Re: [PATCH v11 0/4] AT91: replace old i2c-at91.c TWI driver

From: Nicolas Ferre
Date: Wed Sep 12 2012 - 03:59:21 EST


On 08/29/2012 09:28 AM, Nikolaus Voss :
> 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.
>
> Changes since v11:
> - corrected wrong id_entry on sam9261 twi gpio pdev

Hi Wolfram,

Despite the patch revision written in the subject, it is actually the
real v12 patch series from Nikolaus.
BTW, I suspect that you were not in copy...

In addition to the "Tested-By" tag by Ludovic, you can add my:

Reviewed-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>


> Nikolaus Voss (4):
> drivers/i2c/busses/i2c-at91.c: remove old polling 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/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/at91sam9261_devices.c | 9 +
> 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/at91sam9x5.c | 3 +
> arch/arm/mach-at91/include/mach/at91_twi.h | 68 ----
> drivers/i2c/busses/Kconfig | 11 +-
> drivers/i2c/busses/i2c-at91.c | 591 ++++++++++++++++++----------
> 13 files changed, 418 insertions(+), 287 deletions(-)
> delete mode 100644 arch/arm/mach-at91/include/mach/at91_twi.h
>


--
Nicolas Ferre
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