flexspi connects to 4 devices

[Luke-Hsieh]

Hi,

Does anyone have the experience using i.mx8 SPI with multiple devices ?

Initially, I was trying to use ECSPI1, but there's only one CS pin supported on ECSPI.

I read i.mx8m nano reference manual and find that flex spi supports multiple devices.

In figure 10-15, there're 2 pairs of CLK & DATA in parallel mode which is not what I need.

Can I use the individual mode to support 4 devices which are sharing one CLK+MISO+MOSI ?

Is my expectation correct ?

Attach the figure10-15 for reference.

Thanks.

[igorpadykov · Accepted solution]

Hi Luke

>I was trying to use ECSPI1, but there's only one CS pin supported on ECSPI.

one can use gpio as CS as described in linux documentation "- cs-gpios : GPIOs to use as chip selects"

https://source.codeaurora.org/external/imx/linux-imx/tree/Documentation/devicetree/bindings/spi/fsl-...

>In figure 10-15, there're 2 pairs of CLK & DATA in parallel mode which is not what I need.

>Can I use the individual mode to support 4 devices which are sharing one CLK+MISO+MOSI ?

>Is my expectation correct ?

not sorry. Only option as described exactly in Figure10-15 is possible.

Best regards
igor

[Luke-Hsieh]

Hi Igor,

Thanks for the confirmation!

The good news is that I can discuss further with HW reviewer.

https://source.codeaurora.org/external/imx/linux-imx/tree/Documentation/devicetree/bindings/spi/spi-...