Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1415590

Re: [PATCH 27/32] gpio: Add support for the FXL6408 GPIO expander.

From Eric Anholt <eric@anholt.net>
Newsgroups linux.kernel
Subject Re: [PATCH 27/32] gpio: Add support for the FXL6408 GPIO expander.
Date 2016-06-07 02:00 +0200
Message-ID <rHcB4-3jH-13@gated-at.bofh.it> (permalink)
References <rFmbv-5DL-15@gated-at.bofh.it> <rFmbv-5DL-13@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


[Multipart message — attachments visible in raw view] - view raw

Gerd Hoffmann <kraxel@redhat.com> writes:

> From: Eric Anholt <eric@anholt.net>
>
> This commit needs to be split up and cleaned up.  Also we should add
> interrupt support before pushing upstream.
>
> Signed-off-by: Eric Anholt <eric@anholt.net>

OK, I've confirmed with the firmware maintainers: We really can't drive
this natively from Linux.  The firmware is polling one of the fxl6408's
pins 10 times a second for detecting under-voltage, so if we also try to
drive it we'll end up smashing each others' I2C transactions.  We'll
need to do a GPIO driver using the GET/SET_GPIO_STATE firmware calls,
instead.  Unfortunately, we don't have a direction-setting API for that
at the moment, but it'll at least let us read the HDMI HPD signal.

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[PATCH 27/32] gpio: Add support for the FXL6408 GPIO expander. Gerd Hoffmann <kraxel@redhat.com> - 2016-06-01 23:50 +0200
  Re: [PATCH 27/32] gpio: Add support for the FXL6408 GPIO expander. Eric Anholt <eric@anholt.net> - 2016-06-07 02:00 +0200
  Re: [PATCH 27/32] gpio: Add support for the FXL6408 GPIO expander. Florian Fainelli <f.fainelli@gmail.com> - 2016-06-07 02:10 +0200
  Re: [PATCH 27/32] gpio: Add support for the FXL6408 GPIO expander. Linus Walleij <linus.walleij@linaro.org> - 2016-06-08 11:20 +0200
    Re: [PATCH 27/32] gpio: Add support for the FXL6408 GPIO expander. Eric Anholt <eric@anholt.net> - 2016-06-09 19:30 +0200

csiph-web