[PATCH v2 00/12] gpio: implement the configfs testing module

[Bartosz Golaszewski <brgl@bgdev.pl>]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

This series adds a new GPIO testing module based on configfs committable items
and sysfs. The goal is to provide a testing driver that will be configurable
at runtime (won't need module reload) and easily extensible. The control over
the attributes is also much more fine-grained than in gpio-mockup.

This series also contains a respin of the patches I sent separately to the
configfs maintainers - these patches implement the concept of committable
items that was well defined for a long time but never actually completed.

Apart from the new driver itself, its selftests and the configfs patches, this
series contains some changes to the bitmap API - most importantly: it adds
devres managed variants of bitmap_alloc() and bitmap_zalloc().

v1 -> v2:
- add selftests for gpio-sim
- add helper programs for selftests
- update the configfs rename callback to work with the new API introduced in
  v5.11
- fix a missing quote in the documentation
- use !! whenever using bits operation that are required to return 0 or 1
- use provided bitmap API instead of reimplementing copy or fill operations
- fix a deadlock in gpio_sim_direction_output()
- add new read-only configfs attributes for mapping of configfs items to GPIO
  device names
- and address other minor issues pointed out in reviews of v1

Bartosz Golaszewski (12):
  configfs: increase the item name length
  configfs: use (1UL << bit) for internal flags
  configfs: implement committable items
  samples: configfs: add a committable group
  lib: bitmap: remove the 'extern' keyword from function declarations
  lib: bitmap: order includes alphabetically
  lib: bitmap: provide devm_bitmap_alloc() and devm_bitmap_zalloc()
  drivers: export device_is_bound()
  gpio: sim: new testing module
  selftests: gpio: provide a helper for reading chip info
  selftests: gpio: add a helper for reading GPIO line names
  selftests: gpio: add test cases for gpio-sim

 Documentation/admin-guide/gpio/gpio-sim.rst   |  72 ++
 Documentation/filesystems/configfs.rst        |   6 +-
 drivers/base/dd.c                             |   1 +
 drivers/gpio/Kconfig                          |   8 +
 drivers/gpio/Makefile                         |   1 +
 drivers/gpio/gpio-sim.c                       | 878 ++++++++++++++++++
 fs/configfs/configfs_internal.h               |  22 +-
 fs/configfs/dir.c                             | 245 ++++-
 include/linux/bitmap.h                        | 129 +--
 include/linux/configfs.h                      |   3 +-
 lib/bitmap.c                                  |  42 +-
 samples/configfs/configfs_sample.c            | 153 +++
 tools/testing/selftests/gpio/.gitignore       |   2 +
 tools/testing/selftests/gpio/Makefile         |   4 +-
 tools/testing/selftests/gpio/config           |   1 +
 tools/testing/selftests/gpio/gpio-chip-info.c |  57 ++
 tools/testing/selftests/gpio/gpio-line-name.c |  55 ++
 tools/testing/selftests/gpio/gpio-sim.sh      | 229 +++++
 18 files changed, 1822 insertions(+), 86 deletions(-)
 create mode 100644 Documentation/admin-guide/gpio/gpio-sim.rst
 create mode 100644 drivers/gpio/gpio-sim.c
 create mode 100644 tools/testing/selftests/gpio/gpio-chip-info.c
 create mode 100644 tools/testing/selftests/gpio/gpio-line-name.c
 create mode 100755 tools/testing/selftests/gpio/gpio-sim.sh

-- 
2.29.1