xref: /linux/drivers/video/vgastate.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
1 /*
2  * linux/drivers/video/vgastate.c -- VGA state save/restore
3  *
4  * Copyright 2002 James Simmons
5  *
6  * Copyright history from vga16fb.c:
7  *	Copyright 1999 Ben Pfaff and Petr Vandrovec
8  *	Based on VGA info at http://www.goodnet.com/~tinara/FreeVGA/home.htm
9  *	Based on VESA framebuffer (c) 1998 Gerd Knorr
10  *
11  * This file is subject to the terms and conditions of the GNU General
12  * Public License.  See the file COPYING in the main directory of this
13  * archive for more details.
14  *
15  */
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/fb.h>
19 #include <linux/vmalloc.h>
20 #include <video/vga.h>
21 
22 struct regstate {
23 	__u8 *vga_font0;
24 	__u8 *vga_font1;
25 	__u8 *vga_text;
26 	__u8 *vga_cmap;
27 	__u8 *attr;
28 	__u8 *crtc;
29 	__u8 *gfx;
30 	__u8 *seq;
31 	__u8 misc;
32 };
33 
34 static inline unsigned char vga_rcrtcs(void __iomem *regbase, unsigned short iobase,
35 				       unsigned char reg)
36 {
37 	vga_w(regbase, iobase + 0x4, reg);
38 	return vga_r(regbase, iobase + 0x5);
39 }
40 
41 static inline void vga_wcrtcs(void __iomem *regbase, unsigned short iobase,
42 			      unsigned char reg, unsigned char val)
43 {
44 	vga_w(regbase, iobase + 0x4, reg);
45 	vga_w(regbase, iobase + 0x5, val);
46 }
47 
48 static void save_vga_text(struct vgastate *state, void __iomem *fbbase)
49 {
50 	struct regstate *saved = (struct regstate *) state->vidstate;
51 	int i;
52 	u8 misc, attr10, gr4, gr5, gr6, seq1, seq2, seq4;
53 
54 	/* if in graphics mode, no need to save */
55 	attr10 = vga_rattr(state->vgabase, 0x10);
56 	if (attr10 & 1)
57 		return;
58 
59 	/* save regs */
60 	misc = vga_r(state->vgabase, VGA_MIS_R);
61 	gr4 = vga_rgfx(state->vgabase, VGA_GFX_PLANE_READ);
62 	gr5 = vga_rgfx(state->vgabase, VGA_GFX_MODE);
63 	gr6 = vga_rgfx(state->vgabase, VGA_GFX_MISC);
64 	seq2 = vga_rseq(state->vgabase, VGA_SEQ_PLANE_WRITE);
65 	seq4 = vga_rseq(state->vgabase, VGA_SEQ_MEMORY_MODE);
66 
67 	/* force graphics mode */
68 	vga_w(state->vgabase, VGA_MIS_W, misc | 1);
69 
70 	/* blank screen */
71 	seq1 = vga_rseq(state->vgabase, VGA_SEQ_CLOCK_MODE);
72 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x1);
73 	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE, seq1 | 1 << 5);
74 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x3);
75 
76 	/* save font at plane 2 */
77 	if (state->flags & VGA_SAVE_FONT0) {
78 		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x4);
79 		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
80 		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x2);
81 		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
82 		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
83 		for (i = 0; i < 4 * 8192; i++)
84 			saved->vga_font0[i] = vga_r(fbbase, i);
85 	}
86 
87 	/* save font at plane 3 */
88 	if (state->flags & VGA_SAVE_FONT1) {
89 		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x8);
90 		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
91 		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x3);
92 		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
93 		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
94 		for (i = 0; i < state->memsize; i++)
95 			saved->vga_font1[i] = vga_r(fbbase, i);
96 	}
97 
98 	/* save font at plane 0/1 */
99 	if (state->flags & VGA_SAVE_TEXT) {
100 		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x1);
101 		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
102 		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x0);
103 		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
104 		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
105 		for (i = 0; i < 8192; i++)
106 			saved->vga_text[i] = vga_r(fbbase, i);
107 
108 		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x2);
109 		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
110 		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x1);
111 		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
