mtd: rawnand: denali: optimize timing parameters for data interface

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This commit improves the ->setup_data_interface() hook.

The denali_setup_data_interface() needs the frequency of clk_x
and the ratio of clk_x / clk.

The latter is currently hardcoded in the driver, like this:

  #define DENALI_CLK_X_MULT       6

The IP datasheet requires that clk_x / clk be 4, 5, or 6.  I just
chose 6 because it is the most defensive value, but it is not optimal.
By getting the clock rate of both "clk" and "clk_x", the driver can
compute the timing values more precisely.

To not break the existing platforms, the fallback value, 50 MHz is
provided.  It is true for all upstreamed platforms.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Tested-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

...

This commit is contained in:

Masahiro Yamada 2018-06-23 01:06:38 +09:00 • committed by Miquel Raynal

parent 6f1fe97bec

commit 1dfac31a5a

4 changed files with 28 additions and 25 deletions

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49

drivers/mtd/nand/raw/denali.c

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drivers/mtd/nand/raw/denali.h

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2

drivers/mtd/nand/raw/denali_dt.c

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1

drivers/mtd/nand/raw/denali_pci.c

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