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add jpeg coding and test stuff
author Peter Meerwald <pmeerw@pmeerw.net>
date Sun, 08 May 2011 18:22:22 +0200
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1:111d4bbce605 2:bac8ed8d6eb9
1 /*
2 * linux/drivers/video/vfb.c -- Virtual frame buffer device
3 *
4 * Copyright (C) 2002 James Simmons
5 *
6 * Copyright (C) 1997 Geert Uytterhoeven
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file COPYING in the main directory of this archive for
10 * more details.
11 */
12
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/string.h>
17 #include <linux/mm.h>
18 #include <linux/vmalloc.h>
19 #include <linux/delay.h>
20 #include <linux/interrupt.h>
21 #include <linux/platform_device.h>
22
23 #include <linux/fb.h>
24 #include <linux/init.h>
25
26 /*
27 * RAM we reserve for the frame buffer. This defines the maximum screen
28 * size
29 *
30 * The default can be overridden if the driver is compiled as a module
31 */
32
33 #define VIDEOMEMSIZE (1*1024*1024) /* 1 MB */
34
35 static void *videomemory;
36 static u_long videomemorysize = VIDEOMEMSIZE;
37 module_param(videomemorysize, ulong, 0);
38
39 /**********************************************************************
40 *
41 * Memory management
42 *
43 **********************************************************************/
44 static void *rvmalloc(unsigned long size)
45 {
46 void *mem;
47 unsigned long adr;
48
49 size = PAGE_ALIGN(size);
50 mem = vmalloc_32(size);
51 if (!mem)
52 return NULL;
53
54 memset(mem, 0, size); /* Clear the ram out, no junk to the user */
55 adr = (unsigned long) mem;
56 while (size > 0) {
57 SetPageReserved(vmalloc_to_page((void *)adr));
58 adr += PAGE_SIZE;
59 size -= PAGE_SIZE;
60 }
61
62 return mem;
63 }
64
65 static void rvfree(void *mem, unsigned long size)
66 {
67 unsigned long adr;
68
69 if (!mem)
70 return;
71
72 adr = (unsigned long) mem;
73 while ((long) size > 0) {
74 ClearPageReserved(vmalloc_to_page((void *)adr));
75 adr += PAGE_SIZE;
76 size -= PAGE_SIZE;
77 }
78 vfree(mem);
79 }
80
81 static struct fb_var_screeninfo vfb_default __devinitdata = {
82 .xres = 640,
83 .yres = 480,
84 .xres_virtual = 640,
85 .yres_virtual = 480,
86 .bits_per_pixel = 8,
87 .red = { 0, 8, 0 },
88 .green = { 0, 8, 0 },
89 .blue = { 0, 8, 0 },
90 .activate = FB_ACTIVATE_TEST,
91 .height = -1,
92 .width = -1,
93 .pixclock = 20000,
94 .left_margin = 64,
95 .right_margin = 64,
96 .upper_margin = 32,
97 .lower_margin = 32,
98 .hsync_len = 64,
99 .vsync_len = 2,
100 .vmode = FB_VMODE_NONINTERLACED,
101 };
102
103 static struct fb_fix_screeninfo vfb_fix __devinitdata = {
104 .id = "Virtual FB",
105 .type = FB_TYPE_PACKED_PIXELS,
106 .visual = FB_VISUAL_PSEUDOCOLOR,
107 .xpanstep = 1,
108 .ypanstep = 1,
109 .ywrapstep = 1,
110 .accel = FB_ACCEL_NONE,
111 };
112
113 static int vfb_enable __initdata = 0; /* disabled by default */
114 module_param(vfb_enable, bool, 0);
115
116 static int vfb_check_var(struct fb_var_screeninfo *var,
117 struct fb_info *info);
118 static int vfb_set_par(struct fb_info *info);
119 static int vfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
120 u_int transp, struct fb_info *info);
121 static int vfb_pan_display(struct fb_var_screeninfo *var,
122 struct fb_info *info);
123 static int vfb_mmap(struct fb_info *info,
124 struct vm_area_struct *vma);
125
126 static struct fb_ops vfb_ops = {
127 .fb_read = fb_sys_read,
128 .fb_write = fb_sys_write,
129 .fb_check_var = vfb_check_var,
130 .fb_set_par = vfb_set_par,
131 .fb_setcolreg = vfb_setcolreg,
132 .fb_pan_display = vfb_pan_display,
133 .fb_fillrect = sys_fillrect,
134 .fb_copyarea = sys_copyarea,
135 .fb_imageblit = sys_imageblit,
136 .fb_mmap = vfb_mmap,
137 };
138
139 /*
140 * Internal routines
141 */
142
143 static u_long get_line_length(int xres_virtual, int bpp)
144 {
145 u_long length;
146
147 length = xres_virtual * bpp;
148 length = (length + 31) & ~31;
149 length >>= 3;
150 return (length);
151 }
152
153 /*
154 * Setting the video mode has been split into two parts.
