sysLed Linux Device Model

sysLed4_devModel.c

#include <linux/gpio.h> 
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <asm/uaccess.h>
#include <linux/module.h>

#define GPIO 164		//GPIO port-nr
#define myMAJOR 64
#define myMINOR 0
#define ch 1
#define MAXLEN 512


static struct class *led_class;

//static struct cdev My
struct file_operations my_fops;
static int devno;
int err;


MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("NKB");
MODULE_DESCRIPTION("Reads the user_key");
MODULE_LICENSE("Dual BSD/GPL");

ssize_t mygpio_write(struct file *filep, const char __user *ubuf, size_t count, loff_t *f_pos);
int  mygpio_open (struct inode *inode, struct file *file);
int  mygpio_release (struct inode *inode, struct file *file);

struct file_operations my_fops = {
	.owner = THIS_MODULE,
	.write = mygpio_write,
	.open =  mygpio_open,
	.release =  mygpio_release,
};

static struct cdev my_cdev;

static int mygpio_init(void)
{
	printk(KERN_ALERT "Hello, world\n");

	err = gpio_request_one(GPIO, GPIOF_DIR_OUT, "Init User-key");	//Request GPIO, set GPIO direction (in)
	if (err != 0)
		goto requestError;
	devno = MKDEV(myMAJOR,myMINOR);					//make device number

	cdev_init(&my_cdev, &my_fops);

	err = cdev_add(&my_cdev, devno, ch);
	if (err != 0)
		goto cdevAddError;
	err = register_chrdev_region(devno,ch,"User-key");
	if (err != 0)
		goto registerChrdevError;
	// alloc_chrdev_region() kunne bruges for dynamisk allkoering
		
		
	/* Create a class, ie a folder in sysfs */
	led_class = class_create(THIS_MODULE, "ledKlasse");


      /* Create an object (device), ie a file under the class just created */
      /* (New version of class_device_create) */
	device_create(led_class, NULL, devno, NULL, "ledDevice");
	

	return 0;

	requestError:
	{
		printk(KERN_ALERT "Request FAILED!\n");
		gpio_free(GPIO);
		return 0;
	}

	cdevAddError:
	{
		printk(KERN_ALERT "cdev add FAILED!\n");
		cdev_del(&my_cdev);
		return 0;
	}

	registerChrdevError:
	{
		printk(KERN_ALERT "registering FAILED!\n");
		unregister_chrdev_region(devno,ch);
		return 0;
	}
}

static void mygpio_exit(void)
{
	printk(KERN_ALERT "Goodbye, cruel world\n");
	
	/* Destroy device from Device Model / Sysfs */
	device_destroy(led_class, devno);

	/* Remove class from Device Model / Sysfs */
	class_destroy(led_class);
	
	unregister_chrdev_region(devno,ch); // skal den ikke være i cleanup func?
	cdev_del(&my_cdev);
	gpio_free(GPIO);
}

int mygpio_open(struct inode *inode, struct file *file)
{
	int major, minor;
	major = MAJOR(inode->i_rdev);
	minor = MINOR(inode->i_rdev);
	printk("Opening MyGpio Device [major], [minor]: %i, %i\n", major, minor);
	return 0;
}

int mygpio_release(struct inode *inode, struct file *file)
{
	int minor, major;
	   
	major = MAJOR(inode->i_rdev);
	minor = MINOR(inode->i_rdev);
	return 0;
}


ssize_t mygpio_write(struct file *filep, const char __user *ubuf, size_t count, loff_t *f_pos)
{
 int minor, len, scanValue;
 char kbuf[MAXLEN];

 
 minor = MINOR(filep->f_dentry->d_inode->i_rdev);
 
 if(count < MAXLEN)
   len = count;
 else
   len = MAXLEN;
 
 copy_from_user(kbuf, ubuf, len);
 kbuf[len]= '\0';
 sscanf(kbuf, "%d",&scanValue);
 
 gpio_set_value(GPIO, scanValue);
 
 // Hvilke trin er det der skal udføres?
 // Hint konvertering fra string til int kan gøres via sscanf() - antagelsen er at det er strenge der sendes til og fra user space. Det debugging lettere.
*f_pos += count;
 return count;
}


module_init(mygpio_init);
module_exit(mygpio_exit);

sysLed4_devModel_dynamisk.c

#include <linux/gpio.h> 
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <asm/uaccess.h>
#include <linux/module.h>

#define GPIO 164		//GPIO port-nr
//#define myMAJOR 64
#define MINOR_START 0		// minor nummer starter ved 0
#define ch 10			// Antal minor numre
#define MAXLEN 512


static struct class *led_class;

//static struct cdev My
struct file_operations my_fops;
static dev_t devno;
int err;

MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("NKB");
MODULE_DESCRIPTION("Reads the user_key");
MODULE_LICENSE("Dual BSD/GPL");

