Re: [PATCH v6 0/7] gpio: expose line bias flags to userspace

[Bartosz Golaszewski <bgolaszewski@baylibre.com>]

wt., 5 lis 2019 o 03:04 Kent Gibson <warthog618@gmail.com> napisał(a):
>
> The changes from v5:
>   - rebased onto Bart's gpio/for-kent branch.
>
> The changes from v4:
> Review changes:
>  - relocate restriction on applying bias to as-is from patch 2 to patch 1.
>  - propagate errors, other than ENOTSUPP, from gpio_set_bias. (squashed
>    into patches 3 and 4).
>  - include SET_CONFIG patch series v2 (patch 6 and 7 here).
>
> I've also fixed a few other nits I noticed along the way:
>  - rework gpio_set_bias as flags are mutually exclusive.
>  - remove input flag required to set bias restriction from
>    lineevent_create as events are implicitly assumed inputs anyway.
>  - reorder patches to group gpiolib bias patches together before the
>    gpio-mockup changes.
>
>
> This series adds gross control of pull-up/pull-down to the GPIO uAPI.
> Gross control means enabling and disabling of bias functionality,
> not finer grained control such as setting biasing impedances.
>
> The support allows both input and output lines to have any one of the
> following biases applied as part of the line handle or event request:
>  0. As Is - bias is left alone.  This is the default for ABI compatibility.
>  1. Bias Disable - bias is explicitly disabled.
>  2. Pull Down - pull-down bias is enabled.
>  3. Pull Up - pull-up bias is enabled.
>
> The biases are set via three flags, BIAS_DISABLE, BIAS_PULL_DOWN
> and BIAS_PULL_UP.  These map directly to the similarly named
> pinctrl pin_config_param flags.
> As Is corresponds to none of the flags being set.
>
> The setting of biases on output lines may seem odd, but is to allow for
> utilisation of internal pull-up/pull-down on open drain and open source
> outputs, where supported in hardware.
>
> The series also adds the GPIOHANDLE_SET_CONFIG_IOCTL to the gpio chardev.
> The ioctl allows some of the configuration of a requested handle to be
> changed without having to release the line.
> The primary use case is the changing of direction for bi-directional
> lines.
>
> Patches are against Bart's gpio/for-kent branch[1].
>
> The patch has been successfully tested against gpio-mockup, and
> on a Raspberry Pi, in both cases using the feature/pud_set_config
> branch of my Go gpiod library[2], as well as with my feature/pud
> development branch of libgpiod[3].  Patch 7 has only been tested using
> my gpiod library as libgpiod has not yet been updated to support the
> SET_CONFIG ioctl.
>
> Patch 1 adds pull-up/pull-down support to line handle requests.
> Patch 2 adds pull-up/pull-down support to line event requests.
> Patch 3 adds support for disabling bias.
> Patch 4 adds support for setting bias on output lines.
> Patch 5 adds pull-up/down support to the gpio-mockup for uAPI testing.
> Patch 6 refactors the flag validation from linehandle_create.
> Patch 7 adds the SET_CONFIG ioctl.
>
> Drew Fustini (1):
>   gpio: expose pull-up/pull-down line flags to userspace
>
> Kent Gibson (6):
>   gpiolib: add support for pull up/down to lineevent_create
>   gpiolib: add support for disabling line bias
>   gpiolib: add support for biasing output lines
>   gpio: mockup: add set_config to support pull up/down
>   gpiolib: move validation of line handle flags into helper function
>   gpio: add new SET_CONFIG ioctl() to gpio chardev
>
>  drivers/gpio/gpio-mockup.c |  94 ++++++++++------
>  drivers/gpio/gpiolib.c     | 213 +++++++++++++++++++++++++++++++------
>  drivers/gpio/gpiolib.h     |   1 +
>  include/uapi/linux/gpio.h  |  24 +++++
>  4 files changed, 264 insertions(+), 68 deletions(-)
>
> --
> 2.23.0
>

Ok, all looks good now and since Linus already said he's fine with
this series, I'll take it through my tree for v5.5.

Thanks!
Bartosz