[PATCH v4 0/6] iio: core: Add mmap interface infrastructure

[Alexandru Ardelean <alexandru.ardelean@analog.com>]

Changelog v3 -> v4:
* https://lore.kernel.org/linux-iio/20210215143234.3248-5-alexandru.ardelean@analog.com/T/
* added patch 'iio: buffer-dma: reduce the type of block.size to u32'
  - resolves error on 64 bit archs; 32 bit block size should be enough
* in patch 'iio: buffer-dma: Add mmap support'
  - added 'linux/types.h' include in uapi buffer.h header; an error
    shows up when building with 'make allmodconfig'
* in patch 'tools: iio: add example for high-speed buffer support'
  - calling ioctl(BOCK_FREE) only if use_high_speed is true

Changelog v2 -> v3:
* https://lore.kernel.org/linux-iio/20210212101143.18993-1-alexandru.ardelean@analog.com/T/#u
* added 'Documentation: iio: add doc for high-speed buffer API'
* add 'iio: buffer-dma: split iio_dma_buffer_fileio_free() function'
* patch 'iio: buffer-dma: Add mmap support'
   - unwind free on error path in iio_dma_buffer_alloc_blocks()
   - removed double mm.h include
* patch 'tools: iio: add example for high-speed buffer support'
   - call IIO_BUFFER_BLOCK_FREE_IOCTL on the error path of the
     enable_high_speed() function

Changelog v1 -> v2:
* https://lore.kernel.org/linux-iio/20210211123353.78963-1-alexandru.ardelean@analog.com/T/#t
* removed IIO_BUFFER_BLOCK_FLAG_CYCLIC flag; will be added in a later
  patch
* removed extra line in tools/iio/iio_generic_buffer.c
* patch 'iio: core: Add mmap interface infrastructure'
  added docstrings for new hooks (alloc_blocks, mmap, etc)

This is basically Lars' work adapted from branch:
  https://github.com/larsclausen/linux/commits/iio-high-speed-5.10
[hopefully i got the stuff correctly from that branch]

What is different, is that this one is adapted on top of the multibuffer
support (currently at v5) discussed here:
  https://lore.kernel.org/linux-iio/20210211122452.78106-1-alexandru.ardelean@analog.com/T/#t

Also, adapted an example for high-speed/mmap support in
'tools/iio/iio_generic_buffer.c'

The example is adapted from libiio:
  https://github.com/analogdevicesinc/libiio/blob/master/local.c#L51
but will all the ioctl()s organized after the one that are reserved
(hopefully) for IIO

Tested that mmap() works.
Moved (artifically) valid buffer0 as buffer2 and the operation still
works.

Alexandru Ardelean (4):
  Documentation: iio: add doc for high-speed buffer API
  iio: buffer-dma: split iio_dma_buffer_fileio_free() function
  iio: buffer-dma: reduce the type of block.size to u32
  tools: iio: add example for high-speed buffer support

Lars-Peter Clausen (2):
  iio: core: Add mmap interface infrastructure
  iio: buffer-dma: Add mmap support

 Documentation/iio/iio_high_speed_buffers.rst  | 100 ++++++
 Documentation/iio/index.rst                   |   2 +
 drivers/iio/buffer/industrialio-buffer-dma.c  | 324 ++++++++++++++++--
 .../buffer/industrialio-buffer-dmaengine.c    |  28 +-
 drivers/iio/industrialio-buffer.c             | 158 +++++++++
 include/linux/iio/buffer-dma.h                |  27 +-
 include/linux/iio/buffer_impl.h               |  23 ++
 include/uapi/linux/iio/buffer.h               |  51 +++
 tools/iio/iio_generic_buffer.c                | 185 +++++++++-
 9 files changed, 847 insertions(+), 51 deletions(-)
 create mode 100644 Documentation/iio/iio_high_speed_buffers.rst

-- 
2.17.1