From: Nikolaus Voss <n.voss@weinmann.de>
To: linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Cc: ben-linux@fluff.org, khali@linux-fr.org, nicolas.ferre@atmel.com,
rmallon@gmail.com, balbi@ti.com
Subject: [PATCH V3 0/4] AT91: replace broken TWI driver i2c-at91.c
Date: Tue, 8 Nov 2011 12:52:22 +0100 [thread overview]
Message-ID: <cover.1320753142.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.
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 +
drivers/i2c/busses/Kconfig | 11 +-
drivers/i2c/busses/i2c-at91.c | 453 +++++++++++++++++++-----------
5 files changed, 292 insertions(+), 182 deletions(-)
--
1.7.5.4
next reply other threads:[~2011-11-08 11:52 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-08 11:52 Nikolaus Voss [this message]
2011-11-08 10:49 ` [PATCH V3 1/4] drivers/i2c/busses/i2c-at91.c: remove broken driver Nikolaus Voss
[not found] ` <458dd879d1fcdfc093e038426a581d86d30ecd5e.1320753142.git.n.voss-+umVssTZoCsb1SvskN2V4Q@public.gmane.org>
2011-11-08 14:36 ` Felipe Balbi
2011-11-08 10:49 ` [PATCH V3 2/4] drivers/i2c/busses/i2c-at91.c: add new driver Nikolaus Voss
[not found] ` <7bdd6b456b0e055441cb25634c8cb6d483718f6c.1320753142.git.n.voss-+umVssTZoCsb1SvskN2V4Q@public.gmane.org>
2011-11-08 14:41 ` Felipe Balbi
[not found] ` <20111108144115.GH20728-UiBtZHVXSwEVvW8u9ZQWYwjfymiNCTlR@public.gmane.org>
2011-11-08 15:15 ` Nicolas Ferre
[not found] ` <4EB9477E.8070002-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
2011-11-08 15:23 ` Felipe Balbi
[not found] ` <20111108152343.GJ20728-UiBtZHVXSwEVvW8u9ZQWYwjfymiNCTlR@public.gmane.org>
2011-11-08 18:29 ` Russell King - ARM Linux
[not found] ` <20111108182955.GH12913-l+eeeJia6m9vn6HldHNs0ANdhmdF6hFW@public.gmane.org>
2011-11-08 18:44 ` Felipe Balbi
2011-11-08 18:55 ` Russell King - ARM Linux
[not found] ` <20111108185525.GI12913-l+eeeJia6m9vn6HldHNs0ANdhmdF6hFW@public.gmane.org>
2011-11-08 19:02 ` Felipe Balbi
2011-11-08 19:39 ` Russell King - ARM Linux
[not found] ` <20111108193930.GJ12913-l+eeeJia6m9vn6HldHNs0ANdhmdF6hFW@public.gmane.org>
2011-11-08 19:58 ` Felipe Balbi
[not found] ` <20111108195854.GD24399-UiBtZHVXSwEVvW8u9ZQWYwjfymiNCTlR@public.gmane.org>
2011-11-08 21:14 ` Russell King - ARM Linux
2011-11-08 15:35 ` Voss, Nikolaus
[not found] ` <EF2E73589CA71846A15D0B2CDF79505D087B38B899-qhZVaJ2D3XF9OWT4OSQXE9BPR1lH4CV8@public.gmane.org>
2011-11-08 15:40 ` Felipe Balbi
[not found] ` <20111108154004.GK20728-UiBtZHVXSwEVvW8u9ZQWYwjfymiNCTlR@public.gmane.org>
2011-11-08 15:49 ` Voss, Nikolaus
[not found] ` <EF2E73589CA71846A15D0B2CDF79505D087B38B8B5-qhZVaJ2D3XF9OWT4OSQXE9BPR1lH4CV8@public.gmane.org>
2011-11-08 18:06 ` Felipe Balbi
2011-11-08 22:50 ` Ryan Mallon
[not found] ` <4EB9B24A.5040809-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2011-11-09 16:01 ` Voss, Nikolaus
2011-11-09 19:11 ` Russell King - ARM Linux
2011-11-08 23:58 ` Ryan Mallon
2011-11-08 11:09 ` [PATCH V3 4/4] Add lookup entries for twi_clk for devices with more than one TWI port Nikolaus Voss
2011-11-08 11:11 ` [PATCH V3 3/4] G45 TWI: remove open drain setting for twi function gpios Nikolaus Voss
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