Re: [PATCH 0/5] gpio: expose pull-up/pull-down line flags to userspace

[Bartosz Golaszewski <brgl@xxxxxxxx>]

pt., 11 paź 2019 o 17:47 Kent Gibson <warthog618@xxxxxxxxx> napisał(a):
>
> 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. Pull Up - pull-up bias is enabled.
>  2. Pull Down - pull-down bias is enabled.
>  3. Pull None - bias is explicitly disabled.
>
> The biases are encoded in two flags, PULL_UP and PULL_DOWN, where
> setting both is interpreted as Pull None. So the flags effectively form
> a two bit field encoding the values above.
>
> 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.
>
> Patches are against:
>   github.com/brgl/linux/commit/82fc38f6ab599ee03f7a8ed078de8abb41e6e611
> which contains the initial patch from Drew Fustini, with Bartosz Golaszewski,
> that adds support for pull-up/down flags in line handle requests.
>
> Patch 1 adds support to line event requests.
> Patch 2 adds pull-up/down support to the gpio-mockup for uAPI testing.
> Patch 3 rejects biasing changes to lines requested as-is.
> Patch 4 adds support for disabling bias (pull none).
> Patch 5 adds support for setting bias on output lines.
>
> Kent Gibson (5):
>   gpiolib: add support for pull up/down to lineevent_create
>   gpio: mockup: add set_config to support pull up/down
>   gpiolib: pull requires explicit input mode
>   gpiolib: disable bias on inputs when pull up/down are both set
>   gpiolib: allow pull up/down on outputs
>
>  drivers/gpio/gpio-mockup.c | 94 ++++++++++++++++++++++++--------------
>  drivers/gpio/gpiolib.c     | 55 ++++++++++++++++------
>  2 files changed, 100 insertions(+), 49 deletions(-)
>
> --
> 2.23.0
>

Hi Kent,

thanks for doing that, but please make it easier to review. The cover
letter shouldn't be sent in response to this thread but be part of the
patch series. Please don't rebase the patches on top of my
development/experimental branch - every patch needs to spend some time
on the mailing list. Rebase the series on top of the latest mainline
release candidate. Pull in Drew's changes and just squash my code into
your patches - it was not finished anyway. You can send patches from
other developers or make them part of your series - there's no problem
with that as long as you keep the authorship.

That'll make it much easier to review and understand.

Thanks in advance!
Bartosz