155 * First part, xxxfb_check_var, must not write anything
156 * to hardware, it should only verify and adjust var.
157 * This means it doesn't alter par but it does use hardware
158 * data from it to check this var.
159 */
160
161 static int vfb_check_var(struct fb_var_screeninfo *var,
162 struct fb_info *info)
163 {
164 u_long line_length;
165
166 /*
167 * FB_VMODE_CONUPDATE and FB_VMODE_SMOOTH_XPAN are equal!
168 * as FB_VMODE_SMOOTH_XPAN is only used internally
169 */
170
171 if (var->vmode & FB_VMODE_CONUPDATE) {
172 var->vmode |= FB_VMODE_YWRAP;
173 var->xoffset = info->var.xoffset;
174 var->yoffset = info->var.yoffset;
175 }
176
177 /*
178 * Some very basic checks
179 */
180 if (!var->xres)
181 var->xres = 1;
182 if (!var->yres)
183 var->yres = 1;
184 if (var->xres > var->xres_virtual)
185 var->xres_virtual = var->xres;
186 if (var->yres > var->yres_virtual)
187 var->yres_virtual = var->yres;
188 if (var->bits_per_pixel <= 1)
189 var->bits_per_pixel = 1;
190 else if (var->bits_per_pixel <= 8)
191 var->bits_per_pixel = 8;
192 else if (var->bits_per_pixel <= 16)
193 var->bits_per_pixel = 16;
194 else if (var->bits_per_pixel <= 24)
195 var->bits_per_pixel = 24;
196 else if (var->bits_per_pixel <= 32)
197 var->bits_per_pixel = 32;
198 else
199 return -EINVAL;
200
201 if (var->xres_virtual < var->xoffset + var->xres)
202 var->xres_virtual = var->xoffset + var->xres;
203 if (var->yres_virtual < var->yoffset + var->yres)
204 var->yres_virtual = var->yoffset + var->yres;
205
206 /*
207 * Memory limit
208 */
209 line_length =
210 get_line_length(var->xres_virtual, var->bits_per_pixel);
211 if (line_length * var->yres_virtual > videomemorysize)
212 return -ENOMEM;
213
214 /*
215 * Now that we checked it we alter var. The reason being is that the video
216 * mode passed in might not work but slight changes to it might make it
217 * work. This way we let the user know what is acceptable.
