GDISP framebuffer driver + an implementation for the linux kernel framebuffer device

1 files changed, 217 insertions, 0 deletions

diff --git a/boards/base/Linux-Framebuffer/board_framebuffer.h b/boards/base/Linux-Framebuffer/board_framebuffer.h
new file mode 100644
index 00000000..71e00937
--- /dev/null
+++ b/boards/base/Linux-Framebuffer/board_framebuffer.h
@@ -0,0 +1,217 @@
+/*
+ * This file is subject to the terms of the GFX License. If a copy of
+ * the license was not distributed with this file, you can obtain one at:
+ *
+ *              http://ugfx.org/license.html
+ */
+
+// Set this to your frame buffer pixel format. Note Linux frame buffer only supports RGB modes (no BGR modes).
+#ifndef GDISP_LLD_PIXELFORMAT
+	#define GDISP_LLD_PIXELFORMAT		GDISP_PIXELFORMAT_RGB565
+#endif
+
+#ifdef GDISP_DRIVER_VMT
+
+	#define FBDEV_PATH1		"/dev/fb0"
+	#define FBDEV_PATH2		"/dev/fb/0"			// Optional - comment this out to only try the one device
+	#define USE_SET_MODE						// Optional - comment this out to not to try to set the color mode we want
+	//#define VTDEV_PATH	"/dev/tty0"			// Optional - if defined use this tty to switch from text to graphics mode
+
+	#define _GNU_SOURCE 1
+	#include <fcntl.h>
+	#include <limits.h>
+	#include <linux/fb.h>
+	#include <linux/kd.h>
+	#include <linux/vt.h>
+	#include <stdarg.h>
+	#include <stdio.h>
+	#include <stdlib.h>
+	#include <string.h>
+	#include <sys/ioctl.h>
+	#include <sys/mman.h>
+	#include <sys/stat.h>
+	#include <sys/time.h>
+	#include <sys/types.h>
+	#include <unistd.h>
+
+	#if VTDEV_PATH
+		static void board_revert2textmode(void) {
+			int tty;
+
+			// Go back to text mode
+			if ((tty = open(VTDEV_PATH, O_RDWR)) >= 0) {
+				ioctl(tty, KDSETMODE, KD_TEXT);
+				close(tty);
+			}
+		}
+		static void board_switch2graphicsmode(void) {
+			int tty;
+
+			// Open the tty
+			if ((tty = open (VTDEV_PATH, O_RDWR)) < 0) {
+				fprintf(stderr, "GDISP Framebuffer: Cannot open tty %s\n", VTDEV_PATH);
+				exit(-1);
+			}
+			if (ioctl (tty, KDSETMODE, KD_GRAPHICS) == -1) {
+				fprintf(stderr, "GDISP Framebuffer: Cannot set to graphics mode\n");
+				exit(-1);
+			}
+			close(tty);
+
+			// Make sure we clean up properly
+			atexit(board_revert2textmode)
+		}
+	#endif
+
+	static void board_init(GDisplay *g, fbInfo *fbi) {
+		int							fb;
+		char *						env;
+		size_t						fblen;
+		struct fb_fix_screeninfo	fb_fix;
+		struct fb_var_screeninfo	fb_var;
+
+		// Open the frame buffer device
+		if((env = getenv("FRAMEBUFFER")) != 0)
+			fb = open(env, O_RDWR);
+		else {
+			fb = open(FBDEV_PATH1, O_RDWR);
+			#ifdef FBDEV_PATH2
+				if (fb < 0) fb = open(FBDEV_PATH2, O_RDWR);
+			#endif
+		}
+		if(fb < 0) {
+			fprintf(stderr, "GDISP Framebuffer: Error opening the framebuffer device\n");
+			exit(-1);
+		}
+
+		// Get screen info
+		if (ioctl(fb, FBIOGET_FSCREENINFO, &fb_fix) == -1 || ioctl(fb, FBIOGET_VSCREENINFO, &fb_var) == -1) {
+			fprintf(stderr, "GDISP Framebuffer: Error getting screen info\n");
+			exit(-1);
+		}
+
+		#ifdef USE_SET_MODE
+			info.reserved[0] = 0;
+			fb_var.reserved[1] = 0;
+			fb_var.reserved[2] = 0;
+			fb_var.xoffset = 0;
+			fb_var.yoffset = 0;
+			fb_var.bits_per_pixel = LLDCOLOR_BITS;
+			fb_var.activate = FB_ACTIVATE_NOW;
+			if (ioctl(fb, FBIOPUT_VSCREENINFO, &fb_var) == -1 || ioctl (fb, FBIOGET_VSCREENINFO, &fb_var) == -1) {
+				fprintf(stderr, "GDISP Framebuffer: Failed to set video mode\n");
+				exit(-1);
+			}
+		#endif
+
+		// Check things are as they should be
+		if (fb_fix.type != FB_TYPE_PACKED_PIXELS) {
