[PATCH v3 00/11] gpio: implement the configfs testing module

Bartosz Golaszewski
2021-03-09T21:00:13Z

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

v2 -> v3:
- use devm_bitmap_alloc() instead of the zalloc variant if we're initializing
the bitmap with 1s
- drop the patch exporting device_is_bound()
- don't return -ENODEV from dev_nam and chip_name configfs attributes, return
a string indicating that the device is not available yet ('n/a')
- fix indentation where it makes sense
- don't protect IDA functions which use their own locking and where it's not
needed
- use kmemdup() instead of kzalloc() + memcpy()
- collected review tags
- minor coding style fixes

Bartosz Golaszewski (11):
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()
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/gpio/Kconfig | 8 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-sim.c | 879 ++++++++++++++++++
fs/configfs/configfs_internal.h | 22 +-
fs/configfs/dir.c | 245 ++++-
include/linux/bitmap.h | 127 +--
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 +++++
17 files changed, 1820 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

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2.30.1