[PATCH v7 0/5] Add initial configfs support for IIO

[Daniel Baluta <daniel.baluta@intel.com>]

This patchset introduces IIO software triggers, offers a way of configuring
them via configfs and adds the IIO hrtimer based interrupt source to be used
with software triggers.

The arhitecture is now split in 3 parts, to remove all IIO trigger specific
parts from IIO configfs core:

(1) IIO configfs - offers a generic way of creating IIO objects. So far there
	is one default group for triggers.
(2) IIO software triggers - software trigger implementation.
(3) IIO hrtimer trigger - is the first interrupt source for software triggers
        (with syfs to follow). Each trigger type can implement its own set of
        attributes.

Also this patchset introduces configfs_(un)register_group to the configfs core
in order to allow drivers to dynamically create groups on demand.

Changes since v6:
	* implemented Lars-Peter's idea (https://lkml.org/lkml/2015/5/13/302)
	to switch from /config/iio/triggers/hrtimer-instance1 to
	/config/iio/triggers/instance1.

Changes since v5: (after Lars comments)
        * the most important change is that we moved sampling_frequency attribute
        from configfs to trigger's directory in /sys.
        * couple of const added to strings
        * documentation to public API in sw_trigger.h
        * replace pr_err with WARN_ONCE in trigger_make_group to avoid spamming
        kernel log, but without leaving user clueless in case of errors.
        * we still need to decide if we get a real gain by adding min/max limits
        for sampling frequency in /config dir. Anyhow, this can be done in a later
        patch.
        * fix race in hrtimer_remove

Changes since v4:
        * patch 1/4
                - fixed "new line" nit in industrialio-sw-trigger.c
                - added license header in sw_trigger.h o
        * patch 2/4
                - none
        * patch 3/4
                - none
        * patch 4/4
                - removed "Further work" chapter in iio_configfs.txt

                - added configfs-iio file in Documentation/ABI/testing
Daniel Baluta (5):
  configfs: Allow dynamic group (un)registration
  iio: core: Introduce IIO configfs support
  iio: core: Introduce IIO software triggers
  iio: trigger: Introduce IIO hrtimer based trigger
  iio: Documentation: Add IIO configfs documentation

 Documentation/ABI/testing/configfs-iio |  20 ++++
 Documentation/iio/iio_configfs.txt     |  57 ++++++++++
 drivers/iio/Kconfig                    |  16 +++
 drivers/iio/Makefile                   |   2 +
 drivers/iio/industrialio-configfs.c    | 116 ++++++++++++++++++++
 drivers/iio/industrialio-sw-trigger.c  | 119 ++++++++++++++++++++
 drivers/iio/trigger/Kconfig            |  10 ++
 drivers/iio/trigger/Makefile           |   2 +
 drivers/iio/trigger/iio-trig-hrtimer.c | 193 +++++++++++++++++++++++++++++++++
 fs/configfs/dir.c                      |  39 ++++++-
 include/linux/configfs.h               |   4 +
 include/linux/iio/sw_trigger.h         |  99 +++++++++++++++++
 12 files changed, 675 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/ABI/testing/configfs-iio
 create mode 100644 Documentation/iio/iio_configfs.txt
 create mode 100644 drivers/iio/industrialio-configfs.c
 create mode 100644 drivers/iio/industrialio-sw-trigger.c
 create mode 100644 drivers/iio/trigger/iio-trig-hrtimer.c
 create mode 100644 include/linux/iio/sw_trigger.h

-- 
2.1.4