/*********************************************************************************
 *      Copyright:  (C) 2021 Guo Wenxue<Email:guowenxue@gmail.com QQ:281143292>
 *                  All rights reserved.
 *
 *       Filename:  test_key.c
 *    Description:  This file used to test GPIO button driver builtin Linux kernel on ARM board
 *                 
 *        Version:  1.0.0(11/17/2021~)
 *         Author:  Guo Wenxue <guowenxue@gmail.com>
 *      ChangeLog:  1, Release initial version on "11/17/2021 02:46:18 PM"
 *                 
 *     Linux Clear LCD screen command : 
 *
 *                  dd if=/dev/zero of=/dev/fb0 bs=320 count=720  [ 240*(24bpp/8)=720 ] 
 *
 ********************************************************************************/
 
#include <unistd.h>  
#include <stdio.h>  
#include <fcntl.h>  
#include <linux/fb.h>  
#include <sys/mman.h>  
#include <stdlib.h>  
#include <string.h>
#include <sys/ioctl.h>


#define CONFIG_RGB565

#ifdef  CONFIG_RGB565  /* RRRR RGGG GGGB BBBB  */
#define RED       0xF800
#define GREEN     0x07E0
#define BLUE      0x001F
#define YELLOW    0xFFE0
#define WHITE     0xFFFF 
#endif


void fill_color16(short *fb_addr, short bit_map, int psize)
{
    int i;
    for(i=0; i<psize; i++) {
        *fb_addr = bit_map;
        fb_addr++;
    }
}

int main ()   
{  
    int fp=0;  
    struct fb_var_screeninfo vinfo;  
    struct fb_fix_screeninfo finfo;  
    long screensize=0;  
    char *fbp = NULL, *test_fbp=NULL;    
    int x = 0, y = 0;  
    long location = 0;
    int i;
    int num = 5;
    int pix_size=0;

    fp = open("/dev/fb0", O_RDWR);  

    if(fp < 0) {  
        printf("Error : Can not open framebuffer device/n");  
        exit(1);  
    }  

    if(ioctl(fp, FBIOGET_FSCREENINFO, &finfo)){  
        printf("Error reading fixed information/n");  
        exit(2);  
    }  

    if(ioctl(fp, FBIOGET_VSCREENINFO, &vinfo)){  
        printf("Error reading variable information/n");  
        exit(3);  
    }  

    screensize = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8;  

    printf("The phy mem = 0x%x, total size = %d(byte)\n", finfo.smem_start, finfo.smem_len);  
    printf("xres =  %d, yres =  %d, bits_per_pixel = %d\n", vinfo.xres, vinfo.yres, vinfo.bits_per_pixel);  
    printf("So the screensize = %d(byte), using %d frame\n", screensize, finfo.smem_len/screensize);
    printf("vinfo.xoffset = %d, vinfo.yoffset = %d\n", vinfo.xoffset, vinfo.yoffset);  
    printf("vinfo.vmode is :%d\n", vinfo.vmode);  
    printf("finfo.ypanstep is :%d\n", finfo.ypanstep);  
    printf("vinfo.red.offset=0x%x\n", vinfo.red.offset);
    printf("vinfo.red.length=0x%x\n", vinfo.red.length);
    printf("vinfo.green.offset=0x%x\n", vinfo.green.offset);
    printf("vinfo.green.length=0x%x\n", vinfo.green.length);
    printf("vinfo.blue.offset=0x%x\n", vinfo.blue.offset);
    printf("vinfo.blue.length=0x%x\n", vinfo.blue.length);
    printf("vinfo.transp.offset=0x%x\n", vinfo.transp.offset);
    printf("vinfo.transp.length=0x%x\n", vinfo.transp.length);
    

    fbp =(char *)mmap(0, screensize, PROT_READ | PROT_WRITE, MAP_SHARED, fp,0);  
    if ((int)fbp == -1)  
    {    
        printf ("Error: failed to map framebuffer device to memory./n");  
        exit (4);  
    }
    printf("Get virt mem = %p\n", fbp);  


    pix_size = vinfo.xres * vinfo.yres;
    /* using first frame, for FBIOPAN_DISPLAY
     * 当刷新需要调用FBIOPAN_DISPLAY， 要告知驱动刷哪块帧， 用到下面两个参数
     * 如果使用第二帧buffer -> vinfo.xoffset = 0; vinfo.yoffset = vinfo.yres;
     */
    vinfo.xoffset = 0;
    vinfo.yoffset = 0;

    /* show color loop */
    while(num--) {
        printf("\ndrawing red ...\n");
        fill_color16((short *)fbp, RED, pix_size);
        //ioctl(fp, FBIOPAN_DISPLAY, &vinfo);
        sleep(3);

        printf("\ndrawing green ...\n");
        fill_color16((short *)fbp, GREEN, pix_size);
        //ioctl(fp, FBIOPAN_DISPLAY, &vinfo);
        sleep(3);

        printf("\ndrawing blue ...\n");
        fill_color16((short *)fbp, BLUE, pix_size);
        //ioctl(fp, FBIOPAN_DISPLAY, &vinfo);
        sleep(3);
        
        printf("\ndrawing yellow ...\n");
        fill_color16((short *)fbp, YELLOW, pix_size);
        //ioctl(fp, FBIOPAN_DISPLAY, &vinfo);
        sleep(3);

    }
#if 1
    /*这是你想画的点的位置坐标,(0，0)点在屏幕左上角*/    
    x = 10;  
    y = 10;  
    location = x * (vinfo.bits_per_pixel / 8) + y  *  finfo.line_length;  
    test_fbp = fbp + location;
    printf("draw line.......\n");
    for(i = 0; i < (vinfo.xres - x); i++)
        *test_fbp++ = i+30;

    //ioctl(fp, FBIOPAN_DISPLAY, &vinfo);
#endif

    munmap(fbp, screensize); /*解除映射*/  

    close (fp);
    return 0;
}