Linux Driver LCD Driver Learning Summary

This article is written in November 13, this is only a record of the knowledge that has been covered in this area, may be useful for some knowledge of the future

For the platform bus model, you can refer to a previous article on the Linux driver platform bus model, which may be helpful for framebuffer driver registration

First, the LCD hardware framework

Second, LCD software framework

Third, LCD initialization process

Four, the LCD on and off process

Five, LCD data flow

VI. Driver Framebuffer

Location file

/android/kernel/drivers/video/fbmem.c

/android/kernel/drivers/video/msm/msm_fb.c

Frame buffering (framebuffer) is an interface provided by the Linux system to the thread device, which shows the buffer abstraction, shielding the underlying differences of the image hardware, and the upper application can read and write directly to the framebuffer.

Calling Register_framebuffer (struct Fb_info *fb_info) can register framebuffer, and registering framebuffer actually puts fb_info into a global array, To the back of the time will be in the array to fetch relevant information

There are more important fb_info in structural body

①struct fb_var_screeninfo Var, recording user-modifiable display controller parameters

Color bit domain struct Fb_bitfield in fb_var_screeninfo structure

②struct Fb_fix_screeninfo fix, record the user cannot modify the display controller parameters, such as physical address, length

Seven, driver Mipi_dsi

Location file/android/kernel/drivers/video/msm/mipi_dis.c

Viii. Driver MDP

Location file/android/kernel/drivers/video/msm/mdp.c

Nine, driver hx8369

Location file

/android/kernel/drivers/video/msm/mipi_hx8369b_video_wvga_pt.c

/android/kernel/drivers/video/msm/mipi_hx8369b.c

X. Driver board-level files

Location file/android/kernel/arch/arm/mach-msm/board-msm7627a-display.c

Finally, it's hard.

Linux Driver LCD Driver Learning Summary