I need to enable CKO2 in uboot with a 24mhz output frequency. I've added this function which is called in board_init()
static void setup_camera_clk(void)
struct mxc_ccm_reg *mxc_ccm = (struct mxc_ccm_reg *)CCM_BASE_ADDR;
SETUP_IOMUX_PAD(PAD_GPIO_3__CCM_CLKO2 | 0x000000b0); //this is how the pin is set up in device tree
//enable clock output
reg = readl(&mxc_ccm->ccosr);
printf("ccosr is 0x%x\n",reg);
reg |= (MXC_CCM_CCOSR_CKO2_EN_OFFSET //CKO2 enabled
| MXC_CCM_CCOSR_CLK_OUT_SEL //CKO2 output is selected
| (0x0e << MXC_CCM_CCOSR_CKO2_SEL_OFFSET) //clock is derived from osc_clk, should be 24mhz
printf("writing ccosr to 0x%x\n",reg);
It looks like this is setting the registers, but my clock is not outputting.
First of all, is this the proper way to set the pinmux from u-boot?
Second of all, I noticed that some clocks get disabled in u-boot, although I would assume the osc_clk is derived from the main crystal and should be running... Either way I'm not sure I chose correctly.