how to set sdio clock on imx6q (Android)

stevenshi — Thu, 21 May 2015 07:30:32 GMT

hi Freescale:

our board is designed base on SDB, and android os is 4.4.2.

our wifi moudle use SDIO, the SDIO clock need 10~20M, i know the default SDIO Clock is 50M, so we try to reduce the clock to 10~20M, we change kernel_imx/arch/arm/mach-mx6/clock.c

static int _clk_usdhc3_set_rate(struct clk *clk, unsigned long rate)

{

u32 reg, div;

u32 parent_rate = clk_get_rate(clk->parent);

div = parent_rate / rate;

printk(KERN_ERR "++++++++++++++++++++++++++++++++++usdhc3 div is \n",div);

if (div == 0)

div++;

if (((parent_rate / div) != rate) || (div > 8))

return -EINVAL;

reg = __raw_readl(MXC_CCM_CSCDR1);

reg &= ~MXC_CCM_CSCDR1_USDHC3_PODF_MASK;

reg |= (4 - 1) << MXC_CCM_CSCDR1_USDHC3_PODF_OFFSET;

//reg |= (div - 1) << MXC_CCM_CSCDR1_USDHC3_PODF_OFFSET;

__raw_writel(reg, MXC_CCM_CSCDR1);

return 0;

}

this change is right???

Re: how to set sdio clock on imx6q (Android)

alejandrolozan1 — Mon, 01 Jun 2015 14:22:23 GMT

Hi,

That way the divisor will be hardcoded. I believe there must be other place in the code or configuration you could modify instead of that file.

Did that change work?

/Alejandro

i.MX Processors中的主题 how to set sdio clock on imx6q (Android)

how to set sdio clock on imx6q (Android)

Re: how to set sdio clock on imx6q (Android)