Re: [PATCH V8 1/2] mtd: spi-nor: Bindings for Cadence Quad SPI Flash Controller driver.

On 02/06/2016 01:12 PM, Marek Vasut wrote:

On Thursday, February 04, 2016 at 06:30:27 PM, R, Vignesh wrote:

quoted

On 2/4/2016 4:55 PM, Marek Vasut wrote:

[...]

quoted

Yeah, there is delay(of few ns) required between writing to
INDIRECTWR_START bit and actually writing data to flash(i.e writesl()
call). This is specific to TI K2G SoC and needs to be tied to the new
binding.

Can't you somehow poll the hardware to check whether or not it's ready instead
of adding some random delay ?

There is no dedicated register to poll as such.

According to TRM:
"Wait for couple of cycles of QSPI_REF_CLK(functional clock of QSPI
@384MHz) until CQSPI_REG_INDIRECTWR[0] bit is internally synchronized by
the QSPI module before writing to flash".

So, a few ns(~6ns @384MHz) delay is needed (or accessing a QSPI module
register should be sufficient as it will take more than 2 clock cycles).
I believe this delay is specific to TI K2G SoC and maybe needs to be
tied to the binding.


-- 
Regards
Vignesh
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