UM0851 Datasheet, PDF (197/245 Pages) STMicroelectronics – SPEAr is a family of highly customizable ARM-based embedded

UM0851
Audio/video drivers
Note:
8.1.6
fbfd = open("/dev/fb0", O_RDWR);
/* Open the file for reading and
writing */
ioctl(fbfd, FBIOGET_FSCREENINFO, &finfo) /* Get fixed screen information */
ioctl(fbfd, FBIOGET_VSCREENINFO, &vinfo) /* Get variable screen information */
vinfo.activate |= FB_ACTIVATE_FORCE | FB_ACTIVATE_NOW;
ioctl(fbfd, FBIOPUT_VSCREENINFO, &vinfo) /* Put variable screen information to
Switch ON CLCD Panel */
screensize = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8; /* Figure out the
size of the screen in bytes */
/* Map the device to memory */
fbp = (char *)mmap( 0, screensize, PROT_READ | PROT_WRITE, MAP_SHARED, fbfd, 0 );
/*Loop will draw 3 color bands: blue, green and red */
for ( location = 0, y = 0; y < vinfo.yres; y++ )
for ( x = 0; x < vinfo.xres; x++ ) {
if ( y < (vinfo.yres/3) )
{
*(fbp + location) = 0xFF;/*show Blue */
*(fbp + location+1) = 0; /*no Green*/
*(fbp + location+2) = 0; /*no Red */
*(fbp + location+3) = 0; /*No Transparency */
}
else if ( y < (2*vinfo.yres/3) )
{
*(fbp + location) = 0xFF;/* no Blue */
*(fbp + location + 1) = 0;/* show Green */
*(fbp + location + 2) = 0;/* no Red */
*(fbp + location + 3) = 0;/* No transparency */
}
else {
*(fbp + location) = 0;/* no Blue */
*(fbp + location + 1) = 0; /* no Green */
*(fbp + location + 2) = 0xFF;/* show Red */
*(fbp + location + 3) = 0;/* No transparency */
}
location +=4;
}
The CLCD controller is connected to DDR through port of MPMC (DDR controller). The
priority of the MPMC ports can be tuned by Xloader. A low proirity for port of CLCD can
cause a slow performance hence resulting in flickering on the CLCD panel. Therefore,
currently Xloader sets the highest priority for the CLCD port.
Kernel configuration options
Table 51. CLCD configuration options
Configuration option
CONFIG_FB
CONFIG_FB_ARMCLCD
CONFIG_FB_ARMCLCD_SAMSUNG_LMS700
CONFIG_FB_ARMCLCD_SHARP_LQ043T1DG01
CONFIG_FB_CFB_FILLRECT
Comment
This option is used to enable the framebuffer
Driver support
This framebuffer device driver is for the ARM
PrimeCell PL110 Colour LCD controller.
This option selects the Samsung 7" panel.
This option selects the Sharp 4.3" panel.
This option includes the cfb_fillrect function
for generic software rectangle filling.
Doc ID 16604 Rev 2
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