Hi Richard, 2018-06-18 16:22 GMT+09:00 Richard Weinberger <richard@xxxxxx>: > 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? No. Not available in public. I got the datasheet because Socionext (formerly, Panasonic) bought this IP. > Mine clearly states that the factor is 4. > "The frequency of nand_x_clk is four times the frequency of nand_clk." I checked "Denali NAND Flash Memory Controller User's Guide" released by Denali. I also get access to a newer version "Cadence Design IP - NAND Flash Memory Controller User's Guide" because Cadence acquired Denali. My datasheet says: "clk_x - Cadence NAND Flash Memory Controller bus interface clock. This runs at a configured multiple of clk as is phase aligned. Configured multiple can be between 4-6 times." Various parts of this IP are configurable. Is yours talking about this IP, or about a particular configuration for SOCFPGA? >> 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@xxxxxxxxxxxxx> > > Reviewed-by: Richard Weinberger <richard@xxxxxx> > > Thanks, > //richard > -- > To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Best Regards Masahiro Yamada -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
