• Masahiro Yamada's avatar
    mmc: tmio: move tmio_mmc_set_clock() to platform hook · 0196c8db
    Masahiro Yamada authored
    tmio_mmc_set_clock() is full of quirks because different SoC vendors
    extended this in different ways.
    
    The original IP defines the divisor range 1/2 ... 1/512.
    
     bit 7 is set:    1/512
     bit 6 is set:    1/256
       ...
     bit 0 is set:    1/4
     all bits clear:  1/2
    
    It is platform-dependent how to achieve the 1/1 clock.
    
    I guess the TMIO-MFD variant uses the clock selector outside of this IP,
    as far as I see tmio_core_mmc_clk_div() in drivers/mfd/tmio_core.c
    
    I guess bit[7:0]=0xff is Renesas-specific extension.
    
    Socionext (and Panasonic) uses bit 10 (CLKSEL) for 1/1.  Also, newer
    versions of UniPhier SoC variants use bit 16 for 1/1024.
    
    host->clk_update() is only used by the Renesas variants, whereas
    host->set_clk_div() is only used by the TMIO-MFD variants.
    
    To cope with this mess, promote tmio_mmc_set_clock() to a new
    platform hook ->set_clock(), and melt the old two hooks into it.
    Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
    Reviewed-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
    Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
    0196c8db
tmio_mmc.h 8.82 KB