acpi device driver

Original URL: http://www.cnblogs.com/geneil/archive/2011/12/03/2272869.htmlfirst, the Linux system divides the device into 3 categories: Character device, block device, network device. Using drivers:1, character device : Refers to a byte can only one byte read and write devi

Access to the character device is performed through the device name in the file system. Those device names are simply nodes that are called file system trees, and they are typically located in the/dev directory. Device files for character device drivers can be identified by

Access to the character device is done through the device name in the file system. Those device names are simply nodes that are called file system trees, and they are typically located in the/dev folder.Device files for character device drivers can be identified by ' C ' in the first column of the ls-l command output.

processor can be considered as peripherals compared with the ARM core, after successful registration, the ldd0 directory appears in the SYS/Device directory. If (RET) Printk (kern_notice "unable to register LDD/N "); Printk (kern_notice "Mount ldw. OK! /Nbus device is ldd0! /Nyou can see me in sys/module/, sys/devices/and sys/bus /!/N "); Return ret; } Static void ldd_bus_exit (void) { Device_unregister

Access to the character device is performed through the device name in the file system. Those device names are simply nodes that are called file system trees, and they are typically located in the/dev directory. Device files for character device drivers can be identified by

In the Linux device driver first: Introduction to the device driver briefly describes the character driver, this article briefly describes how to write a simple character device driver.

In the Linux device driver first: Introduction to the device driver briefly describes the character driver, this article briefly describes how to write a simple character device driver.

Character Device Driver: 1. Generally, we use APIs that dynamically allocate device numbers: Int alloc_chrdev_region (dev_t * Dev, unsigned int firstminor, unsigned int count, char * Name ); Dev is a function used for output. After successful call, the first number of the allocated range will be saved. Void unregister_chrdev_region (dev_t first, unsigned int coun

How to use the platform device driver to write the driver:-------------------------------------------------------------------------1. Implement device orientation first:1) read the chip manual and obtain resources from the schematic diagram.2) construct a platform device str

first, the Linux system divides the device into 3 categories: Character device, block device, network device. Using drivers:1, character device : Refers to a byte can only one byte read and write devices, can not randomly read the device