developing linux device drivers using libusb programming interface

... the system uptime. Drivers can use the current value of jiffies to calculate time intervals across events (for example, to tell double clicks from single clicks in input device drivers) . In short, ... available in Linux 2.0, sysdep.h fills the gap Task Queues One feature many drivers need is the ability to schedule execution of some tasks at a later time without resorting to interrupts Linux ... according to the value of HZ, which is an architecture-dependent value defined in < ;linux/ param.h>. Current Linux versions define HZ to be 100 for most platforms, but some platforms use 1024,

Ngày tải lên: 24/12/2013, 01:17

... spin_unlock( &device- >lock);... when the device can issue interrupts with different meanings DEVICE_ ON(kdev_t device) DEVICE_ OFF(kdev_t device) These macros are intended to help devices that ... char device using the same major number since the two ranges are separate. The functions for registering and unregistering block devices look similar to those for char devices: #include < ;linux/ fs.h> ... before including blk.h */ #define DEVICE_ NR (device) MINOR (device) /* has no partition bits */ #define DEVICE_ NAME "sbull" /* name for messaging */ #define DEVICE_ INTR sbull_intrptr /* pointer

Ngày tải lên: 21/01/2014, 07:20

... minor numbers of the device holding the file that has been mapped Confusingly, for device mappings, the major and minor numbers refer to the disk partition holding the device special file ... in memory Device drivers, too, must be able to build page tables and handle faults when implementing mmap It's interesting to note how software memory management... the current Linux implementation ... user-space addresses to device memory Whenever the program reads or writes in the assigned address range, it is actually accessing the device In the X server example, using mmap allows quick

Ngày tải lên: 21/01/2014, 07:20

... :Network Drivers We are now through discussing char and block drivers and are ready to move on to the fascinating world of networking. Network interfaces are the third standard class of Linux devices, ... kernel, the network device asksto push incoming packets toward the kernel. The kernel interface for network drivers is designed for this different mode of operation. Network drivers also have ... network interfaces fit in with the rest of the Linux kernel and shows a memory-based modularized network interface, which is called (you guessed it) snull. To simplify the discussion, the interface

Ngày tải lên: 21/01/2014, 07:20

... architectures. A bus is made up of both an electrical interface and a programming interface. In this chapter, we deal with the programming interface. This chapter covers a number of bus architectures. ... jail_find_all_devices perform a little more work than in the example The function should check the newly found device against a list of vendor /device pairs, possibly using dev->vendor and dev- >device ... word device to refer to a device function, because each function in a multifunction board acts as an independent entity. When we refer to a device, we mean the tuple "bus number, device

Ngày tải lên: 21/01/2014, 07:20

... architectures, and describing them all would make no sense Drivers Current Linux kernels support a huge number of devices Device drivers account for half of the size of the source ... conditional compilation in the code: morgana% grep -c ifdef linux- 2.[024]/init/main.c linux- 2.0/init/main.c:120 linux- 2.2/init/main.c:246 linux- 2.4/init/main.c:35 Despite the huge addition of ... software device drivers that are inherently cross-platform, just like the sbull and spull drivers that we introduced in this book They are the RAM disk rd.c, the "network block device"

Ngày tải lên: 21/01/2014, 07:20

... the different device drivers concepts are introduced. Events User functions Kernel functions Load module Open device Read device Write device Close device Remove module Table 1. Device driver ... includes for device drivers */ #include < ;linux/ init.h> #include < ;linux/ config.h> #include < ;linux/ module.h> #include < ;linux/ kernel.h> /* printk() */ #include < ;linux/ slab.h> ... going on Bibliography A Rubini, J Corbert 2001 Linux device drivers. ..Events Load module Open device Read device Write device Close device Remove module User functions Kernel functions

Ngày tải lên: 03/07/2014, 16:21

... gadgets work with Linux But this book is also about how the Linux kernel works and... since then Keeping Linux Device Drivers up to date is increasingly a challenge; the Linux kernel hackers ... device (a USB memory card reader), or a network device (a USB Ethernet interface) Other classes of device drivers have been added to the kernel in recent times, including FireWire drivers ... :11 PM Linux continues to succeed... Thursday, January 20, 2005 9: 21 AM Block devices Like char devices, block devices are accessed by filesystem nodes in the /dev directory A block device

Ngày tải lên: 09/08/2014, 04:21

... -f /dev/$ {device} [0-3] major=$(awk "\\$2= =\"$module\" {print \\$1}" /proc/devices) mknod /dev/$ {device} 0 c $major 0 mknod /dev/$ {device} 1 c $major 1 mknod /dev/$ {device} 2 ... Allocation of Major Numbers Some major device numbers are statically assigned to the most common devices. A list of those devices can be found in Documentation/devices.txt within the kernel source ... “methods,” using object-oriented programming terminology to denote actions declared by an object to act on itself. This is the first sign of object-oriented programming we see in the Linux kernel,

Ngày tải lên: 09/08/2014, 04:21

... read/write permission on the device, ... to write fully featured char device drivers We start with implementing the ioctl system call, which is a common interface used for device control Then we ... Chapter 9 ioctl Most drivers need—in addition to the ability to read and write the device the ability to perform various types of hardware control via the device driver Most devices can perform ... scull_nr_devs; i++) { scull_devices[i].quantum = scull_quantum; scull_devices[i].qset = scull_qset; init_MUTEX(&scull_devices[i].sem); scull_setup_cdev(&scull_devices[i], i); } Note that

Ngày tải lên: 09/08/2014, 04:21

... the same device) is often best solved by implementing one device node for each access policy. An example of this practice can be found in the Linux tape driver, which provides multi- ple device ... same device. Different device files will, for example, cause the drive to record with or without compression, or to automatically rewind the tape when the device is closed. Cloning the Device ... /dev/scullpriv device node implements virtual devices within the scull package. The scullpriv implementation uses the device number of the process’s controlling tty as a key to access the virtual device.

