[v3,00/11] iio: core,buffer: add support for multiple IIO buffers per IIO device

Message

Alexandru Ardelean Feb. 1, 2021, 2:50 p.m. UTC

Changelog v2 -> v3:
* added commit 'docs: ioctl-number.rst: reserve IIO subsystem ioctl() space'
  reserving 'i' 0x90-0x9F ioctls for IIO
  I did not see any conflicts with others (in the doc)
  - related to this, the new IIO_BUFFER_GET_FD_IOCTL is now at 'i' 0x91
* changed approach for creating sysfs buffer directories;
  - they are now created as groups on the IIO device; that also means
    that the groups array needs to be krealloc-ed and assign later in
    the registration
  - merged bufferX/ and scan_elementsX/ directories into a single
    bufferX/ directory
  - for legacy the buffer/ & scan_elements/ directories are kept; but
    they're groups objects have been moved on the iio_dev_opaque object
  - internally, the iio_dev_attr type is being extended to hold a
    reference for an IIO buffer;
    = this is great for scan_elements attributes
    = and for the rest of the iio_buffer attributes, it means we need to
      wrap them into iio_dev_attr

One thing to be determined: if IIO_BUFFER_GET_FD_IOCTL for buffer0 should
return an FD or not.
Right now, it's returning 0.

Alexandru Ardelean (11):
  docs: ioctl-number.rst: reserve IIO subsystem ioctl() space
  iio: core: register chardev only if needed
  iio: core-trigger: make iio_device_register_trigger_consumer() an int
    return
  iio: core: rework iio device group creation
  iio: buffer: group attr count and attr alloc
  iio: core: merge buffer/ & scan_elements/ attributes
  iio: add reference to iio buffer on iio_dev_attr
  iio: buffer: wrap all buffer attributes into iio_dev_attr
  iio: core: wrap iio device & buffer into struct for character devices
  iio: buffer: introduce support for attaching more IIO buffers
  iio: buffer: add ioctl() to support opening extra buffers for IIO
    device

 .../userspace-api/ioctl/ioctl-number.rst      |   1 +
 drivers/iio/iio_core.h                        |  10 +
 drivers/iio/iio_core_trigger.h                |   4 +-
 drivers/iio/industrialio-buffer.c             | 420 +++++++++++++++---
 drivers/iio/industrialio-core.c               |  87 +++-
 drivers/iio/industrialio-event.c              |   6 +-
 drivers/iio/industrialio-trigger.c            |   6 +-
 include/linux/iio/buffer.h                    |   4 +-
 include/linux/iio/buffer_impl.h               |  21 +-
 include/linux/iio/iio-opaque.h                |  14 +
 include/linux/iio/iio.h                       |   5 -
 include/linux/iio/sysfs.h                     |   3 +
 include/uapi/linux/iio/buffer.h               |  10 +
 13 files changed, 487 insertions(+), 104 deletions(-)
 create mode 100644 include/uapi/linux/iio/buffer.h