This series first converts the debugfs files in the pinctrl subsystem to octal permissions and then adds a new debugfs file "pinmux-select". Function name and group name can be written to "pinmux-select" which will cause the function and group to be activated on the pin controller. The final patch in this series documents the debugfs files for pinctrl. Notes for PATCH v6: - add 'Suggested-by:' for Joe Perches to octal permissions patch - add 'Reviewed-by:' from Andy and Geert to octal permissions patch - reword example in the pinmux-select patch per Andy's advice - indent the example output per Andy's advice - remove usage error messages as Andy advised it is too verbose - return -ENOMEM when write is too big for the input buffer per Andy's advice - handle whitespace before, in between, and after the function name and group name as suggested by Andy - rename free_buf to exit_free_buf per Andy's advice - add documentation patch to series which documents the debugfs files for the pinctrl subsystem including the new pinmux-select file Notes for PATCH v5: - convert permissions from symbolic to octal for debugfs_create_file() calls in core.c that Joe Perches pointed out I had missed - Linus W: please let me know if I should break this series apart as you already applied an earlier version of octal conversion patch today [1] - switch from sscanf() to just pointing to function name and group name inside of the buffer. This also avoids having to allocate additional buffers for fname and gname. Geert and Andy highlighted this security issue and Andy suggested code to use instead of sscanf(). - switch from devm_kfree() to kfree() after Dan Carpenter warned me - remove .read from pinmux_select_ops per Geert since it is write only - add usage format to error when unable find fname or gname in buffer Notes for PATCH v4: - correct the commit message in the second patch to reference function and group name instead of integer selectors. Apologies for not fixing that in v3 - fix typos in cover letter Notes for PATCH v3: - add Suggested-by: Andy Shevchenko to the "pinctrl: use to octal permissions for debugfs files" patch - change the octal permissions from 0400 to 0444 to correctly match the symbolic permissions (thanks to Joe Perches and Geert Uytterhoeven) - note that S_IFREG flag is added to the mode in __debugfs_create_file() (thanks to Andy for highlighting this and Joe for suggesting I should add a note to the commit message) - fix order of the goto labels so that the buffers are freed correctly as suggested by Dan Carpenter - move from devm_kzalloc() to kzalloc() as the buffers are only used inside the pinmux_select() function and not related to the lifetime of the pin controller device (thanks to Andy for pointing this out) - correct the pinmux-select example in commit message to use the function and group name instead of selector (thanks to Geert) Notes for PATCH v2: - create patch series that includes patch to switch all the debugfs files in pinctrl subsystem over to octal permission - write function name and group name, instead of error-prone selector numbers, to the 'pinmux-select' file - switch from static to dynamic allocation for the kernel buffer filled by strncpy_from_user() - look up function selector from function name using pinmux_func_name_to_selector() - validate group name with get_function_groups() and match_string() - look up selector for group name with pinctrl_get_group_selector() Notes for PATCH v1: - posted seperate patch to switch all the debugfs files in pinctrl subsystem over to octal permission - there is no existing documentation for any of the debugfs enteries for pinctrl, so it seemed to have a bigger scope than just this patch. I also noticed that rst documentation is confusingly named "pinctl" (no 'r') and started thread about that [2]. Linus suggested chaning that to 'pin-control'. Thus I am planning a seperate documentation patch series where the file is renamed, references changed and a section on the pinctrl debugfs files is added. Notes for RFC v2 [3]: - rename debugfs file "pinmux-set" to "pinmux-select" - renmae pinmux_set_write() to pinmux_select() - switch from memdup_user_nul() to strncpy_from_user() - switch from pr_warn() to dev_err() [1] https://lore.kernel.org/linux-gpio/20210126044742.87602-1-drew@xxxxxxxxxxxxxxx/ [2] https://lore.kernel.org/linux-gpio/20210126050817.GA187797@x1/ [3] https://lore.kernel.org/linux-gpio/20210123064909.466225-1-drew@xxxxxxxxxxxxxxx/ Drew Fustini (3): pinctrl: use to octal permissions for debugfs files pinctrl: pinmux: Add pinmux-select debugfs file docs/pinctrl: document debugfs files Documentation/driver-api/pinctl.rst | 37 ++++++++++ drivers/pinctrl/core.c | 12 ++-- drivers/pinctrl/pinconf.c | 4 +- drivers/pinctrl/pinmux.c | 106 +++++++++++++++++++++++++++- 4 files changed, 149 insertions(+), 10 deletions(-) -- 2.25.1
