vfb.c 12.6 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
/*
 *  linux/drivers/video/vfb.c -- Virtual frame buffer device
 *
 *      Copyright (C) 2002 James Simmons
 *
 *	Copyright (C) 1997 Geert Uytterhoeven
 *
 *  This file is subject to the terms and conditions of the GNU General Public
 *  License. See the file COPYING in the main directory of this archive for
 *  more details.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/tty.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
23 24
#include <linux/platform_device.h>

L
Linus Torvalds 已提交
25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83
#include <asm/uaccess.h>
#include <linux/fb.h>
#include <linux/init.h>

    /*
     *  RAM we reserve for the frame buffer. This defines the maximum screen
     *  size
     *
     *  The default can be overridden if the driver is compiled as a module
     */

#define VIDEOMEMSIZE	(1*1024*1024)	/* 1 MB */

static void *videomemory;
static u_long videomemorysize = VIDEOMEMSIZE;
module_param(videomemorysize, ulong, 0);

static struct fb_var_screeninfo vfb_default __initdata = {
	.xres =		640,
	.yres =		480,
	.xres_virtual =	640,
	.yres_virtual =	480,
	.bits_per_pixel = 8,
	.red =		{ 0, 8, 0 },
      	.green =	{ 0, 8, 0 },
      	.blue =		{ 0, 8, 0 },
      	.activate =	FB_ACTIVATE_TEST,
      	.height =	-1,
      	.width =	-1,
      	.pixclock =	20000,
      	.left_margin =	64,
      	.right_margin =	64,
      	.upper_margin =	32,
      	.lower_margin =	32,
      	.hsync_len =	64,
      	.vsync_len =	2,
      	.vmode =	FB_VMODE_NONINTERLACED,
};

static struct fb_fix_screeninfo vfb_fix __initdata = {
	.id =		"Virtual FB",
	.type =		FB_TYPE_PACKED_PIXELS,
	.visual =	FB_VISUAL_PSEUDOCOLOR,
	.xpanstep =	1,
	.ypanstep =	1,
	.ywrapstep =	1,
	.accel =	FB_ACCEL_NONE,
};

static int vfb_enable __initdata = 0;	/* disabled by default */
module_param(vfb_enable, bool, 0);

static int vfb_check_var(struct fb_var_screeninfo *var,
			 struct fb_info *info);
static int vfb_set_par(struct fb_info *info);
static int vfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
			 u_int transp, struct fb_info *info);
static int vfb_pan_display(struct fb_var_screeninfo *var,
			   struct fb_info *info);
84
static int vfb_mmap(struct fb_info *info,
L
Linus Torvalds 已提交
85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370
		    struct vm_area_struct *vma);

static struct fb_ops vfb_ops = {
	.fb_check_var	= vfb_check_var,
	.fb_set_par	= vfb_set_par,
	.fb_setcolreg	= vfb_setcolreg,
	.fb_pan_display	= vfb_pan_display,
	.fb_fillrect	= cfb_fillrect,
	.fb_copyarea	= cfb_copyarea,
	.fb_imageblit	= cfb_imageblit,
	.fb_mmap	= vfb_mmap,
};

    /*
     *  Internal routines
     */

static u_long get_line_length(int xres_virtual, int bpp)
{
	u_long length;

	length = xres_virtual * bpp;
	length = (length + 31) & ~31;
	length >>= 3;
	return (length);
}

    /*
     *  Setting the video mode has been split into two parts.
     *  First part, xxxfb_check_var, must not write anything
     *  to hardware, it should only verify and adjust var.
     *  This means it doesn't alter par but it does use hardware
     *  data from it to check this var. 
     */

static int vfb_check_var(struct fb_var_screeninfo *var,
			 struct fb_info *info)
{
	u_long line_length;

	/*
	 *  FB_VMODE_CONUPDATE and FB_VMODE_SMOOTH_XPAN are equal!
	 *  as FB_VMODE_SMOOTH_XPAN is only used internally
	 */

	if (var->vmode & FB_VMODE_CONUPDATE) {
		var->vmode |= FB_VMODE_YWRAP;
		var->xoffset = info->var.xoffset;
		var->yoffset = info->var.yoffset;
	}