218 */
219 switch (var->bits_per_pixel) {
220 case 1:
221 case 8:
222 var->red.offset = 0;
223 var->red.length = 8;
224 var->green.offset = 0;
225 var->green.length = 8;
226 var->blue.offset = 0;
227 var->blue.length = 8;
228 var->transp.offset = 0;
229 var->transp.length = 0;
230 break;
231 case 16: /* RGBA 5551 */
232 if (var->transp.length) {
233 var->red.offset = 0;
234 var->red.length = 5;
235 var->green.offset = 5;
236 var->green.length = 5;
237 var->blue.offset = 10;
238 var->blue.length = 5;
239 var->transp.offset = 15;
240 var->transp.length = 1;
241 } else { /* RGB 565 */
242 var->red.offset = 0;
243 var->red.length = 5;
244 var->green.offset = 5;
245 var->green.length = 6;
246 var->blue.offset = 11;
247 var->blue.length = 5;
248 var->transp.offset = 0;
249 var->transp.length = 0;
250 }
251 break;
252 case 24: /* RGB 888 */
253 var->red.offset = 0;
254 var->red.length = 8;
255 var->green.offset = 8;
256 var->green.length = 8;
257 var->blue.offset = 16;
258 var->blue.length = 8;
259 var->transp.offset = 0;
260 var->transp.length = 0;
261 break;
262 case 32: /* RGBA 8888 */
263 var->red.offset = 0;
264 var->red.length = 8;
265 var->green.offset = 8;
266 var->green.length = 8;
267 var->blue.offset = 16;
268 var->blue.length = 8;
269 var->transp.offset = 24;
270 var->transp.length = 8;
271 break;
272 }
273 var->red.msb_right = 0;
274 var->green.msb_right = 0;
275 var->blue.msb_right = 0;
276 var->transp.msb_right = 0;
277
278 return 0;
279 }
280
281 /* This routine actually sets the video mode. It's in here where we
282 * the hardware state info->par and fix which can be affected by the
283 * change in par. For this driver it doesn't do much.
284 */
285 static int vfb_set_par(struct fb_info *info)
286 {
287 info->fix.line_length = get_line_length(info->var.xres_virtual,
288 info->var.bits_per_pixel);
289 return 0;
290 }
291
292 /*
293 * Set a single color register. The values supplied are already
294 * rounded down to the hardware's capabilities (according to the
295 * entries in the var structure). Return != 0 for invalid regno.
296 */
297
298 static int vfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
299 u_int transp, struct fb_info *info)
300 {
301 if (regno >= 256) /* no. of hw registers */
302 return 1;
303 /*
304 * Program hardware... do anything you want with transp
305 */
306
307 /* grayscale works only partially under directcolor */
308 if (info->var.grayscale) {
309 /* grayscale = 0.30*R + 0.59*G + 0.11*B */
310 red = green = blue =
311 (red * 77 + green * 151 + blue * 28) >> 8;
312 }
313
314 /* Directcolor:
315 * var->{color}.offset contains start of bitfield
316 * var->{color}.length contains length of bitfield
317 * {hardwarespecific} contains width of RAMDAC
318 * cmap[X] is programmed to (X << red.offset) | (X << green.offset) | (X << blue.offset)
319 * RAMDAC[X] is programmed to (red, green, blue)
320 *
321 * Pseudocolor:
322 * var->{color}.offset is 0 unless the palette index takes less than
323 * bits_per_pixel bits and is stored in the upper
324 * bits of the pixel value
325 * var->{color}.length is set so that 1 << length is the number of available
326 * palette entries
327 * cmap is not used
328 * RAMDAC[X] is programmed to (red, green, blue)
329 *
330 * Truecolor:
331 * does not use DAC. Usually 3 are present.
