Undefinedreferenceto...

Undefinedreferenceto. /*
* Copyright 2004-2007 Freescale semicondu, Inc. All Rights Reserved.
*/

/*
* The code contained herein is licensed under the GNU General Public
* License. You may be obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* Http://www.opensource.org/licenses/gpl-license.html
* Http://www.gnu.org/copyleft/gpl.html
*/

# Include
# Include
# Include
# Include
# Include
# Include
# Include
# Include
# Include

# Include "gpio_mux.h"
# Include "crm_regs.h"

# Include


Void gpio_fs1__reset_high (void)
{
Gpio_free_mux (MX27_PIN_CLS );
If (gpio_request_mux (MX27_PIN_CLS, GPIO_MUX_GPIO )){
Printk (KERN_ERR "bug: request GPIO PA25 failed. \ n ");
Return;
}

/* PA25 (CLS) as output */
Mxc_set_gpio_direction (MX27_PIN_CLS, 0 );
Gpio_config_mux (MX27_PIN_CLS, GPIO_MUX_GPIO );
Mxc_set_gpio_dataout (MX27_PIN_CLS, 1 );
}

Int main (void)
{

Gpio_fs1__reset_high ();
Return 0;

}

I want to set one pin to a high level. This program prompts during compilation:
Undefined reference to 'gpio _ free_mux '. It seems that the prototype of this function cannot be found. However, when I connect the. o file containing this prototype, it is a bunch of errors. It is also a lot of errors to compile the source files that contain this function prototype together. How is it difficult to set a pin to a high level?