	/*
	 *  Some very basic checks
	 */
	if (!var->xres)
		var->xres = 1;
	if (!var->yres)
		var->yres = 1;
	if (var->xres > var->xres_virtual)
		var->xres_virtual = var->xres;
	if (var->yres > var->yres_virtual)
		var->yres_virtual = var->yres;
	if (var->bits_per_pixel <= 1)
		var->bits_per_pixel = 1;
	else if (var->bits_per_pixel <= 8)
		var->bits_per_pixel = 8;
	else if (var->bits_per_pixel <= 16)
		var->bits_per_pixel = 16;
	else if (var->bits_per_pixel <= 24)
		var->bits_per_pixel = 24;
	else if (var->bits_per_pixel <= 32)
		var->bits_per_pixel = 32;
	else
		return -EINVAL;

	if (var->xres_virtual < var->xoffset + var->xres)
		var->xres_virtual = var->xoffset + var->xres;
	if (var->yres_virtual < var->yoffset + var->yres)
		var->yres_virtual = var->yoffset + var->yres;

	/*
	 *  Memory limit
	 */
	line_length =
	    get_line_length(var->xres_virtual, var->bits_per_pixel);
	if (line_length * var->yres_virtual > videomemorysize)
		return -ENOMEM;

	/*
	 * Now that we checked it we alter var. The reason being is that the video
	 * mode passed in might not work but slight changes to it might make it 
	 * work. This way we let the user know what is acceptable.
	 */
	switch (var->bits_per_pixel) {
	case 1:
	case 8:
		var->red.offset = 0;
		var->red.length = 8;
		var->green.offset = 0;
		var->green.length = 8;
		var->blue.offset = 0;
		var->blue.length = 8;
		var->transp.offset = 0;
		var->transp.length = 0;
		break;
	case 16:		/* RGBA 5551 */
		if (var->transp.length) {
			var->red.offset = 0;
			var->red.length = 5;
			var->green.offset = 5;
			var->green.length = 5;
			var->blue.offset = 10;
			var->blue.length = 5;
			var->transp.offset = 15;
			var->transp.length = 1;
		} else {	/* RGB 565 */
			var->red.offset = 0;
			var->red.length = 5;
			var->green.offset = 5;
			var->green.length = 6;
			var->blue.offset = 11;
			var->blue.length = 5;
			var->transp.offset = 0;
			var->transp.length = 0;
		}
		break;
	case 24:		/* RGB 888 */
		var->red.offset = 0;
		var->red.length = 8;
		var->green.offset = 8;
		var->green.length = 8;
		var->blue.offset = 16;
		var->blue.length = 8;
		var->transp.offset = 0;
		var->transp.length = 0;
		break;
	case 32:		/* RGBA 8888 */
		var->red.offset = 0;
		var->red.length = 8;
		var->green.offset = 8;
		var->green.length = 8;
		var->blue.offset = 16;
		var->blue.length = 8;
		var->transp.offset = 24;
		var->transp.length = 8;
		break;
	}
	var->red.msb_right = 0;
	var->green.msb_right = 0;
	var->blue.msb_right = 0;
	var->transp.msb_right = 0;

	return 0;
}

/* This routine actually sets the video mode. It's in here where we
 * the hardware state info->par and fix which can be affected by the 
 * change in par. For this driver it doesn't do much. 
 */
static int vfb_set_par(struct fb_info *info)
{
	info->fix.line_length = get_line_length(info->var.xres_virtual,
						info->var.bits_per_pixel);
	return 0;
}

    /*
     *  Set a single color register. The values supplied are already
     *  rounded down to the hardware's capabilities (according to the
     *  entries in the var structure). Return != 0 for invalid regno.
     */

static int vfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
			 u_int transp, struct fb_info *info)
{
	if (regno >= 256)	/* no. of hw registers */
		return 1;
	/*
	 * Program hardware... do anything you want with transp
	 */

	/* grayscale works only partially under directcolor */
	if (info->var.grayscale) {
		/* grayscale = 0.30*R + 0.59*G + 0.11*B */
		red = green = blue =
		    (red * 77 + green * 151 + blue * 28) >> 8;
	}

