Specifically a helper for reading the available maximum raw value of a
channel and a helper for forwarding read_avail requests for raw values
from one iio driver to an iio channel that is consumed.
These rather specific helpers are in turn built with generic helpers
making it easy to build more helpers for available values as needed.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
A large number of attributes can only take a limited range of values.
Currently in IIO this is handled by directly registering additional
*_available attributes thus providing this information to userspace.
It is desirable to provide this information via the core for much the same
reason this was done for the actual channel information attributes in the
first place. If it isn't there, then it can only really be accessed from
userspace. Other in kernel IIO consumers have no access to what valid
parameters are.
Two forms are currently supported:
* list of values in one particular IIO_VAL_* format.
e.g. 1.300000 1.500000 1.730000
* range specification with a step size:
e.g. [1.000000 0.500000 2.500000]
equivalent to 1.000000 1.5000000 2.000000 2.500000
An addition set of masks are used to allow different sharing rules for the
*_available attributes generated.
This allows for example:
in_accel_x_offset
in_accel_y_offset
in_accel_offset_available.
We could have gone with having a specification for each and every
info_mask element but that would have meant changing the existing userspace
ABI. This approach does not.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
[forward ported, added some docs and fixed buffer overflows /peda]
Acked-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
MCP47x6 chip supports selection of a voltage reference (VDD, VREF buffered
or unbuffered). MCP4725 doesn't have this feature thus the eventual setting
is ignored and user is warned.
The setting is stored only in the volatile memory of the chip. You need to
manually store it to the EEPROM of the chip via 'store_eeprom' sysfs entry.
Signed-off-by: Tomas Novotny <tomas@novotny.cz>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Use a standard framework to get the reference voltage. It is done that way
in the iio subsystem and it will simplify extending of the driver.
Structure mcp4725_platform_data is left undeleted because it used in the
next patch.
This change breaks the current users of the driver, but there is no
mainline user of struct mcp4725_platform_data.
Signed-off-by: Tomas Novotny <tomas@novotny.cz>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This driver predates the availability of IIO_CHAN_INFO_SAMP_FREQ
attribute wherein usage has some advantages like it can be accessed by
in-kernel consumers as well as reduces the code size.
Therefore, use IIO_CHAN_INFO_SAMP_FREQ to implement the
sampling_frequency attribute instead of using IIO_DEV_ATTR_SAMP_FREQ()
macro.
Move code from the functions associated with IIO_DEV_ATTR_SAMP_FREQ()
into respective read and write hooks with the mask set to
IIO_CHAN_INFO_SAMP_FREQ.
Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Add new macros: IIO_ATTR_RO, IIO_ATTR_WO, IIO_ATTR_RW,
IIO_DEVICE_ATTR_RO, IIO_DEVICE_ATTR_WO and IIO_DEVICE_ATTR_RW to reduce
the amount of boiler plate code that is needed for creating new
attributes. This mimics the *_RO, *_WO, and *_RW macros that are found
in include/linux/device.h and include/linux/sysfs.h.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
The event_attrs field of iio_info structure is only initialized once
whenever an object of iio_info is created. After that this field
is never modified again anywhere in the kernel. So, declare event_attrs
field of iio_info as a const struct attribute_group.
Checked for occurences throughout the kernel using grep and
coccinelle.
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Allow access to underlying channel IIO_CHAN_INFO_OFFSET from a consumer.
Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Some triggers can only be attached to the IIO device that corresponds to
the same physical device. Currently each driver that requires this
implements its own trigger validation function.
Introduce a new helper function called iio_trigger_validate_own_device()
that can be used to do this check. Having a common implementation avoids
code duplication and unnecessary boiler-plate code.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
New device support
* ad8801 dac
- new driver supporting ad8801 and ad8803 DACs.
* adc12138
- new driver supporting TI adc12130/adc12132 and adc12138 ADCs.
* ltc2485 adc
- new driver
* mxc6255
- add support for the mxc6225 part name and fixup the ID check so it works.
