pmaports/main/fbdebug/fbdebug.c

/*
Copyright (C) 2018 drebrez <drebrez@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

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

void usage(char *appname)
{
	printf("Usage: %s [-d DEV] [-i] [-c length] [-p] [-m mode] [-h]\n\
    -d  Framebuffer device (default /dev/fb0)\n\
    -i  Show fixed and variable screen info\n\
    -c  Show colormap values (length 0-256)\n\
    -p  Perform the panning of the display\n\
    -m  Set mode: 0 => Normal\n\
                  2 => Standby\n\
                  3 => Suspend\n\
                  4 => Off\n\
    -h  Show this help\n",
		appname);
}

void print_fix_screeninfo(struct fb_fix_screeninfo *scr_fix)
{
	// ref: https://elixir.bootlin.com/linux/latest/ident/fb_fix_screeninfo
	printf("Fixed screen info:\n");
	printf("\tid           = %s\n", scr_fix->id);
	printf("\tsmem_start   = %lu\n", scr_fix->smem_start);
	printf("\tsmem_len     = %u\n", scr_fix->smem_len);
	printf("\ttype         = %u\n", scr_fix->type);
	printf("\ttype_aux     = %u\n", scr_fix->type_aux);
	printf("\tvisual       = %u\n", scr_fix->visual);
	printf("\txpanstep     = %hu\n", scr_fix->xpanstep);
	printf("\typanstep     = %hu\n", scr_fix->ypanstep);
	printf("\tywrapstep    = %hu\n", scr_fix->ywrapstep);
	printf("\tline_length  = %u\n", scr_fix->line_length);
	printf("\tmmio_start   = %lu\n", scr_fix->mmio_start);
	printf("\tmmio_len     = %u\n", scr_fix->mmio_len);
	printf("\taccel        = %u\n", scr_fix->accel);
	printf("\tcapabilities = %hu\n", scr_fix->capabilities);
	printf("\treserved[0]  = %hu\n", scr_fix->reserved[0]);
	printf("\treserved[1]  = %hu\n", scr_fix->reserved[1]);
}

void print_var_screeninfo(struct fb_var_screeninfo *scr_var)
{
	// ref: https://elixir.bootlin.com/linux/latest/ident/fb_var_screeninfo
	printf("Variable screen info:\n");
	printf("\txres             = %u\n", scr_var->xres);
	printf("\tyres             = %u\n", scr_var->yres);
	printf("\txres_virtual     = %u\n", scr_var->xres_virtual);
	printf("\tyres_virtual     = %u\n", scr_var->yres_virtual);
	printf("\txoffset          = %u\n", scr_var->xoffset);
	printf("\tyoffset          = %u\n", scr_var->yoffset);
	printf("\tbits_per_pixel   = %u\n", scr_var->bits_per_pixel);
	printf("\tgrayscale        = %u\n", scr_var->grayscale);
	printf("\tred.offset       = %u\n", scr_var->red.offset);
	printf("\tred.length       = %u\n", scr_var->red.length);
	printf("\tred.msb_right    = %u\n", scr_var->red.msb_right);
	printf("\tgreen.offset     = %u\n", scr_var->green.offset);
	printf("\tgreen.length     = %u\n", scr_var->green.length);
	printf("\tgreen.msb_right  = %u\n", scr_var->green.msb_right);
	printf("\tblue.offset      = %u\n", scr_var->blue.offset);
	printf("\tblue.length      = %u\n", scr_var->blue.length);
	printf("\tblue.msb_right   = %u\n", scr_var->blue.msb_right);
	printf("\ttransp.offset    = %u\n", scr_var->transp.offset);
	printf("\ttransp.length    = %u\n", scr_var->transp.length);
	printf("\ttransp.msb_right = %u\n", scr_var->transp.msb_right);
	printf("\tnonstd           = %u\n", scr_var->nonstd);
	printf("\tactivate         = %u\n", scr_var->activate);
	printf("\theight           = %u\n", scr_var->height);
	printf("\twidth            = %u\n", scr_var->width);
	printf("\taccel_flags      = %u\n", scr_var->accel_flags);
	printf("\tpixclock         = %u\n", scr_var->pixclock);
	printf("\tleft_margin      = %u\n", scr_var->left_margin);
	printf("\tright_margin     = %u\n", scr_var->right_margin);
	printf("\tupper_margin     = %u\n", scr_var->upper_margin);
	printf("\tlower_margin     = %u\n", scr_var->lower_margin);
	printf("\thsync_len        = %u\n", scr_var->hsync_len);
	printf("\tvsync_len        = %u\n", scr_var->vsync_len);
	printf("\tsync             = %u\n", scr_var->sync);
	printf("\tvmode            = %u\n", scr_var->vmode);
	printf("\trotate           = %u\n", scr_var->rotate);
	printf("\tcolorspace       = %u\n", scr_var->colorspace);
	printf("\treserved[0]      = %u\n", scr_var->reserved[0]);
	printf("\treserved[1]      = %u\n", scr_var->reserved[1]);
	printf("\treserved[2]      = %u\n", scr_var->reserved[2]);
	printf("\treserved[3]      = %u\n", scr_var->reserved[3]);
}

