How do you access MMC driver set_ios?

[Larry Martin <Larry@xxxxxxxxxxxxx>]

Hi, this post was originally made on
gumstix-users@xxxxxxxxxxxxxxxxxxxxx, but it concerns the MMC stack for
PXA270.  I hope someone here at the source can help me:


What is the accepted method for getting to the mmc_set_ios() method?

I want to lower the Verdex Pro MMC clock by passing in a nonstandard
clock rate.  The pxamci driver refreshes the CLKRT register from the
stored value on each pxamci_start_cmd(), which chains from
mmc_start_request().  It looks like you have to compute your desired
clock rate by dividing the max clock by a power of two between 0 and 6.
 You then pass that value in to mmc_set_ios(), using an mmc_ios
structure, and let pxamci_set_ios() reverse the computation.  The end
result is a three bit number in CLKRT.

I have looked for a command line interface in /proc and /sys with no
success.  I am currently looking at modprobe with parameters and
eventually a C program, but would be very grateful if someone would
share a command line access method.

Related Posts:
http://old.nabble.com/slowing-down-MMC-clock-on-Verdex-Pro--to29765291.html#a29765291
http://old.nabble.com/Sporadic-SD---MMC-failure-to28603343.html

--
Larry Martin
www.GlueLogix.com



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