* vz89x VOC sensor
- add support for the vz89te part which drops the voc_short channel and adds
CRCs compared to other supported parts.
New features
* core
- immutable triggers. These effectively grant exclusive control over a
trigger. The typical usecase is a device representing an analog part
(perhaps a MUX) that needs to control the sampling of a downstream
ADC.
- resource managed trigger registration and triggered_buffer_init.
- iio_push_event now protected against case of the event interface
registration not having yet occured. Only matters if an interrupt
can occur during this window - might happen on shared interrupt lines.
- helper to let a driver query if the trigger it is using is provided by
itself (using the convention of both device and trigger having the same
parent).
* tools
- iio-utils. Used channel modifier scaling in preference to generic scaling
when both exist.
* at91-adc
- Add support for touchscreen switches closure time needed by some newer
parts.
* stx104
- support the ADC channels on this ADC/DAC board. As these are the primary
feature of the board also move the driver to the iio/adc directory.
* sx9500
- device tree bindings.
Cleanups / Fixes
* ad5755
- fix an off-by-one on devnr limit check (introduced earlier this cycle)
* ad7266
- drop NULL check on devm_regulator_get_optional as it can't return NULL.
* ak8974
- avoid an unused functional warning due to rework in PM core code.
- remove .owner field setting as done by i2c_core.
* ina2xx
- clear out a left over debug field from chip global data.
* hid-sensors
- avoid an unused functional warning due to rework in PM core code.
* maxim-thermocouple
- fix non static symbol warnings.
* ms5611
- fetch and enable regulators unconditionally when they aren't optional.
* sca3000
- whitespace cleanup.
* st_sensors
- fetch and enable regulators unconditionally rather than having them
supported as optional regulators (missunderstanding on my part amongst
others a while back)
- followup to previous patch fixes error checking on the regulators.
- mark symbols static where possible.
- use the 'is it my trigger' help function. This prevents the odd case
of another device triggering from the st-sensors trigger whilst the
st-sensors trigger is itself not using it but rather using say an hrtimer.
* ti-ads1015
- add missing of_node_put.
* vz89x
- rework to all support of new devices.
- prevent reading of a corrupted buffer.
- fixup a return value of 0/1 in a bool returning function.
Address updates
- Vlad Dogaru email address change.
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Merge tag 'iio-for-4.9b' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next
Jonathan writes:
Second set of iio new device support, features and cleanups for the 4.9 cycle.
New device support
* ad8801 dac
- new driver supporting ad8801 and ad8803 DACs.
* adc12138
- new driver supporting TI adc12130/adc12132 and adc12138 ADCs.
* ltc2485 adc
- new driver
* mxc6255
- add support for the mxc6225 part name and fixup the ID check so it works.
* vz89x VOC sensor
- add support for the vz89te part which drops the voc_short channel and adds
CRCs compared to other supported parts.
New features
* core
- immutable triggers. These effectively grant exclusive control over a
trigger. The typical usecase is a device representing an analog part
(perhaps a MUX) that needs to control the sampling of a downstream
ADC.
- resource managed trigger registration and triggered_buffer_init.
- iio_push_event now protected against case of the event interface
registration not having yet occured. Only matters if an interrupt
can occur during this window - might happen on shared interrupt lines.
- helper to let a driver query if the trigger it is using is provided by
itself (using the convention of both device and trigger having the same
parent).
* tools
- iio-utils. Used channel modifier scaling in preference to generic scaling
when both exist.
* at91-adc
- Add support for touchscreen switches closure time needed by some newer
parts.
* stx104
- support the ADC channels on this ADC/DAC board. As these are the primary
feature of the board also move the driver to the iio/adc directory.
* sx9500
- device tree bindings.
Cleanups / Fixes
* ad5755
- fix an off-by-one on devnr limit check (introduced earlier this cycle)
* ad7266
- drop NULL check on devm_regulator_get_optional as it can't return NULL.
* ak8974
- avoid an unused functional warning due to rework in PM core code.
- remove .owner field setting as done by i2c_core.
* ina2xx
- clear out a left over debug field from chip global data.
