ar531xgpio.c

atheros ar531x gpio driver

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright © 2006 Atheros Communications, Inc.,  All Rights Reserved.
 */


/*******************************************************************************
 * ar531x_proc provides a channel for communication between user-level
 * and this AR531X BSP.  Communication is through files in /proc/ar531x.
 */

#include <linux/config.h>
#include <linux/version.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <asm/gdb-stub.h>

#include "ar531xlnx.h"
#include "ar531x.h"

/* GPIO Control Register bit field definitions */
#define GPIO_CR_M(x)    (1 << (x))                      /* mask for i/o */
#define GPIO_CR_O(x)    (1 << (x))                      /* mask for output */
#define GPIO_CR_I(x)    (0 << (x))                      /* mask for input */
#define GPIO_CR_INT(x)  (1 << ((x)+8))                  /* mask for interrupt */
#define GPIO_CR_UART(x) (1 << ((x)+16))                 /* uart multiplex */

#define NUM_GPIO     7               /* 7 GPIO pins */

/* Chun modify for PUSH-BUTTON LED 
 * Atheros driver use GPIO 1 and GPIO 3 as a tri-color LED
 * But, DIR-300 only use GPIO 3 as push_button LED and GPIO 1 for other purpose
 * Since each hardware may use different GPIO, we define the GPIO in bsp.h 
 */
//#define TRICOLOR_LED_GREEN_PIN  1         /* GPIO 1 */ 
#ifdef BLW_54CW3
#define TRICOLOR_LED_YELLOW_PIN 7         /* GPIO 7 */
#else
#define TRICOLOR_LED_YELLOW_PIN 3         /* GPIO 3 */
#endif
/* Chun end */

#define OFF 0
#define ON 1

struct proc_dir_entry *ar531x_proc_entry=NULL;
struct proc_dir_entry *ar531x_gpio_entry=NULL;
/* Chun modify for PUSH-BUTTON LED */
/* Chun comment
typedef enum {
	LED_STATE_OFF	=	0,
	LED_STATE_GREEN =	1,
	LED_STATE_YELLOW = 	2,
	LED_STATE_ORANGE =	3,
	LED_STATE_MAX =		4
} led_state_e;
*/
/* Chun add */
typedef enum {
	LED_STATE_OFF	=	0,
	LED_STATE_BLUE =	1,
	LED_STATE_MAX =		2
} led_state_e;
/* Chun end */
static led_state_e gpio_tricolorled = LED_STATE_OFF;

/*
 * Configure GPIO Output lines
 */
static int
ar531x_gpio_cfg_output( u_int32_t gpio_pin)
{
        u_int32_t reg_val;

        if( gpio_pin > NUM_GPIO)
                return -EINVAL;

        reg_val = sysRegRead(AR5315_GPIO_CR);

        reg_val &= ~(GPIO_CR_M(gpio_pin) |
		     GPIO_CR_UART(gpio_pin) |
                     GPIO_CR_INT(gpio_pin));

        reg_val |= GPIO_CR_O(gpio_pin);

	sysRegWrite(AR5315_GPIO_CR, reg_val);
        sysRegRead(AR5315_GPIO_CR);

        return 1;
}
/*
 * Once configured for I/O - set output lines
 */
static int
ar531x_gpio_write(u_int32_t gpio_pin, u_int32_t val)
{
        u_int32_t reg_val;

        if( gpio_pin > NUM_GPIO)
                return -EINVAL;

        reg_val = sysRegRead(AR5315_GPIO_DO);

        reg_val &= ~(1 << gpio_pin);
        reg_val |= (val&1) << gpio_pin;

	sysRegWrite(AR5315_GPIO_DO, reg_val);
        sysRegRead(AR5315_GPIO_DO);

        return 1;
}

static int
ar531x_gpio_tricolorled_read(char *page, char **start, off_t off,
               int count, int *eof, void *data)
{
    return sprintf(page, "%d\n", gpio_tricolorled); 
}