332 * var->{color}.offset contains start of bitfield
333 * var->{color}.length contains length of bitfield
334 * cmap is programmed to (red << red.offset) | (green << green.offset) |
335 * (blue << blue.offset) | (transp << transp.offset)
336 * RAMDAC does not exist
337 */
338 #define CNVT_TOHW(val,width) ((((val)<<(width))+0x7FFF-(val))>>16)
339 switch (info->fix.visual) {
340 case FB_VISUAL_TRUECOLOR:
341 case FB_VISUAL_PSEUDOCOLOR:
342 red = CNVT_TOHW(red, info->var.red.length);
343 green = CNVT_TOHW(green, info->var.green.length);
344 blue = CNVT_TOHW(blue, info->var.blue.length);
345 transp = CNVT_TOHW(transp, info->var.transp.length);
346 break;
347 case FB_VISUAL_DIRECTCOLOR:
348 red = CNVT_TOHW(red, 8); /* expect 8 bit DAC */
349 green = CNVT_TOHW(green, 8);
350 blue = CNVT_TOHW(blue, 8);
351 /* hey, there is bug in transp handling... */
352 transp = CNVT_TOHW(transp, 8);
353 break;
354 }
355 #undef CNVT_TOHW
356 /* Truecolor has hardware independent palette */
357 if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
358 u32 v;
359
360 if (regno >= 16)
361 return 1;
362
363 v = (red << info->var.red.offset) |
364 (green << info->var.green.offset) |
365 (blue << info->var.blue.offset) |
366 (transp << info->var.transp.offset);
367 switch (info->var.bits_per_pixel) {
368 case 8:
369 break;
370 case 16:
371 ((u32 *) (info->pseudo_palette))[regno] = v;
372 break;
373 case 24:
374 case 32:
375 ((u32 *) (info->pseudo_palette))[regno] = v;
376 break;
377 }
378 return 0;
379 }
380 return 0;
381 }
382
383 /*
384 * Pan or Wrap the Display
385 *
386 * This call looks only at xoffset, yoffset and the FB_VMODE_YWRAP flag
387 */
388
389 static int vfb_pan_display(struct fb_var_screeninfo *var,
390 struct fb_info *info)
391 {
392 if (var->vmode & FB_VMODE_YWRAP) {
393 if (var->yoffset < 0
394 || var->yoffset >= info->var.yres_virtual
395 || var->xoffset)
396 return -EINVAL;
397 } else {
398 if (var->xoffset + var->xres > info->var.xres_virtual ||
399 var->yoffset + var->yres > info->var.yres_virtual)
400 return -EINVAL;
401 }
402 info->var.xoffset = var->xoffset;
403 info->var.yoffset = var->yoffset;
404 if (var->vmode & FB_VMODE_YWRAP)
405 info->var.vmode |= FB_VMODE_YWRAP;
406 else
407 info->var.vmode &= ~FB_VMODE_YWRAP;
408 return 0;
409 }
410
411 /*
412 * Most drivers don't need their own mmap function
413 */
414
415 static int vfb_mmap(struct fb_info *info,
416 struct vm_area_struct *vma)
417 {
418 unsigned long start = vma->vm_start;
419 unsigned long size = vma->vm_end - vma->vm_start;
420 unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
421 unsigned long page, pos;
422
423 if (offset + size > info->fix.smem_len) {
424 return -EINVAL;
425 }
426
427 pos = (unsigned long)info->fix.smem_start + offset;
428
429 while (size > 0) {
430 page = vmalloc_to_pfn((void *)pos);
431 if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED)) {
432 return -EAGAIN;
433 }
434 start += PAGE_SIZE;
435 pos += PAGE_SIZE;
436 if (size > PAGE_SIZE)
437 size -= PAGE_SIZE;
438 else
439 size = 0;
440 }
441
442 vma->vm_flags |= VM_RESERVED; /* avoid to swap out this VMA */
443 return 0;
444
445 }
446
447 #ifndef MODULE
448 /*
449 * The virtual framebuffer driver is only enabled if explicitly
450 * requested by passing 'video=vfb:' (or any actual options).
451 */
452 static int __init vfb_setup(char *options)
453 {
454 char *this_opt;
455
456 vfb_enable = 0;
457
458 if (!options)
459 return 1;
460
461 vfb_enable = 1;
462
463 if (!*options)
464 return 1;
465
466 while ((this_opt = strsep(&options, ",")) != NULL) {
467 if (!*this_opt)
468 continue;
469 /* Test disable for backwards compatibility */
470 if (!strcmp(this_opt, "disable"))
471 vfb_enable = 0;
472 }
473 return 1;
474 }
475 #endif /* MODULE */
476
477 /*
478 * Initialisation
479 */
480
481 static int __devinit vfb_probe(struct platform_device *dev)
482 {
483 struct fb_info *info;
484 int retval = -ENOMEM;
485
486 /*
487 * For real video cards we use ioremap.
