Re: [PATCH V2 2/2] mtd: spi-nor: Bindings for Cadence Quad SPI Flash Controller driver.

[Graham Moore]

On 01/08/2015 04:30 PM, Rob Herring wrote:
> This controller only works with flash devices and is different than this one:?
>
> Documentation/devicetree/bindings/spi/spi-cadence.txt

Yes, it is a different controller and is for flash only.  The docs call 
it the "QSPI Flash Controller".
...

> The above binding already uses "is-decoded-cs". Let's not invent something new.

OK.
...

> > > +- cdns,tshsl-ns : Delay in master reference clocks for the length that the master mode chip select outputs are de-asserted between transactions.
> > > +- cdns,tsd2d-ns : Delay in master reference clocks between one chip select being de-activated and the activation of another.
> > > +- cdns,tchsh-ns : Delay in master reference clocks between last bit of current transaction and deasserting the device chip select (qspi_n_ss_out).
> > > +- cdns,tslch-ns : Delay in master reference clocks between setting qspi_n_ss_out low and first bit transfer.
>
> Aren't these properties probeable at all? We really should have
> standard bindings for this. It seems spi NOR flash devices have gone
> somewhat undocumented, but it is not hard to find examples already in
> use.

They are not probeable, afaik.  I don't see these values in any 
probeable info block in the datasheet, only in the AC params table.

I can't find an example of these timing parameters, do you have one in mind?

> Is it master reference clocks or nanoseconds for the units?

Yeah, they are actually nanoseconds in the dts, converted to clocks in 
the driver.  I'll change the docs.

...

Thanks,
Graham
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