init_osd1.c

TI dm6446 video subsytem window blending programme

/*
 * osd1: the attribute window
 *
 */

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

#include "davinci_fb.h"

/******************************************************************************
 * setOsdTransparency
 ******************************************************************************/
#define TRANS_ALL  ((char)0x77)
#define TRANS_NONE ((char)0x0)

#ifdef SVIDEO_OUTPUT
# define IMAGE_REGION_X0 0
# define IMAGE_REGION_Y0 0
# define IMAGE_REGION_XL 720
# define IMAGE_REGION_YH 480
#else
# define IMAGE_REGION_X0 0
# define IMAGE_REGION_Y0 0
# define IMAGE_REGION_XL 800
# define IMAGE_REGION_YH 600
#endif

#define IMAGE_REGION_TRANS     TRANS_NONE
#define NONIMAGE_REGION_TRANS  TRANS_ALL

void setTransBuffer(unsigned char *buf, unsigned int xres, unsigned int yres)
{
	int i, j;
	unsigned int bufsize = xres * yres / 2;
	unsigned int imagesize;

	unsigned char *imageshadow;
	unsigned int x0, y0, xl, yh;

	x0 = IMAGE_REGION_X0;
	y0 = IMAGE_REGION_Y0;
	xl = IMAGE_REGION_XL;
	yh = IMAGE_REGION_YH;

	DBG("xres: %d, yres:%d\n", xres, yres);
	memset(buf, NONIMAGE_REGION_TRANS, bufsize);

	imagesize = xl * yh / 2;
	imageshadow = malloc(imagesize);

	memset(imageshadow, IMAGE_REGION_TRANS, imagesize);
	{
		unsigned char * pi, * po;
		unsigned int image_startx = (y0 * xres + x0) / 2, imagelinelen = xl / 2;
		unsigned int screenlinelen = xres / 2;

		pi = imageshadow;
		po = buf + image_startx;

		for(i = 0; i < yh; i++)
		{
			//DBG("0x%x -> 0x%x, len=%d\n", pi - imageshadow, po - buf, imagelinelen);
			memcpy(po, pi, imagelinelen);

			pi += imagelinelen;
			po += screenlinelen;
		}
	}
}

static int setOsdTransparency(int on)
{
    struct fb_var_screeninfo vInfo;
    unsigned short          *attrDisplay;
    int                      attrSize;
    int                      fd;

    fd = open(ATTR_DEVICE, O_RDWR);

    if (fd == -1) {
        ERR("Failed to open attribute window %s\n", ATTR_DEVICE);
        return FAILURE;
    }
	DBG("Open device %s OK.\n", ATTR_DEVICE);

    if (ioctl(fd, FBIOGET_VSCREENINFO, &vInfo) == -1) {
        ERR("Error reading variable information.\n");
        return FAILURE;
    }

    /* One nibble per pixel */
    attrSize = vInfo.xres_virtual * vInfo.yres / 2; 

    attrDisplay = (unsigned short *) mmap(NULL, attrSize,
                                          PROT_READ | PROT_WRITE,
                                          MAP_SHARED, fd, 0);
    if (attrDisplay == MAP_FAILED) {
        ERR("Failed mmap on %s\n", ATTR_DEVICE);
        return FAILURE;
    }

    /* Fill the window with the new attribute value */
    if(on == 0)
    {
		memset(attrDisplay, TRANS_ALL, attrSize);
	}
	else
	{
		setTransBuffer(attrDisplay, vInfo.xres_virtual, vInfo.yres);
	}

    munmap(attrDisplay, attrSize);
    close(fd);

    return SUCCESS;
}

int init_osd1(int on)
{
	return setOsdTransparency(on);
}