488 */
489 if (!(videomemory = rvmalloc(videomemorysize)))
490 return retval;
491
492 /*
493 * VFB must clear memory to prevent kernel info
494 * leakage into userspace
495 * VGA-based drivers MUST NOT clear memory if
496 * they want to be able to take over vgacon
497 */
498 memset(videomemory, 0, videomemorysize);
499
500 info = framebuffer_alloc(sizeof(u32) * 256, &dev->dev);
501 if (!info)
502 goto err;
503
504 info->screen_base = (char __iomem *)videomemory;
505 info->fbops = &vfb_ops;
506
507 retval = fb_find_mode(&info->var, info, NULL,
508 NULL, 0, NULL, 8);
509
510 if (!retval || (retval == 4))
511 info->var = vfb_default;
512 vfb_fix.smem_start = (unsigned long) videomemory;
513 vfb_fix.smem_len = videomemorysize;
514 info->fix = vfb_fix;
515 info->pseudo_palette = info->par;
516 info->par = NULL;
517 info->flags = FBINFO_FLAG_DEFAULT;
518
519 retval = fb_alloc_cmap(&info->cmap, 256, 0);
520 if (retval < 0)
521 goto err1;
522
523 retval = register_framebuffer(info);
524 if (retval < 0)
525 goto err2;
526 platform_set_drvdata(dev, info);
527
528 printk(KERN_INFO
529 "fb%d: Virtual frame buffer device, using %ldK of video memory\n",
530 info->node, videomemorysize >> 10);
531 return 0;
532 err2:
533 fb_dealloc_cmap(&info->cmap);
534 err1:
535 framebuffer_release(info);
536 err:
537 rvfree(videomemory, videomemorysize);
538 return retval;
539 }
540
541 static int vfb_remove(struct platform_device *dev)
542 {
543 struct fb_info *info = platform_get_drvdata(dev);
544
545 if (info) {
546 unregister_framebuffer(info);
547 rvfree(videomemory, videomemorysize);
548 fb_dealloc_cmap(&info->cmap);
549 framebuffer_release(info);
550 }
551 return 0;
552 }
553
554 static struct platform_driver vfb_driver = {
555 .probe = vfb_probe,
556 .remove = vfb_remove,
557 .driver = {
558 .name = "vfb",
559 },
560 };
561
562 static struct platform_device *vfb_device;
563
564 static int __init vfb_init(void)
565 {
566 int ret = 0;
567
568 #ifndef MODULE
569 char *option = NULL;
570
571 if (fb_get_options("vfb", &option))
572 return -ENODEV;
573 vfb_setup(option);
574 #endif
575
576 if (!vfb_enable)
577 return -ENXIO;
578
579 ret = platform_driver_register(&vfb_driver);
580
581 if (!ret) {
582 vfb_device = platform_device_alloc("vfb", 0);
583
584 if (vfb_device)
585 ret = platform_device_add(vfb_device);
586 else
587 ret = -ENOMEM;
588
589 if (ret) {
590 platform_device_put(vfb_device);
591 platform_driver_unregister(&vfb_driver);
592 }
593 }
594
595 return ret;
596 }
597
598 module_init(vfb_init);
599
600 #ifdef MODULE
601 static void __exit vfb_exit(void)
602 {
603 platform_device_unregister(vfb_device);
604 platform_driver_unregister(&vfb_driver);
605 }
606
607 module_exit(vfb_exit);
608
609 MODULE_LICENSE("GPL");
610 #endif /* MODULE */

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