Expose a rotation matrix to indicate userspace the chip orientation with
respect to the overall hardware system.
Matrix is retrieved from "in_mount_matrix". It is declared into ak8975 DTS
entry as a "mount-matrix" property.
Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Expose a rotation matrix to indicate userspace the chip placement with
respect to the overall hardware system. This is needed to adjust
coordinates sampled from a sensor chip when its position deviates from the
main hardware system.
Final coordinates computation is delegated to userspace since:
* computation may involve floating point arithmetics ;
* it allows an application to combine adjustments with arbitrary
transformations.
This 3 dimentional space rotation matrix is expressed as 3x3 array of
strings to support floating point numbers. It may be retrieved from a
"[<dir>_][<type>_]mount_matrix" sysfs attribute file. It is declared into a
device / driver specific DTS property or platform data.
Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Some of kernel driver uses the IIO framework to get the sensor
value via ADC or IIO HW driver. The client driver get iio channel
by iio_channel_get_all() and release it by calling
iio_channel_release_all().
Add resource managed version (devm_*) of these APIs so that if client
calls the devm_iio_channel_get_all() then it need not to release it
explicitly, it can be done by managed device framework when driver
get un-binded.
This reduces the code in error path and also need of .remove callback in
some cases.
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Some of kernel driver uses the IIO framework to get the sensor
value via ADC or IIO HW driver. The client driver get iio channel
by iio_channel_get() and release it by calling iio_channel_release().
Add resource managed version (devm_*) of these APIs so that if client
calls the devm_iio_channel_get() then it need not to release it explicitly,
it can be done by managed device framework when driver get un-binded.
This reduces the code in error path and also need of .remove callback in
some cases.
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.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>
Some variants of the devices from the ADIS family don't auto-clear the
self-test bit after the self-test has completed. Instead we have to
manually clear. Add support for this to the ADIS library.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
The members buffer_group and attrs of iio_buffer_access_funcs have no
descriptions for the documentation. Adding them.
Fixes: 08e7e0adaa ("iio: buffer: Allocate standard attributes in the core")
Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
It is often the case that the driver wants to be sure a device stays
in direct mode while it is executing a task or series of tasks. To
accomplish this today, the driver performs this sequence: 1) take the
device state lock, 2) verify it is not in a buffered mode, 3) execute
some tasks, and 4) release that lock.
This patch introduces a pair of helper functions that simplify these
steps and make it more semantically expressive.
iio_device_claim_direct_mode()
If the device is not in any buffered mode it is guaranteed
to stay that way until iio_release_direct_mode() is called.
iio_device_release_direct_mode()
Release the claim. Device is no longer guaranteed to stay
in direct mode.
Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This patch fixes a few minor typos in the documentation comments for the
scan_type member of the iio_event_spec structure. The sign member name
was improperly capitalized as "Sign" in the comments. The storagebits
member name was improperly listed as "storage_bits" in the comments. The
endianness member entry in the comments was moved after the repeat
member entry in order to maintain consistency with the actual struct
iio_event_spec layout.
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
mlock *must* be used by core and drivers to protect access
to devices state changes.
Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
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>
Make IIO value formating function globally available to allow IIO drivers
to output values as the core does.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This exported element needs to be accesible to all drivers using configfs
within IIO. Previously it was in the sw_trig.h file which only convered one
such usecase. This also fixes a sparse warning as it is now in a header
that makes sense to include from industrialio-configfs.c
Signed-off-by: Jonathan Cameron < jic23@kernel.org>
A software trigger associates an IIO device trigger with a software
interrupt source (e.g: timer, sysfs). This patch adds the generic
infrastructure for handling software triggers.
Software interrupts sources are kept in a iio_trigger_types_list and
registered separately when the associated kernel module is loaded.
Software triggers can be created directly from drivers or from user
space via configfs interface.
To sum up, this dynamically creates "triggers" group to be found under
/config/iio/triggers and offers the possibility of dynamically
creating trigger types groups. The first supported trigger type is
"hrtimer" found under /config/iio/triggers/hrtimer.
Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Add a generic fully device independent DMA buffer implementation that uses
the DMAegnine framework to perform the DMA transfers. This can be used by
converter drivers that whish to provide a DMA buffer for converters that
are connected to a DMA core that implements the DMAengine API.
Apart from allocating the buffer using iio_dmaengine_buffer_alloc() and
freeing it using iio_dmaengine_buffer_free() no additional converter driver
specific code is required when using this DMA buffer implementation.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
The traditional approach used in IIO to implement buffered capture requires
the generation of at least one interrupt per sample. In the interrupt
handler the driver reads the sample from the device and copies it to a
software buffer. This approach has a rather large per sample overhead
associated with it. And while it works fine for samplerates in the range of
up to 1000 samples per second it starts to consume a rather large share of
the available CPU processing time once we go beyond that, this is
especially true on an embedded system with limited processing power. The
regular interrupt also causes increased power consumption by not allowing
the hardware into deeper sleep states, which is something that becomes more
and more important on mobile battery powered devices.
