Re: [PATCH] spi: spi-geni-qcom: Add SPI driver support for GENI based QUP

From: Mark Brown
Date: Tue Aug 14 2018 - 11:03:46 EST


On Tue, Aug 14, 2018 at 02:30:02PM +0530, dkota@xxxxxxxxxxxxxx wrote:
> On 2018-08-10 22:16, Mark Brown wrote:
> > On Fri, Aug 10, 2018 at 09:59:46PM +0530, dkota@xxxxxxxxxxxxxx wrote:

> > > delay_usecs is for inter-transfer delays within a message rather than
> > > after the initial chip select assert (it can be used to keep chip
> > > select
> > > asserted for longer after the final transfer too). Obviously this is
> > > also something that shouldn't be configured in a driver specific
> > > fashion.

> > Hmmm ok, so you mean don't send these as controller_data, rather add
> > new
> > members to the spi_device struct ?

> spi_cs_clk_delay -> Adds Delay from CS line toggle to Clock line toggle
> spi_inter_words_delay -> Adds inter-word delay for each transfer.

> Could you please provide more information on accommodating these
> parameters in SPI core structures like spi_device or spi_transfer? Why
> because these are very
> specific to Qualcomm SPI GENI controller.

I'm not sure what specific information you're looking for here - these
things are not obviously specific to your controller, I'm even aware of
other controllers which can do them.

> If we define them in spi core framework structures, SPI Slave driver will
> program and expect it in the SPI transfers.

Sure.

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