xref: /netbsd-src/sys/arch/sgimips/gio/light.c (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
1 /*	$Id: light.c,v 1.7 2012/10/27 17:18:09 chs Exp $	*/
2 
3 /*
4  * Copyright (c) 2006 Stephen M. Rumble
5  * Copyright (c) 2003 Ilpo Ruotsalainen
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  *
30  * <<Id: LICENSE_GC,v 1.1 2001/10/01 23:24:05 cgd Exp>>
31  */
32 
33 /*
34  * SGI "Light" graphics, a.k.a. "Entry", "Starter", "LG1", and "LG2".
35  *
36  * 1024x768 8bpp at 60Hz.
37  *
38  * This driver supports the boards found in Indigo R3k and R4k machines.
39  * There is a Crimson variant, but the register offsets differ significantly.
40  *
41  * Light's REX chip is the precursor of the REX3 found in "newport", hence
42  * much similarity exists.
43  */
44 
45 #include <sys/cdefs.h>
46 __KERNEL_RCSID(0, "$NetBSD: light.c,v 1.7 2012/10/27 17:18:09 chs Exp $");
47 
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/device.h>
51 #include <sys/malloc.h>
52 
53 #include <machine/sysconf.h>
54 
55 #include <dev/wscons/wsconsio.h>
56 #include <dev/wscons/wsdisplayvar.h>
57 #include <dev/wsfont/wsfont.h>
58 
59 #include <sgimips/gio/giovar.h>
60 #include <sgimips/gio/lightvar.h>
61 #include <sgimips/gio/lightreg.h>
62 
63 struct light_softc {
64 	struct light_devconfig *sc_dc;
65 };
66 
67 struct light_devconfig {
68 	uint32_t		dc_addr;
69 
70 	bus_space_tag_t		dc_st;
71 	bus_space_handle_t	dc_sh;
72 
73 	int			dc_boardrev;
74 	int                     dc_font;
75 	struct wsdisplay_font  *dc_fontdata;
76 };
77 
78 /* always 1024x768x8 */
79 #define LIGHT_XRES	1024
80 #define LIGHT_YRES	768
81 #define LIGHT_DEPTH	8
82 
83 static int	light_match(device_t, cfdata_t, void *);
84 static void	light_attach(device_t, device_t, void *);
85 
86 CFATTACH_DECL_NEW(light, sizeof(struct light_softc), light_match, light_attach,
87     NULL, NULL);
88 
89 /* wsdisplay_emulops */
90 static void	light_cursor(void *, int, int, int);
91 static int	light_mapchar(void *, int, unsigned int *);
92 static void	light_putchar(void *, int, int, u_int, long);
93 static void	light_copycols(void *, int, int, int, int);
94 static void	light_erasecols(void *, int, int, int, long);
95 static void	light_copyrows(void *, int, int, int);
96 static void	light_eraserows(void *, int, int, long);
97 static int	light_allocattr(void *, int, int, int, long *);
98 
99 /* wsdisplay_accessops */
100 static int	light_ioctl(void *, void *, u_long, void *, int, struct lwp *);
101 static paddr_t	light_mmap(void *, void *, off_t, int);
102 static int	light_alloc_screen(void *, const struct wsscreen_descr *,
103     void **, int *, int *, long *);
104 static void	light_free_screen(void *, void *);
105 static int	light_show_screen(void *, void *, int,
106     void (*)(void *, int, int), void *);
107 
108 static const struct wsdisplay_accessops light_accessops = {
109 	.ioctl		= light_ioctl,
110 	.mmap		= light_mmap,
111 	.alloc_screen	= light_alloc_screen,
112 	.free_screen	= light_free_screen,
113 	.show_screen	= light_show_screen,
114 	.load_font	= NULL,
115 	.pollc		= NULL,
116 	.scroll		= NULL
117 };
118 
119 static const struct wsdisplay_emulops light_emulops = {
120 	.cursor		= light_cursor,
121 	.mapchar	= light_mapchar,
122 	.putchar	= light_putchar,
123 	.copycols	= light_copycols,
124 	.erasecols	= light_erasecols,
125 	.copyrows	= light_copyrows,
126 	.eraserows	= light_eraserows,
127 	.allocattr	= light_allocattr,
128 	.replaceattr	= NULL
129 };
130 
131 static const struct wsscreen_descr light_screen = {
132 	.name           = "1024x768",
