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From: Richard Weinberger <richard@sigma-star.at>
To: Boris Brezillon <boris.brezillon@bootlin.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>,
 linux-mtd <linux-mtd@lists.infradead.org>,
 Philipp Rosenberger <p.rosenberger@linutronix.de>,
 Benedikt Spranger <b.spranger@linutronix.de>
Subject: Re: DENALI: can't detect NAND chip
Date: Tue, 05 Jun 2018 00:01:51 +0200
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Am Montag, 4. Juni 2018, 22:57:32 CEST schrieb Richard Weinberger:
> Am Montag, 4. Juni 2018, 22:51:17 CEST schrieb Boris Brezillon:
> > > According to the datasheet, the NAND clock rate should be 50Mhz, which is what
> > > is returned in both cases.
> > > So this does not really look invalid to me. :)
> > 
> > Did you try to put a scope on the RE or WE pin? The x2 factor looks too
> > perfect to be just a coincidence.
> 
> Not yet, but you are right the x2 factor is really interesting.

The NFC uses two clocks, nand_x_clk and nand_clk.
nand_clk is nand_x_clk / 4.
In the device tree nand_clk is referenced, and therefore used to calculate
the timings. So we might need to use the 200Mhz clock instead of the 50Mhz
for the calculation.

Thanks,
//richard

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