Originally device and buffer registration were kept as separate operations
in IIO to allow to register two distinct sets of channels for buffered and
non-buffered operations. This has since already been further restricted and
the channel set registered for the buffer needs to be a subset of the
channel set registered for the device. Additionally the possibility to not
have a raw (or processed) attribute for a channel which was registered for
the device was added a while ago. This means it is possible to not register
any device level attributes for a channel even if it is registered for the
device. Also if a channel's scan_index is set to -1 and the channel is
registered for the buffer it is ignored.
So in summary it means it is possible to register the same channel array for
both the device and the buffer yet still end up with distinctive sets of
channels for both of them. This makes the argument for having to have to
manually register the channels for both the device and the buffer invalid.
Considering that the vast majority of all drivers want to register the same
set of channels for both the buffer and the device it makes sense to move
the buffer registration into the core to avoid some boiler-plate code in the
device driver setup path.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This callback is introduced to overcome some limitations of existing
read_raw callback. The functionality of both existing read_raw and
read_raw_multi is similar, both are used to request values from the
device. The current read_raw callback allows only two return values.
The new read_raw_multi allows returning multiple values. Instead of
passing just address of val and val2, it passes length and pointer
to values. Depending on the type and length of passed buffer, iio
client drivers can return multiple values.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
We have the same code to free a IIO device attribute list in multiple place.
This patch adds a new helper function to take care of this and replaces the
custom instances with a call to the helper function. Note that we do not need to
call list_del() for each of the list items since we will never look at any of
the list items nor the list itself again.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Once the device has been unregistered there won't be any new data no matter how
long a userspace application waits, so we might as well wake them up and let
them know.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This resolves the merge problem with two iio drivers that Stephen
Rothwell pointed out.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make sure to stop sampling when the device is removed, otherwise it will
continue to sample forever.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Introduce an enum to specify whether the attribute is separate or
shared.
Factor out the bitmap handling for loop into a separate function.
Tidy up error handling and add a NULL assignment to squish a false
positive warning from GCC.
Change ext_info shared type from boolean to enum and update in all
drivers.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Provide bindings and parse OF data during initialization.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
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>
