For ADCs or DACs the denominator for fractional types often is a power of two.
In this case we can use a shift operation instead of the rather expensive 64 bit
division. This patch adds a new fractional type which expects the denominator to
be specified as the log2 of the actual denominator. E.g. for ADCs and DACs this
will usually be the number of significant bits.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Some datasheets use a different unit to specify the channel scale than what IIO
expects it to be. This patch adds two helper macros which allow to convert units
commonly used in datasheets to IIO units:
* acceleration: g -> meter / second**2
* angular velocity: degree (/ second) -> rad (/ second)
This makes it much more convenient to specify and also easier to verify a
channel's scale attribute.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Add a function to read a processed value from a channel. The function will first
attempt to read the IIO_CHAN_INFO_PROCESSED attribute. If that fails it will
read the IIO_CHAN_INFO_RAW attribute and convert the result from a raw value to
a processed value.
The patch also introduces a function to convert raw value to a processed value
and exports it, in case a user needs or wants to do the conversion by itself.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
For the iio_read_channel_raw and iio_read_channel_scale the kerneldoc comment
refers to an argument called "channel", while the argument is called "chan" in
the function signature. This leads to the following warnings from kerneldoc:
Warning(include/linux/iio/consumer.h:71): No description found for parameter 'chan'
Warning(include/linux/iio/consumer.h:71): Excess function parameter 'channel' description in 'iio_read_channel_raw'
Warning(include/linux/iio/consumer.h:109): No description found for parameter 'chan'
Warning(include/linux/iio/consumer.h:109): Excess function parameter 'channel' description in 'iio_read_channel_scale'
This patch fixes the warnings by naming them consistently.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Currently IIO uses a decimal fixed point representations for real type numbers.
This patch introduces a new representation for rational type numbers. The number
will be expressed by specifying a numerator and denominator. For converting a
raw value to a processed value multiply it by the numerator and divide it by the
denominator.
The reasoning for introducing this new type is that for a lot of devices the
scale can be represented easily by a fractional number, but it is not possible
to represent it as fixed point number without rounding. E.g. for a simple DAC
the scale is often the reference voltage divided by the number of possible
values (Usually 2**n_bits - 1). Each driver currently implements the conversion
of this fraction to a fixed point number on its own.
Also when it comes to the in-kernel interface this allows to directly use the
fractional factors to convert a raw value to a processed value. This should on
one hand require less instructions and on the other hand increase the
precision.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Drop timestamp parameter from buffer store_to callback and subsequently from
iio_push_to_buffer. The timestamp parameter is unused and it seems likely that
it will stay unused in the future, so it should be safe to remove it.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Added hysteresis to the list of channel info enumeration, shared
/separate bit defines and to postfix channel info strings.
Signed-off-by: srinivas pandruvada <srinivas.pandruvada@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Add includes and forward declarations for types used in this file. This avoids
compile errors if the other files have not been included before.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Add include guards to the IIO headers where they are missing. This avoids
compile errors due to redefined types if a file is included more than once.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
The symbol name for the #ifndef and the #define of the include guard do not
match and thus it becomes quite ineffective. Add the missing '_' to fix this.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Most devices from the Analog Devices Sigma Delta family use a similar scheme for
communication with the device. This includes register access, as well as trigger
handling. But each device sub-family has different features and different
register layouts (some even have no registers at all) and thus it is impractical
to try to support all of the devices by the same driver. This patch adds a
common base library for Sigma Delta converter devices. It will be used by
individual drivers.
This code is mostly based on the three existing Sigma Delta drivers the AD7192,
AD7780 and AD7793, but has been improved for more robustness and flexibility.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Introduce two new helper functions to attach a arbitrary pointer to a IIO
device. This is useful to get access to external non-global data from within a
IIO device callbacks where only the IIO device is available.
Internally these functions use dev_{set,get}_drvdata() on the struct device
embedded in the IIO device.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
With small channel spacing values and high reference frequencies it is
possible to exceed the range of the 10-bit counter.
Workaround by checking the range and widening some constrains.
We don't use the REG1_PHASE value in this case the datasheet recommends to set
it to 1 if not used.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Add iio channel type and modifiers for Correlated Color Temperature (CCT)
and RGBC (red/green/blue/clear) data.
Add CCT and RGBC descriptions to documentation.
Changes:
Revised/condensed RGBC descriptions.
Merge and trivial fix done by Jonathan Cameron.
Signed-off-by: Jon Brenner <jbrenner@taosinc.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Add a helper function for validating a scan mask for devices where exactly one
channel must be selected during sampling. This is a common case among devices
which have scan mask restrictions so it makes sense to provide this function in
the core.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This is useful for cases where the number of valid scan masks grows
exponentially, but it is rather easy to check whether a mask is valid or not
programmatically.
An example of such a case is a device with multiple ADCs where each ADC has a
upstream MUX, which allows to select from a number of physical channels.
+-------+ +-------+
| | | | --- Channel 1
| ADC 1 |---| MUX 1 | --- ...
| | | | --- Channel M
+-------+ +-------+
. . .
. . .
. . .
