I am using imx28evk running linux kernel 3.10.29. I have found that the SSP0 (MMC slot 0) can only run maximum of clock 28.8MHz as mentioned in the
mmc->f_min = 400000;
mmc->f_max = 288000000;
I want to plug the TI wifi module that runs on 50MHz. In this case, I would like to increase the clock frequency of SSP0 to 50 MHz. Is there any way I can change it?
Moreover, I found that "ref_io0" is set to 288 MHz below from file: drivers/clk/mxs/clk-imx28.c. Which code changes the frequency from 228 MHz to 28.8 MHz (maximum) ?
118 * 480 MHz seems too high to be ssp clock source directly,
119 * so set frac0 to get a 288 MHz ref_io0 and ref_io1.
121 val = readl_relaxed(FRAC0);
122 val &= ~((0x3f << BP_FRAC0_IO0FRAC) | (0x3f << BP_FRAC0_IO1FRAC));
123 val |= (30 << BP_FRAC0_IO0FRAC) | (30 << BP_FRAC0_IO1FRAC);
124 writel_relaxed(val, FRAC0);
Any help is highly appreciated.