[PATCH v7 0/6] iio: new DMABUF based API

[Nuno Sa]

Hi Jonathan, likely you're wondering why I'm sending v7. Well, to be
honest, we're hoping to get this merged this for the 6.9 merge window.
Main reason is because the USB part is already in (so it would be nice
to get the whole thing in). Moreover, the changes asked in v6 were simple
(even though I'm not quite sure in one of them) and Paul has no access to
it's laptop so he can't send v7 himself. So he kind of said/asked for me to do it.

v6:
 * https://lore.kernel.org/linux-iio/20240129170201.133785-1-paul@crapouillou.net/

v7:
 - Patch 1
  * Renamed *device_prep_slave_dma_vec() -> device_prep_peripheral_dma_vec();
  * Added a new flag parameter to the function as agreed between Paul
    and Vinod. I renamed the first parameter to prep_flags as it's supposed to
    be used (I think) with enum dma_ctrl_flags. I'm not really sure how that API
    can grow but I was thinking in just having a bool cyclic parameter (as the
    first intention of the flags is to support cyclic transfers) but ended up
    "respecting" the previously agreed approach.
- Patch 2
  * Adapted patch for the changes made in patch 1.
- Patch 5
  * Adapted patch for the changes made in patch 1.

Patchset based on next-20240223.

---
Paul Cercueil (6):
      dmaengine: Add API function dmaengine_prep_peripheral_dma_vec()
      dmaengine: dma-axi-dmac: Implement device_prep_peripheral_dma_vec
      iio: core: Add new DMABUF interface infrastructure
      iio: buffer-dma: Enable support for DMABUFs
      iio: buffer-dmaengine: Support new DMABUF based userspace API
      Documentation: iio: Document high-speed DMABUF based API

 Documentation/iio/dmabuf_api.rst                   |  54 +++
 Documentation/iio/index.rst                        |   2 +
 drivers/dma/dma-axi-dmac.c                         |  40 ++
 drivers/iio/buffer/industrialio-buffer-dma.c       | 181 +++++++-
 drivers/iio/buffer/industrialio-buffer-dmaengine.c |  59 ++-
 drivers/iio/industrialio-buffer.c                  | 462 +++++++++++++++++++++
 include/linux/dmaengine.h                          |  27 ++
 include/linux/iio/buffer-dma.h                     |  31 ++
 include/linux/iio/buffer_impl.h                    |  33 ++
 include/uapi/linux/iio/buffer.h                    |  22 +
 10 files changed, 894 insertions(+), 17 deletions(-)
---
base-commit: 33e1d31873f87d119e5120b88cd350efa68ef276
change-id: 20240223-iio-dmabuf-5ee0530195ca
--

Thanks!
- Nuno Sá