133 	.ncols          = 128,
134 	.nrows          = 48,
135 	.textops        = &light_emulops,
136 	.fontwidth      = 8,
137 	.fontheight     = 16,
138 	.capabilities   = WSSCREEN_WSCOLORS | WSSCREEN_HILIT | WSSCREEN_REVERSE
139 };
140 
141 const struct wsscreen_descr *_light_screenlist[] = {
142 	&light_screen
143 };
144 
145 static const struct wsscreen_list light_screenlist = {
146 	sizeof(_light_screenlist) / sizeof(_light_screenlist[0]),
147 	_light_screenlist
148 };
149 
150 static struct light_devconfig	light_console_dc;
151 static int			light_is_console = 0;
152 
153 #define LIGHT_ATTR_ENCODE(fg, bg)	(((fg << 8) & 0xff00) | (bg * 0x00ff))
154 #define LIGHT_ATTR_FG(attr)		((attr >> 8) & 0x00ff)
155 #define LIGHT_ATTR_BG(attr)		(attr & 0x00ff)
156 
157 #define LIGHT_IS_LG1(_rev)		((_rev) < 2)	/* else LG2 */
158 
159 /*******************************************************************************
160  * REX routines and helper functions
161  ******************************************************************************/
162 
163 static uint32_t
164 rex_read(struct light_devconfig *dc, uint32_t rset, uint32_t r)
165 {
166 
167 	return (bus_space_read_4(dc->dc_st, dc->dc_sh, rset + r));
168 }
169 
170 static void
171 rex_write(struct light_devconfig *dc, uint32_t rset, uint32_t r, uint32_t v)
172 {
173 
174 	bus_space_write_4(dc->dc_st, dc->dc_sh, rset + r, v);
175 }
176 
177 static uint8_t
178 rex_vc1_read(struct light_devconfig *dc)
179 {
180 
181 	rex_write(dc, REX_PAGE1_GO, REX_P1REG_CFGSEL, REX_CFGSEL_VC1_SYSCTL);
182 	rex_read(dc, REX_PAGE1_GO, REX_P1REG_VC1_ADDRDATA);
183 	return (rex_read(dc, REX_PAGE1_SET, REX_P1REG_VC1_ADDRDATA));
184 }
185 
186 static void
187 rex_vc1_write(struct light_devconfig *dc, uint8_t val)
188 {
189 
190 	rex_write(dc, REX_PAGE1_GO, REX_P1REG_CFGSEL, REX_CFGSEL_VC1_SYSCTL);
191 	rex_write(dc, REX_PAGE1_SET, REX_P1REG_VC1_ADDRDATA, val);
192 	rex_write(dc, REX_PAGE1_GO, REX_P1REG_VC1_ADDRDATA, val);
193 }
194 
195 static void
196 rex_wait(struct light_devconfig *dc)
197 {
198 
199 	while (rex_read(dc, REX_PAGE1_SET,REX_P1REG_CFGMODE) & REX_CFGMODE_BUSY)
200 		;
201 }
202 
203 static int
204 rex_revision(struct light_devconfig *dc)
205 {
206 
207 	rex_write(dc, REX_PAGE1_SET, REX_P1REG_CFGSEL, REX_CFGSEL_VC1_LADDR);
208 	rex_read(dc, REX_PAGE1_GO, REX_P1REG_WCLOCKREV);
209 	return (rex_read(dc, REX_PAGE1_SET, REX_P1REG_WCLOCKREV) & 0x7);
210 }
211 
212 static void
213 rex_copy_rect(struct light_devconfig *dc, int from_x, int from_y, int to_x,
214     int to_y, int width, int height)
215 {
216 	int dx, dy, ystarti, yendi;
217 
218 	dx = from_x - to_x;
219 	dy = from_y - to_y;
220 
221 	/* adjust for y. NB: STOPONX, STOPONY are inclusive */
222 	if (to_y > from_y) {
223 		ystarti = to_y + height - 1;
224 		yendi = to_y;
225 	} else {
226 		ystarti = to_y;
227 		yendi = to_y + height - 1;
228 	}
229 
230 	rex_wait(dc);
231 
232 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_XSTARTI, to_x);
233 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_XENDI, to_x + width);
234 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_YSTARTI, ystarti);
235 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_YENDI, yendi);
236 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_COMMAND, REX_OP_DRAW |
237 	    REX_LOGICOP_SRC | REX_OP_FLG_LOGICSRC | REX_OP_FLG_QUADMODE |
238 	    REX_OP_FLG_BLOCK | REX_OP_FLG_STOPONX | REX_OP_FLG_STOPONY);
239 	rex_write(dc, REX_PAGE0_GO, REX_P0REG_XYMOVE,
240 	    ((dx << 16) & 0xffff0000) | (dy & 0x0000ffff));
241 }
242 
243 static void
244 rex_fill_rect(struct light_devconfig *dc, int from_x, int from_y, int to_x,
245     int to_y, long attr)
246 {
247 
248 	rex_wait(dc);
249 
250 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_YSTARTI, from_y);
251 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_YENDI, to_y);
252 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_XSTARTI, from_x);
253 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_XENDI, to_x);
254 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_COLORREDI, LIGHT_ATTR_BG(attr));
255 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_COMMAND, REX_OP_DRAW |
256 	    REX_LOGICOP_SRC | REX_OP_FLG_QUADMODE | REX_OP_FLG_BLOCK |
257 	    REX_OP_FLG_STOPONX | REX_OP_FLG_STOPONY);
258 	rex_read(dc, REX_PAGE0_GO, REX_P0REG_COMMAND);
259 }
260 
261 /*******************************************************************************
262  * match/attach functions
263  ******************************************************************************/
264 
265 static int
266 light_match(device_t parent, cfdata_t cf, void *aux)
267 {
268 	struct gio_attach_args *ga = aux;
269 
270 	if (ga->ga_addr != LIGHT_ADDR_0 && ga->ga_addr != LIGHT_ADDR_1)
271 		return (0);
272 
273 	if (platform.badaddr(
274 	    (void *)(ga->ga_ioh + REX_PAGE1_SET + REX_P1REG_XYOFFSET),
275 	    sizeof(uint32_t)))
276 		return (0);
277 
278 	if (bus_space_read_4(ga->ga_iot, ga->ga_ioh,
279 	    REX_PAGE1_SET + REX_P1REG_XYOFFSET) != 0x08000800)
280 		return (0);
281 
282 	return (1);
283 }
284 
285 static void
286 light_attach_common(struct light_devconfig *dc, struct gio_attach_args *ga)
287 {
288 
289 	dc->dc_addr = ga->ga_addr;
290 	dc->dc_st = ga->ga_iot;
291 	dc->dc_sh = ga->ga_ioh;
292 
293 	dc->dc_boardrev = rex_revision(dc);
294 
295 	wsfont_init();
296 
297 	dc->dc_font = wsfont_find(NULL, 8, 16, 0, WSDISPLAY_FONTORDER_L2R,
298 	    WSDISPLAY_FONTORDER_L2R, WSFONT_FIND_BITMAP);
299 
300 	if (dc->dc_font < 0)
301 		panic("light_attach_common: no suitable fonts");
302 
303 	if (wsfont_lock(dc->dc_font, &dc->dc_fontdata))
304 		panic("light_attach_common: unable to lock font data");
305 
306 	rex_vc1_write(dc, rex_vc1_read(dc) & ~(VC1_SYSCTL_CURSOR |
307 	    VC1_SYSCTL_CURSOR_ON));
308 	rex_fill_rect(dc, 0, 0, LIGHT_XRES - 1, LIGHT_YRES - 1, 0);
309 }
310 
311 static void
312 light_attach(device_t parent, device_t self, void *aux)
313 {
314 	struct gio_attach_args *ga = aux;
315 	struct light_softc *sc = device_private(self);
316 	struct wsemuldisplaydev_attach_args wa;
317 
318 	if (light_is_console && ga->ga_addr == light_console_dc.dc_addr) {
319 		wa.console = 1;
320 		sc->sc_dc = &light_console_dc;
321 	} else {
322 		wa.console = 0;
323 		sc->sc_dc = malloc(sizeof(struct light_devconfig), M_DEVBUF,
324 		    M_WAITOK | M_ZERO);
325 		if (sc->sc_dc == NULL)
326 			panic("light_attach: out of memory");
327 
328 		light_attach_common(sc->sc_dc, ga);
329 	}
330 
331 	aprint_naive(": Display adapter\n");
332 
333 	aprint_normal(": SGI LG%d (board revision %d)\n",
334 	    LIGHT_IS_LG1(sc->sc_dc->dc_boardrev) ? 1 : 2,
335 	    sc->sc_dc->dc_boardrev);
336 
337 	wa.scrdata = &light_screenlist;
338 	wa.accessops = &light_accessops;
339 	wa.accesscookie = sc->sc_dc;
340 
341 	config_found(self, &wa, wsemuldisplaydevprint);
342 }
343 
344 int
345 light_cnattach(struct gio_attach_args *ga)
346 {
347 
348 	if (!light_match(NULL, NULL, ga))
349 		return (ENXIO);
350 
351 	light_attach_common(&light_console_dc, ga);
352 
353 	wsdisplay_cnattach(&light_screen, &light_console_dc, 0, 0,
354 	    LIGHT_ATTR_ENCODE(WSCOL_WHITE, WSCOL_BLACK));
