From: Stephen Warren <swarren@wwwdotorg.org>
To: u-boot@lists.denx.de
Subject: [U-Boot] [RFC PATCH v2 13/13] tegra: Convert tegra GPIO driver to use driver model
Date: Tue, 06 May 2014 14:37:28 -0600 [thread overview]
Message-ID: <53694808.3090202@wwwdotorg.org> (raw)
In-Reply-To: <CAPnjgZ3qgVw8SHwZ_Nx1Re0qCGbGpGbqFWX_QkDbzU1mogMNgQ@mail.gmail.com>
On 05/06/2014 02:28 PM, Simon Glass wrote:
...
> The GPIO uclass does sequentially number GPIOs, but be aware that on
> platforms with multiple GPIO controllers (e.g. an I2C GPIO extender) you
> might hit a problem where the tegra GPIOs are not first, so might start
> at 8 or 16, for example. However I think that probably can be resolved
> when we come to it.
That fact shouldn't be exposed to the user. If all the GPIO IDs are
relative to a specific named GPIO device, then the user will never see
the internal offset. Indeed, the GPIO driver for a particular GPIO HW
module/chip wouldn't ever see the offset either. In fact, we shouldn't
have/introduce a flat/global GPIO numbering space at all. The Linux
community has learned that doesn't work very well, and is moving away
from it in the more recent "gpiod" API for example. Everything should be
identified as a tuple (GPIO controller handle, GPIO ID within that GPIO
controller).
next prev parent reply other threads:[~2014-05-06 20:37 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-05 16:08 [U-Boot] [RFC PATCH v2 0/13] Enable driver model for GPIOs on Tegra Simon Glass
2014-05-05 16:08 ` [U-Boot] [RFC PATCH v2 01/13] Add an I/O tracing feature Simon Glass
2014-05-05 16:08 ` [U-Boot] [RFC PATCH v2 02/13] arm: Support iotrace feature Simon Glass
2014-05-05 16:09 ` [U-Boot] [RFC PATCH v2 03/13] sandbox: " Simon Glass
2014-05-05 16:09 ` [U-Boot] [RFC PATCH v2 04/13] Makefile: Support include files for .dts files Simon Glass
2014-05-05 16:54 ` Stephen Warren
2014-05-07 2:15 ` Masahiro Yamada
2014-05-07 22:37 ` Simon Glass
2014-05-05 16:09 ` [U-Boot] [RFC PATCH v2 05/13] tegra: dts: Bring in GPIO bindings from linux Simon Glass
2014-05-05 16:57 ` Stephen Warren
2014-05-07 23:11 ` Simon Glass
2014-05-05 16:09 ` [U-Boot] [RFC PATCH v2 06/13] dm: Update README to encourage conversion to driver model Simon Glass
2014-05-05 16:09 ` [U-Boot] [RFC PATCH v2 07/13] dm: Use case-insensitive comparison for GPIO banks Simon Glass
2014-05-05 16:09 ` [U-Boot] [RFC PATCH v2 08/13] dm: Add missing header files in lists and root Simon Glass
2014-05-05 16:09 ` [U-Boot] [RFC PATCH v2 09/13] dm: Case away the const-ness of the global_data pointer Simon Glass
2014-05-05 16:09 ` [U-Boot] [RFC PATCH v2 10/13] dm: Allow driver model tests only for sandbox Simon Glass
2014-05-05 16:09 ` [U-Boot] [RFC PATCH v2 11/13] dm: Fix printf() strings in the 'dm' command Simon Glass
2014-05-05 16:09 ` [U-Boot] [RFC PATCH v2 12/13] tegra: Enable driver model Simon Glass
2014-05-05 16:58 ` Stephen Warren
2014-05-05 19:01 ` Simon Glass
2014-05-05 16:09 ` [U-Boot] [RFC PATCH v2 13/13] tegra: Convert tegra GPIO driver to use " Simon Glass
2014-05-05 17:29 ` Stephen Warren
2014-05-05 19:53 ` Simon Glass
2014-05-05 21:14 ` Stephen Warren
2014-05-05 21:30 ` Simon Glass
2014-05-05 22:07 ` Stephen Warren
2014-05-05 23:00 ` Simon Glass
2014-05-06 17:34 ` Stephen Warren
2014-05-06 20:28 ` Simon Glass
2014-05-06 20:37 ` Stephen Warren [this message]
2014-05-06 20:41 ` Simon Glass
-- strict thread matches above, loose matches on Subject: below --
2014-05-09 17:28 [U-Boot] [RFC PATCH v2 0/13] Enable driver model for GPIOs on Tegra Simon Glass
2014-05-09 17:28 ` [U-Boot] [RFC PATCH v2 13/13] tegra: Convert tegra GPIO driver to use driver model Simon Glass
2014-05-13 19:30 ` Stephen Warren
2014-05-22 1:25 ` Simon Glass
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=53694808.3090202@wwwdotorg.org \
--to=swarren@wwwdotorg.org \
--cc=u-boot@lists.denx.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox