[PATCH v2 00/12][RESEND] iio: core,buffer: add support for multiple IIO buffers per IIO device

[Alexandru Ardelean]

Continuing from:
 https://lore.kernel.org/linux-iio/20201117162340.43924-1-alexandru.ardelean@xxxxxxxxxx/

Changelog v1 -> v2:
* 'iio: buffer: rework buffer & scan_elements dir creation'
  add more doc-strings detailing the reasoning for this change
* 'iio: buffer: re-route scan_elements via it's kobj_type'
  move list_del() before the kfree()'s in the list destruction
* 'iio: buffer: introduce support for attaching more IIO buffers'
  - changed to 'cnt' variable vs re-using the 'i' for unwinding in
    iio_buffer_alloc_sysfs_and_mask()
  - removed kfree(old) in iio_device_attach_buffer()
  - made iio_device_attach_buffer() an int return; this means that some
    follow up patches are needed to make this return value be used;
* 'iio: buffer: add ioctl() to support opening extra buffers for IIO device'
  - tested ioctl() with a simple C program; attached to comment;
  - changed 'i' variable usage to 'sz' for alloc
  - changed logic for buffer0; returning FD 0; userspace should know
    that the IIO_BUFFER_GET_FD_IOCTL call returns 0 for buffer0;
    this is because I can't find a way to determine the FD of the
    ioctl() in the kernel; duplicating an ioctl() for buffer0 is also bad;

Alexandru Ardelean (12):
  iio: core: register chardev only if needed
  iio: buffer: add back-ref from iio_buffer to iio_dev
  iio: buffer: rework buffer & scan_elements dir creation
  iio: buffer: add index to the first IIO buffer dir and symlink it back
  iio: core: split __iio_device_attr_init() to init only the attr object
  iio: buffer: re-route scan_elements via it's kobj_type
  iio: buffer: re-route core buffer attributes via it's new kobj_type
  iio: buffer: add helper to get the IIO device to which a buffer
    belongs
  iio: re-route all buffer attributes through new buffer kobj_type
  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

 drivers/iio/accel/adxl372.c                   |  36 +-
 drivers/iio/accel/bmc150-accel-core.c         |  34 +-
 drivers/iio/adc/at91-sama5d2_adc.c            |  30 +-
 .../buffer/industrialio-buffer-dmaengine.c    |  13 +-
 .../cros_ec_sensors/cros_ec_sensors_core.c    |  30 +-
 .../common/hid-sensors/hid-sensor-trigger.c   |  32 +-
 drivers/iio/iio_core.h                        |  11 +
 drivers/iio/industrialio-buffer.c             | 647 ++++++++++++++----
 drivers/iio/industrialio-core.c               | 117 ++--
 include/linux/iio/buffer.h                    |   6 +-
 include/linux/iio/buffer_impl.h               |  25 +-
 include/linux/iio/iio-opaque.h                |   6 +
 include/linux/iio/iio.h                       |   2 +-
 include/linux/iio/sysfs.h                     |  50 ++
 include/uapi/linux/iio/buffer.h               |  10 +
 15 files changed, 790 insertions(+), 259 deletions(-)
 create mode 100644 include/uapi/linux/iio/buffer.h

-- 
2.17.1