/* Sysfs "read" method prototype */
static ssize_t show_ledAttrs(struct device *dev, struct device_attribute *attr)
{
  printk("SHOW !!! \n");
}

/* Sysfs "write" method prototype */
static ssize_t store_ledAttrs(struct device *dev, struct device_attribute *attr )
{
  /* //OPGAVE h
  int *num = dev_get_drvdata(dev);
  ssize_t ret = -EINVAL;
  char *after;
  unsigned long value = simple_strtoul(buf, &after, 10);
  size_t count = after - buf;
  if (isspace(*after))
    count++;


  printk("using Store to set gpio #%i to %i\n", *num, (int)value);
  gpio_set_value(*num, value);
  return count;
  */
}

ssize_t mygpio_write(struct file *filep, const char __user *ubuf, size_t count, loff_t *f_pos);
int  mygpio_open (struct inode *inode, struct file *file);
int  mygpio_release (struct inode *inode, struct file *file);

struct file_operations my_fops = {
	.owner = THIS_MODULE,
	.write = mygpio_write,
	.open =  mygpio_open,
	.release =  mygpio_release,
};

static struct cdev my_cdev;

static int mygpio_init(void)
{
	int gpio_sysLed4_no = 164;
	printk(KERN_ALERT "Hello, world\n");

	err = gpio_request_one(GPIO, GPIOF_DIR_OUT, "Init User-key");	//Request GPIO, set GPIO direction (in)
	if (err != 0)
		goto requestError;
	
	cdev_init(&my_cdev, &my_fops);

	err = cdev_add(&my_cdev, devno, ch);
	if (err != 0)
		goto cdevAddError;
	err = alloc_chrdev_region(&devno,MINOR_START,ch,"User-key");
	if (err != 0)
		goto registerChrdevError;
	// alloc_chrdev_region() kunne bruges for dynamisk allkoering
		
		
	/* Create a class, ie a folder in sysfs */
	led_class = class_create(THIS_MODULE, "ledKlasse");

	/* Macro to create attributes */
	static struct device_attribute led_class_attrs[] = {__ATTR(ledAttrs, S_IWUSR|S_IRUGO, show_ledAttrs, store_ledAttrs), __ATTR_NULL,};
	
	/*	ATTRIBUTER ???	*/
	led_class->dev_attrs = led_class_attrs;
	
	  
      /* Create an object (device), ie a file under the class just created */
      /* (New version of class_device_create) */
	device_create(led_class, NULL, devno, NULL, "ledDevice", drvdata(&gpio_sysLed4_no));
	

	return 0;

	requestError:
	{
		printk(KERN_ALERT "Request FAILED!\n");
		gpio_free(GPIO);
		return 0;
	}

	cdevAddError:
	{
		printk(KERN_ALERT "cdev add FAILED!\n");
		cdev_del(&my_cdev);
		return 0;
	}

	registerChrdevError:
	{
		printk(KERN_ALERT "registering FAILED!\n");
		unregister_chrdev_region(devno,ch);
		return 0;
	}
}

static void mygpio_exit(void)
{
	printk(KERN_ALERT "Goodbye, cruel world\n");
	
	/* Destroy device from Device Model / Sysfs */
	device_destroy(led_class, devno);

	/* Remove class from Device Model / Sysfs */
	class_destroy(led_class);
	
	unregister_chrdev_region(devno,ch); // skal den ikke være i cleanup func?
	cdev_del(&my_cdev);
	gpio_free(GPIO);
}

int mygpio_open(struct inode *inode, struct file *file)
{
	int major, minor;
	major = MAJOR(inode->i_rdev);
	minor = MINOR(inode->i_rdev);
	printk("Opening MyGpio Device [major], [minor]: %i, %i\n", major, minor);
	return 0;
}

int mygpio_release(struct inode *inode, struct file *file)
{
	int minor, major;
	   
	major = MAJOR(inode->i_rdev);
	minor = MINOR(inode->i_rdev);
	return 0;
}


ssize_t mygpio_write(struct file *filep, const char __user *ubuf, size_t count, loff_t *f_pos)
{
 int minor, len, scanValue;
 char kbuf[MAXLEN];

 
 minor = MINOR(filep->f_dentry->d_inode->i_rdev);
 
 if(count < MAXLEN)
   len = count;
 else
   len = MAXLEN;
 
 copy_from_user(kbuf, ubuf, len);
 kbuf[len]= '\0';
 sscanf(kbuf, "%d",&scanValue);
 
 gpio_set_value(GPIO, scanValue);
 
 // Hvilke trin er det der skal udføres?
 // Hint konvertering fra string til int kan gøres via sscanf() - antagelsen er at det er strenge der sendes til og fra user space. Det debugging lettere.
*f_pos += count;
 return count;
}


module_init(mygpio_init);
module_exit(mygpio_exit);