And while the recently added watermark support mitigates some of the issues
by allowing the device to generate interrupts at a rate lower than the data
output rate, this still requires a storage buffer inside the device and
even if it exists it is only a few 100 samples deep at most.
DMA support on the other hand allows to capture multiple millions or even
more samples without any CPU interaction. This allows the CPU to either go
to sleep for longer periods or focus on other tasks which increases overall
system performance and power consumption. In addition to that some devices
might not even offer a way to read the data other than using DMA, which
makes DMA mandatory to use for them.
The tasks involved in implementing a DMA buffer can be divided into two
categories. The first category is memory buffer management (allocation,
mapping, etc.) and hooking this up the IIO buffer callbacks like read(),
enable(), disable(), etc. The second category of tasks is to setup the
DMA hardware and manage the DMA transfers. Tasks from the first category
will be very similar for all IIO drivers supporting DMA buffers, while the
tasks from the second category will be hardware specific.
This patch implements a generic infrastructure that take care of the former
tasks. It provides a set of functions that implement the standard IIO
buffer iio_buffer_access_funcs callbacks. These can either be used as is or
be overloaded and augmented with driver specific code where necessary.
For the DMA buffer support infrastructure that is introduced in this series
sample data is grouped by so called blocks. A block is the basic unit at
which data is exchanged between the application and the hardware. The
application is responsible for allocating the memory associated with the
block and then passes the block to the hardware. When the hardware has
captured the amount of samples equal to size of a block it will notify the
application, which can then read the data from the block and process it.
The block size can freely chosen (within the constraints of the hardware).
This allows to make a trade-off between latency and management overhead.
The larger the block size the lower the per sample overhead but the latency
between when the data was captured and when the application will be able to
access it increases, in a similar way smaller block sizes have a larger per
sample management overhead but a lower latency. The ideal block size thus
depends on system and application requirements.
For the time being the infrastructure only implements a simple double
buffered scheme which allocates two blocks each with half the size of the
configured buffer size. This provides basic support for capturing
continuous uninterrupted data over the existing file-IO ABI. Future
extensions to the DMA buffer infrastructure will give applications a more
fine grained control over how many blocks are allocated and the size of
each block. But this requires userspace ABI additions which are
intentionally not part of this patch and will be added separately.
Tasks of the second category need to be implemented by a device specific
driver. They can be hooked up into the generic infrastructure using two
simple callbacks, submit() and abort().
The submit() callback is used to schedule DMA transfers for blocks. Once a
DMA transfer has been completed it is expected that the buffer driver calls
iio_dma_buffer_block_done() to notify. The abort() callback is used for
stopping all pending and active DMA transfers when the buffer is disabled.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This patch adds a enable and disable callback that is called when the
buffer is enabled/disabled. This can be used by buffer implementations that
need to do some setup or teardown work. E.g. a DMA based buffer can use
this to start/stop the DMA transfer.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
For buffers which have a fixed wake-up watermark the watermark attribute
should be read-only. Add a new FIXED_WATERMARK flag to the
struct iio_buffer_access_funcs, which can be set by a buffer
implementation.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Support triggered events.
This is useful for chips that don't have their own interrupt sources.
It allows to use generic/standalone iio triggers for those drivers.
Signed-off-by: Vladimir Barinov <vladimir.barinov@cogentembedded.com>
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>
Add inverse unit conversion macro to convert from standard IIO units to
units that might be used by some devices.
Those are useful in combination with scale factors that are specified as
IIO_VAL_FRACTIONAL. Typically the denominator for those specifications will
contain the maximum raw value the sensor will generate and the numerator
the value it maps to in a specific unit. Sometimes datasheets specify those
in different units than the standard IIO units (e.g. degree/s instead of
rad/s) and so we need to do a unit conversion.
From a mathematical point of view it does not make a difference whether we
apply the unit conversion to the numerator or the inverse unit conversion
to the denominator since (x / y) / z = x / (y * z). But as the denominator
is typically a larger value and we are rounding both the numerator and
denominator to integer values using the later method gives us a better
precision (E.g. the relative error is smaller if we round 8000.3 to 8000
rather than rounding 8.3 to 8).
This is where in inverse unit conversion macros will be used.
Marked for stable as used by some upcoming fixes.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
When compile iio related driver the following warning shown:
include/linux/iio/trigger.h:35:34: warning: 'struct iio_trigger'
declared inside parameter list
int (*set_trigger_state)(struct iio_trigger *trig, bool state);
include/linux/iio/trigger.h:38:18: warning: 'struct iio_dev'
declared inside parameter list
struct iio_dev *indio_dev);
'struct iio_dev' and 'struct iio_trigger' was used before declaration,
forward declaration for these structs to fix warning.
Signed-off-by: Pengyu Ma <pengyu.ma@windriver.com>
Acked-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Fix kernel doc for the iio_dev_attr structure by adding its missing field.
Signed-off-by: Cristina Opriceana <cristina.opriceana@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Fix buffer name from kernel doc according to the function parameter.
Signed-off-by: Cristina Opriceana <cristina.opriceana@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
