linux device drivers programming at kernel level

the methods in the previous chapter to see information about this device in SYSFS:# Ls/sys/block/simp_blkdevDev holders range removable size slaves stat subsystem uevent#We found that our driver was missing the queue subdirectory in the SYSFS directory.It's not surprising, or it's going to freak out.In this chapter we implement our own make_request function to deal with bio, which is to get rid of the I/O Scheduler and the General __make_request () o

1, the concept and role of asynchronous notification Impact: Blocking-The application does not need to poll the device for access Non-blocking--notification of interrupts That is, initiated by the driver, actively notifies the application 2. Linux Asynchronous Notification programming 2.1 Linux Signal Role: In

Basic conceptsBlock Devices (Blockdevice)---is a random access device with a certain structure, the reading and writing of this device is block -based, he uses buffer zone to hold temporary data, waiting for the condition to mature, from the cache once written to the device or from the device to read the buffer at once

4.linux Network device driver architecture -------------------------------------- | Packet Sending | Packet Reception | -----> Network Protocol interface Layer | Dev_queue_xmit () | Netif_rx () | | -------------------------------------- | Structural Body Net_device | -----> Network Device

(struct work_struct *work, void (*function) (void *), void *data); int queue_work (struct workqueue_struct *queue, struct work_struct *work); int queue_delayed_work (struct workqueue_struct *queue, struct work_struct *work, unsigned long delay); The return value of the above two functions is nonzero means that the given work_struct structure is already waiting in the queue int cancel_delayed_work (struct work_struct *work); The entry

Article Title: how to add your own device driver in embedded Linux. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source. The driver can be co

Article Title: how to add your own device driver in embedded LINUX. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source. The driver can be co

in the queue, and returns null if none. Do not delete this request after processing struct Sbull_dev *dev = Req->rq_disk->private_data ; if (! blk_fs_request (req)) {//Determine if a file system request is not a block device request PRINTK (kern_notice "Skip non-fs request.\ n "); end_request (req, 0); continue; } The//sbull_transfer () function is a real processing block device request function Sbull

corresponding to a command code, to do some corresponding action. How to implement these operations, this is every programmer's own thing, because the devices are specific. The key is how to organize the command code, because in the IOCTL command code is the only way to contact the user program commands and driver support.In the Linux kernel, this defines a command code :___________________________________

Porting real-time device drivers to embedded Linux-general Linux technology-Linux programming and kernel information. The following is a detailed description.

For more information about linux Device Drivers-general Linux technology-Linux programming and kernel, see the following. The device driver

blocking and non-blocking IO in Linux device drivers:Blocking and non-blocking in 1.Linux device drivers Summary: http://m.blog.csdn.net/blog/dongteen/17264501Blocking and non-blocking io:http://m.blog.csdn.net/blog/dongteen/17264501 in 2.