void print_cmap(struct fb_cmap *scr_cmap)
{
	// ref: https://elixir.bootlin.com/linux/latest/ident/fb_cmap
	printf("Colormap:\n");
	printf("\tstart  = %u\n", scr_cmap->start);
	printf("\tlen    = %u\n", scr_cmap->len);
	printf("\tred    = ");
	for (int i = 0; i < scr_cmap->len; i++) {
		if (i > 0 && i % 8 == 0) {
			printf("\n\t\t ");
		}
		printf("0x%04hX ", scr_cmap->red[i]);
	}
	printf("\n");
	printf("\tgreen  = ");
	for (int i = 0; i < scr_cmap->len; i++) {
		if (i > 0 && i % 8 == 0) {
			printf("\n\t\t ");
		}
		printf("0x%04hX ", scr_cmap->green[i]);
	}
	printf("\n");
	printf("\tblue   = ");
	for (int i = 0; i < scr_cmap->len; i++) {
		if (i > 0 && i % 8 == 0) {
			printf("\n\t\t ");
		}
		printf("0x%04hX ", scr_cmap->blue[i]);
	}
	printf("\n");
	printf("\ttransp = ");
	for (int i = 0; i < scr_cmap->len; i++) {
		if (i > 0 && i % 8 == 0) {
			printf("\n\t\t ");
		}
		printf("0x%04hX ", scr_cmap->transp[i]);
	}
	printf("\n");
}

int main(int argc, char **argv)
{
	const char *fb_device;
	struct fb_fix_screeninfo scr_fix;
	struct fb_var_screeninfo scr_var;
	struct fb_cmap scr_cmap;
	int fb_fd;

	// parse command line options
	fb_device = "/dev/fb0";
	bool show_info = false;
	bool show_cmap = false;
	int cmap_len;
	bool pan_display = false;
	bool set_fbmode = false;
	int fbmode;

	if (argc < 2) {
		usage(argv[0]);
		exit(1);
	}
	int opt;
	while ((opt = getopt(argc, argv, "d:ic:pm:h")) != -1) {
		switch (opt) {
		case 'd':
			fb_device = optarg;
			break;
		case 'i':
			show_info = true;
			break;
		case 'c':
			show_cmap = true;
			cmap_len = atoi(optarg);
			break;
		case 'p':
			pan_display = true;
			break;
		case 'm':
			set_fbmode = true;
			fbmode = atoi(optarg);
			break;
		case 'h':
		default:
			usage(argv[0]);
			exit(1);
		}
	}

	// open the framebuffer device
	fb_fd = open(fb_device, O_RDWR);
	if (fb_fd < 0) {
		printf("Unable to open %s.\n", fb_device);
		return 1;
	}

	// call ioctl. retrieve fixed screen info
	if (ioctl(fb_fd, FBIOGET_FSCREENINFO, &scr_fix) < 0) {
		printf("Unable to retrieve fixed screen info: %s\n",
			strerror(errno));
		close(fb_fd);
		return 1;
	}

	// print all the fixed screen info values
	if (show_info)
		print_fix_screeninfo(&scr_fix);

	// call ioctl. retrieve variable screen info
	if (ioctl(fb_fd, FBIOGET_VSCREENINFO, &scr_var) < 0) {
		printf("Unable to retrieve variable screen info: %s\n",
			strerror(errno));
		close(fb_fd);
		return 1;
	}

	// print all the variable screen info values
	if (show_info)
		print_var_screeninfo(&scr_var);

	// call ioctl. retrieve colormap
	if (show_cmap) {
		scr_cmap.start = 0;
		scr_cmap.len = cmap_len;
		scr_cmap.red = calloc(256, sizeof(unsigned short));
		scr_cmap.green = calloc(256, sizeof(unsigned short));
		scr_cmap.blue = calloc(256, sizeof(unsigned short));
		scr_cmap.transp = calloc(256, sizeof(unsigned short));
		if (ioctl(fb_fd, FBIOGETCMAP, &scr_cmap) < 0) {
			printf("Unable to retrieve cmap info: %s\n",
				strerror(errno));
			free(scr_cmap.red);
			free(scr_cmap.green);
			free(scr_cmap.blue);
			free(scr_cmap.transp);
			close(fb_fd);
			return 1;
		}

		// print all the cmap values
		print_cmap(&scr_cmap);

		free(scr_cmap.red);
		free(scr_cmap.green);
		free(scr_cmap.blue);
		free(scr_cmap.transp);
	}

	if (pan_display) {
		// call ioctl. pan the display
		if (ioctl(fb_fd, FBIOPAN_DISPLAY, &scr_var) < 0) {
			printf("Unable to pan the display: %s\n",
				strerror(errno));
			close(fb_fd);
			return 1;
		}
	}

	if (set_fbmode) {
		if (ioctl(fb_fd, FBIOBLANK, (void *)fbmode) < 0) {
			printf("Unable to set fb mode: %s\n",
				strerror(errno));
			close(fb_fd);
			return 1;
		}
	}

	// close the framebuffer device
	close(fb_fd);
}