• Alexandru M Stan's avatar
    clk: rockchip: Add support for the mmc clock phases using the framework · 89bf26cb
    Alexandru M Stan authored
    This patch adds the 2 physical clocks for the mmc (drive and sample). They're
    mostly there for the phase properties, but they also show the true clock
    (by dividing by RK3288_MMC_CLKGEN_DIV).
    
    The drive and sample phases are generated by dividing an upstream parent clock
    by 2, this allows us to adjust the phase by 90 deg.
    
    There's also an option to have up to 255 delay elements (40-80 picoseconds long).
    This driver uses those elements (under the assumption that they're 60 ps long)
    to generate approximate 22.5 degrees options. 67.5 (22.5*3) might be as high as
    90 deg if the delay elements are as big as 80 ps, so a finer division (smaller
    than 22.5) was not picked because the phase might not be monotonic anymore.
    Suggested-by: default avatarHeiko Stuebner <heiko@sntech.de>
    Signed-off-by: default avatarAlexandru M Stan <amstan@chromium.org>
    Signed-off-by: default avatarHeiko Stuebner <heiko@sntech.de>
    89bf26cb
Makefile 231 Bytes