Leonard Crestez observed the following phenomenon: when using
hard interrupt triggers (the DRDY line coming out of an ST
sensor) sometimes a new value would arrive while reading the
previous value, due to latencies in the system.
We discovered that the ST hardware as far as can be observed
is designed for level interrupts: the DRDY line will be held
asserted as long as there are new values coming. The interrupt
handler should be re-entered until we're out of values to
handle from the sensor.
If interrupts were handled as occurring on the edges (usually
low-to-high) new values could appear and the line be held
asserted after that, and these values would be missed, the
interrupt handler would also lock up as new data was
available, but as no new edges occurs on the DRDY signal,
nothing happens: the edge detector only detects edges.
To counter this, do the following:
- Accept interrupt lines to be flagged as level interrupts
using IRQF_TRIGGER_HIGH and IRQF_TRIGGER_LOW. If the line
is marked like this (in the device tree node or ACPI
table or similar) it will be utilized as a level IRQ.
We mark the line with IRQF_ONESHOT and mask the IRQ
while processing a sample, then the top half will be
entered again if new values are available.
- If we are flagged as using edge interrupts with
IRQF_TRIGGER_RISING or IRQF_TRIGGER_FALLING: remove
IRQF_ONESHOT so that the interrupt line is not
masked while running the thread part of the interrupt.
This way we will never miss an interrupt, then introduce
a loop that polls the data ready registers repeatedly
until no new samples are available, then exit the
interrupt handler. This way we know no new values are
available when the interrupt handler exits and
new (edge) interrupts will be triggered when data arrives.
Take some extra care to update the timestamp in the poll
loop if this happens. The timestamp will not be 100%
perfect, but it will at least be closer to the actual
events. Usually the extra poll loop will handle the new
samples, but once in a blue moon, we get a new IRQ
while exiting the loop, before returning from the
thread IRQ bottom half with IRQ_HANDLED. On these rare
occasions, the removal of IRQF_ONESHOT means the
interrupt will immediately fire again.
- If no interrupt type is indicated from the DT/ACPI,
choose IRQF_TRIGGER_RISING as default, as this is necessary
for legacy boards.
Tested successfully on the LIS331DL and L3G4200D by setting
sampling frequency to 400Hz/800Hz and stressing the system:
extra reads in the threaded interrupt handler occurs.
Cc: Giuseppe Barba <giuseppe.barba@st.com>
Cc: Denis Ciocca <denis.ciocca@st.com>
Tested-by: Crestez Dan Leonard <cdleonard@gmail.com>
Reported-by: Crestez Dan Leonard <cdleonard@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
We want the fixes in here, and we can resolve a merge issue in
drivers/iio/industrialio-trigger.c
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 98ad8b41f58dff6b30713d7f09ae3834b8df7ded
("iio: st_sensors: verify interrupt event to status") caused
a regression when reading ST sensors from a HRTimer trigger
rather than the intrinsic interrupts: the HRTimer may
trigger faster than the sensor provides new values, and
as the check against new values available as a cause of
the interrupt trigger was done in the poll function,
this would bail out of the HRTimer interrupt with
IRQ_NONE.
So clearly we need to only check the new values available
from the proper interrupt handler and not from the poll
function, which should rather just read the raw values
from the registers, put them into the buffer and be happy.
To achieve this: switch the ST Sensors over to using a true
threaded interrupt handler.
In the interrupt thread, check if new values are available,
else yield to the (potential) next device on the same
interrupt line to check the registers. If the interrupt
was ours, proceed to poll the values.
Instead of relying on iio_trigger_generic_data_rdy_poll() as
a top half to wake up the thread that polls the sensor for
new data, have the thread call iio_trigger_poll_chained()
after determining that is is the proper source of the
interrupt. This is modelled on drivers/iio/accel/mma8452.c
which is already using a properly threaded interrupt handler.
In order to get the same precision in timestamps as
previously, where samples would be timestamped in the
poll function pf->timestamp when calling
iio_trigger_generic_data_rdy_poll() we introduce a
local timestamp in the sensor data, set it in the top half
(fastpath) of the interrupt handler and provide that to the
core when calling iio_push_to_buffers_with_timestamp().
Additionally: if the active scanmask is not set for the
sensor no IRQs should be enabled and we need to bail out
with IRQ_NONE. This can happen if spurious IRQs fire when
installing the threaded interrupt handler.
Tested with hard interrupt triggers on LIS331DL, then also
tested with hrtimers on the same sensor by creating a 75Hz
HRTimer and using it to poll the sensor.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Giuseppe Barba <giuseppe.barba@st.com>
Cc: Denis Ciocca <denis.ciocca@st.com>
Reported-by: Crestez Dan Leonard <cdleonard@gmail.com>
Tested-by: Crestez Dan Leonard <cdleonard@gmail.com>
Tested-by: Jonathan Cameron <jic23@kernel.org>
Fixes: 97865fe413 ("iio: st_sensors: verify interrupt event to status")
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Ensure failure to enable power regulators is properly handled.
Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Remove st_sensors_get_buffer_element symbol export since not explicitly
used outside of st_sensors driver.
Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Some types of ST Sensors can be connected to the same IRQ line
as other peripherals using open drain. Add a device tree binding
and a sensor data property to flip the right bit in the interrupt
control register to enable open drain mode on the INT line.
If the line is set to be open drain, also tag on IRQF_SHARED
to the IRQ flags when requesting the interrupt, as the whole
point of using open drain interrupt lines is to share them with
more than one peripheral (wire-or).
Cc: devicetree@vger.kernel.org
Cc: Giuseppe Barba <giuseppe.barba@st.com>
Cc: Denis Ciocca <denis.ciocca@st.com>
Acked-by: Rob Herring <rob@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This makes all ST sensor drivers check that they actually have
new data available for the requested channel(s) before claiming
an IRQ, by reading the status register (which is conveniently
the same for all ST sensors) and check that the channel has new
data before proceeding to read it and fill the buffer.
This way sensors can share an interrupt line: it can be flaged
as shared and then the sensor that did not fire will return
NO_IRQ, and the sensor that fired will handle the IRQ and
return IRQ_HANDLED.
Cc: Giuseppe Barba <giuseppe.barba@st.com>
Cc: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Most ST MEMS Sensors that support interrupts can also handle sending
an active low interrupt, i.e. going from high to low on data ready
(or other interrupt) and thus triggering on a falling edge to the
interrupt controller.
Set up logic to inspect the interrupt line we get for a sensor: if
it is triggering on rising edge, leave everything alone, but if it
triggers on falling edges, set up active low, and if unsupported
configurations appear: warn with errors and reconfigure the interrupt
to a rising edge, which all interrupt generating sensors support.
Create a local header for st_sensors_core.h to share functions
between the sensor core and the trigger setup code.
Cc: Giuseppe Barba <giuseppe.barba@st.com>
Cc: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This adds a debugfs hook to read/write registers in the ST
sensors using debugfs. Proved to be awesome help when trying
to debug why IRQs do not arrive.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This patch permits to configure the WhoAmI register address
because some device could have not a standard address for
this register.
Signed-off-by: Giuseppe Barba <giuseppe.barba@st.com>
Reviewed-by: Denis Ciocca <denis.ciocca@st.com>
Acked-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Sensorhub is MCU dedicated to collect data and manage several sensors.
Sensorhub is a spi device which provides a layer for IIO devices. It provides
some data parsing and common mechanism for sensorhub sensors.
Adds common sensorhub library for sensorhub driver and iio drivers
which uses sensorhub MCU to communicate with sensors.
Signed-off-by: Karol Wrona <k.wrona@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This patch change structure name and related variables names.
Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
The I2C devices that make up the STMicroelectronics MEMS sensors
may be sneakily enabled by cleverly giving the device node the same
name as a string match from the platform device ID table. However
the right method is to use the compatible string.
On detection, the ST sensors use the ID string to probe and
instatiate the right sensor driver, so pass the kernel-internal ID
string in the .data field of the OF match table, and set the I2C
client name to this name when a compatible match is used.
This avoids having misc Linux-specific strings floating around in
the device tree.
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Denis CIOCCA <denis.ciocca@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This allows in kernel client drivers to access this
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Cc: Denis Ciocca <denis.ciocca@st.com>
Reviewed-by: Hartmut Knaack <knaack.h@gmx.de>
Currently the pressure sensor has code to retrieve and enable two
regulators for Vdd and Vdd IO, but actually these voltage inputs
are found on all of these ST sensors, so move the regulator
handling to the core and make sure all the ST sensors call these
functions on probe() and remove() to enable/disable power.
Here also mover over to obtaining the regulator from the *parent*
device of the IIO device, as the IIO device is created on-the-fly
in this very subsystem it very unlikely evert have any regulators
attached to it whatsoever. It is much more likely that the parent
is a platform device, possibly instantiated from a device tree,
which in turn have Vdd and Vdd IO supplied assigned to it.
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Denis CIOCCA <denis.ciocca@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
The power to some of the sensors are controlled by regulators. In most
cases these are 'always on', but if not they will fail to work until
the regulator is enabled using the relevant APIs. This patch allows for
the Vdd_IO power supply to be specified by either platform data or
Device Tree.
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
The power to some of the sensors are controlled by regulators. In most
cases these are 'always on', but if not they will fail to work until
the regulator is enabled using the relevant APIs. This patch allows for
the Vdd power supply to be specified by either platform data or Device
Tree.
