lumension device control

Control controls Release Date: 7/19/2004 | Renew Date: 7/19/2004 Chris Tacke, Windows Embedded MVP Applied Data Systems Apply to: Microsoft Windows CE. NET Smart Device Extensions for Microsoft Visual Studio. NET Summary: Learn how to create a custom control using Smart Device Extensions for Microsoft Visual Studio.

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.Linux device driversBlocking and non-blocking I/O in 3.Linux device driversExampl

semaphore to 0//common Operation Declare_mutex (Mount_sem);d Own (MOUNT_SEM); Get the semaphore ... critical section//Critical area ... up (MOUNT_SEM); Release semaphoreSemaphores are used to wake up only one execution unit when synchronizing, while the completion amount (completion) is used for synchronization to wake up all waiting execution units.　The choice of spin lock and mutual exclusion lock When a lock cannot be acquired, the cost of using semaphores is the process conte

) Defining a mutual exclusion lock struct Mutex Mymutex; (2) Initialize mutex lock Mutex_init (struct mutex *mymutex) (3) Obtaining a mutual exclusion lock void Mutex_lock (struct mutex mymutex;) Of course there are, void mutex_lock_interruptible (struct mutex mymutex;) and void Mutex_trylock (struct mutex mymutex;) (4) Releasing the mutex lock void Mutex_unlock (struct mutex Mymutex) Selection of 1.5.1, spin-lock and mutex (1) Spin lock in the absen

atomic variable, assigned a value of 1*/ Static intXxx_open (structInode *inode,structFile *Filp) { ... if(!atomic_dec_and_test (xxx_available))/*A test value of 0 returns true otherwise false*/{atomic_inc (xxx_available); return-Ebusy;/*has been opened*/ } ... return 0;/*Success*/ } Static intXxx_release (structInode *inode,structFile *Filp) {Atomic_inc (xxx_available);/*releasing the device*/ return 0; }Spin lockspin

, . put = My_control_put }; The IFACE field indicates the type of control, ALSA defines several types (snddrv_ctl_elem_iface_xxx), the common type is mixer, and of course you can define a card type that belongs to the global, or you can define a type that belongs to a class of devices. such as Hwdep,pcmrawmidi,timer, you need to indicate the device logic number of the card in the

, And reset controller?108. Memory controller?104? Controls the writing of data to and the reading of data from memory device?102. Power module?106? Provides power to memory device?102? Via power lines?112? And to memory controller?104? Via main power lines?114? And backup power lines?116. Reset controller?108? Controls the operations of memory controller?104? Via contr