Commit Graph

8 Commits

Author SHA1 Message Date
Greg Kroah-Hartman
bd972ff317 One new driver and a couple of nice cleanups.
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Merge tag 'togreg-3.6a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

IIO: One new driver and a couple of nice cleanups.
2012-07-12 12:29:44 -07:00
Lars-Peter Clausen
8163663205 iio: Introduce iio_validate_scan_mask_onehot
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>
2012-07-09 18:18:15 +01:00
Lars-Peter Clausen
939546d1a9 iio: Add callback to check whether a scan mask is valid
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>
2012-07-09 18:18:15 +01:00
Lars-Peter Clausen
e1dc7bee74 iio: iio_buffer_register: Use correct channel when calculating masklength
The channel set assigned to the iio device is not necessarily the same has the
channel set passed to iio_buffer_register. So to avoid possible complications
always work with the channel set pass to iio_buffer_register and ignore the
channel set assigned to the iio device.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-07-08 20:02:23 +01:00
Lars-Peter Clausen
f5b81ddd12 iio: iio_buffer_register: Skip channels with negative scan index
It is not always the case that all channels can be used in buffered mode. This
patch allows channels, which can not be used in buffered mode, to set their scan
index to a negative number, which will cause iio_buffer_register to ignore the
channel.

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>
2012-06-18 17:26:09 -07:00
Lars-Peter Clausen
aff1eb4e3d iio: buffer: Fix NULL pointer deref caused by empty scan mask
iio_scan_mask_match() returns NULL if the passed in scan mask is empty. This
will happen if no channel has been selected and buffer is enabled.
iio_sw_buffer_preenable() will assign NULL to indio_dev->active_scan_mask in
this case. As a result iio_update_demux() will cause a NULL pointer deref,
because it expects active_scan_mask to be non-NULL.

Since it does not make much sense to start data capture if there is no data to
capture this patch updates the code to fail gracefully in iio_scan_mask_match()
instead of crashing the kernel.

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>
2012-06-15 14:39:19 -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
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