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
At the moment the number of channels specified is dictated by the first
sensor supported by the driver. As we add support for more sensors this
is likely to vary. Instead of using the ARRAY_SIZE() of the LPS331AP's
channel specifier we'll use a new adaptable 'struct st_sensors' element
instead.
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This patch add support to redirect the DRDY interrupt on INT1 or INT2
on accelerometer and pressure sensors.
Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This patch introduce num_data_channels variable on st_sensors struct
to manage different type of channels (size or number) in
st_sensors_get_buffer_element function.
Removed ST_SENSORS_NUMBER_DATA_CHANNELS and ST_SENSORS_BYTE_FOR_CHANNEL
and used struct iio_chan_spec const *ch to catch data.
Added 3 byte channel data support on one-shot reads.
Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
New stuff
1) Add OF support for specifying mappings between iio devices and their
in kernel consumers.
2) Driver for AD7923 (extra functionality and support for ad7904, ad7914 and
ad7924 added later in series)
3) Driver for Exynos adc (dt suppor for phy added later in series).
4) Make iio_push_event save IRQ context - necessary if it is to be used
within an interrupt handler. Users of this functionality to follow.
5) For iio use the device tree node name to provide the hwmon name attribute
if available.
Removal and moves out of staging
1) Drop the adt7410 driver from IIO now that there is a hmwon driver with
equivalent support. This device is very much targeted at hardware
monitoring so hwmon is a more appropriate host for the driver.
2) Move iio_hwmon driver to drivers/hwmon.
Cleanups
1) Minor cleanup in ST common library.
2) Large set of patches to break the info_mask element which previously used
odd and even bits to specify if a channel attribute was either shared across
similar channels or specific to only one. Now we have two bitmaps, one for
those parameters that are specific to this channel and one for those shared
by all channels with the same type as this one. This has no effect on the
userspace abi. It simplifies the core code and provides more space for new
channel parameters. It has been on the todo list for a long time!
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Merge tag 'iio-for-3.10a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next
Jonathan writes:
First set of IIO new drivers and cleanup for the 3.10 cycle.
New stuff
1) Add OF support for specifying mappings between iio devices and their
in kernel consumers.
2) Driver for AD7923 (extra functionality and support for ad7904, ad7914 and
ad7924 added later in series)
3) Driver for Exynos adc (dt suppor for phy added later in series).
4) Make iio_push_event save IRQ context - necessary if it is to be used
within an interrupt handler. Users of this functionality to follow.
5) For iio use the device tree node name to provide the hwmon name attribute
if available.
Removal and moves out of staging
1) Drop the adt7410 driver from IIO now that there is a hmwon driver with
equivalent support. This device is very much targeted at hardware
monitoring so hwmon is a more appropriate host for the driver.
2) Move iio_hwmon driver to drivers/hwmon.
Cleanups
1) Minor cleanup in ST common library.
2) Large set of patches to break the info_mask element which previously used
odd and even bits to specify if a channel attribute was either shared across
similar channels or specific to only one. Now we have two bitmaps, one for
those parameters that are specific to this channel and one for those shared
by all channels with the same type as this one. This has no effect on the
userspace abi. It simplifies the core code and provides more space for new
channel parameters. It has been on the todo list for a long time!
Conflicts:
drivers/iio/dac/ad5064.c
The original info_mask is going away in favour of the broken out versions.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Denis Ciocca <denis.ciocca@st.com>
If CONFIG_IIO_TRIGGER is defined but CONFIG_IIO_BUFFER is not, the following
build error is seen.
drivers/iio/common/st_sensors/st_sensors_trigger.c:21:5: error:
redefinition of ‘st_sensors_allocate_trigger’
In file included from
drivers/iio/common/st_sensors/st_sensors_trigger.c:18:0:
include/linux/iio/common/st_sensors.h:239:19: note: previous
definition of ‘st_sensors_allocate_trigger’ was here
drivers/iio/common/st_sensors/st_sensors_trigger.c:65:6: error:
redefinition of ‘st_sensors_deallocate_trigger’
In file included from
drivers/iio/common/st_sensors/st_sensors_trigger.c:18:0:
include/linux/iio/common/st_sensors.h:244:20: note: previous
definition of ‘st_sensors_deallocate_trigger’ was here
This occurs because st_sensors_deallocate_trigger is built if CONFIG_IIO_TRIGGER
is defined, but the dummy function is compiled if CONFIG_IIO_BUFFER is defined.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This patch resolve a bugfix when driver is compiled without trigger.
Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This patch remove st_sensors_get_sampling_frequency_avl and
st_sensors_get_scale_avl functions used only in
st_sensors_sysfs_sampling_frequency_avail and st_sensors_sysfs_scale_avail
sysfs functions.
Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