355 
356 	light_is_console = 1;
357 
358 	return (0);
359 }
360 
361 /*******************************************************************************
362  * wsdisplay_emulops
363  ******************************************************************************/
364 
365 static void
366 light_cursor(void *c, int on, int row, int col)
367 {
368 	/* XXX */
369 }
370 
371 static int
372 light_mapchar(void *c, int ch, unsigned int *cp)
373 {
374 	struct light_devconfig *dc = (void *)c;
375 
376 	if (dc->dc_fontdata->encoding != WSDISPLAY_FONTENC_ISO) {
377 		ch = wsfont_map_unichar(dc->dc_fontdata, ch);
378 
379 		if (ch < 0)
380 			goto fail;
381 	}
382 
383 	if (ch < dc->dc_fontdata->firstchar ||
384 	    ch >= dc->dc_fontdata->firstchar + dc->dc_fontdata->numchars)
385 		goto fail;
386 
387 	*cp = ch;
388 	return 5;
389 
390 fail:
391 	*cp = ' ';
392 	return 0;
393 }
394 
395 static void
396 light_putchar(void *c, int row, int col, u_int ch, long attr)
397 {
398         struct light_devconfig *dc = c;
399 	struct wsdisplay_font *font = dc->dc_fontdata;
400 	uint8_t *bitmap;
401 	uint32_t pattern;
402 	int i, x, y;
403 
404 	bitmap = (u_int8_t *)font->data +
405 	    ((ch - font->firstchar) * font->fontheight * font->stride);
406 	x = col * font->fontwidth;
407 	y = row * font->fontheight;
408 
409 	rex_wait(dc);
410 
411 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_YSTARTI, y);
412 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_YENDI, y + font->fontheight - 1);
413 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_XSTARTI, x);
414 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_XENDI, x + font->fontwidth - 1);
415 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_COLORREDI, LIGHT_ATTR_FG(attr));
416 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_COLORBACK, LIGHT_ATTR_BG(attr));
417 	rex_write(dc, REX_PAGE0_GO,  REX_P0REG_COMMAND, REX_OP_NOP);
418 
419 	rex_wait(dc);
420 
421 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_COMMAND, REX_OP_DRAW |
422 	    REX_LOGICOP_SRC | REX_OP_FLG_ENZPATTERN | REX_OP_FLG_QUADMODE |
423 	    REX_OP_FLG_XYCONTINUE | REX_OP_FLG_STOPONX | REX_OP_FLG_BLOCK |
424 	    REX_OP_FLG_LENGTH32 | REX_OP_FLG_ZOPAQUE);
425 
426 	for (i = 0; i < font->fontheight; i++) {
427 		/* XXX assumes font->fontwidth == 8 */
428 		pattern = *bitmap << 24;
429 		rex_write(dc, REX_PAGE0_GO, REX_P0REG_ZPATTERN, pattern);
430 		bitmap += font->stride;
431 	}
432 }
433 
434 /* copy set of columns within the same line */
435 static void
436 light_copycols(void *c, int row, int srccol, int dstcol, int ncols)
437 {
438 	struct light_devconfig *dc = c;
439 	struct wsdisplay_font *font = dc->dc_fontdata;
440 	int from_x, from_y, to_x, to_y, width, height;
441 
442 	from_x	= srccol * font->fontwidth;
443 	from_y	= row * font->fontheight;
444 	to_x	= dstcol * font->fontwidth;
445 	to_y	= from_y;
446 	width	= ncols * font->fontwidth;
447 	height	= font->fontheight;
448 
449 	rex_copy_rect(c, from_x, from_y, to_x, to_y, width, height);
450 }
451 
452 /* erase a set of columns in the same line */
453 static void
454 light_erasecols(void *c, int row, int startcol, int ncols, long attr)
455 {
456 	struct light_devconfig *dc = c;
457 	struct wsdisplay_font *font = dc->dc_fontdata;
458 	int from_x, from_y, to_x, to_y;
459 
460 	from_x	= startcol * font->fontwidth;
461 	from_y	= row * font->fontheight;
462 	to_x	= from_x + (ncols * font->fontwidth) - 1;
463 	to_y	= from_y + font->fontheight - 1;
464 
465 	rex_fill_rect(c, from_x, from_y, to_x, to_y, attr);
