Hello,Larry,
By default, USB OTG works as device, It's power is not opened. If you want it to work as a host, you do a little modification in BSP source code. open linux/arch/arm/mach-mx6/board-mx6q_sabresd.c,and find function "static void __init imx6q_sabresd_init_usb(void)", in this function, open USB OTG POWER. see following:
static void __init imx6q_sabresd_init_usb(void)
{
....
//gpio_direction_output(SABRESD_USB_OTG_PWR, 0);
gpio_direction_output(SABRESD_USB_OTG_PWR, 1);
...
}
then recompile linux kernel and burn it into iNAND FLASH or SD card , boot your board, USB OTG can be used as HOST, your mouse can be used.
Reards,
Weidong