112 		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
113 		for (i = 0; i < 8192; i++)
114 			saved->vga_text[8192+i] = vga_r(fbbase + 2 * 8192, i);
115 	}
116 
117 	/* restore regs */
118 	vga_wattr(state->vgabase, 0x10, attr10);
119 
120 	vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, seq2);
121 	vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, seq4);
122 
123 	vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, gr4);
124 	vga_wgfx(state->vgabase, VGA_GFX_MODE, gr5);
125 	vga_wgfx(state->vgabase, VGA_GFX_MISC, gr6);
126 	vga_w(state->vgabase, VGA_MIS_W, misc);
127 
128 	/* unblank screen */
129 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x1);
130 	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE, seq1 & ~(1 << 5));
131 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x3);
132 
133 	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE, seq1);
134 }
135 
136 static void restore_vga_text(struct vgastate *state, void __iomem *fbbase)
137 {
138 	struct regstate *saved = (struct regstate *) state->vidstate;
139 	int i;
140 	u8 misc, gr1, gr3, gr4, gr5, gr6, gr8;
141 	u8 seq1, seq2, seq4;
142 
143 	/* save regs */
144 	misc = vga_r(state->vgabase, VGA_MIS_R);
145 	gr1 = vga_rgfx(state->vgabase, VGA_GFX_SR_ENABLE);
146 	gr3 = vga_rgfx(state->vgabase, VGA_GFX_DATA_ROTATE);
147 	gr4 = vga_rgfx(state->vgabase, VGA_GFX_PLANE_READ);
148 	gr5 = vga_rgfx(state->vgabase, VGA_GFX_MODE);
149 	gr6 = vga_rgfx(state->vgabase, VGA_GFX_MISC);
150 	gr8 = vga_rgfx(state->vgabase, VGA_GFX_BIT_MASK);
151 	seq2 = vga_rseq(state->vgabase, VGA_SEQ_PLANE_WRITE);
152 	seq4 = vga_rseq(state->vgabase, VGA_SEQ_MEMORY_MODE);
153 
154 	/* force graphics mode */
155 	vga_w(state->vgabase, VGA_MIS_W, misc | 1);
156 
157 	/* blank screen */
158 	seq1 = vga_rseq(state->vgabase, VGA_SEQ_CLOCK_MODE);
159 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x1);
160 	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE, seq1 | 1 << 5);
161 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x3);
162 
163 	if (state->depth == 4) {
164 		vga_wgfx(state->vgabase, VGA_GFX_DATA_ROTATE, 0x0);
165 		vga_wgfx(state->vgabase, VGA_GFX_BIT_MASK, 0xff);
166 		vga_wgfx(state->vgabase, VGA_GFX_SR_ENABLE, 0x00);
167 	}
168 
169 	/* restore font at plane 2 */
170 	if (state->flags & VGA_SAVE_FONT0) {
171 		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x4);
172 		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
173 		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x2);
174 		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
175 		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
176 		for (i = 0; i < 4 * 8192; i++)
177 			vga_w(fbbase, i, saved->vga_font0[i]);
178 	}
179 
180 	/* restore font at plane 3 */
181 	if (state->flags & VGA_SAVE_FONT1) {
182 		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x8);
183 		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
184 		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x3);
185 		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
186 		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
187 		for (i = 0; i < state->memsize; i++)
188 			vga_w(fbbase, i, saved->vga_font1[i]);
189 	}
190 
191 	/* restore font at plane 0/1 */
192 	if (state->flags & VGA_SAVE_TEXT) {
193 		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x1);
194 		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
195 		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x0);
196 		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
197 		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
198 		for (i = 0; i < 8192; i++)
199 			vga_w(fbbase, i, saved->vga_text[i]);
200 
201 		vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x2);
202 		vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x6);
203 		vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x1);
204 		vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x0);
205 		vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x5);