	/* Directcolor:
	 *   var->{color}.offset contains start of bitfield
	 *   var->{color}.length contains length of bitfield
	 *   {hardwarespecific} contains width of RAMDAC
	 *   cmap[X] is programmed to (X << red.offset) | (X << green.offset) | (X << blue.offset)
	 *   RAMDAC[X] is programmed to (red, green, blue)
	 * 
	 * Pseudocolor:
	 *    uses offset = 0 && length = RAMDAC register width.
	 *    var->{color}.offset is 0
	 *    var->{color}.length contains widht of DAC
	 *    cmap is not used
	 *    RAMDAC[X] is programmed to (red, green, blue)
	 * Truecolor:
	 *    does not use DAC. Usually 3 are present.
	 *    var->{color}.offset contains start of bitfield
	 *    var->{color}.length contains length of bitfield
	 *    cmap is programmed to (red << red.offset) | (green << green.offset) |
	 *                      (blue << blue.offset) | (transp << transp.offset)
	 *    RAMDAC does not exist
	 */
#define CNVT_TOHW(val,width) ((((val)<<(width))+0x7FFF-(val))>>16)
	switch (info->fix.visual) {
	case FB_VISUAL_TRUECOLOR:
	case FB_VISUAL_PSEUDOCOLOR:
		red = CNVT_TOHW(red, info->var.red.length);
		green = CNVT_TOHW(green, info->var.green.length);
		blue = CNVT_TOHW(blue, info->var.blue.length);
		transp = CNVT_TOHW(transp, info->var.transp.length);
		break;
	case FB_VISUAL_DIRECTCOLOR:
		red = CNVT_TOHW(red, 8);	/* expect 8 bit DAC */
		green = CNVT_TOHW(green, 8);
		blue = CNVT_TOHW(blue, 8);
		/* hey, there is bug in transp handling... */
		transp = CNVT_TOHW(transp, 8);
		break;
	}
#undef CNVT_TOHW
	/* Truecolor has hardware independent palette */
	if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
		u32 v;

		if (regno >= 16)
			return 1;

		v = (red << info->var.red.offset) |
		    (green << info->var.green.offset) |
		    (blue << info->var.blue.offset) |
		    (transp << info->var.transp.offset);
		switch (info->var.bits_per_pixel) {
		case 8:
			break;
		case 16:
			((u32 *) (info->pseudo_palette))[regno] = v;
			break;
		case 24:
		case 32:
			((u32 *) (info->pseudo_palette))[regno] = v;
			break;
		}
		return 0;
	}
	return 0;
}

    /*
     *  Pan or Wrap the Display
     *
     *  This call looks only at xoffset, yoffset and the FB_VMODE_YWRAP flag
     */

static int vfb_pan_display(struct fb_var_screeninfo *var,
			   struct fb_info *info)
{
	if (var->vmode & FB_VMODE_YWRAP) {
		if (var->yoffset < 0
		    || var->yoffset >= info->var.yres_virtual
		    || var->xoffset)
			return -EINVAL;
	} else {
		if (var->xoffset + var->xres > info->var.xres_virtual ||
		    var->yoffset + var->yres > info->var.yres_virtual)
			return -EINVAL;
	}
	info->var.xoffset = var->xoffset;
	info->var.yoffset = var->yoffset;
	if (var->vmode & FB_VMODE_YWRAP)
		info->var.vmode |= FB_VMODE_YWRAP;
	else
		info->var.vmode &= ~FB_VMODE_YWRAP;
	return 0;
}

    /*
     *  Most drivers don't need their own mmap function 
     */

371
static int vfb_mmap(struct fb_info *info,
L
Linus Torvalds 已提交
372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403
		    struct vm_area_struct *vma)
{
	return -EINVAL;
}

#ifndef MODULE
static int __init vfb_setup(char *options)
{
	char *this_opt;

	vfb_enable = 1;

	if (!options || !*options)
		return 1;

	while ((this_opt = strsep(&options, ",")) != NULL) {
		if (!*this_opt)
			continue;
		if (!strncmp(this_opt, "disable", 7))
			vfb_enable = 0;
	}
	return 1;
}
#endif  /*  MODULE  */

