AM3352: usb的peripheral配置问题，以及两端的通信

static struct omap_musb_board_data musb_board_data = {
	.interface_type	= MUSB_INTERFACE_ULPI,
	/*
	 * mode[0:3] = USB0PORT's mode
	 * mode[4:7] = USB1PORT's mode
	 * AM335X beta EVM has USB0 in OTG mode and USB1 in host mode.
	 */
	.mode           = (MUSB_HOST << 4) | MUSB_OTG,
	//.mode           = (MUSB_HOST << 4) | MUSB_HOST,
	.power		= 500,
	.instances	= 1,
};
static void __init am335x_evm_init(void)
{
	am33xx_cpuidle_init();
	am33xx_mux_init(board_mux);
	omap_serial_init();
	am335x_evm_i2c_init();
	am335x_evm_setup(NULL, NULL);
	omap_sdrc_init(NULL, NULL);
	usb_musb_init(&musb_board_data);
	omap_board_config = am335x_evm_config;
	omap_board_config_size = ARRAY_SIZE(am335x_evm_config);
	/* Create an alias for icss clock */
	if (clk_add_alias("pruss", NULL, "pruss_uart_gclk", NULL))
		pr_warn("failed to create an alias: icss_uart_gclk --> pruss\n");
	/* Create an alias for gfx/sgx clock */
	if (clk_add_alias("sgx_ck", NULL, "gfx_fclk", NULL))
		pr_warn("failed to create an alias: gfx_fclk --> sgx_ck\n");
}