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light.c revision 1.5
      1 /*	$Id: light.c,v 1.5 2007/03/04 06:00:39 christos 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 1.5 2007/03/04 06:00:39 christos 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 device sc_dev;
     65 
     66 	struct light_devconfig *sc_dc;
     67 };
     68 
     69 struct light_devconfig {
     70 	uint32_t		dc_addr;
     71 
     72 	bus_space_tag_t		dc_st;
     73 	bus_space_handle_t	dc_sh;
     74 
     75 	int			dc_boardrev;
     76 	int                     dc_font;
     77 	struct wsdisplay_font  *dc_fontdata;
     78 };
     79 
     80 /* always 1024x768x8 */
     81 #define LIGHT_XRES	1024
     82 #define LIGHT_YRES	768
     83 #define LIGHT_DEPTH	8
     84 
     85 static int	light_match(struct device *, struct cfdata *, void *);
     86 static void	light_attach(struct device *, struct device *, void *);
     87 
     88 CFATTACH_DECL(light, sizeof(struct light_softc), light_match, light_attach,
     89     NULL, NULL);
     90 
     91 /* wsdisplay_emulops */
     92 static void	light_cursor(void *, int, int, int);
     93 static int	light_mapchar(void *, int, unsigned int *);
     94 static void	light_putchar(void *, int, int, u_int, long);
     95 static void	light_copycols(void *, int, int, int, int);
     96 static void	light_erasecols(void *, int, int, int, long);
     97 static void	light_copyrows(void *, int, int, int);
     98 static void	light_eraserows(void *, int, int, long);
     99 static int	light_allocattr(void *, int, int, int, long *);
    100 
    101 /* wsdisplay_accessops */
    102 static int	light_ioctl(void *, void *, u_long, void *, int, struct lwp *);
    103 static paddr_t	light_mmap(void *, void *, off_t, int);
    104 static int	light_alloc_screen(void *, const struct wsscreen_descr *,
    105     void **, int *, int *, long *);
    106 static void	light_free_screen(void *, void *);
    107 static int	light_show_screen(void *, void *, int,
    108     void (*)(void *, int, int), void *);
    109 
    110 static const struct wsdisplay_accessops light_accessops = {
    111 	.ioctl		= light_ioctl,
    112 	.mmap		= light_mmap,
    113 	.alloc_screen	= light_alloc_screen,
    114 	.free_screen	= light_free_screen,
    115 	.show_screen	= light_show_screen,
    116 	.load_font	= NULL,
    117 	.pollc		= NULL,
    118 	.scroll		= NULL
    119 };
    120 
    121 static const struct wsdisplay_emulops light_emulops = {
    122 	.cursor		= light_cursor,
    123 	.mapchar	= light_mapchar,
    124 	.putchar	= light_putchar,
    125 	.copycols	= light_copycols,
    126 	.erasecols	= light_erasecols,
    127 	.copyrows	= light_copyrows,
    128 	.eraserows	= light_eraserows,
    129 	.allocattr	= light_allocattr,
    130 	.replaceattr	= NULL
    131 };
    132 
    133 static const struct wsscreen_descr light_screen = {
    134 	.name           = "1024x768",
    135 	.ncols          = 128,
    136 	.nrows          = 48,
    137 	.textops        = &light_emulops,
    138 	.fontwidth      = 8,
    139 	.fontheight     = 16,
    140 	.capabilities   = WSSCREEN_WSCOLORS | WSSCREEN_HILIT | WSSCREEN_REVERSE
    141 };
    142 
    143 const struct wsscreen_descr *_light_screenlist[] = {
    144 	&light_screen
    145 };
    146 
    147 static const struct wsscreen_list light_screenlist = {
