Linux I2C development
 help / color / mirror / Atom feed
From: David Brownell <david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
To: i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
Subject: [patch/rfc 2.6.26-rc5] i2c: schedule legacy gpio driver removal
Date: Wed, 11 Jun 2008 13:17:20 -0700	[thread overview]
Message-ID: <200806111317.21060.david-b@pacbell.net> (raw)

Just sending this as an RFC ... clearly it shouldn't merge until
the GPIO_SYSFS code merges, which I'm assuming is 2.6.27.  And
presumably Jean will want to be the "who removes this"?

I think the only other blocking issue would be a way to configure
such new-style drivers from sysfs, primarily for one-off hardware
hacking usage (in at least this case).  Teaching the two new-style
drivers to use dynamic GPIO number allocation when there's no
platform_data is trivial, and not otherwise desirable.

- Dave


=========== CUT HERE
--- a/Documentation/feature-removal-schedule.txt	2008-06-11 12:00:20.000000000 -0700
+++ b/Documentation/feature-removal-schedule.txt	2008-06-11 13:10:44.000000000 -0700
@@ -312,3 +312,21 @@ When:	2.6.26
 Why:	Implementation became generic; users should now include
 	linux/semaphore.h instead.
 Who:	Matthew Wilcox <willy-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
+
+---------------------------
+
+What:	drivers/i2c/chips/{pca9539,pcf8574,pcf8575}.c
+When:	January 2010
+Why:	replaced by gpiolib and GPIO_SYSFS with
+	drivers/gpio/{pca953x,pcf857x}.c
+
+	The gpiolib I2C adapter drivers support more chips and moved
+	away from legacy driver binding.  From the embedded systems
+	perspective, they provide a critical capability missing in
+	those now-obsoleted drivers:  GPIOs are now accessible to
+	in-kernel code for common uses like LED control, switching
+	power domains, and chip configuration.
+
+	With GPIO_SYSFS the userspace interface is a bit different,
+	but is more generic and is available for use with all GPIO
+	controllers.

_______________________________________________
i2c mailing list
i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
http://lists.lm-sensors.org/mailman/listinfo/i2c

             reply	other threads:[~2008-06-11 20:17 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-06-11 20:17 David Brownell [this message]
     [not found] ` <200806111317.21060.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2008-06-12 10:57   ` [patch/rfc 2.6.26-rc5] i2c: schedule legacy gpio driver removal Jean Delvare
     [not found]     ` <20080612125729.136d642b-ig7AzVSIIG7kN2dkZ6Wm7A@public.gmane.org>
2008-06-12 20:55       ` David Brownell

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=200806111317.21060.david-b@pacbell.net \
    --to=david-b-ybekhbn/0ldr7s880joybq@public.gmane.org \
    --cc=i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org \
    /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