Commit Graph

21 Commits

Author SHA1 Message Date
Lars-Peter Clausen 7985e7c100 iio: Introduce a new fractional value type
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>
2012-09-15 10:12:22 +01:00
srinivas pandruvada 7c9ab035ac iio: core: Add hysteresis in channel spec
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>
2012-09-06 19:04:45 +01:00
Jonathan Cameron c8b95952e7 IIO: Update email address for Jonathan Cameron.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-09-03 20:26:46 +01:00
Peter Meerwald 99698b4567 iio: whitespace cleanup and removal of semicolon after functions
Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-09-03 20:26:43 +01:00
Peter Meerwald d25b3808db iio: fix typos
Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-09-03 20:26:43 +01:00
Jon Brenner 21cd1fab05 IIO channel type and modifiers for CCT and RGBC data
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>
2012-07-10 18:49:26 +01:00
Jonathan Cameron cf82cb8128 IIO: Add a modifier for x^2+y^2+z^2
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>
2012-06-30 10:15:28 +01:00
Jonathan Cameron 8f5879b20b IIO: Add a modifier for sqrt(x^2+y^2)
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>
2012-06-30 10:15:22 +01:00
Greg Kroah-Hartman 89a86a2da3 Merge branch 'staging-linus' into staging-next
We need this for the pstore fixes that went into the staging-linus branch, so
that things apply properly for the pstore/android code merge.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13 16:57:09 -07:00
Lars-Peter Clausen 74dcd439bf iio: iio_enum_available_read: Prevent possible buffer overflow
Use scnprint instead of snprintf, because snprintf returns the number of bytes
that would have been written to the buffer if there was enough space, and as a
result writing to buf[len-1] might cause a access beyond the buffers limits.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
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>
2012-06-07 14:26:29 +09:00
Lars-Peter Clausen 5212cc8a9d iio: Add helper functions for enum style channel attributes
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>
2012-06-05 13:47:29 +09:00
Lars-Peter Clausen e407fd655b iio: Fix potential use after free
There is no guarantee that the last reference to the iio device has already been
dropped when iio_device_free is called. This means that we can up calling
iio_dev_release after iio_device_free which will lead to a use after free. As
the general rule the struct containing the device should always be freed in the
release callback.

This is what this patch does, it moves freeing the iio device struct as well as
releasing the idr reference to the release callback. To ensure that the device
is not freed before calling iio_device_free the device_unregister call in
iio_device_unregister is broken apart. iio_device_unregister will now only call
device_del to remove the device from the system and iio_device_free will call
put_device to drop the reference we obtained in iio_devce_alloc.

We also have to take care that calling iio_device_free without having called
iio_device_register still works (i.e. this can happen if something failed during
device initialization). For this to work properly two minor changes were
necessary: channel_attr_list needs to be initialized in iio_device_alloc and we
have to check whether the chrdev has been registered before releasing it in
iio_device_release.

This change also brings iio_device_unregister and iio_device_free more in sync
with iio_device_register and iio_device_alloc which call device_add and
device_initialize respectively.

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>
2012-06-04 21:15:31 -07:00
Lars-Peter Clausen e53f5ac52e iio: Use dev_to_iio_dev()
Replace open-coded instances of getting a iio_dev struct from a device struct
with dev_to_iio_dev().

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>
2012-05-14 13:37:45 -07:00
Michael Hennerich b65d62122f iio: core: introduce IIO_CHAN_INFO_HARDWAREGAIN
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>
2012-05-14 13:15:39 -07:00
Michael Hennerich 67eedba39e iio: core: introduce dB scle: IIO_VAL_INT_PLUS_MICRO_DB
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>
2012-05-14 13:15:38 -07:00
Axel Lin abd5a2fb39 IIO: industrialio-core: Checking NULL instead of IS_ERR for debugfs_create_dir()
If defined CONFIG_DEBUG_FS, debugfs_create_dir returns NULL on failure.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-08 16:04:11 -07:00
Axel Lin 5a28c87397 IIO: industrialio-core: Use simple_open
Use simple_open to replace iio_debugfs_open.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-08 16:04:11 -07:00
Michael Hennerich fc6d11398e iio: core: iio_chan_spec_ext_info: Add private handle
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>
2012-04-29 21:26:17 -04:00
Michael Hennerich a6b12855b5 iio: core: Introduce IIO_ALTVOLTAGE and appropriate channel info elements
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>
2012-04-29 21:26:17 -04:00
Lars-Peter Clausen 7cbb753701 staging:iio: Streamline API function naming
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>
2012-04-29 21:23:49 -04:00
Jonathan Cameron a980e04609 IIO: Move the core files to drivers/iio
Take the core support + the kfifo buffer implentation out of
staging.  Whilst we are far from done in improving this subsystem
it is now at a stage where the userspae interfaces (provided by
the core) can be considered stable.

Drivers will follow over a longer time scale.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-25 11:11:38 -07:00