2018年10月12日 | Tiny210按键分层分离(总线-驱动-设备模型)

led_dev.c驱动源码：

#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"

// 分配/设置/注册一个platform_device 

static struct resource led_resource[] = {

    [0] = {

        .start = 0xE0200280,

        .end   = 0xE0200280 + 8 - 1,

        .flags = IORESOURCE_MEM,

    },

    [1] = {

        .start = 0,

        .end   = 0,

        .flags = IORESOURCE_IRQ,

    }

};

static void led_release(struct device * dev)

{

}

static struct platform_device led_dev = {

    .name                  = "myled",

    .id                        = -1,

    .num_resources  = ARRAY_SIZE(led_resource),

    .resource             = led_resource,

    .dev = { 

        .release            = led_release, 

    },

};

static int led_dev_init(void)

{

    platform_device_register(&led_dev);

    return 0;

}

static void led_dev_exit(void)

{

    platform_device_unregister(&led_dev);

}

module_init(led_dev_init);

module_exit(led_dev_exit);

MODULE_LICENSE("GPL");

===================================================================

led_drv.c驱动源码：

// 分配/设置/注册一个platform_driver 

#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"

static int major;

static struct class *cls;

static volatile unsigned long *gpio_con;

static volatile unsigned long *gpio_dat;

static int pin;

static int led_open(struct inode *inode, struct file *file)

{

    //printk("first_drv_open\n");

    // 配置为输出 

    *gpio_con &= ~(0xf<<(pin*4));

    *gpio_con |= (0x1<<(pin*4));

    return 0;    

}

static ssize_t led_write(struct file *file, const char __user *buf, size_t count, loff_t * ppos)

{

    int val;

    //printk("first_drv_write\n");

    copy_from_user(&val, buf, count); //    copy_to_user();

    if (val == 1)

    {

        // 点灯

        *gpio_dat &= ~(1<

    }

    else

    {

        // 灭灯

        *gpio_dat |= (1<

    }

    return 0;

}

static struct file_operations led_fops = {

    .owner  =   THIS_MODULE,    // 这是一个宏，推向编译模块时自动创建的__this_module变量 

    .open   =   led_open,     

    .write  =   led_write,       

};

static int led_probe(struct platform_device *pdev)

{

    struct resource        *res;

    // 根据platform_device的资源进行ioremap 

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

    gpio_con = ioremap(res->start, res->end - res->start + 1);

    gpio_dat = gpio_con + 1;

    res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);

    pin = res->start;

    // 注册字符设备驱动程序 

    printk("led_probe, found led\n");

    major = register_chrdev(0, "myled", &led_fops);

    cls = class_create(THIS_MODULE, "myled");

    device_create(cls, NULL, MKDEV(major, 0), NULL, "led"); // /dev/led 

    return 0;

}

static int led_remove(struct platform_device *pdev)

{

    // 卸载字符设备驱动程序 

    // iounmap 

    printk("led_remove, remove led\n");

    device_destroy(cls, MKDEV(major, 0));

    class_destroy(cls);

    unregister_chrdev(major, "myled");

    iounmap(gpio_con);

    return 0;

}

struct platform_driver led_drv = {

    .probe    = led_probe,

    .remove  = led_remove,

    .driver     = {

        .name = "myled",

    }

};

static int led_drv_init(void)

{

    platform_driver_register(&led_drv);

    return 0;

}

static void led_drv_exit(void)

{

    platform_driver_unregister(&led_drv);

}

module_init(led_drv_init);

module_exit(led_drv_exit);

MODULE_LICENSE("GPL");

====================================================================

led_test.c测试程序：

#include "sys/types.h"

#include "sys/stat.h"

#include "fcntl.h"

#include "stdio.h"

// led_test on

// led_test off

int main(int argc, char **argv)

{

    int fd;

    int val = 1;

    fd = open("/dev/led", O_RDWR);

    if (fd < 0)

    {

        printf("can't open!\n");

    }

    if (argc != 2)

    {

        printf("Usage :\n");

        printf("%s 《on|off》\n", argv[0]); //实际为"<"

        return 0;

    }

    if (strcmp(argv[1], "on") == 0)

    {

        val  = 1;

    }

    else

    {

        val = 0;

    }

    write(fd, &val, 4);

    return 0;

}