7d67bace9622b66ad51e81c5f9b upstream.

If an IIO device returns an error code for a read access via debugfs, it
is currently ignored by the IIO core (other than emitting an error
message). Instead, return this error code to user space, so upper layers
can detect it correctly.

Signed-off-by: Matt Fornero <matt.fornero@mathworks.com>
Signed-off-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>
2017-10-12 11:27:34 +02:00
Dragos Bogdan
4b9c62a00a iio: ad_sigma_delta: Implement a dedicated reset function
commit 7fc10de8d49a748c476532c9d8e8fe19e548dd67 upstream.

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>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-12 11:27:34 +02:00
Christophe JAILLET
0bab54141b iio: adc: twl4030: Disable the vusb3v1 rugulator in the error handling path of 'twl4030_madc_probe()'
commit 7f70be6e4025db0551e6863e7eb9cca07122695c upstream.

Commit 7cc97d77ee has introduced a call to 'regulator_disable()' in the
.remove function.
So we should also have such a call in the .probe function in case of
error after a successful 'regulator_enable()' call.

Add a new label for that and use it.

Fixes: 7cc97d77ee ("iio: adc: twl4030: Fix ADC[3:6] readings")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-12 11:27:34 +02:00
Christophe JAILLET
0141f858d2 iio: adc: twl4030: Fix an error handling path in 'twl4030_madc_probe()'
commit 245a396a9b1a67ac5c3228737c261b3e48708a2a upstream.

If 'devm_regulator_get()' fails, we should go through the existing error
handling path instead of returning directly, as done is all the other
error handling paths in this function.

Fixes: 7cc97d77ee ("iio: adc: twl4030: Fix ADC[3:6] readings")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-12 11:27:34 +02:00
Hans de Goede
a1f7b8ff49 iio: adc: axp288: Drop bogus AXP288_ADC_TS_PIN_CTRL register modifications
[ Upstream commit fa2849e9649b5180ffc4cb3c3b005261c403093a ]

For some reason the axp288_adc driver was modifying the
AXP288_ADC_TS_PIN_CTRL register, changing bits 0-1 depending on
whether the GP_ADC channel or another channel was written.

These bits control when a bias current is send to the TS_PIN, the
GP_ADC has its own pin and a separate bit in another register to
control the bias current.

Not only does changing when to enable the TS_PIN bias current
(always or only when sampling) when reading the GP_ADC make no sense
at all, the code is modifying these bits is writing the entire register,
assuming that all the other bits have their default value.

So if the firmware has configured a different bias-current for either
pin, then that change gets clobbered by the write, likewise if the
firmware has set bit 2 to indicate that the battery has no thermal sensor,
this will get clobbered by the write.

This commit fixes all this, by simply removing all writes to the
AXP288_ADC_TS_PIN_CTRL register, they are not needed to read the
GP_ADC pin, and can actually be harmful.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-08 10:14:17 +02:00
Srinivas Pandruvada
1d7e8cf01e iio: hid-sensor-trigger: Fix the race with user space powering up sensors
commit f1664eaacec31035450132c46ed2915fd2b2049a upstream.

It has been reported for a while that with iio-sensor-proxy service the
rotation only works after one suspend/resume cycle. This required a wait
in the systemd unit file to avoid race. I found a Yoga 900 where I could
reproduce this.

The problem scenerio is:
- During sensor driver init, enable run time PM and also set a
  auto-suspend for 3 seconds.
	This result in one runtime resume. But there is a check to avoid
a powerup in this sequence, but rpm is active
- User space iio-sensor-proxy tries to power up the sensor. Since rpm is
  active it will simply return. But sensors were not actually
powered up in the prior sequence, so actaully the sensors will not work
- After 3 seconds the auto suspend kicks

If we add a wait in systemd service file to fire iio-sensor-proxy after
3 seconds, then now everything will work as the runtime resume will
actually powerup the sensor as this is a user request.