* hid-sensors
- avoid an unused functional warning due to rework in PM core code.
* maxim-thermocouple
- fix non static symbol warnings.
* ms5611
- fetch and enable regulators unconditionally when they aren't optional.
* sca3000
- whitespace cleanup.
* st_sensors
- fetch and enable regulators unconditionally rather than having them
supported as optional regulators (missunderstanding on my part amongst
others a while back)
- followup to previous patch fixes error checking on the regulators.
- mark symbols static where possible.
- use the 'is it my trigger' help function. This prevents the odd case
of another device triggering from the st-sensors trigger whilst the
st-sensors trigger is itself not using it but rather using say an hrtimer.
* ti-ads1015
- add missing of_node_put.
* vz89x
- rework to all support of new devices.
- prevent reading of a corrupted buffer.
- fixup a return value of 0/1 in a bool returning function.
Address updates
- Vlad Dogaru email address change.
This adds a helper function to the IIO trigger framework:
iio_trigger_using_own(): for an IIO device, this tells
whether the device is using itself as a trigger.
This is true if the indio device:
(A) supplies a trigger and
(B) has assigned its own buffer poll function to use this
trigger.
This helper function is good when constructing triggered,
buffered drivers that can either use its own hardware *OR*
an external trigger such as a HRTimer or even the trigger from
a totally different sensor.
Under such circumstances it is important to know for example
if the timestamp from the same trigger hardware should be used
when populating the buffer: if iio_trigger_using_own() is true,
we can use this timestamp, else we need to pick a unique
timestamp directly in the trigger handler.
For this to work of course IIO devices registering hardware
triggers must follow the convention to set the parent device
properly, as as well as setting the parent of the IIO device
itself.
When a new poll function is attached, we check if the parent
device of the IIO of the poll function is the same as the
parent device of the trigger and in that case we conclude that
the hardware is using itself as trigger.
Cc: Giuseppe Barba <giuseppe.barba@st.com>
Cc: Denis Ciocca <denis.ciocca@st.com>
Cc: Crestez Dan Leonard <leonard.crestez@intel.com>
Cc: Gregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Add resource managed devm_iio_triggered_buffer_setup() and
devm_iio_triggered_buffer_cleanup() to automatically clean up triggered
buffers setup by IIO drivers, thus leading to simplified IIO drivers code.
Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Add resource managed devm_iio_trigger_register() and
devm_iio_triger_unregister() to automatically clean up registered triggers
allocated by IIO drivers, thus leading to simplified IIO drivers code.
Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
There are times when an assigned trigger to a device shouldn't ever
change after intialization.
Examples of this being used is when an provider device has a trigger
that is assigned to an ADC, which uses it populate data into a callback
buffer.
Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Add iio_channel_cb_get_iio_dev function to allow getting the
underlying iio_dev. This is useful for setting the trigger of the
consumer ADC device.
Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Use the IS_ENABLED() helper macro to ensure that the configfs group is
initialized either when configfs is built-in or when configfs is built as a
module. Otherwise software trigger creation will result in undefined
behaviour when configfs is built as a mdoule since the configfs group for
the trigger is not properly initialized.
Fixes: b662f809d4 ("iio: core: Introduce IIO software triggers")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Daniel Baluta <daniel.baluta@intel.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
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>
Adds a new per-device sysfs attribute "current_timestamp_clock" to allow
userspace to select a particular POSIX clock for buffered samples and
events timestamping.
Following clocks, as listed in clock_gettime(2), are supported:
CLOCK_REALTIME, CLOCK_MONOTONIC, CLOCK_MONOTONIC_RAW,
CLOCK_REALTIME_COARSE, CLOCK_MONOTONIC_COARSE, CLOCK_BOOTTIME and
CLOCK_TAI.
Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Acked-by: Sanchayan Maity <maitysanchayan@gmail.com>
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>
This is similar with support for creating triggers via configfs.
Devices will be hosted under:
* /config/iio/devices
We allow users to register "device types" under:
* /config/iio/devices/<device_types>/
Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
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>
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>
Peter Rosin