+-------+ +-------+
| | | | --- Channel M * N + 1
| ADC N |---| MUX N | --- ...
| | | | --- Channel M * N + M
+-------+ +-------+
The number of necessary scan masks for this case is (M+1)**N - 1, on the other
hand it is easy to check whether subsets for each ADC of the scanmask have only
one bit set.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
There will probably be a number of such modifiers eventually but
this one is used in the adis16240 accelerometer driver.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
There will probably be a number of such modifiers eventually but
this one is used in the adis16204 accelerometer driver.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
These were originally introduced when the plan was to have parallel
IIO cores in and out of staging with a slow move between them.
Now we have reached the point where the whole core has moved,
they need clearing up!
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Add a helper function for executing the common tasks which are usually involved
in setting up a simple software ringbuffer. It will allocate the buffer,
allocate the pollfunc and register the buffer.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
v5:
* fix warnings (Jonathan Cameron)
v4:
* remove unused indio_dev pointer in mcp4725_data (Jonathan Cameron)
* use u16 instead of unsigned short in mcp4725_data (Jonathan Cameron)
* #include mcp4725.h from linux/iio/dac/
v3:
* move from staging to drivers/iio
* switch to chan_spec
* dev_get_drvdata() -> dev_to_iio_dev()
* annotate probe() and remove() with __devinit and __devexit
v2 (based on comments from Jonathan Cameron and Lars-Peter Clausen):
* did NOT switch to chan_spec yet
* rebase to staging-next tree, update iio header locations
* dropped dac.h #include, not needed
* strict_strtol() -> kstrtol()
* call iio_device_unregister() in remove()
* everything in one patch
Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The IIO DAC drivers are in a reasonably good shape. They all make use of channel
spec and non of them provides non-documented sysfs attributes. Code style should
be OK as well, both checkpatch and coccicheck only report trivial issues.
So lets move the whole folder out of staging.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We often have the case were we do have a enum style channel attribute. These
attributes have in common that they are a list of string values which usually
map in a 1-to-1 fashion to integer values.
This patch implements some common helper code for implementing enum style
channel attributes using extended channel attributes. The helper functions take
care of converting between the string and integer values, as well providing a
function for "_available" attributes which list all available enum items.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch add the iio_device_get() function, which increases the reference
count of a iio device. The matching function to decrease the reference count -
iio_device_put() - already exists.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Changes since V1:
Apply Jonathan's review feedback:
Introduce and use IIO_ALTVOLTAGE.
Fix up comments and documentation.
Remove dead code.
Reorder some code fragments.
Add missing iio_device_free.
Convert to new API.
Fix-up out of staging includes.
Removed pll_locked attribute.
Changes since V2:
Use module_spi_driver.
adf4350_remove: move gpio_free after regulator.
target patch to drivers/iio
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Changes since V1:
Apply Jonathan's review feedback:
Revise device status attribute names, and split documentation into two sections.
Add additional comments, and fix indention issues.
Remove pointless zero initializations.
Revise return value handling.
Simplify some code sections.
Split store_eeprom and sync handling into separate functions.
Use strtobool where applicable.
Document platform data structures using kernel-doc style.
Use dev_to_iio_dev
write_raw IIO_CHAN_INFO_FREQUENCY: Reject values <= 0
Make patch target drivers/iio
Changes since V2:
Use for_each_clear_bit() and __set_bit() where applicable.
Add descriptive comment.
Avoid temporary for struct regulator.
spi_device_id name use ad9523-1, ad9523 will be added later.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds a helper function for retriving a iio_dev struct from a device
struct. Currently we open-code this in two different ways. One is using
dev_get_drvdata on the device and the other is using container_of. The new
helper function uses the container_of solution as it creates slightly smaller
code and also will eventually free up the drvdata pointer for usage by invidual
drivers.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is currently no user, but we might need it in future.
So better add it now, before we have to convert drivers afterwards.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently we use two different naming schemes in the IIO API, iio_verb_object
and iio_object_verb. E.g iio_device_register and iio_allocate_device. This
patches renames instances of the later to the former. The patch also renames allocate to
alloc as this seems to be the preferred form throughout the kernel.
In particular the following renames are performed by the patch:
iio_put_device -> iio_device_put
iio_allocate_device -> iio_device_alloc
iio_free_device -> iio_device_free
iio_get_trigger -> iio_trigger_get
iio_put_trigger -> iio_trigger_put
iio_allocate_trigger -> iio_trigger_alloc
iio_free_trigger -> iio_trigger_free
The conversion was done with the following coccinelle patch with manual fixes to
comments and documentation.
<smpl>
@@
@@
-iio_put_device
+iio_device_put
@@
@@
-iio_allocate_device
+iio_device_alloc
@@
@@
-iio_free_device
+iio_device_free
@@
@@
-iio_get_trigger
+iio_trigger_get
@@
@@
-iio_put_trigger
+iio_trigger_put
@@
@@
-iio_allocate_trigger
+iio_trigger_alloc
@@
@@
-iio_free_trigger
+iio_trigger_free
</smpl>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Step 1 in moving the IIO core out of staging.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