466 }
467 
468 /* copy a set of complete rows */
469 static void
470 light_copyrows(void *c, int srcrow, int dstrow, int nrows)
471 {
472 	struct light_devconfig *dc = c;
473 	struct wsdisplay_font *font = dc->dc_fontdata;
474 	int from_x, from_y, to_x, to_y, width, height;
475 
476 	from_x	= 0;
477 	from_y	= srcrow * font->fontheight;
478 	to_x	= 0;
479 	to_y	= dstrow * font->fontheight;
480 	width	= LIGHT_XRES;
481 	height	= nrows * font->fontheight;
482 
483 	rex_copy_rect(c, from_x, from_y, to_x, to_y, width, height);
484 }
485 
486 /* erase a set of complete rows */
487 static void
488 light_eraserows(void *c, int row, int nrows, long attr)
489 {
490 	struct light_devconfig *dc = c;
491 	struct wsdisplay_font *font = dc->dc_fontdata;
492 	int from_x, from_y, to_x, to_y;
493 
494 	from_x	= 0;
495 	from_y	= row * font->fontheight;
496 	to_x	= LIGHT_XRES - 1;
497 	to_y	= from_y + (nrows * font->fontheight) - 1;
498 
499 	rex_fill_rect(c, from_x, from_y, to_x, to_y, attr);
500 }
501 
502 static int
503 light_allocattr(void *c, int fg, int bg, int flags, long *attr)
504 {
505 
506 	if (flags & ~(WSATTR_WSCOLORS | WSATTR_HILIT | WSATTR_REVERSE))
507 		return (EINVAL);
508 
509 	if ((flags & WSATTR_WSCOLORS) == 0) {
510 		fg = WSCOL_WHITE;
511 		bg = WSCOL_BLACK;
512 	}
513 
514 	if (flags & WSATTR_HILIT)
515 		fg += 8;
516 
517 	if (flags & WSATTR_REVERSE) {
518 		int tmp = fg;
519 		fg = bg;
520 		bg = tmp;
521 	}
522 
523 	*attr = LIGHT_ATTR_ENCODE(fg, bg);
524 	return (0);
525 }
526 
527 /*******************************************************************************
528  * wsdisplay_accessops
529  ******************************************************************************/
530 
531 static int
532 light_ioctl(void *c, void *vs, u_long cmd, void *data, int flag,
533     struct lwp *l)
534 {
535 	struct wsdisplay_fbinfo *fbinfo = (struct wsdisplay_fbinfo *)data;
536 
537 	switch (cmd) {
538 	case WSDISPLAYIO_GINFO:
539 		fbinfo->width	= LIGHT_XRES;
540 		fbinfo->height	= LIGHT_YRES;
541 		fbinfo->depth	= LIGHT_DEPTH;
542 		fbinfo->cmsize	= 1 << LIGHT_DEPTH;
543 		return (0);
544 
545 	case WSDISPLAYIO_GMODE:
546 		*(u_int *)data = WSDISPLAYIO_MODE_EMUL;
547 		break;
548 
549 	case WSDISPLAYIO_GTYPE:
550 		*(u_int *)data = WSDISPLAY_TYPE_LIGHT;
551 		return (0);
552 
553 	case WSDISPLAYIO_SVIDEO:
554 		/*
555 		 * Turning off VC1 will stop refreshing the video ram (or so I
556 		 * suspect). We'll blank the screen after bringing it back up,
557 		 * since that's nicer than displaying garbage.
558 		 */
559 		if (*(u_int *)data == WSDISPLAYIO_VIDEO_OFF)
560 			rex_vc1_write(c,rex_vc1_read(c) & ~VC1_SYSCTL_VIDEO_ON);
561 		else {
562 			rex_vc1_write(c, rex_vc1_read(c) | VC1_SYSCTL_VIDEO_ON);
563 			rex_fill_rect(c, 0, 0, LIGHT_XRES-1, LIGHT_YRES-1, 0);
564 		}
565 		return (0);
566 	}
567 
568 	return (EPASSTHROUGH);
569 }
570 
571 static paddr_t
572 light_mmap(void *c, void *vs, off_t off, int prot)
573 {
574         struct light_devconfig *dc = c;
575 
576 	if (off >= 0x7fff)
577 		return (-1);
578 
579 	return (mips_btop(dc->dc_addr + off));
580 }
581 
582 static int
583 light_alloc_screen(void *c, const struct wsscreen_descr *type, void **cookiep,
584     int *curxp, int *curyp, long *attr)
585 {
586 
587 	return (ENOMEM);
588 }
589 
590 static void
591 light_free_screen(void *c, void *cookie)
592 {
593 
594 	panic("light_free_screen");
595 }
596 
597 static int
598 light_show_screen(void *c, void *cookie, int waitok,
599     void (*cb)(void *, int, int), void *cbarg)
600 {
601 
602 	return (0);
603 }
604