精通linux设备驱动程序开发：并行端口 parport

7216阅读　0评论2012-01-08　yuweixian4230
分类：LINUX


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自己没有测试成功，这部分内容以后看
比较好的这方面资料：
lt
编写并行接口字符驱动程序
linux device driver p246 并口
精通d板
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并口编程一些重要的函数：
struct pardevice *pdev;
parport_claim_or_block(pdev);请求并口
parport_write_data(pdev->port,buf);
parport_release(pdev);释放并口

parport_register_device();
parport_register_driver();
parport_unregister_driver();

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附件： parport.rar   将rar修改为tar.bz2
  1. #include <linux/init.h>
  2. #include <linux/module.h>
  3. #include <linux/kernel.h>
  4. #include <linux/fs.h>
  5. #include <linux/cdev.h>
  6. #include <linux/parport.h>
  7. #include <asm/uaccess.h>
  8. #include <linux/platform_device.h>
  9. #include <linux/pci.h>
  10. #include <linux/device.h> //class

  12. #define DEVICE_NAME "led"

  14. static dev_t dev_number; /* Allotted device number */
  15. static struct class *led_class; /* Class to which this device
  16.                                    belongs */
  17. struct cdev led_cdev; /* Associated cdev */
  18. struct pardevice *pdev; /* Parallel port device */

  20. /* LED open */
  21. int led_open(struct inode *inode, struct file *file)
  22. {
  23.     return 0;
  24. }

  26. /* Write to the LED */
  27. ssize_t led_write(struct file *file, const char *buf,size_t count, loff_t *ppos)
  28. {
  29.     char kbuf;
  30.     if (copy_from_user(&kbuf, buf, 1)) return -EFAULT;
  31.     /* Claim the port */
  32.     parport_claim_or_block(pdev);
  33.     /* Write to the device */
  34.     parport_write_data(pdev->port, kbuf);
  35.     /* Release the port */
  36.     parport_release(pdev);
  37.     return count;
  38. }

  40. /* Release the device */
  41. int led_release(struct inode *inode, struct file *file)
  42. {
  43.     return 0;
  44. }

  46. /* File Operations */
  47. static struct file_operations led_fops = {
  48.     .owner = THIS_MODULE,
  49.     .open = led_open,
  50.     .write = led_write,
  51.     .release = led_release,
  52. };

  54. static int
  55. led_preempt(void *handle)
  56. {
  57.     return 1;
  58. }

  60. /* Parport attach method */
  61. static void led_attach(struct parport *port)
  62. {
  63.     /* Register the parallel LED device with parport */
  64.     pdev = parport_register_device(port, DEVICE_NAME,
  65.          led_preempt, NULL,
  66.          NULL, 0, NULL);
  67.     if (pdev == NULL) printk("Bad register\n");
  68. }

  70. /* Parport detach method */
  71. static void led_detach(struct parport *port)
  72. {
  73.     /* Do nothing */
  74. }

  76. /* Parport driver operations */
  77. static struct parport_driver led_driver = {
  78.     .name = "led",
  79.     .attach = led_attach,
  80.     .detach = led_detach,
  81. };

  83. /* Driver Initialization */
  84. int __init led_init(void)
  85. {
  86.     /* Request dynamic allocation of a device major number */
  87.     if (alloc_chrdev_region(&dev_number, 0, 1, DEVICE_NAME)< 0)
  88.     {
  89.         printk(KERN_DEBUG "Can't register device\n");
  90.         return -1;
  91.     }
  92.     printk("alloc_chrdev_region..ok.\n");

  94.     /* Create the led class */
  95.     led_class = class_create(THIS_MODULE, DEVICE_NAME);
  96.     if(IS_ERR(led_class))
  97.         printk("Bad class create\n");
  98.     else
  99.         printk("class_create ok.\n");

  101.     /* Connect the file operations with the cdev */
  102.     cdev_init(&led_cdev, &led_fops);
  103.     led_cdev.owner = THIS_MODULE;
  104.     /* Connect the major/minor number to the cdev */
  105.     if (cdev_add(&led_cdev, dev_number, 1))
  106.     {
  107.         printk("Bad cdev add\n");
  108.         return 1;
  109.     }
  110.     else
  111.         printk("cdev_add ok.\n");

  113.     //class_device_create(led_class, NULL, dev_number,
  114.     //     NULL, DEVICE_NAME);
  115.     device_create(led_class, NULL, dev_number,
  116.          NULL, DEVICE_NAME);

  118.     /* Register this driver with parport */
  119.     if(parport_register_driver(&led_driver))
  120.     {
  121.         printk(KERN_ERR "Bad Parport Register\n");
  122.         return -EIO;
  123.     }
  124.     else
  125.         printk("parport_register_driver ok\n");

  127.     printk("LED Driver Initialized.\n");
  128.     return 0;
  129. }

  131. /* Driver Exit */
  132. void __exit led_cleanup(void)
  133. {
  134.     unregister_chrdev_region(dev_number, 1);
  135.     //parport_unregister_driver();
  136.     device_destroy(led_class,dev_number);
  137.     class_destroy(led_class);
  138.     return;
  139. }

  141. module_init(led_init);
  142. module_exit(led_cleanup);
  143. MODULE_LICENSE("GPL");

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