res= register_chrdev(I2C_MAJOR,"i2c", &i2cdev_fops); 3. 对设备文件进行读写时,可以调用read、write或者ioctl等方法,他们都是通过调用函数i2c_transfer来实现对I2C设备的操作的 inti2c_transfer(structi2c_adapter * adap,structi2c_msg *msgs,intnum) {intret;/*REVISIT the fault reporting model here is...
In order to support 32-bit user space running on a 64-bit machine, each subsystem or driver that implements an ioctl callback handler must also implement the corresponding compat_ioctl handler. As long as all the rules for data structures are followed, this is as easy as setting the .compa...
“/var/log/messages”日志文件可以看到内核的输出: [root@localhost driver_study]#tail -n 2 /var/log/messages Jul 2 01:03:10 localhost kernel: <6> book name:dissecting Linux Device Driver Jul 2 01:03:10 localhost kernel: book num:4 000 当用户运行“insmod book.ko book_name='GoodBook' ...
*/ void (*alert)(struct i2c_client *, unsigned int data); /* a ioctl like command that can be used to perform specific functions * with the device. */ int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); struct device_driver driver; const struct i2c_device_id ...
/* a ioctl like command that can be used to perform specific functions * with the device. */ int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); struct device_driver driver; const struct i2c_device_id *id_table; ...
{.owner=THIS_MODULE,.unlocked_ioctl=my_ioctl,};staticint__initmy_driver_init(void){if((alloc_chrdev_region(&dev,0,1,"my_dev"))<0)return-1;cdev_init(&my_cdev,&fops);if((cdev_add(&my_cdev,dev,1))<0)gotor_class;if(IS_ERR(dev_class=class_create(THIS_MODULE,"...
destroy(dev_class);cdev_del(&my_cdev);unregister_chrdev_region(dev,1);pr_info("Device Driver ...
RTC_VL_DATA_INVALID : 0, (unsigned int __user *)arg); default: return -ENOIOCTLCMD; } } static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm) { struct pcf8563 *pcf8563 = dev_get_drvdata(dev); unsigned char buf[4]; int err; err = regmap_bulk_read(pcf85...
ioctl(container, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU)) /* Doesn't support the IOMMU driver we want. */ /* Open the group */ group = open("/dev/vfio/26", O_RDWR); /* Test the group is viable and available */ ioctl(group, VFIO_GROUP_GET_STATUS, &group_status); ...
unique to each driver 7-0 function # So for example 0x82187201 is a read with arg length of 0x218, character 'r' function 1. Grepping the source reveals this is: #define VFAT_IOCTL_READDIR_BOTH _IOR('r', 1, struct dirent [2]) ...