To avoid this:
- Remove the check to match user requested state, this will cause a
  brief powerup, but if the iio-sensor-proxy starts immediately it will
still work as the sensors are ON.
- Also move the autosuspend delay to place when user requested turn off
  of sensors, like after user finished raw read or buffer disable

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Tested-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-30 10:19:27 +02:00
Dragos Bogdan
d2c072cb63 iio: imu: adis16480: Fix acceleration scale factor for adis16480
commit fdd0d32eb95f135041236a6885d9006315aa9a1d upstream.

According to the datasheet, the range of the acceleration is [-10 g, + 10 g],
so the scale factor should be 10 instead of 5.

Signed-off-by: Dragos Bogdan <dragos.bogdan@analog.com>
Acked-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>
2017-08-30 10:19:27 +02:00
Stefan-Gabriel Mirea
7b5a9de376 iio: adc: vf610_adc: Fix VALT selection value for REFSEL bits
commit d466d3c1217406b14b834335b5b4b33c0d45bd09 upstream.

In order to select the alternate voltage reference pair (VALTH/VALTL), the
right value for the REFSEL field in the ADCx_CFG register is "01", leading
to 0x800 as register mask. See section 8.2.6.4 in the reference manual[1].

[1] http://www.nxp.com/docs/en/reference-manual/VFXXXRM.pdf

Fixes: a775427632 ("iio:adc:imx: add Freescale Vybrid vf610 adc driver")
Signed-off-by: Stefan-Gabriel Mirea <stefan-gabriel.mirea@nxp.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-16 13:40:30 -07:00
Akinobu Mita
dedeba47c5 iio: light: tsl2563: use correct event code
commit a3507e48d3f99a93a3056a34a5365f310434570f upstream.

The TSL2563 driver provides three iio channels, two of which are raw ADC
channels (channel 0 and channel 1) in the device and the remaining one
is calculated by the two.  The ADC channel 0 only supports programmable
interrupt with threshold settings and this driver supports the event but
the generated event code does not contain the corresponding iio channel
type.

This is going to change userspace ABI.  Hopefully fixing this to be
what it should always have been won't break any userspace code.

Cc: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-16 13:40:30 -07:00
Hans de Goede
dfb5cc919c iio: accel: bmc150: Always restore device to normal mode after suspend-resume
commit e59e18989c68a8d7941005f81ad6abc4ca682de0 upstream.

After probe we would put the device in normal mode, after a runtime
suspend-resume we would put it back in normal mode. But for a regular
suspend-resume we would only put it back in normal mode if triggers
or events have been requested.  This is not consistent and breaks
reading raw values after a suspend-resume.

This commit changes the regular resume path to also unconditionally put
the device back in normal mode, fixing reading of raw values not working
after a regular suspend-resume cycle.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-16 13:40:29 -07:00
Matt Ranostay
7e2ad8b207 iio: proximity: as3935: recalibrate RCO after resume
commit 6272c0de13abf1480f701d38288f28a11b4301c4 upstream.

According to the datasheet the RCO must be recalibrated
on every power-on-reset. Also remove mutex locking in the
calibration function since callers other than the probe
function (which doesn't need it) will have a lock.

Fixes: 24ddb0e4bb ("iio: Add AS3935 lightning sensor support")
Cc: George McCollister <george.mccollister@gmail.com>
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-26 07:13:09 +02:00
Matt Ranostay
ff7739a287 iio: proximity: as3935: fix AS3935_INT mask
commit 275292d3a3d62670b1b13484707b74e5239b4bb0 upstream.

AS3935 interrupt mask has been incorrect so valid lightning events
would never trigger an buffer event. Also noise interrupt should be
BIT(0).

Fixes: 24ddb0e4bb ("iio: Add AS3935 lightning sensor support")
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-14 13:16:23 +02:00
Franziska Naepelt
64276cdbd4 iio: light: ltr501 Fix interchanged als/ps register field
commit 7cc3bff4efe6164a0c8163331c8aa55454799f42 upstream.