206 		for (i = 0; i < 8192; i++)
207 			vga_w(fbbase, i, saved->vga_text[8192+i]);
208 	}
209 
210 	/* unblank screen */
211 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x1);
212 	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE, seq1 & ~(1 << 5));
213 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x3);
214 
215 	/* restore regs */
216 	vga_w(state->vgabase, VGA_MIS_W, misc);
217 
218 	vga_wgfx(state->vgabase, VGA_GFX_SR_ENABLE, gr1);
219 	vga_wgfx(state->vgabase, VGA_GFX_DATA_ROTATE, gr3);
220 	vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, gr4);
221 	vga_wgfx(state->vgabase, VGA_GFX_MODE, gr5);
222 	vga_wgfx(state->vgabase, VGA_GFX_MISC, gr6);
223 	vga_wgfx(state->vgabase, VGA_GFX_BIT_MASK, gr8);
224 
225 	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE, seq1);
226 	vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, seq2);
227 	vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, seq4);
228 }
229 
230 static void save_vga_mode(struct vgastate *state)
231 {
232 	struct regstate *saved = (struct regstate *) state->vidstate;
233 	unsigned short iobase;
234 	int i;
235 
236 	saved->misc = vga_r(state->vgabase, VGA_MIS_R);
237 	if (saved->misc & 1)
238 		iobase = 0x3d0;
239 	else
240 		iobase = 0x3b0;
241 
242 	for (i = 0; i < state->num_crtc; i++)
243 		saved->crtc[i] = vga_rcrtcs(state->vgabase, iobase, i);
244 
245 	vga_r(state->vgabase, iobase + 0xa);
246 	vga_w(state->vgabase, VGA_ATT_W, 0x00);
247 	for (i = 0; i < state->num_attr; i++) {
248 		vga_r(state->vgabase, iobase + 0xa);
249 		saved->attr[i] = vga_rattr(state->vgabase, i);
250 	}
251 	vga_r(state->vgabase, iobase + 0xa);
252 	vga_w(state->vgabase, VGA_ATT_W, 0x20);
253 
254 	for (i = 0; i < state->num_gfx; i++)
255 		saved->gfx[i] = vga_rgfx(state->vgabase, i);
256 
257 	for (i = 0; i < state->num_seq; i++)
258 		saved->seq[i] = vga_rseq(state->vgabase, i);
259 }
260 
261 static void restore_vga_mode(struct vgastate *state)
262 {
263 	struct regstate *saved = (struct regstate *) state->vidstate;
264 	unsigned short iobase;
265 	int i;
266 
267 	vga_w(state->vgabase, VGA_MIS_W, saved->misc);
268 
269 	if (saved->misc & 1)
270 		iobase = 0x3d0;
271 	else
272 		iobase = 0x3b0;
273 
274 	/* turn off display */
275 	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE,
276 		 saved->seq[VGA_SEQ_CLOCK_MODE] | 0x20);
277 
278 	/* disable sequencer */
279 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x01);
280 
281 	/* enable palette addressing */
282 	vga_r(state->vgabase, iobase + 0xa);
283 	vga_w(state->vgabase, VGA_ATT_W, 0x00);
284 
285 	for (i = 2; i < state->num_seq; i++)
286 		vga_wseq(state->vgabase, i, saved->seq[i]);
287 
288 
289 	/* unprotect vga regs */
290 	vga_wcrtcs(state->vgabase, iobase, 17, saved->crtc[17] & ~0x80);
291 	for (i = 0; i < state->num_crtc; i++)
292 		vga_wcrtcs(state->vgabase, iobase, i, saved->crtc[i]);
293 
294 	for (i = 0; i < state->num_gfx; i++)
295 		vga_wgfx(state->vgabase, i, saved->gfx[i]);
296 
297 	for (i = 0; i < state->num_attr; i++) {
298 		vga_r(state->vgabase, iobase + 0xa);
299 		vga_wattr(state->vgabase, i, saved->attr[i]);
300 	}
301 
302 	/* reenable sequencer */
303 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x03);
304 	/* turn display on */
305 	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE,
306 		 saved->seq[VGA_SEQ_CLOCK_MODE] & ~(1 << 5));
307 
308 	/* disable video/palette source */
309 	vga_r(state->vgabase, iobase + 0xa);
310 	vga_w(state->vgabase, VGA_ATT_W, 0x20);
311 }
312 
313 static void save_vga_cmap(struct vgastate *state)
314 {
315 	struct regstate *saved = (struct regstate *) state->vidstate;
316 	int i;
317 
318 	vga_w(state->vgabase, VGA_PEL_MSK, 0xff);
319 
320 	/* assumes DAC is readable and writable */
321 	vga_w(state->vgabase, VGA_PEL_IR, 0x00);
322 	for (i = 0; i < 768; i++)
323 		saved->vga_cmap[i] = vga_r(state->vgabase, VGA_PEL_D);
324 }
325 
326 static void restore_vga_cmap(struct vgastate *state)
327 {
328 	struct regstate *saved = (struct regstate *) state->vidstate;
