设备树下的 LED 驱动开发

alphaled
{
    #address-cells = <1>;
    #size-cells = <1>;
    compatible = "alphaled-led";
    status = "okay";
    reg = < 0X020c406c 0X04
            0X020E0068 0X04
            0X020E02F4 0X04
            0X0209C000 0X04
            0X0209C004 0X04 >
};

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/ide.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/gpio.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <asm/mach/map.h>
#include <asm/uaccess.h>
#include <asm/io.h>

#define    DTSLED_CNT     1
#define    DTSLED_NAME    "dtsled"
#define    LEDOFF         0
#define    LEDON          1

static void __iomem *IMX6U_CCM_CCGR1;
static void __iomem *SW_MUX_GPIO1_IO03;
static void __iomem *SW_PAD_GPIO1_IO03;
static void __iomem *GPIO1_DR;
static void __iomem *GPIO1_GDIR;

struct dtsled_dev
{
    dev_t devid;
    struct cdev cdev;
    struct class *class;
    struct device *device;
    int maior;
    int minor;
    struct device_node *nd;
};

struct dtsled_dev dtsled;

void led_switch(u8 sta)
{
    u32 val = 0;
    if(sta == LEDON)
    {
        val = readl(GPIO1_DR);
        VAL &= ~(1 << 3);
        writel(val, GPIO1_DR);
    }
    else if(sta == LEDOFF)
    {
        val = readl(GPIO1_DR);
        val |= (1 << 3);
        write1(val, GPIO1_DR);
    }
}