Re: [RFC PATCH 0/2] spi: add dual parallel & stacked mode support in Zynq MPSoC GQSPI controller

Mark Brown
2015-07-15T16:01:46Z

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On Wed, Jul 15, 2015 at 02:12:54PM +0000, Ranjit Abhimanyu Waghmode wrote:

> > > What is stacked mode?
> > > ---------------------
> > > ZynqMP GQSPI controller supports stacked mode with following
> > functionalities:
> > > 1) The Generic Quad-SPI controller also supports two SPI flash memories
> > > in a shared bus arrangement to reduce IO pin count.
> > > 2) Separate chip select lines
> > > 3) Shared I/O lines
> > > 4) This mode is targeted for increasing the flash memory and no performance
> > > improvement when compared with single.

> > This is just a normal SPI controller from a SPI point of view.

> How can we really represent the stacked mode in current configuration?

In the same way as any other controller with two chip selects... there
are quite a few other drivers that provide examples of this, you should
look for one that has hardware control similar to yours.

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