From: Nikolaus Voss <n.voss-+umVssTZoCsb1SvskN2V4Q@public.gmane.org>
To: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org,
ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org,
balbi-l0cyMroinI0@public.gmane.org,
h.feurstein-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
rmallon-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org
Subject: [PATCH v9 0/4] AT91: replace broken TWI driver i2c-at91.c
Date: Mon, 19 Mar 2012 16:07:10 +0100 [thread overview]
Message-ID: <cover.1322479017a.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.
Signed-off-by: Nikolaus Voss <n.voss-+umVssTZoCsb1SvskN2V4Q@public.gmane.org>
Reviewed-by: Felipe Balbi <balbi-l0cyMroinI0@public.gmane.org>
Tested-by: Hubert Feurstein <h.feurstein-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
v9: i) merge i2c-at91.c patches to single patch
ii) rewrite cwgr reg after timeout to reenable the right twi clock
v8: i) remove local include
ii) remove cpu_is_rm9200() and put twi hw bug info in platform_device
iii) use readl/writel_relaxed instead of __raw_readl/writel
v7: i) fix bug if internal address > 1 byte
ii) send stop when len == 1 (both reported by Carsten Behling)
v6: support for I2C_SMBUS_BLOCK_DATA transfers.
Better use of clk_(un)prepare().
More sensible transfer timeout.
v5: Another round of review comments from Ryan Mallon, Felipe Balbi
and Russell King: convert twi clk to use .dev_id, cleanups
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
Replace clk_lookup.con_id with clk_lookup.dev_id entries for twi clk
drivers/i2c/busses/i2c-at91.c: add new driver
G45 TWI: remove open drain setting for twi function gpios
arch/arm/mach-at91/at91cap9.c | 1 +
arch/arm/mach-at91/at91rm9200.c | 1 +
arch/arm/mach-at91/at91rm9200_devices.c | 9 +
arch/arm/mach-at91/at91sam9260.c | 1 +
arch/arm/mach-at91/at91sam9261.c | 1 +
arch/arm/mach-at91/at91sam9263.c | 1 +
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 | 561 +++++++++++++++++-----------
12 files changed, 373 insertions(+), 291 deletions(-)
delete mode 100644 arch/arm/mach-at91/include/mach/at91_twi.h
--
1.7.5.4
next reply other threads:[~2012-03-19 15:07 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-19 15:07 Nikolaus Voss [this message]
2011-11-08 10:49 ` [PATCH v9 1/4] drivers/i2c/busses/i2c-at91.c: remove broken driver Nikolaus Voss
2011-11-08 10:49 ` [PATCH v9 3/4] drivers/i2c/busses/i2c-at91.c: add new driver Nikolaus Voss
[not found] ` <201203191534.q2JFYl1b012744-vb1CFJ/PVqUnDeILM3HATdG/hX4sBvbD@public.gmane.org>
2012-04-13 10:17 ` Hubert Feurstein
[not found] ` <CAFfN3gWCu5RnKb6dK4YMCAhpkfLncYdk1Cwqxb3wxMVznSiSFQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-04-13 10:39 ` Felipe Balbi
[not found] ` <20120413103937.GH7154-S8G//mZuvNWo5Im9Ml3/Zg@public.gmane.org>
2012-04-13 11:44 ` [PATCH] i2c-at91: fix data-loss issue Hubert Feurstein
[not found] ` <1334317476-10044-1-git-send-email-h.feurstein-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2012-04-13 22:06 ` Ryan Mallon
2012-04-16 7:30 ` Voss, Nikolaus
[not found] ` <EF2E73589CA71846A15D0B2CDF79505D0905D5A1AA-qhZVaJ2D3XF9OWT4OSQXE9BPR1lH4CV8@public.gmane.org>
2012-04-16 9:27 ` Hubert Feurstein
2012-04-18 14:39 ` Wolfram Sang
2012-04-21 19:33 ` Adrian Yanes
2012-04-23 5:39 ` Voss, Nikolaus
2012-04-23 6:24 ` Adrian Yanes
2012-04-25 5:26 ` Adrian Yanes
[not found] ` <cover.1322479017a.git.n.voss-+umVssTZoCsb1SvskN2V4Q@public.gmane.org>
2011-11-08 11:09 ` [PATCH v9 2/4] Replace clk_lookup.con_id with clk_lookup.dev_id entries for twi clk Nikolaus Voss
2011-11-08 11:11 ` [PATCH v9 4/4] G45 TWI: remove open drain setting for twi function gpios Nikolaus Voss
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