平台设备驱动框架

框架入口源文件： led_drv.c  led_dev.c

可根据入口源文件，再按着框架到内核走一遍

内核版本：linux_2.6.22.6 硬件平台：JZ2440

 以下是驱动框架：

以下是驱动代码 led_dev.c：

#include <linux/module.h>
#include <linux/version.h>

#include <linux/init.h>

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/timer.h>
#include <linux/init.h>
#include <linux/serial_core.h>
#include <linux/platform_device.h>




//定义一个资源结构体
static struct resource led_drv_resource[]=
{
   [0] = {.start =0x56000050 , .end = 0x56000050 + 8 - 1 , .flags = IORESOURCE_MEM, },
   [1] = {.start = 5, .end  = 5,.flags = IORESOURCE_IRQ,}
};


static void led_platform_release(struct device * dev)
{}


//定义一个 device_platform 结构体
static struct platform_device led_dev_platform =
{
  .name = "platform_led",
  .id = -1,
  .num_resources = ARRAY_SIZE(led_drv_resource),
  .resource = led_drv_resource,
  .dev = { .release = led_platform_release,  },
};


static int led_device_init(void)
{
  platform_device_register(&led_dev_platform);
  return 0;
}

static void led_device_exit(void)
{
   platform_device_unregister(&led_dev_platform);
}

module_init(led_device_init);
module_exit(led_device_exit);
MODULE_LICENSE("GPL");

以下是驱动代码led_drv.c：

#include <linux/module.h>
#include <linux/version.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/sched.h>
#include <linux/pm.h>
#include <linux/sysctl.h>
#include <linux/proc_fs.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/irq.h>
#include <asm/uaccess.h>
#include <asm/io.h>

//引脚定义
static unsigned long *gpfcon;
static unsigned long *gpfdat;
static int pin;

//为设备定义一个类
static struct class *led_platform_class;

//定义主设备号
static int major;
static ssize_t led_drv_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
    int val;
    copy_from_user(&val, buf, count); 

    if (val == 1) *gpfdat &= ~(1<<pin);
    else *gpfdat |= (1<<pin);
    
    return 0;
}

static int led_drv_open(struct inode *inode, struct file *file)
{
   //配置寄存器
   *gpfcon &= ~(0x3<<(pin*2));
   *gpfcon |= (0x1<<(pin*2));
    return 0;    
}

static struct file_operations led_fops =
{
   .owner = THIS_MODULE,
   .write   = led_drv_write,
   .open   = led_drv_open,
};


static int probe_led(struct platform_device *pfdrv)
{
    // 引脚初始化
    struct resource *sodrv;
    sodrv = platform_get_resource(pfdrv,IORESOURCE_MEM,0);
    gpfcon = ioremap(sodrv->start,sodrv->end - sodrv->start+1);    
    gpfdat = gpfcon +1;

    sodrv =  platform_get_resource(pfdrv,IORESOURCE_IRQ,0);
    pin = sodrv->start;

    //注册字符设备 类 节点
    major = register_chrdev(0,"led_devices",&led_fops);                                  //  proc/devices/led_class
    led_platform_class = class_create(THIS_MODULE,"led_class");                          //  sys/class/led_class
    class_device_create(led_platform_class,NULL, MKDEV(major,0), NULL, "led_dev");       //  dev/led_dev
    return 0;
}

static int  remove_led(struct platform_device *pfdrv)
{
   iounmap(gpfcon);
   unregister_chrdev(major,"led_platform");
   class_destroy(led_platform_class);
   class_device_destroy(led_platform_class,MKDEV(major,0));
   return 0;
}

static struct platform_driver led_platform =
{
   .probe = probe_led,
   .remove = remove_led,
   .driver ={.name = "platform_led",}
};


static int led_drv_init(void)
{
   platform_driver_register(&led_platform);
   return 0;
}


static void led_drv_exit(void)
{
   platform_driver_unregister(&led_platform);
}


module_init(led_drv_init);
module_exit(led_drv_exit);
MODULE_LICENSE("GPL");

以下是编译驱动的Makefile：

KER_DIR=/work/systems/kernel/linux-2/linux-2.6.22.6
all:
    make -C $(KER_DIR) M=`pwd` modules
clean:
    make -C $(KER_DIR) M=`pwd` modules clean
    rm -fr modules.order

obj-m += led_dev.o
obj-m += led_drv.o