On Wed, 8 Dec 2010, Elvis Dowson wrote: > What should I do to change the output frequency of mmc2_clk > signal to 48Mhz for the OMAP35xx processor? > > Right now it is giving an output of 96MHz and the signal output looks > more like a sine wave than a square wave clock output signal.
Assuming you're using the mainline kernel, it doesn't look like the MMC driver changes its functional clock at all. So perhaps your bootloader is programming it incorrectly? I guess at some point we will need to reprogram all the clocks on boot also, to deal with buggy bootloaders... Anyway, if you want to try changing it from the kernel side, you'll need code like this in the MMC driver or OMAP integration code (off the top of my head, untested): struct clk *c; c = clk_get(dev, "fck"); clk_set_rate(c, 48000000); clk_put(c); Please let me know if this doesn't work. - Paul -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