/*
 * Control tri color LED via /proc.
 * Example: echo 2 > /proc/ar531x/gpio/tricolor_led   for yellow color
 */
static int
ar531x_gpio_tricolorled_write(struct file *file, const char *buf, unsigned long count, void *data)
{
	u_int32_t val, green_led_onoff, yellow_led_onoff;

    	if (sscanf(buf, "%d", &val) != 1)
        	return -EINVAL;
    	if (val >= LED_STATE_MAX)
        	return -EINVAL;
	if( val == gpio_tricolorled)
		return count;
/* Chun modify for PUSH-BUTTON LED */
/* Chun add */
	switch( val ) {
	case LED_STATE_OFF :		
		yellow_led_onoff = OFF;
		break;
	case LED_STATE_BLUE:		
		yellow_led_onoff = ON;
		break;
	}
/* Chun comment
	switch( val ) {
	case LED_STATE_OFF :
		green_led_onoff = OFF;   // both LEDs OFF
		yellow_led_onoff = OFF;
		break;
	case LED_STATE_GREEN:
		green_led_onoff = ON;    // green ON, Yellow OFF
		yellow_led_onoff = OFF;
		break;
	case LED_STATE_YELLOW:
		green_led_onoff = OFF;   // green OFF, Yellow ON
		yellow_led_onoff = ON;
		break;
	case LED_STATE_ORANGE:
		green_led_onoff = ON;    // both LEDs ON
		yellow_led_onoff = ON;
		break;
	}
	ar531x_gpio_write( TRICOLOR_LED_GREEN_PIN, green_led_onoff);
*/
	ar531x_gpio_write( TRICOLOR_LED_YELLOW_PIN, yellow_led_onoff);
        gpio_tricolorled = val;

    	return count;
}


/*******************************************************************************
* ar531x_gpio_setup - Initialize the /proc files needed for AR531X.
*/
int __init
ar531x_gpio_setup(void)
{
        struct proc_dir_entry *ar531x_gpio_entry, *ar531x_tricolorled_entry;

	//printk ("\nGoing to gpio_proc_entry\n");

	if (ar531x_proc_entry != NULL) {
		printk ("Already have a proc entry for /proc/ar531x\n");
		return -ENOENT;
	}
	ar531x_proc_entry = proc_mkdir("ar531x", NULL);
	if (!ar531x_proc_entry) {
		return -ENOENT;
	}

	// create /proc/ar531x/gpio
	ar531x_gpio_entry = proc_mkdir("gpio", ar531x_proc_entry);
	if (!ar531x_gpio_entry) {
		return -ENOENT;
	}
	
	// create /proc/ar531x/gpio/tricolorled
        ar531x_tricolorled_entry = create_proc_entry("tricolor_led", 0644, ar531x_gpio_entry);
	if (!ar531x_tricolorled_entry) {
		return -ENOENT;
	}
        ar531x_tricolorled_entry->write_proc = ar531x_gpio_tricolorled_write;
        ar531x_tricolorled_entry->read_proc = ar531x_gpio_tricolorled_read;

	// Configure GPIO 1 (green) GPIO3 (yellow) as outputs
	//ar531x_gpio_cfg_output(TRICOLOR_LED_GREEN_PIN);	/* Chun comment for PUSH-BUTTON LED */
	ar531x_gpio_cfg_output(TRICOLOR_LED_YELLOW_PIN);

	// switch OFF both Yellow and Green LEDs
        //ar531x_gpio_write( TRICOLOR_LED_GREEN_PIN, 0);	/* Chun comment for PUSH-BUTTON LED */
        ar531x_gpio_write( TRICOLOR_LED_YELLOW_PIN, 0);

    	return 0;
}

module_init(ar531x_gpio_setup);

/*
* ar531x_gpio_unload - Remove the /proc files needed for AR531X and
* for module unload
*/
static void __exit
ar531x_gpio_unload(void)
{
    remove_proc_entry("tricolor_led", ar531x_gpio_entry);
}

module_exit(ar531x_gpio_unload);
MODULE_AUTHOR("Atheros Communications, Inc.");
MODULE_DESCRIPTION("Support for Atheros WiSoC GPIO");
#ifdef MODULE_LICENSE
MODULE_LICENSE("Atheros");
#endif