dragino2 ar9331将LED管脚当做普通gpio使用

1、 将gpio13和gpio17也当作普通gpio使用，修改

target/linux/ar71xx/files/arch/mips/ath79/mach-dragino2.c文件如下

/*
 *  DRAGINO V2 board support, based on Atheros AP121 board support
 *
 *  Copyright (C) 2011-2012 Gabor Juhos <juhosg@openwrt.org>
 *  Copyright (C) 2012 Elektra Wagenrad <elektra@villagetelco.org>
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU General Public License version 2 as published
 *  by the Free Software Foundation.
 */

#include <linux/gpio.h>
#include <asm/mach-ath79/ath79.h>
#include <asm/mach-ath79/ar71xx_regs.h>
#include "common.h"
#include "dev-eth.h"
#include "dev-gpio-buttons.h"
#include "dev-leds-gpio.h"
#include "dev-m25p80.h"
#include "dev-spi-gpio.h"    // add by merlin
#include "dev-spi.h"
#include "dev-usb.h"
#include "dev-wmac.h"
#include "machtypes.h"

#define DRAGINO2_GPIO_LED_WLAN        0
//#define DRAGINO2_GPIO_LED_LAN        13
//#define DRAGINO2_GPIO_LED_WAN        17

/*
 * The following GPIO is actually named "Router" on the board.
 * However, since the "Router" feature is not supported as of yet
 * we use it to display USB activity.
 */

#define DRAGINO2_GPIO_LED_USB        28
#define DRAGINO2_GPIO_BTN_JUMPSTART    11
#define DRAGINO2_GPIO_BTN_RESET        12

#define DRAGINO2_KEYS_POLL_INTERVAL    20    /* msecs */
#define DRAGINO2_KEYS_DEBOUNCE_INTERVAL    (3 * DRAGINO2_KEYS_POLL_INTERVAL)

#define DRAGINO2_MAC0_OFFSET        0x0000
#define DRAGINO2_MAC1_OFFSET        0x0006
#define DRAGINO2_CALDATA_OFFSET        0x1000
#define DRAGINO2_WMAC_MAC_OFFSET    0x1002

static struct gpio_led dragino2_leds_gpio[] __initdata = {
//    {
//        .name        = "dragino2:red:lan",
//        .gpio        = DRAGINO2_GPIO_LED_LAN,
//        .active_low    = 0,
//    },
    {
        .name        = "dragino2:red:wlan",
        .gpio        = DRAGINO2_GPIO_LED_WLAN,
        .active_low    = 0,
    },
//        {
//        .name        = "dragino2:red:wan",
//        .gpio        = DRAGINO2_GPIO_LED_WAN,
//        .active_low    = 0,
//    },
    {
        .name        = "dragino2:red:usb",
        .gpio        = DRAGINO2_GPIO_LED_USB,
        .active_low    = 0,
    },
};

static struct gpio_keys_button dragino2_gpio_keys[] __initdata = {
    {
        .desc        = "jumpstart button",
        .type        = EV_KEY,
        .code        = KEY_WPS_BUTTON,
        .debounce_interval = DRAGINO2_KEYS_DEBOUNCE_INTERVAL,
        .gpio        = DRAGINO2_GPIO_BTN_JUMPSTART,
        .active_low    = 1,
    },
    {
        .desc        = "reset button",
        .type        = EV_KEY,
        .code        = KEY_RESTART,
        .debounce_interval = DRAGINO2_KEYS_DEBOUNCE_INTERVAL,
        .gpio        = DRAGINO2_GPIO_BTN_RESET,
        .active_low    = 1,
    }
};

static void __init dragino2_common_setup(void)
{
    u8 *art = (u8 *) KSEG1ADDR(0x1fff0000);

    ath79_register_m25p80(NULL);
    ath79_register_wmac(art + DRAGINO2_CALDATA_OFFSET,
                art + DRAGINO2_WMAC_MAC_OFFSET);

    ath79_init_mac(ath79_eth0_data.mac_addr, art + DRAGINO2_MAC0_OFFSET, 0);
    ath79_init_mac(ath79_eth1_data.mac_addr, art + DRAGINO2_MAC1_OFFSET, 0);

    ath79_register_mdio(0, 0x0);

    /* Enable GPIO15 and GPIO16 and possibly GPIO26 and GPIO27 */
    //ath79_gpio_function_disable(AR933X_GPIO_FUNC_ETH_SWITCH_LED2_EN |
    //                AR933X_GPIO_FUNC_ETH_SWITCH_LED3_EN);
    ath79_gpio_function_disable(AR933X_GPIO_FUNC_ETH_SWITCH_LED0_EN |
                    AR933X_GPIO_FUNC_ETH_SWITCH_LED1_EN |
                    AR933X_GPIO_FUNC_ETH_SWITCH_LED2_EN |
                    AR933X_GPIO_FUNC_ETH_SWITCH_LED3_EN |
                    AR933X_GPIO_FUNC_ETH_SWITCH_LED4_EN);

    /* LAN ports */
    ath79_register_eth(1);

    /* WAN port */
    ath79_register_eth(0);

    // add by merlin 2014-07-18
    ath79_register_spi_gpio();
}

static void __init dragino2_setup(void)
{
    dragino2_common_setup();

    ath79_register_leds_gpio(-1, ARRAY_SIZE(dragino2_leds_gpio),
                 dragino2_leds_gpio);
    ath79_register_gpio_keys_polled(-1, DRAGINO2_KEYS_POLL_INTERVAL,
                    ARRAY_SIZE(dragino2_gpio_keys),
                    dragino2_gpio_keys);
    ath79_register_usb();
}

MIPS_MACHINE(ATH79_MACH_DRAGINO2, "DRAGINO2", "Dragino Dragino v2",
         dragino2_setup);

注意两点，1，将DRAGINO2_GPIO_LED_LAN和DRAGINO2_GPIO_LED_WAN相关定义注释掉；2，将管脚当做普通gpio使用，要在ath79_gpio_function_disable函数中添加相关内容，按默认的即可。

2、测试

如测试LED3 (GPIO_14)和LED6 (GPIO_17)

root@SC-M-BASE:/sys/class/gpio# echo 14 > export 
root@SC-M-BASE:/sys/class/gpio# echo out > gpio14/direction 
root@SC-M-BASE:/sys/class/gpio# echo 1 > gpio14/value 
root@SC-M-BASE:/sys/class/gpio# echo 17 > export 
root@SC-M-BASE:/sys/class/gpio# echo out > gpio17/direction 
root@SC-M-BASE:/sys/class/gpio# echo 1 > gpio17/value

参考：

http://www.cnblogs.com/tfanalysis/p/4206513.html