The register mapping for the IIO driver for the Liteon Light and Proximity
sensor LTR501 interrupt mode is interchanged (ALS/PS).
There is a register called INTERRUPT register (address 0x8F)
Bit 0 represents PS measurement trigger.
Bit 1 represents ALS measurement trigger.
This two bit fields are interchanged within the driver.
see datasheet page 24:
http://optoelectronics.liteon.com/upload/download/DS86-2012-0006/S_110_LTR-501ALS-01_PrelimDS_ver1%5B1%5D.pdf

Signed-off-by: Franziska Naepelt <franziska.naepelt@idt.com>
Fixes: 7ac702b314 ("iio: ltr501: Add interrupt support")
Acked-by: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-14 13:16:23 +02:00
Matt Ranostay
0e9e19a665 iio: proximity: as3935: fix as3935_write
commit 84ca8e364acb26aba3292bc113ca8ed4335380fd upstream.

AS3935_WRITE_DATA macro bit is incorrect and the actual write
sequence is two leading zeros.

Cc: George McCollister <george.mccollister@gmail.com>
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25 14:30:13 +02:00
Pavel Roskin
060d264268 iio: dac: ad7303: fix channel description
commit ce420fd4251809b4c3119b3b20c8b13bd8eba150 upstream.

realbits, storagebits and shift should be numbers, not ASCII characters.

Signed-off-by: Pavel Roskin <plroskin@gmail.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25 14:30:10 +02:00
Quentin Schulz
8ff7eb4bc8 iio: bmg160: reset chip when probing
commit 4bdc9029685ac03be50b320b29691766d2326c2b upstream.

The gyroscope chip might need to be reset to be used.

Without the chip being reset, the driver stopped at the first
regmap_read (to get the CHIP_ID) and failed to probe.

The datasheet of the gyroscope says that a minimum wait of 30ms after
the reset has to be done.

This patch has been checked on a BMX055 and the datasheet of the BMG160
and the BMI055 give the same reset register and bits.

Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-12 12:38:33 +02:00
Song Hongyan
7413d1f899 iio: hid-sensor-trigger: Change get poll value function order to avoid sensor properties losing after resume from S3
commit 3bec247474469f769af41e8c80d3a100dd97dd76 upstream.

In function _hid_sensor_power_state(), when hid_sensor_read_poll_value()
is called, sensor's all properties will be updated by the value from
sensor hardware/firmware.
In some implementation, sensor hardware/firmware will do a power cycle
during S3. In this case, after resume, once hid_sensor_read_poll_value()
is called, sensor's all properties which are kept by driver during S3
will be changed to default value.
But instead, if a set feature function is called first, sensor
hardware/firmware will be recovered to the last status. So change the
sensor_hub_set_feature() calling order to behind of set feature function
to avoid sensor properties lose.

Signed-off-by: Song Hongyan <hongyan.song@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-30 09:35:17 +02:00
Michael Engl
8f189e1d0e iio: adc: ti_am335x_adc: fix fifo overrun recovery
commit e83bb3e6f3efa21f4a9d883a25d0ecd9dfb431e1 upstream.

The tiadc_irq_h(int irq, void *private) function is handling FIFO
overruns by clearing flags, disabling and enabling the ADC to
recover.

If the ADC is running in continuous mode a FIFO overrun happens
regularly. If the disabling of the ADC happens concurrently with
a new conversion. It might happen that the enabling of the ADC
is ignored by the hardware. This stops the ADC permanently. No
more interrupts are triggered.

According to the AM335x Reference Manual (SPRUH73H October 2011 -
Revised April 2013 - Chapter 12.4 and 12.5) it is necessary to
check the ADC FSM bits in REG_ADCFSM before enabling the ADC
again. Because the disabling of the ADC is done right after the
current conversion has been finished.

To trigger this bug it is necessary to run the ADC in continuous
mode. The ADC values of all channels need to be read in an endless
loop. The bug appears within the first 6 hours (~5.4 million
handled FIFO overruns). The user space application will hang on
reading new values from the character device.

Fixes: ca9a563805 ("iio: ti_am335x_adc: Add continuous sampling support")
Signed-off-by: Michael Engl <michael.engl@wjw-solutions.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-30 09:35:17 +02:00