Date:   Tue,  7 Dec 2021 10:34:05 +0100
From:   Bartosz Golaszewski <brgl@...ev.pl>
To:     Kent Gibson <warthog618@...il.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Shuah Khan <shuah@...nel.org>,
        Geert Uytterhoeven <geert@...ux-m68k.org>,
        Viresh Kumar <viresh.kumar@...aro.org>
Cc:     linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-kselftest@...r.kernel.org,
        Bartosz Golaszewski <brgl@...ev.pl>
Subject: [PATCH v13 0/7] gpio-sim: configfs-based GPIO simulator

Hopefully this will be the last iteration of this series. Just some
minor changes requested by Andy in this one.

Tested both with configfs as well as device-tree.

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

v3 -> v4:
- return 'none' instead of 'n/a' from dev_name and chip_name before the device
  is registered
- use sysfs_emit() instead of s*printf()
- drop GPIO_SIM_MAX_PROP as it's only used in an array's definition where it's
  fine to hardcode the value

v4 -> v5:
- drop lib patches that are already upstream
- use BIT() instead of (1UL << bit) for flags
- fix refcounting for the configfs_dirent in rename()
- drop d_move() from the rename() callback
- free memory allocated for the live and pending groups in configfs_d_iput()
  and not in detach_groups()
- make sure that if a group of some name is in the live directory, a new group
  with the same name cannot be created in the pending directory

v5 -> v6:
- go back to using (1UL << bit) instead of BIT()
- if the live group dentry doesn't exist for whatever reason at the time when
  mkdir() in the pending group is called (would be a BUG()), return -ENOENT
  instead of -EEXIST which should only be returned if given subsystem already
  exists in either live or pending group

v6 -> v7:
- as detailed by Andy in commit 6fda593f3082 ("gpio: mockup: Convert to use
  software nodes") removing device properties after the platform device is
  removed but before the GPIO device gets dropped can lead to a use-after-free
  bug - use software nodes to manually control the freeing of the properties

v7 -> v8:
- fixed some minor coding style issues as pointed out by Andy

v8 -> v9:
- dropped the patches implementing committable-items and reworked the
  driver to not use them
- reworked the gpio-line-names property and configuring specific lines
  in general
- many smaller tweaks here and there

v9 -> v10:
- make writing to 'live' wait for the probe to finish and report an
  error to user-space if it failed
- add the ability to hog lines from the kernel-space
- rework locking (drop separate locks for line context objects)
- rework the sysfs interface (create a separate group for each line with
  a constant number of attributes instead of going the other way around)

v10 -> v11:
- rework the configfs structure to represent a deeper hierarchy that
  gpiolib supports, namely: multiple banks per platform device

v11 -> v12:
- simplify patch 2/7 by removing any mentions of OF from gpiolib.c
- improve the documentation by adding rest markups
- add a device-tree sample to the docs
- drop some trailing whitespaces from the driver
- make gpio_sim_make_bank_swnode() static
- fix coding style in patch 6/7
- add patch 3/7 that makes the OF part of gpiolib prefer to use gpio_chip's fwnode (if set) over of_node

v12 -> v13:
- mentioned ACPI not being converted yet in patch 3/7
- avoided one allocation in gpio_sim_strdup_trimmed() by using memmove()
- use kstrtobool() where applicable
- allow all bases in gpio_sim_bank_config_num_lines_store()
- remove unnecessary commas
- use sysfs_match_string() where applicable
- drop unneeded curr_var local variable

Bartosz Golaszewski (7):
  gpiolib: provide gpiod_remove_hogs()
  gpiolib: allow to specify the firmware node in struct gpio_chip
  gpiolib: of: make fwnode take precedence in struct gpio_chip
  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   |  134 ++
 drivers/gpio/Kconfig                          |    8 +
 drivers/gpio/Makefile                         |    1 +
 drivers/gpio/gpio-sim.c                       | 1589 +++++++++++++++++
 drivers/gpio/gpiolib-of.c                     |    3 +
 drivers/gpio/gpiolib.c                        |   18 +-
 include/linux/gpio/driver.h                   |    2 +
 include/linux/gpio/machine.h                  |    2 +
 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      |  396 ++++
 14 files changed, 2269 insertions(+), 3 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

-- 
2.25.1

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