1.利用IO Port的方式：

[cpp] view plain copy

#include linux/module.h

#include linux/moduleparam.h

#include linux/init.h

#include linux/kernel.h/* printk() */

#include linux/slab.h /* kmalloc() */

#include linux/fs.h/* everything... */

#include linux/errno.h /* error codes */

#include linux/types.h /* size_t */

#include linux/proc_fs.h

#include linux/fcntl.h /* O_ACCMODE */

#include linux/seq_file.h

#include linux/cdev.h

#include linux/ioport.h

#include mach/regs-gpio.h

#include asm/system.h /* cli(), *_flags */

#include asm/uaccess.h /* copy_*_user */

#include asm/io.h

#define LED_NUM 4

struct led_dev

{

struct cdev dev

unsigned port

unsigned long offset

}

struct led_dev led[4]

dev_t dev = 0

static struct resource *led_resource

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

{

struct led_dev *led/* device information */

led = container_of(inode-i_cdev, struct led_dev, dev)

filp-private_data = led/* for other methods */

return 0 /* success */

}

int led_release(struct inode *inode, struct file *filp)

{

return 0

}

ssize_t led_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos)

{

return 0

}

ssize_t led_write(struct file *filp, const char __user *buf, size_t count, loff_t *f_pos)

{

char data

struct led_dev *led

u32 value

printk(KERN_INFO "debug by baikal: led dev write\n")

led = (struct led_dev *)filp-private_data

copy_from_user(data,buf,count)

if(data == '0')

{

printk(KERN_INFO "debug by baikal: led off\n")

value = inl((unsigned)(S3C2410_GPBDAT))

outl(value | 1led-offset,(unsigned)(S3C2410_GPBDAT))

//value = ioread32(led-base)

//iowrite32( value | 1led-offset, led-base)

}

else

{

printk(KERN_INFO "debug by baikal: led on\n")

value = inl((unsigned)(S3C2410_GPBDAT))

outl(value ~(1led-offset),(unsigned)(S3C2410_GPBDAT))

//value = ioread32(led-base)

//iowrite32( value ~(1led-offset), led-base)

}

}

struct file_operations led_fops = {

.owner =THIS_MODULE,

.read = led_read,

.write =led_write,

//.ioctl =led_ioctl,

.open = led_open,

.release = led_release,

}

static int led_init(void)

{

int result, i

result = alloc_chrdev_region(dev, 0, LED_NUM,"LED")

if (result 0) {

printk(KERN_WARNING "LED: can't get major %d\n", MAJOR(dev))

return result

}

led_resource = request_region(0x56000014,0x4,"led")

if(led_resource == NULL)

{

printk(KERN_ERR " Unable to register LED I/O addresses\n")

return -1

}

for(i = 0i LED_NUMi++)

{

cdev_init( led[i].dev, led_fops)

//led[i].port = ioport_map(0x56000014,0x4)

//led[i].base = ioremap(0x56000014,0x4)

led[i].offset = i + 5 //leds GPB5\6\7\8

led[i].dev.owner = THIS_MODULE

led[i].dev.ops = led_fops

result = cdev_add(led[i].dev,MKDEV(MAJOR(dev),i),1)

if(result 0)

{

printk(KERN_ERR "LED: can't add led%d\n",i)

return result

}

}

return 0

}

static void led_exit(void)

{

int i

release_region(0x56000014,0x4)

for( i = 0i LED_NUMi++)

{

//iounmap(led[i].base)

cdev_del(led[i].dev)

}

unregister_chrdev_region(dev, LED_NUM)

}

module_init(led_init)

module_exit(led_exit)

MODULE_AUTHOR("Baikal")

MODULE_LICENSE("GPL")

MODULE_DESCRIPTION("Simple LED Driver")

2.利用IO Mem的方式：

[cpp] view plain copy

#include linux/module.h

#include linux/moduleparam.h

#include linux/init.h

#include linux/kernel.h/* printk() */

#include linux/slab.h /* kmalloc() */

#include linux/fs.h/* everything... */

#include linux/errno.h /* error codes */

#include linux/types.h /* size_t */

#include linux/proc_fs.h

#include linux/fcntl.h /* O_ACCMODE */

#include linux/seq_file.h

#include linux/cdev.h

#include linux/ioport.h

#include asm/system.h /* cli(), *_flags */

#include asm/uaccess.h /* copy_*_user */

#include asm/io.h

#define LED_NUM 4

struct led_dev

{

struct cdev dev

void __iomem *base

unsigned long offset

}

struct led_dev led[4]

dev_t dev = 0

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

{

struct led_dev *led/* device information */

led = container_of(inode-i_cdev, struct led_dev, dev)

filp-private_data = led/* for other methods */

return 0 /* success */

}

int led_release(struct inode *inode, struct file *filp)

{

return 0

}

ssize_t led_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos)

{

return 0

}

ssize_t led_write(struct file *filp, const char __user *buf, size_t count, loff_t *f_pos)

{

char data

struct led_dev *led

u32 value

printk(KERN_INFO "debug by baikal: led dev write\n")

led = (struct led_dev *)filp-private_data

copy_from_user(data,buf,count)

if(data == '0')

{

printk(KERN_INFO "debug by baikal: led off\n")

value = ioread32(led-base)

iowrite32( value | 1led-offset, led-base)

}

else

{

printk(KERN_INFO "debug by baikal: led on\n")

value = ioread32(led-base)

iowrite32( value ~(1led-offset), led-base)

}

}

struct file_operations led_fops = {

.owner =THIS_MODULE,

.read = led_read,

.write =led_write,

//.ioctl =led_ioctl,

.open = led_open,

.release = led_release,

}

static int led_init(void)

{

int result, i

result = alloc_chrdev_region(dev, 0, LED_NUM,"LED")

if (result 0) {

printk(KERN_WARNING "LED: can't get major %d\n", MAJOR(dev))

return result

}

for(i = 0i LED_NUMi++)

{

cdev_init( led[i].dev, led_fops)

request_mem_region(0x56000014,0x4,"led")

led[i].base = ioremap(0x56000014,0x4)

led[i].offset = i + 5 //leds GPB5\6\7\8

led[i].dev.owner = THIS_MODULE

led[i].dev.ops = led_fops

result = cdev_add(led[i].dev,MKDEV(MAJOR(dev),i),1)

if(result 0)

{

printk(KERN_ERR "LED: can't add led%d\n",i)

return result

}

}

return 0

}

static void led_exit(void)

{

int i

release_mem_region(0x56000014,0x4)

for( i = 0i LED_NUMi++)

{

iounmap(led[i].base)

cdev_del(led[i].dev)

}

unregister_chrdev_region(dev, LED_NUM)

}

module_init(led_init)

module_exit(led_exit)

MODULE_AUTHOR("Baikal")

MODULE_LICENSE("GPL")

MODULE_DESCRIPTION("Simple LED Driver")

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原文地址:https://outofmemory.cn/yw/7143433.html