Re: [PATCH 3/5] mfd: ti_am335x_tscadc: Don't read back REG_SE

[Lee Jones]

On Thu, 19 Dec 2013, Sebastian Andrzej Siewior wrote:

> The purpose of reg_se_cache has been defeated. It should avoid the
> read-back of the register to avoid the latency and the fact that the
> bits are reset to 0 after the individual conversation took place.
> 
> The reason why this is required like this to work, is that read-back of
> the register removes the bits of the ADC so they do not start another
> conversation after the register is re-written from the TSC side for the
> update.
> To avoid the not required read-back I introduce a "set once" variant which
> does not update the cache mask. After the conversation completes, the
> bit is removed from the SE register anyway and we don't plan a new
> conversation "any time soon". The current set function is renamed to
> set_cache to distinguish the two operations.
> This is a small preparation for a larger sync-rework.
> 
> Acked-by: Lee Jones <lee.jones@xxxxxxxxxx>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> ---
>  drivers/iio/adc/ti_am335x_adc.c           |  4 ++--
>  drivers/input/touchscreen/ti_am335x_tsc.c |  4 ++--

Just need Dmitry's Ack now.

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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