mtd: rawnand: denali: optimize timing parameters for data interface
Based on Linux commit 1dfac31a5a63ac04a9b5fbc3f5105a586560f191
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>
3 files changed