    /*
     *  Initialisation
     */

static void vfb_platform_release(struct device *device)
{
	// This is called when the reference count goes to zero.
404
	dev_err(device, "This driver is broken, please bug the authors so they will fix it.\n");
L
Linus Torvalds 已提交
405 406
}

407
static int __init vfb_probe(struct platform_device *dev)
L
Linus Torvalds 已提交
408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449
{
	struct fb_info *info;
	int retval = -ENOMEM;

	/*
	 * For real video cards we use ioremap.
	 */
	if (!(videomemory = vmalloc(videomemorysize)))
		return retval;

	/*
	 * VFB must clear memory to prevent kernel info
	 * leakage into userspace
	 * VGA-based drivers MUST NOT clear memory if
	 * they want to be able to take over vgacon
	 */
	memset(videomemory, 0, videomemorysize);

	info = framebuffer_alloc(sizeof(u32) * 256, &dev->dev);
	if (!info)
		goto err;

	info->screen_base = (char __iomem *)videomemory;
	info->fbops = &vfb_ops;

	retval = fb_find_mode(&info->var, info, NULL,
			      NULL, 0, NULL, 8);

	if (!retval || (retval == 4))
		info->var = vfb_default;
	info->fix = vfb_fix;
	info->pseudo_palette = info->par;
	info->par = NULL;
	info->flags = FBINFO_FLAG_DEFAULT;

	retval = fb_alloc_cmap(&info->cmap, 256, 0);
	if (retval < 0)
		goto err1;

	retval = register_framebuffer(info);
	if (retval < 0)
		goto err2;
450
	platform_set_drvdata(dev, info);
L
Linus Torvalds 已提交
451 452 453 454 455 456 457 458 459 460 461 462 463 464

	printk(KERN_INFO
	       "fb%d: Virtual frame buffer device, using %ldK of video memory\n",
	       info->node, videomemorysize >> 10);
	return 0;
err2:
	fb_dealloc_cmap(&info->cmap);
err1:
	framebuffer_release(info);
err:
	vfree(videomemory);
	return retval;
}

465
static int vfb_remove(struct platform_device *dev)
L
Linus Torvalds 已提交
466
{
467
	struct fb_info *info = platform_get_drvdata(dev);
L
Linus Torvalds 已提交
468 469 470 471 472 473 474 475 476

	if (info) {
		unregister_framebuffer(info);
		vfree(videomemory);
		framebuffer_release(info);
	}
	return 0;
}

477
static struct platform_driver vfb_driver = {
L
Linus Torvalds 已提交
478 479
	.probe	= vfb_probe,
	.remove = vfb_remove,
480 481 482
	.driver = {
		.name	= "vfb",
	},
L
Linus Torvalds 已提交
483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507
};

static struct platform_device vfb_device = {
	.name	= "vfb",
	.id	= 0,
	.dev	= {
		.release = vfb_platform_release,
	}
};

static int __init vfb_init(void)
{
	int ret = 0;

#ifndef MODULE
	char *option = NULL;

	if (fb_get_options("vfb", &option))
		return -ENODEV;
	vfb_setup(option);
#endif

	if (!vfb_enable)
		return -ENXIO;

508
	ret = platform_driver_register(&vfb_driver);
L
Linus Torvalds 已提交
509 510 511 512

	if (!ret) {
		ret = platform_device_register(&vfb_device);
		if (ret)
513
			platform_driver_unregister(&vfb_driver);
L
Linus Torvalds 已提交
514 515 516 517 518 519 520 521 522 523
	}
	return ret;
}

module_init(vfb_init);

#ifdef MODULE
static void __exit vfb_exit(void)
{
	platform_device_unregister(&vfb_device);
524
	platform_driver_unregister(&vfb_driver);
L
Linus Torvalds 已提交
525 526 527 528 529 530
}

module_exit(vfb_exit);

MODULE_LICENSE("GPL");
#endif				/* MODULE */