+			fprintf(stderr, "GDISP Framebuffer: The display is not in a single plane graphics mode\n");
+			exit(-1);
+		}
+		if (fb_fix.visual != FB_VISUAL_TRUECOLOR) {
+			fprintf(stderr, "GDISP Framebuffer: The display is not in TRUECOLOR mode\n");
+			exit(-1);
+		}
+		if (fb_var.bits_per_pixel != LLDCOLOR_BITS) {
+			fprintf(stderr, "GDISP Framebuffer: The display is not %u bits per pixel\n", LLDCOLOR_BITS);
+			exit(-1);
+		}
+		if (fb_var.red.length != LLDCOLOR_BITS_R || fb_var.green.length != LLDCOLOR_BITS_G || fb_var.blue.length != LLDCOLOR_BITS_B) {
+			fprintf(stderr, "GDISP Framebuffer: The display pixel format is not %d%d%d\n", LLDCOLOR_BITS_R, LLDCOLOR_BITS_G, LLDCOLOR_BITS_B);
+			exit(-1);
+		}
+		if (fb_var.red.offset != LLDCOLOR_SHIFT_R || fb_var.green.offset != LLDCOLOR_SHIFT_G || fb_var.blue.offset != LLDCOLOR_SHIFT_B) {
+			#if LLDCOLOR_SHIFT_B == 0
+				fprintf(stderr, "GDISP Framebuffer: THe display pixel format is not RGB\n");
+			#else
+				fprintf(stderr, "GDISP Framebuffer: The display pixel format is not BGR\n");
+			#endif
+			exit(-1);
+		}
+
+		// Ensure we are at the origin of the virtual display area
+		if (fb_var.xoffset || fb_var.yoffset) {
+			fb_var.xoffset = 0;
+			fb_var.yoffset = 0;
+			ioctl(fb, FBIOPAN_DISPLAY, &fb_var);
+		}
+
+		// Switch to graphics mode (if required)
+		#ifdef VTDEV_PATH
+			board_switch2graphicsmode();
+		#endif
+
+		// Calculate the frame buffer length
+		fblen = fb_var.yres * fb_fix.line_length;
+
+		// Different systems need mapping in slightly different ways - Yuck!
+		#ifdef ARCH_LINUX_SPARC
+			#define CG3_MMAP_OFFSET 0x4000000
+			#define CG6_RAM    		0x70016000
+			#define TCX_RAM8BIT		0x00000000
+			#define TCX_RAM24BIT	0x01000000
+			switch (fb_fix.accel) {
+			case FB_ACCEL_SUN_CGTHREE:
+				fbi->pixels = mmap(0, fblen, PROT_READ|PROT_WRITE, MAP_SHARED, fb, CG3_MMAP_OFFSET);
+				break;
+			case FB_ACCEL_SUN_CGSIX:
+				fbi->pixels = mmap(0, fblen, PROT_READ|PROT_WRITE, MAP_SHARED, fb, CG6_RAM);
+				break;
+			case FB_ACCEL_SUN_TCX:
+				fbi->pixels = mmap(0, fblen, PROT_READ|PROT_WRITE, MAP_SHARED, fb, TCX_RAM24BIT);
+				break;
+			default:
+				fprintf(stderr, "GDISP Framebuffer: Don't know how to mmap with accel %d\n", fb_fix.accel);
+				exit(-1);
+			}
+		#elif defined(BLACKFIN)
+			fbi->pixels = mmap(0, fblen, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FILE, fb, 0);
+		#elif defined(__uClinux__)
+			fbi->pixels = mmap(0, fblen, PROT_READ|PROT_WRITE, 0, fb, 0);
+		#else
+			fbi->pixels = mmap(0, fblen, PROT_READ|PROT_WRITE, MAP_SHARED, fb, 0);
+		#endif
+		if(!fbi->pixels || fbi->pixels == (void *)-1) {
+			fprintf(stderr, "GDISP Framebuffer: mmap of display buffer failed\n");
+			exit(-1);
+		}
+
+		// If this program gets children they should not inherit this file descriptor
+		fcntl(fb, F_SETFD, FD_CLOEXEC);
+
+		// We are finished with the file descriptor
+		close(fb);
+
+		// Set the rest of the details of the frame buffer
+		g->g.Width = fb_var.xres;
+		g->g.Height = fb_var.yres;
+		g->g.Backlight = 100;
+		g->g.Contrast = 50;
+		fbi->linelen = fb_fix.line_length;
+	}
+
+	#if GDISP_HARDWARE_FLUSH
+		static void board_flush(GDisplay *g) {
+			(void) g;
+		}
+	#endif
+
+	#if GDISP_NEED_CONTROL
+		static void board_backlight(GDisplay *g, uint8_t percent) {
+			(void) g;
+			(void) percent;
+		}
+
+		static void board_contrast(GDisplay *g, uint8_t percent) {
+			(void) g;
+			(void) percent;
+		}
+
+		static void board_power(GDisplay *g, powermode_t pwr) {
+			(void) g;
+			(void) pwr;
+		}
+	#endif
+
+#endif /* GDISP_LLD_BOARD_IMPLEMENTATION */