From: Nikolaus Voss <n.voss-+umVssTZoCsb1SvskN2V4Q@public.gmane.org>
To: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org,
khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org,
nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org,
rmallon-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
balbi-l0cyMroinI0@public.gmane.org
Subject: [PATCH v4 0/4] AT91: replace broken TWI driver i2c-at91.c
Date: Wed, 9 Nov 2011 16:52:01 +0100 [thread overview]
Message-ID: <cover.1320853921.git.n.voss@weinmann.de> (raw)
The old driver has two main deficencies:
i) No repeated start (Sr) condiction is possible, this makes it unusable
e.g. for most SMBus transfers.
ii) I/O was done with polling/busy waiting what caused over-/underruns
even at light system loads and clock speeds.
The new driver overcomes these deficencies and in addition allows for
more than one TWI interface.
A remaining limitation is the fact, that only one repeated start is
possible (two concatenated messages). This limitation is imposed by
the hardware. However, this should not be a problem as all common
i2c-client communication does not rely on more than one repeated start.
v4: Integrated more review comments from Ryan Mallon and Felipe Balbi:
Moved register include file to local include, code cleanups
v3: Integrated review comments from Ryan Mallon and Felipe Balbi
v2: Fixed whitespace issue
Nikolaus Voss (4):
drivers/i2c/busses/i2c-at91.c: remove broken driver
drivers/i2c/busses/i2c-at91.c: add new driver
G45 TWI: remove open drain setting for twi function gpios
Add lookup entries for twi_clk for devices with more than one TWI
port
arch/arm/mach-at91/at91sam9g45.c | 2 +
arch/arm/mach-at91/at91sam9g45_devices.c | 6 -
arch/arm/mach-at91/at91sam9rl.c | 2 +
arch/arm/mach-at91/include/mach/at91_twi.h | 68 ----
drivers/i2c/busses/Kconfig | 11 +-
drivers/i2c/busses/i2c-at91.c | 476 +++++++++++++++++-----------
drivers/i2c/busses/i2c-at91.h | 80 +++++
7 files changed, 371 insertions(+), 274 deletions(-)
delete mode 100644 arch/arm/mach-at91/include/mach/at91_twi.h
create mode 100644 drivers/i2c/busses/i2c-at91.h
--
1.7.5.4
next reply other threads:[~2011-11-09 15:52 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-09 15:52 Nikolaus Voss [this message]
[not found] ` <cover.1320853921.git.n.voss-+umVssTZoCsb1SvskN2V4Q@public.gmane.org>
2011-11-08 10:49 ` [PATCH v4 1/4] drivers/i2c/busses/i2c-at91.c: remove broken driver Nikolaus Voss
2011-11-08 10:49 ` [PATCH v4 2/4] drivers/i2c/busses/i2c-at91.c: add new driver Nikolaus Voss
[not found] ` <fc7ccca66f0ffea1aa9c0409162b4a66974c46b3.1320853921.git.n.voss-+umVssTZoCsb1SvskN2V4Q@public.gmane.org>
2011-11-09 19:59 ` Felipe Balbi
[not found] ` <20111109195925.GB17406-UiBtZHVXSwEVvW8u9ZQWYwjfymiNCTlR@public.gmane.org>
2011-11-09 22:22 ` Ryan Mallon
2011-11-08 11:09 ` [PATCH v4 4/4] Add lookup entries for twi_clk for devices with more than one TWI port Nikolaus Voss
2011-11-08 11:11 ` [PATCH v4 3/4] G45 TWI: remove open drain setting for twi function gpios Nikolaus Voss
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=cover.1320853921.git.n.voss@weinmann.de \
--to=n.voss-+umvsstzocsb1svskn2v4q@public.gmane.org \
--cc=balbi-l0cyMroinI0@public.gmane.org \
--cc=ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org \
--cc=khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org \
--cc=linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org \
--cc=linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org \
--cc=rmallon-Re5JQEeQqe8AvxtiuMwx3w@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;
as well as URLs for NNTP newsgroup(s).