Ngày tải lên: 09/08/2014, 04:21

... struct pci _device_ id structure: PCI _DEVICE( vendor, device) This creates a struct pci _device_ id that matches only the specific vendor and device ID. The macro sets the subvendor and subdevice fields ... PCI_ANY_ID. PCI _DEVICE_ CLASS (device_ class, device_ class_mask) This creates a struct pci _device_ id that matches a specific PCI class. An example of using these macros to define the type of devices a ... reserved. The PCI Interface | 311 static struct pci _device_ id i810_ids[ ] = { { PCI _DEVICE( PCI_VENDOR_ID_INTEL, PCI _DEVICE_ ID_INTEL_82810_IG1) }, { PCI _DEVICE( PCI_VENDOR_ID_INTEL, PCI _DEVICE_ ID_INTEL_82810_IG3)

Ngày tải lên: 09/08/2014, 04:21

... struct kset drivers; struct kset devices;... pair of functions: int device_ create_file(struct device *device, struct device_ attribute *entry); void device_ remove_file(struct device *dev, ... information that the device model core needs... driver creates its own device type (struct ldd _device) and expects individual device drivers to register their devices using that type It ... provide an actual name for the device (which can be distinct... class _device *cd); void class _device_ unregister(struct class _device *cd); The class device interface also allows the renaming

Ngày tải lên: 09/08/2014, 04:21

... 2005 11:04 AM [...]... struct device This structure is the low-level representation of a device within the Linux device model It is not something that drivers often have to work with ... Chapter 16 Block Drivers So far, our discussion has been limited to char drivers There are other types of drivers in Linux. .. Accordingly, this chapter discusses block drivers A block ... spinlock, called dma_spin_lock Drivers. .. sbull driver Registration Block drivers, like char drivers, must use a set of registration interfaces to make their devices available to the kernel

Ngày tải lên: 09/08/2014, 04:21

... structure for each newly detected interface into a global list of network devices. Each interface is described by a struct net _device item, which is defined in < ;linux/ netdevice.h>. The snull driver ... of interfaces. The most common is alloc_etherdev, which is defined in < ;linux/ etherdevice.h>: struct net _device *alloc_etherdev(int sizeof_priv); This function allocates a network device using ... for fiber-channel devices, alloc_fddidev (< ;linux/ fddidevice.h>) for FDDI devices, or alloc_trdev (< ;linux/ trdevice.h>) for token ring devices. snull could use alloc_etherdev without

Ngày tải lên: 09/08/2014, 04:21

... numbering, 10 Linux device model, 362–364 buses, 377–381 classes, 387–391 devices,... (net _device structure), 506 char *name variable (USB), 352 character drivers (see char drivers) chars_in_buffer ... class register (PCI), 309 classes devices, 5, 362, 390 functions, 410 interfaces, 391 Linux device. .. critical sections, 109 DMA controllers, 456–459 drivers, 35–37 ether_setup function, ... Friday, January 21, 2005 11:14 AM [...]... kernels, 10 device attribute (firmware), 407 DEVICE variable, 402 deviceID register (PCI), 309 devices access to files, 173–179 adding, 392–395 allocation

Ngày tải lên: 09/08/2014, 04:21

... an interface, that is, a device that is able to exchange data with other hosts. Usually, an interface is a hardware device, but it might also be a pure software device, like the loopback interface. ... independent of the devices attached to the SCSI cable. Other classes of device drivers have been added to the kernel in recent times, including USB drivers, FireWire drivers, and I2O drivers. In ... by Linux, somebody somewhere has written a driver to make it work with the system. Without device drivers, there is no functioning system. Device drivers take on a special role in the Linux...

Ngày tải lên: 24/12/2013, 01:17

... implementations. For example, the video-for -linux set of drivers is split into a generic module that exports symbols used by lower- level device drivers for specific hardware. According to your ... new device, it will be able to avoid probing those ports that are already in use by other drivers. ISA probing is in fact a risky task, and several drivers distributed with the official Linux ... concurrency in kernel programming. Naturally, Linux systems run multiple processes, more than one of which can be trying several versions of modutils returned a " ;Device busy" message...

Ngày tải lên: 24/12/2013, 01:17

... "methods," using object-oriented programming terminology to denote actions declared by an object to act on itself. This is the first sign of object-oriented programming we see in the Linux kernel, ... information from /proc/devices in order to create the files in /dev. the provided interface. In scull, one semaphore is allocated for each device, in the Scull_Dev structure. Since the devices are entirely ... of setting up the devices. for (i=0; i < scull_nr_devs; i++) { scull_devices[i].quantum = scull_quantum; scull_devices[i].qset = scull_qset; sema_init(&scull_devices[i].sem, 1);...

Ngày tải lên: 24/12/2013, 01:17

... /proc is heavily used in the Linux system. Many utilities on a modern Linux distribution, such as ps, top, and uptime, get their information from /proc. Some device drivers also export information ... } exit(0); } setconsole uses the special ioctl command TIOCLINUX, which implements Linux- specific functions. To use TIOCLINUX, you pass it an argument that is a pointer to a byte array. ... the /procfilesystem and using the ioctl driver method. You may use devfs as an alternative to /proc, but /proc is an easier tool to use for information retrieval. Using the /proc Filesystem...

Ngày tải lên: 24/12/2013, 01:17