Linux Device Drivers
Hi guys,
Could someone explain to me what is the difference between simple char device driver and serial drivers which use the tty core? I mean, if i want to develop a char driver for a serial device and there will be a node in /dev/mydev file system, is it mandatory to use another node /dev/tty_x for the the same driver, or I can use the mydev ?
I am confused about these. In all the driver development books is presented the file_operations structure which holds the entries for the device driver, but in another chapter is presented uart_ops structure which in turn stores others entries.
Thank you,
Comments
-
I am not an expert Kernel module writer but I can redirect you to information that I researched. Character devices, from what I read, are devices that transmit data from and to the user. Devices charaterized as char devices are printers, video cards, keyboards and mouses generally.
Serial devices were known to be communication devices for transmition of data from one location to the next in series of bytes. They can now be used by input devices since they follow the some underlyning princible, "communicate".
Most if not all devices are located in /dev/. The driver you want to write will be used to access a device in /dev either serially of characterly. You can either let udev name the device or give it a name you specify like /dev/mydev. A serial driver, to my understanding, handles a "serial device" does not matter how it is connected. TTYs were knoen as "teletypes" and were physical machines used to communicate with another machine until this communication method became software-based. Hopes this helps
http://www.tldp.org/LDP/lkmpg/2.4/html/x579.html (char device drivers)
http://www.linusakesson.net/programming/tty/ (TTYs explained)
0 -
Thank you for your answer,
So, as far as i understood, it is possible to combine both char drivers and serial drivers ? With char driver I expose the data to the user and with the serial driver I handle the lower layer (e.g UART) ?
0 -
Hello again,
For those who still wait for an answer, I found myself an answer.
[ The Linux tty driver core lives right below the standard character driver level and provides a range of features focused on providing an interface for terminal style devices to use ]
https://static.lwn.net/images/pdf/LDD3/ch18.pdf
0 -
Good job finding what you needed. So far what I read was informative. This might me understand tty'sbetter. Thanks for sharing.
0
Categories
- 9.9K All Categories
- 29 LFX Mentorship
- 82 LFX Mentorship: Linux Kernel
- 463 Linux Foundation Boot Camps
- 266 Cloud Engineer Boot Camp
- 93 Advanced Cloud Engineer Boot Camp
- 43 DevOps Engineer Boot Camp
- 28 Cloud Native Developer Boot Camp
- 1 Express Training Courses
- 1 Express Courses - Discussion Forum
- 1.6K Training Courses
- 18 LFC110 Class Forum
- 3 LFC131 Class Forum
- 19 LFD102 Class Forum
- 131 LFD103 Class Forum
- 9 LFD121 Class Forum
- 60 LFD201 Class Forum
- 1 LFD213 Class Forum - Discontinued
- 128 LFD232 Class Forum
- 23 LFD254 Class Forum
- 544 LFD259 Class Forum
- 100 LFD272 Class Forum
- 1 LFD272-JP クラス フォーラム
- 1 LFS145 Class Forum
- 20 LFS200 Class Forum
- 739 LFS201 Class Forum
- 1 LFS201-JP クラス フォーラム
- 1 LFS203 Class Forum
- 36 LFS207 Class Forum
- 295 LFS211 Class Forum
- 53 LFS216 Class Forum
- 45 LFS241 Class Forum
- 39 LFS242 Class Forum
- 33 LFS243 Class Forum
- 10 LFS244 Class Forum
- 27 LFS250 Class Forum
- 1 LFS250-JP クラス フォーラム
- 131 LFS253 Class Forum
- 963 LFS258 Class Forum
- 10 LFS258-JP クラス フォーラム
- 85 LFS260 Class Forum
- 124 LFS261 Class Forum
- 29 LFS262 Class Forum
- 78 LFS263 Class Forum
- 15 LFS264 Class Forum
- 10 LFS266 Class Forum
- 17 LFS267 Class Forum
- 16 LFS268 Class Forum
- 14 LFS269 Class Forum
- 193 LFS272 Class Forum
- 1 LFS272-JP クラス フォーラム
- 206 LFW211 Class Forum
- 148 LFW212 Class Forum
- 890 Hardware
- 212 Drivers
- 74 I/O Devices
- 44 Monitors
- 115 Multimedia
- 206 Networking
- 99 Printers & Scanners
- 85 Storage
- 747 Linux Distributions
- 88 Debian
- 64 Fedora
- 13 Linux Mint
- 13 Mageia
- 24 openSUSE
- 133 Red Hat Enterprise
- 33 Slackware
- 13 SUSE Enterprise
- 354 Ubuntu
- 468 Linux System Administration
- 38 Cloud Computing
- 67 Command Line/Scripting
- Github systems admin projects
- 93 Linux Security
- 77 Network Management
- 107 System Management
- 48 Web Management
- 61 Mobile Computing
- 22 Android
- 25 Development
- 1.2K New to Linux
- 1.1K Getting Started with Linux
- 525 Off Topic
- 127 Introductions
- 211 Small Talk
- 19 Study Material
- 782 Programming and Development
- 256 Kernel Development
- 492 Software Development
- 919 Software
- 255 Applications
- 181 Command Line
- 2 Compiling/Installing
- 76 Games
- 316 Installation
- 46 All In Program
- 46 All In Forum
Upcoming Training
-
August 20, 2018
Kubernetes Administration (LFS458)
-
August 20, 2018
Linux System Administration (LFS301)
-
August 27, 2018
Open Source Virtualization (LFS462)
-
August 27, 2018
Linux Kernel Debugging and Security (LFD440)