6th. Android Driver Programming

6th. Android Driver Programming

By introducing this chapter device driver, character device driver programming,GPIODriver Instances and4*4scanning keyboard drivers and other content, master theAndroidDrive programming. AndroidKernel kernel module programming includes device drivers and kernel modules, module-related commands,AndroidKernel kernel module programming and kernel module instance program. AndroidThe kernel uses a loadable modular design that is typically compiledAndroidThe kernel supports pluggable modules, that is, the most basic core code is compiled into the kernel. In the module-related commandsLsmodlists the modules that are loaded in the current system .Rmmoodfor the current module uninstallation,Insmodand themodprobeused to load the current module. Androidkernel module loading functions are typically_initThe identity declaration, a typical module load function, is as follows:

static int _init initialization_function (void)

{

/* Initialize code * /

}

Module_init (initialization_function);

After the device has completed a registration load in character device driver programming, the application can perform certain operations on the device, such as open (), read (), write ," and so on, and the driver is used to implement these operations, when the application calls the corresponding entry function. In android kernel drivers that involve Span style= "FONT-FAMILY:CALIBRI;" >3 file_ Operation file and inode

LCD Display According to the principle is divided into STN and TFT two kinds. the STN LCD Displays a color filter and divides each pixel in a monochrome display matrix into 3 sub-pixels, displaying red, green, and blue primary colors, respectively, through a color filter. TFT color LCD screen, with the continuous development and progress of LCD display technology,TFT LCD screen is widely used in the production of computer LCD display equipment. Finally, interrupt programming is introduced, and the complete key driver is written as an example. Through this chapter effectively mastered the Android Drive programming, the harvest is very big.

6th. Android Driver Programming