S3c6410 linux内核移植---添加按键驱动

以下为ut-s3c6410开发板的键盘驱动，如果是其他板要做相应的改动。包括arch/arm/machs-3c6410/mach-smdk6410.c的static struct gpio_keys_button smdk6410_buttons[]结构体和drivers/input/keyboard/gpio_keys.c文件下的int s3c_gpio_keys[]结构体。

1、 添加添加 platform 信息

在arch/arm/machs-3c6410/mach-smdk6410.c添加 platform 信息

static struct gpio_keys_button smdk6410_buttons[] =
{
    {
        .gpio = S3C64XX_GPN ( 0 ),
        .code = 158,
        .desc = "Down",
        .active_low = 1,
        .wakeup = 0,
    },
    {
        .gpio = S3C64XX_GPN ( 1 ),
        .code = KEY_ENTER,
        .desc = "Enter",
        .active_low = 1,
        .wakeup = 0,
    },
    {
        .gpio = S3C64XX_GPN ( 2 ),
        .code = KEY_HOME,
        .desc = "Home",
        .active_low = 1,
        .wakeup = 0,
    },
    {
        .gpio = S3C64XX_GPN ( 3 ),
        .code = KEY_POWER,
        .desc = "Power",
        .active_low = 1,
        .wakeup = 0,
    },
    {
        .gpio = S3C64XX_GPN ( 4 ),
        .code = KEY_TAB,
        .desc = "Tab",
        .active_low = 1,
        .wakeup = 0,
    },
    {
        .gpio = S3C64XX_GPN ( 5 ),
        .code = 139,
        .desc = "Menu",
        .active_low = 1,
        .wakeup = 0,
    },
};

static struct gpio_keys_platform_data smdk6410_button_data =
{
    .buttons = smdk6410_buttons,
    .nbuttons = ARRAY_SIZE ( smdk6410_buttons ),
};

static struct platform_device smdk6410_device_button =
{
    .name = "gpio-keys",
    .id = 1,
    .dev = {
        .platform_data = &smdk6410_button_data,
    },
};

并将“&ldd6410_device_button, ”语句填入 struct platform_device *ldd6410_devices[]数组，作为该数组的一个成员。

如果要修改按键对应的GPIO和键值，只需要简单的修改ldd6410_buttons[]数组中的内容。

2、 修改代码drivers / input / keyboard / gpio_keys.c

添加结构体:

int s3c_gpio_keys[] =
{
    IRQ_EINT ( 0 ),
    IRQ_EINT ( 1 ),
    IRQ_EINT ( 2 ),
    IRQ_EINT ( 3 ),
    IRQ_EINT ( 4 ),
    IRQ_EINT ( 5 ),
};

修改函数static int __devinit gpio_keys_probe ( struct platform_device *pdev ) 为:

static int __devinit gpio_keys_probe ( struct platform_device *pdev )
{
    ……

#if 0
    irq = gpio_to_irq ( button->gpio );

    if ( irq < 0 )
    {

        error = irq;

        pr_err ( "gpio-keys: Unable to get irq number"

                 " for GPIO %d, error %d\n",

                 button->gpio, error );

        gpio_free ( button->gpio );

        goto fail2;

    }
#endif

    irq = s3c_gpio_keys[i];

    ……

}

修改函数static irqreturn_t gpio_keys_isr ( int irq, void *dev_id ) 为：

static irqreturn_t gpio_keys_isr ( int irq, void *dev_id )
{
    struct gpio_button_data *bdata = dev_id;
    struct gpio_keys_button *button = bdata->button;

//BUG_ON(irq != gpio_to_irq(button->gpio));

    if ( button->debounce_interval )
        mod_timer ( &bdata->timer,
                    jiffies + msecs_to_jiffies ( button->debounce_interval ) );
    else
        gpio_keys_report_event ( bdata );

    return IRQ_HANDLED;
}

编译内核时选择：

Device Drivers -> Input device support -> [*] Keyboards -> <*> GPIO Buttons

3、 添加数码相框的关机按键驱动
arch / arm / machs - 3c6410 / mach - smdk6410.c文件修改

static struct gpio_keys_button smdk6410_buttons[] =
{
    {
        {
            .gpio = S3C64XX_GPN ( 15 ),
            .code = KEY_POWER,
            .desc = "Power",
            .active_low = 1,
            .wakeup = 0,
        },
    };

    drivers / input / keyboard / gpio_keys.c文件修改：

    int s3c_gpio_keys[] =
    {
        IRQ_EINT ( 15 ),
    };