How to Change resolution of drawing device?

[rakeshmanad]

I'm using IMX6Q board(android R13.3) with ICS 4.0.4 .

In which API resolution of drawing device is set ?

While drawing something on screen which API is responsible for managing resolution and location of different surfaces ? For example assume a app needs both a 2D and a 3D surface.which API is responsible to set location of these surfaces on screen and resolution of these two surfaces ?

And also xres and yres values ,which are used in framebuffer.cpp .Where their values get assigned ?

I know that android HAL layer(gralloc.cpp,framebuffer.cpp) call IOCTLs to get frame buffer data from display driver(Framebuffer driver).But I'm not finding in which API  framebuffer data will be collected?(I mean where the members of structure fb_var_screeninfo i.e xres,yres etc will get assigned with some values)

[jeffreychen · Accepted solution]

I happen to have the same problem as you (My board is MX6Q SABRESD, and use the LVDS interface for LCD), after reviewing the code, I find there is a variable in ldb.c like:

static struct fb_videomode ldb_modedb[] = {

{

  "LDB-XGA", 60, 800, 480, 15385,//"LDB-XGA", 60, 1024, 768, 15385,

  220, 40,

  21, 7,

  60, 10,

  0,

  FB_VMODE_NONINTERLACED,

  FB_MODE_IS_DETAILED,},

{

  "LDB-1080P60", 60, 1920, 1080, 7692,

  100, 40,

  30, 3,

  10, 2,

  0,

  FB_VMODE_NONINTERLACED,

  FB_MODE_IS_DETAILED,},

};

It takes effect by following steps:

mxcfb_init()->mxcfb_dispdrv_init()->ldb_disp_init():

/* must use spec video mode defined by driver */

ret = fb_find_mode(&setting->fbi->var, setting->fbi, setting->dft_mode_str,

    ldb_modedb, ldb_modedb_sz, NULL, setting->default_bpp);

if (ret != 1)

  fb_videomode_to_var(&setting->fbi->var, &ldb_modedb[0]);

Hope this information is helpful for you.

[jimmychan]

We have documents for i.MX6Q API is about 2D and VPU. Please download the document bundle.

• Linux Bundle for i.MX 6Quad/Dual

Hope this can help you.