[PATCH v6 0/6] iio: core,buffer: re-organize chardev creation

[Alexandru Ardelean]

The main intent is to be able to add more chardevs per IIO device, one
for each buffer. To get there, some rework is needed.
This tries to re-organize the init of the chardev.

 
Changelog v5 -> v6:
- patch 'iio: core: register chardev only if needed'
  - sort file_operations fields for iio_event_fileops
- patch 'iio: buffer,event: duplicate chardev creation for buffers & events'
  - fixed-up '**/' -> '*/' for 2 block comments
  - sorted file_operations for iio_buffer_fileops, after move
  - removed 'indio_dev->chrdev = NULL' on IIO device unregister
  - added comment about 'indio_dev->info' NULL check in
    iio_device_event_ioctl()
- patch 'iio: core: add simple centralized mechanism for ioctl() handlers'
  - re-using lock 'indio_dev->info_exist_lock' for new ioctl register
    mechanism in iio_device_ioctl()
  - simplified exit condition from the loop; only need to check
    `ret != IIO_IOCTL_UNHANDLED` to continue looping;
    everything else is just return/break
- patch 'iio: core: use new common ioctl() mechanism'
  - the comment for 'indio_dev->info' NULL check is being moved here to
    highlight why the null-check is being removed; or where it's being
    moved

Changelog v4 -> v5:
- dropped patch 'iio: Use an early return in iio_device_alloc to simplify code.'
  is applied upstream

Changelog v3 -> v4:
- added patch [1] 'iio: Use an early return in iio_device_alloc to simplify code.'
  it's main purpose is so that this patch applies:
     [2]'iio: core: add simple centralized mechanism for ioctl() handlers'
  depending on the final version of patch [1], patch [2] needs some
  minor fixup
- added patch 'iio: core,buffer: wrap iio_buffer_put() call into iio_buffers_put()'
- patch 'iio: core: register buffer fileops only if buffer present'
  is now: 'iio: core: register chardev only if needed'
- dropped 'iio: buffer: move sysfs alloc/free in industrialio-buffer.c'
  it's likely we won't be doing this patch anymore
- patches:
    'iio: buffer: move iio buffer chrdev in industrialio-buffer.c'
    'iio: event: move event-only chardev in industrialio-event.c'
  have been merged into 'iio: buffer,event: duplicate chardev creation for buffers & events'
  since now, the logic is a bit different, and 'indio_dev->chrdev' is
  now a reference to either the buffer's chrdev & or the events-only
  chrdev
- added simple mechanism to register ioctl() handlers for IIO device
  which is currently used only by events mechanism

Changelog v2 -> v3:
* removed double init in
  'iio: event: move event-only chardev in industrialio-event.c'

Changelog v1 -> v2:
* re-reviewed some exit-paths and cleanup some potential leaks on those
  exit paths:
  - for 'iio: buffer: move iio buffer chrdev in industrialio-buffer.c'
    add iio_device_buffers_put() helper and calling iio_buffers_uninit()
    on device un-regsiter
  - for 'move sysfs alloc/free in industrialio-buffer.c'
    call 'iio_buffer_free_sysfs_and_mask()' on exit path if
    cdev_device_add() fails
  - for 'move event-only chardev in industrialio-event.c'
    check if event_interface is NULL in
    iio_device_unregister_event_chrdev()

Alexandru Ardelean (6):
  iio: buffer: add back-ref from iio_buffer to iio_dev
  iio: core,buffer: wrap iio_buffer_put() call into iio_buffers_put()
  iio: core: register chardev only if needed
  iio: buffer,event: duplicate chardev creation for buffers & events
  iio: core: add simple centralized mechanism for ioctl() handlers
  iio: core: use new common ioctl() mechanism

 drivers/iio/iio_core.h            |  29 +++++---
 drivers/iio/industrialio-buffer.c | 102 ++++++++++++++++++++++++--
 drivers/iio/industrialio-core.c   | 116 +++++++++++++-----------------
 drivers/iio/industrialio-event.c  | 100 +++++++++++++++++++++++++-
 include/linux/iio/buffer_impl.h   |  10 +++
 include/linux/iio/iio.h           |   8 +--
 6 files changed, 276 insertions(+), 89 deletions(-)

-- 
2.17.1