329 	int i;
330 
331 	vga_w(state->vgabase, VGA_PEL_MSK, 0xff);
332 
333 	/* assumes DAC is readable and writable */
334 	vga_w(state->vgabase, VGA_PEL_IW, 0x00);
335 	for (i = 0; i < 768; i++)
336 		vga_w(state->vgabase, VGA_PEL_D, saved->vga_cmap[i]);
337 }
338 
339 static void vga_cleanup(struct vgastate *state)
340 {
341 	if (state->vidstate != NULL) {
342 		struct regstate *saved = (struct regstate *) state->vidstate;
343 
344 		vfree(saved->vga_font0);
345 		vfree(saved->vga_font1);
346 		vfree(saved->vga_text);
347 		vfree(saved->vga_cmap);
348 		vfree(saved->attr);
349 		kfree(saved);
350 		state->vidstate = NULL;
351 	}
352 }
353 
354 int save_vga(struct vgastate *state)
355 {
356 	struct regstate *saved;
357 
358 	saved = kzalloc(sizeof(struct regstate), GFP_KERNEL);
359 
360 	if (saved == NULL)
361 		return 1;
362 
363 	state->vidstate = (void *)saved;
364 
365 	if (state->flags & VGA_SAVE_CMAP) {
366 		saved->vga_cmap = vmalloc(768);
367 		if (!saved->vga_cmap) {
368 			vga_cleanup(state);
369 			return 1;
370 		}
371 		save_vga_cmap(state);
372 	}
373 
374 	if (state->flags & VGA_SAVE_MODE) {
375 		int total;
376 
377 		if (state->num_attr < 21)
378 			state->num_attr = 21;
379 		if (state->num_crtc < 25)
380 			state->num_crtc = 25;
381 		if (state->num_gfx < 9)
382 			state->num_gfx = 9;
383 		if (state->num_seq < 5)
384 			state->num_seq = 5;
385 		total = state->num_attr + state->num_crtc +
386 			state->num_gfx + state->num_seq;
387 
388 		saved->attr = vmalloc(total);
389 		if (!saved->attr) {
390 			vga_cleanup(state);
391 			return 1;
392 		}
393 		saved->crtc = saved->attr + state->num_attr;
394 		saved->gfx = saved->crtc + state->num_crtc;
395 		saved->seq = saved->gfx + state->num_gfx;
396 
397 		save_vga_mode(state);
398 	}
399 
400 	if (state->flags & VGA_SAVE_FONTS) {
401 		void __iomem *fbbase;
402 
403 		/* exit if window is less than 32K */
404 		if (state->memsize && state->memsize < 4 * 8192) {
405 			vga_cleanup(state);
406 			return 1;
407 		}
408 		if (!state->memsize)
409 			state->memsize = 8 * 8192;
410 
411 		if (!state->membase)
412 			state->membase = 0xA0000;
413 
414 		fbbase = ioremap(state->membase, state->memsize);
415 
416 		if (!fbbase) {
417 			vga_cleanup(state);
418 			return 1;
419 		}
420 
421 		/*
422 		 * save only first 32K used by vgacon
423 		 */
424 		if (state->flags & VGA_SAVE_FONT0) {
425 			saved->vga_font0 = vmalloc(4 * 8192);
426 			if (!saved->vga_font0) {
427 				iounmap(fbbase);
428 				vga_cleanup(state);
429 				return 1;
430 			}
431 		}
432 		/*
433 		 * largely unused, but if required by the caller
434 		 * we'll just save everything.
435 		 */
436 		if (state->flags & VGA_SAVE_FONT1) {
437 			saved->vga_font1 = vmalloc(state->memsize);
438 			if (!saved->vga_font1) {
439 				iounmap(fbbase);
440 				vga_cleanup(state);
441 				return 1;
442 			}
443 		}
444 		/*
445 		 * Save 8K at plane0[0], and 8K at plane1[16K]
446 		 */
447 		if (state->flags & VGA_SAVE_TEXT) {
448 			saved->vga_text = vmalloc(8192 * 2);
449 			if (!saved->vga_text) {
450 				iounmap(fbbase);
451 				vga_cleanup(state);
452 				return 1;
453 			}
454 		}
455 
456 		save_vga_text(state, fbbase);
457 		iounmap(fbbase);
458 	}
459 	return 0;
460 }
461 
462 int restore_vga (struct vgastate *state)
463 {
464 	if (state->vidstate == NULL)
465 		return 1;
466 
467 	if (state->flags & VGA_SAVE_MODE)
468 		restore_vga_mode(state);
469 
470 	if (state->flags & VGA_SAVE_FONTS) {
471 		void __iomem *fbbase = ioremap(state->membase, state->memsize);
472 
473 		if (!fbbase) {
474 			vga_cleanup(state);
475 			return 1;
476 		}
477 		restore_vga_text(state, fbbase);
478 		iounmap(fbbase);
479 	}
480 
481 	if (state->flags & VGA_SAVE_CMAP)
482 		restore_vga_cmap(state);
483 
484 	vga_cleanup(state);
485 	return 0;
486 }
487 
488 EXPORT_SYMBOL(save_vga);
489 EXPORT_SYMBOL(restore_vga);
490 
491 MODULE_AUTHOR("James Simmons <jsimmons@users.sf.net>");
492 MODULE_DESCRIPTION("VGA State Save/Restore");
493 MODULE_LICENSE("GPL");
494 
495