how to implement sampling clock tuning procedure

how to implement sampling clock tuning procedure

[sami md]

Hi All,

    I need to implement sampling clock tuning procedure in mode-1.
    I have created a timer with initial value taken from "timer count" field
    from caps register, when the timer expires i set the expiration flag.

    on receiving a command request the host driver checks the expiration flag
    and if the flag is set the host driver should perform tuning procedure by
    issuing CMD19 before the command request until buffer read ready.

    my doubt are:

         1) can i call tuning procedure from "sdhci_request".
         2) how to issue CMD19.
         3) is there any patch available for tuning procedure.

Thanks