ALPHA 开发板屏幕显示红绿蓝颜色的问题

wang12zhe · 发表于 2022-8-25 15:00:11

本帖最后由 wang12zhe 于 2022-8-25 15:05 编辑

用出厂自带的程序
想用LCD屏幕做一个显示红绿蓝三原色的例子，但我得的屏幕上显示的颜色明显不正确，还请帮忙查找问题，非常感谢

#include<stdio.h>
#include<stdlib.h>
#include<math.h>
#include<string.h>
#include<unistd.h>
#include<fcntl.h>
#include<sys/mman.h>
#include<sys/ioctl.h>
#include<linux/fb.h>

typedef struct {
int fd;
long size;
unsigned char *fbp;
struct fb_var_screeninfo vinfo;
struct fb_fix_screeninfo finfo;
}fbdev;

//画点函数
void draw_dot2(fbdev dev, int x, int y,unsigned int dwColor){
int xres=dev.vinfo.xres;
int yres=dev.vinfo.yres;
int bpp=dev.vinfo.bits_per_pixel;
long offset=(y*xres+x);
int color = 0;
int iRed;
int iGreen;
int iBlue;

unsigned short wColor16bpp; /* 565 */
iRed = (dwColor >> (16+3)) & 0x1f;
iGreen = (dwColor >> (8+2)) & 0x3f;
iBlue  = (dwColor >> 3) & 0x1f;
wColor16bpp = (iRed << 11) | (iGreen << 5) | iBlue;
//wColor16bpp = 0X8010;
*(dev.fbp+offset)=wColor16bpp | 0xFF; //设置颜色，默认为白色
*(dev.fbp+offset + 1 )=wColor16bpp >> 8; //设置颜色，默认为白色

}

int main(){
fbdev dev;
dev.fd=open("/dev/fb0",O_RDWR);
unsigned int x=0;
unsigned int y=0;
ioctl(dev.fd,FBIOGET_VSCREENINFO,&dev.vinfo);
ioctl(dev.fd,FBIOGET_FSCREENINFO, &dev.finfo);

printf("vinfo.xres=%d\n",dev.vinfo.xres);
printf("vinfo.yres=%d\n",dev.vinfo.yres);
printf("vinfo.bits_per_bits=%d\n",dev.vinfo.bits_per_pixel);
printf("vinfo.xoffset=%d\n",dev.vinfo.xoffset);
printf("vinfo.yoffset=%d\n",dev.vinfo.yoffset);
printf("finfo.line_length=%d\n",dev.finfo.line_length);

dev.size=dev.vinfo.xres*dev.vinfo.yres*dev.vinfo.bits_per_pixel/8;

dev.fbp=(unsigned char*)mmap(0,dev.size,PROT_READ|PROT_WRITE,MAP_SHARED,dev.fd,0);
memset(dev.fbp,0,dev.size);
//红色
for(y=0;y<160;y ++){
      for(x=0;x<800;x++)
      draw_dot2(dev, x,y,0XFF0000);
}
//蓝色
for(;y<320;y ++){
      for(x=0;x<800;x++)
      draw_dot2(dev, x,y,0X00FF00);
}
//绿色
for(;y<480;y ++){
      for(x=0;x<800;x++)
      draw_dot2(dev, x,y,0X0000FF);
}

munmap(dev.fbp,dev.size);
close(dev.fd);
return 0;
}

wang12zhe · 发表于 2022-8-25 15:00:12

routedhust 发表于 2022-8-26 09:33
确定是565吗？我看设备树里怎么是24bit

&lcdif {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_lcdif_dat
      &pinctrl_lcdif_ctrl>;
display = <&display0>;
status = "okay";

      display0: display {
            bits-per-pixel = <16>;
            bus-width = <24>;

            display-timings {
                     native-mode = <&timing0>;
                     timing0: timing0 {
                     clock-frequency = <35500000>;
                     hactive = <800>;
                     vactive = <480>;
                     hfront-porch = <210>;
                     hback-porch = <46>;
                     hsync-len = <20>;
                     vback-porch = <23>;
                     vfront-porch = <22>;
                     vsync-len = <3>;

                     hsync-active = <0>;
                     vsync-active = <0>;
                     de-active = <1>;
/* rgb to hdmi: pixelclk-ative should be set to 1 */
                     pixelclk-active = <0>;
                     };
            };
      };
};