Re: [PATCH 0/2] spi: amlogic: meson-spicc: Use pinctrl to drive CLK line when idle

[Amjad Ouled-Ameur <aouledameur@baylibre.com>]

Hi Neil,

On 9/27/22 10:30, Neil Armstrong wrote:
> Hi Amjad,
>
> On 09/08/2022 19:20, Amjad Ouled-Ameur wrote:
>> Between SPI transactions, all SPI pins are in HiZ state. When using 
>> the SS
>> signal from the SPICC controller it's not an issue because when the
>> transaction resumes all pins come back to the right state at the same 
>> time
>> as SS.
>>
>> The problem is when we use CS as a GPIO. In fact, between the GPIO CS
>> state change and SPI pins state change from idle, you can have a 
>> missing or
>> spurious clock transition.
>>
>> Set a bias on the clock depending on the clock polarity requested 
>> before CS
>> goes active, by passing a special "idle-low" and "idle-high" pinctrl 
>> state
>> and setting the right state at a start of a message.
>>
>> Amjad Ouled-Ameur (2):
>>    spi: dt-bindings: amlogic, meson-gx-spicc: Add pinctrl names for SPI
>>      signal states
>>    spi: meson-spicc: Use pinctrl to drive CLK line when idle
>>
>>   .../bindings/spi/amlogic,meson-gx-spicc.yaml  | 15 +++++++
>>   arch/arm64/boot/dts/amlogic/meson-gxl.dtsi    | 14 +++++++
>>   drivers/spi/spi-meson-spicc.c                 | 39 ++++++++++++++++++-
>>   3 files changed, 67 insertions(+), 1 deletion(-)
>>
>
> Will you send a v2 with comments adresses ?

Planning to send it soon, thank you for the review.

Regards,

Amjad


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