linux-toradex.git/drivers/iio/kfifo_buf.c, branch v4.1.15

iio: kfifo: Set update_needed to false only if a buffer was allocated

2015-05-07T22:36:58+00:00

Check whether the allocation of a new kfifo buffer failed or not before
setting the update_needed flag to false. This will make
iio_request_update_kfifo() try to allocate a new buffer the next time a
buffer update is requested.

Signed-off-by: Gabriele Mazzotta 
Signed-off-by: Jonathan Cameron

iio: add watermark logic to iio read and poll

2015-03-29T15:17:09+00:00

Currently the IIO buffer blocking read only wait until at least one
data element is available.
This patch makes the reader sleep until enough data is collected before
returning to userspace. This should limit the read() calls count when
trying to get data in batches.

Co-author: Yannick Bedhomme 
Signed-off-by: Josselin Costanzi 
[rebased and remove buffer timeout]
Signed-off-by: Octavian Purdila 
Reviewed-by: Lars-Peter Clausen 
Signed-off-by: Jonathan Cameron

iio: kfifo: Add resource management devm_iio_kfifo_allocate/free

2014-12-26T11:39:57+00:00

iio kfifo allocate/free gained their devm_ wrappers.

Signed-off-by: Karol Wrona 
Suggested-by: Jonathan Cameron 
Signed-off-by: Jonathan Cameron

iio: kfifo: Remove unused argument in iio_kfifo_allocate

2014-12-26T11:20:38+00:00

indio_dev was unused in function body plus some small style fix - add new
lines after "if(sth) return sth" and before the last return statement.

The argument was removed also in its client.

Signed-off-by: Karol Wrona 
Signed-off-by: Jonathan Cameron

iio: buffer: Drop get_length callback

2014-12-12T12:28:34+00:00

We already do have the length field in the struct iio_buffer which is
expected to be in sync with the current size of the buffer. And currently
all implementations of the get_length callback either return this field or a
constant number.

This patch removes the get_length callback and replaces all occurrences in
the IIO core with directly accessing the length field of the buffer.

Signed-off-by: Lars-Peter Clausen 
Signed-off-by: Jonathan Cameron

iio: buffer: Allocate standard attributes in the core

2014-12-12T12:28:33+00:00

All buffers want at least the length and the enable attribute. Move the
creation of those attributes to the core instead of having to do this in
each individual buffer implementation. This allows us to get rid of some
boiler-plate code.

Signed-off-by: Lars-Peter Clausen 
Signed-off-by: Jonathan Cameron

iio: Remove get_bytes_per_datum() from iio_buffer_access_funcs

2014-12-12T12:28:32+00:00

There haven't been any users of the get_bytes_per_datum() callback for a
while. The core assumes that the number of bytes per datum can be calculated
based on the enabled channels and the storage size of the channel and
iio_compute_scan_bytes() is used to compute this number. So remove the
callback.

Signed-off-by: Lars-Peter Clausen 
Signed-off-by: Jonathan Cameron

iio: kfifo_buf: Implement data_available() callback

2013-12-03T20:22:28+00:00

This patch implements the data_available() callback for the kfifo buffer instead
of using the stufftoread flag. The kfifo used by the buffer already knows
whether it is empty or not based on the position of its read and write pointer.
Using this makes it a lot easier to tell whether data is available or not and it
is not necessary to take special measures to ensure that no race conditions
between reading and writing from the buffer occur.

Note, that we still have to take the buffers lock to protect against concurrent
resizeing of the kfifo.

Signed-off-by: Lars-Peter Clausen 
Signed-off-by: Jonathan Cameron

iio:kfifo: Set update_needed to false after allocating a new buffer

2013-10-15T18:20:55+00:00

update_needed is used to decide whether the kfifo buffer needs to be
re-allocated. It is set to true whenever the size of the buffer is changed. It
is never set to false though, causing the buffer to always be re-allocated.
Setting update_needed to false after the new buffer has been allocated fixes the
problem.

Signed-off-by: Lars-Peter Clausen 
Signed-off-by: Jonathan Cameron

iio:kfifo: Empty buffer on update

2013-10-15T18:20:51+00:00

The kfifo's request_update callback will free the current buffer and allocate a
new one if the size has changed. This will remove any samples that might still
be left in the buffer. If the size has not changed the buffer content is
left untouched though. This is a bit inconsistent and might cause an application
to see data from a previous capture. This patch inserts a call to
kfifo_reset_out() when the size did not change. This makes sure that any pending
samples are removed from the buffer.

Note, due to a different bug the buffer is currently always re-allocated, even
if the size did not change. So this patch will not change the behavior. In the
next patch the bug will be fixed and this patch makes sure that the current
behavior is kept.

Signed-off-by: Lars-Peter Clausen 
Signed-off-by: Jonathan Cameron