电子书需要通过屏幕显示出来，首先写了LCD模块。代码上传到了 github https://github.com/qq2216691777/E-book
本次完善了lcd模块的程序。可以适用在其他地方。
代码：fb.c fb.h
#include <sys/types.h> #include <sys/stat.h> #include <sys/mman.h> #include <fcntl.h> #include <linux/fb.h> #include <stdlib.h> #include "fb.h" #include "main.h" static int Device_FB_Init(void); static void lcd_put_pixel(int x, int y, unsigned int color ); static void lcd_clean( unsigned int color ); static void Device_FB_Destory(void); fb_t g_fb={ 0, 0, 0, 0, 0, 0, NULL, &Device_FB_Init, &lcd_put_pixel, &lcd_clean, &Device_FB_Destory, }; static void lcd_put_pixel(int x, int y, unsigned int color ) { unsigned char *pen_8 = g_fb.fbmem + y*g_fb.xres*g_fb.pixel_chars+x*g_fb.pixel_chars; unsigned short *pen_16 = (unsigned short *)pen_8; unsigned short *pen_32 = (unsigned short *)pen_8; unsigned char red,blue,green; switch(g_fb.pixel_bits) { case 8: *pen_8 = color; break; case 16: /* 565 */ red = (color>>16) & 0xff; green = (color>>8) & 0xff; blue = (color>>0) & 0xff; color = ((red>>3)<<11) | ((green>>2)<<5) |((blue>>3)); *pen_16 = color; break; case 32: *pen_32 = color; break; default: DEBUG_PRINT("ERROR: can't support %ddpp ",g_fb.pixel_bits); break; } } static void lcd_clean( unsigned int color ) { unsigned char *pen_8 = g_fb.fbmem; unsigned short *pen_16 = (unsigned short *)pen_8; unsigned short *pen_32 = (unsigned short *)pen_8; unsigned char red,blue,green; int i = g_fb.screen_size; switch(g_fb.pixel_bits) { case 8: break; case 16: /* 565 */ red = (color>>16) & 0xff; green = (color>>8) & 0xff; blue = (color>>0) & 0xff; color = ((red>>3)<<11) | ((green>>2)<<5) |((blue>>3)); break; case 32: break; default: DEBUG_PRINT("ERROR: can't support %ddpp ",g_fb.pixel_bits); return; } while(i) { switch(g_fb.pixel_bits) { case 8: *pen_8 = color; pen_8++; i--; break; case 16: *pen_16 = color; pen_16++; i-=2; break; case 32: *pen_32 = color; pen_32++; i-=4; break; } } } static int Device_FB_Init(void) { int fb_fd; struct fb_fix_screeninfo fix; struct fb_var_screeninfo var; fb_fd = open(DEVICE_NAME, O_RDWR); if (fb_fd<0) { DEBUG_PRINT("open device fb failed "); return -1; } if( ioctl( fb_fd, FBIOGET_VSCREENINFO, &var ) ) { DEBUG_PRINT("can't get var "); return -1; } if( ioctl( fb_fd, FBIOGET_FSCREENINFO, &fix ) ) { DEBUG_PRINT("can't get fix "); return -1; } g_fb.fd = fb_fd; g_fb.xres = var.xres; g_fb.yres = var.yres; g_fb.pixel_bits = var.bits_per_pixel; g_fb.pixel_chars = var.bits_per_pixel/8; g_fb.screen_size = var.xres*var.yres*var.bits_per_pixel/8; g_fb.fbmem = (unsigned char *)mmap( NULL, g_fb.screen_size, PROT_READ | PROT_WRITE, MAP_SHARED,fb_fd,0 ); printf("xres:%d ", g_fb.xres); printf("yres:%d ", g_fb.yres); printf("pixel bit:%d ", g_fb.pixel_bits); printf("pixel char:%d ", g_fb.pixel_chars); return 0; } static void Device_FB_Destory(void) { free(g_fb.fbmem); }
#ifndef _FB_H__ #define _FB_H__ #define DEVICE_NAME "/dev/fb0" typedef struct { int fd; int xres; int yres; int pixel_bits; int pixel_chars; int screen_size; unsigned char *fbmem; void (*Devie_Init)(void); void (*put_pixel)(int x, int y, unsigned int color ); void (*cleanscreen)( unsigned int color ); void (*Devie_Destory)(void); }fb_t; extern fb_t g_fb; #endif