Messages in this thread | | | From | Richard Weinberger <> | Subject | Re: [PATCH v3 3/3] mtd: rawnand: denali: optimize timing parameters for data interface | Date | Mon, 18 Jun 2018 09:22:44 +0200 |
| |
Am Freitag, 15. Juni 2018, 03:18:52 CEST schrieb Masahiro Yamada: > 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.
What datasheet do you have, is it public? Mine clearly states that the factor is 4. "The frequency of nand_x_clk is four times the frequency of nand_clk."
> 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>
Thanks, //richard
| |