    148 	sizeof(_light_screenlist) / sizeof(_light_screenlist[0]),
    149 	_light_screenlist
    150 };
    151 
    152 static struct light_devconfig	light_console_dc;
    153 static int			light_is_console = 0;
    154 
    155 #define LIGHT_ATTR_ENCODE(fg, bg)	(((fg << 8) & 0xff00) | (bg * 0x00ff))
    156 #define LIGHT_ATTR_FG(attr)		((attr >> 8) & 0x00ff)
    157 #define LIGHT_ATTR_BG(attr)		(attr & 0x00ff)
    158 
    159 #define LIGHT_IS_LG1(_rev)		((_rev) < 2)	/* else LG2 */
    160 
    161 /*******************************************************************************
    162  * REX routines and helper functions
    163  ******************************************************************************/
    164 
    165 static uint32_t
    166 rex_read(struct light_devconfig *dc, uint32_t rset, uint32_t r)
    167 {
    168 
    169 	return (bus_space_read_4(dc->dc_st, dc->dc_sh, rset + r));
    170 }
    171 
    172 static void
    173 rex_write(struct light_devconfig *dc, uint32_t rset, uint32_t r, uint32_t v)
    174 {
    175 
    176 	bus_space_write_4(dc->dc_st, dc->dc_sh, rset + r, v);
    177 }
    178 
    179 static uint8_t
    180 rex_vc1_read(struct light_devconfig *dc)
    181 {
    182 
    183 	rex_write(dc, REX_PAGE1_GO, REX_P1REG_CFGSEL, REX_CFGSEL_VC1_SYSCTL);
    184 	rex_read(dc, REX_PAGE1_GO, REX_P1REG_VC1_ADDRDATA);
    185 	return (rex_read(dc, REX_PAGE1_SET, REX_P1REG_VC1_ADDRDATA));
    186 }
    187 
    188 static void
    189 rex_vc1_write(struct light_devconfig *dc, uint8_t val)
    190 {
    191 
    192 	rex_write(dc, REX_PAGE1_GO, REX_P1REG_CFGSEL, REX_CFGSEL_VC1_SYSCTL);
    193 	rex_write(dc, REX_PAGE1_SET, REX_P1REG_VC1_ADDRDATA, val);
    194 	rex_write(dc, REX_PAGE1_GO, REX_P1REG_VC1_ADDRDATA, val);
    195 }
    196 
    197 static void
    198 rex_wait(struct light_devconfig *dc)
    199 {
    200 
    201 	while (rex_read(dc, REX_PAGE1_SET,REX_P1REG_CFGMODE) & REX_CFGMODE_BUSY)
    202 		;
    203 }
    204 
    205 static int
    206 rex_revision(struct light_devconfig *dc)
    207 {
    208 
    209 	rex_write(dc, REX_PAGE1_SET, REX_P1REG_CFGSEL, REX_CFGSEL_VC1_LADDR);
    210 	rex_read(dc, REX_PAGE1_GO, REX_P1REG_WCLOCKREV);
    211 	return (rex_read(dc, REX_PAGE1_SET, REX_P1REG_WCLOCKREV) & 0x7);
    212 }
    213 
    214 static void
    215 rex_copy_rect(struct light_devconfig *dc, int from_x, int from_y, int to_x,
    216     int to_y, int width, int height)
    217 {
    218 	int dx, dy, ystarti, yendi;
    219 
    220 	dx = from_x - to_x;
    221 	dy = from_y - to_y;
    222 
    223 	/* adjust for y. NB: STOPONX, STOPONY are inclusive */
    224 	if (to_y > from_y) {
    225 		ystarti = to_y + height - 1;
    226 		yendi = to_y;
    227 	} else {
    228 		ystarti = to_y;
    229 		yendi = to_y + height - 1;
    230 	}
    231 
    232 	rex_wait(dc);
    233 
    234 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_XSTARTI, to_x);
    235 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_XENDI, to_x + width);
    236 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_YSTARTI, ystarti);
    237 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_YENDI, yendi);
    238 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_COMMAND, REX_OP_DRAW |
    239 	    REX_LOGICOP_SRC | REX_OP_FLG_LOGICSRC | REX_OP_FLG_QUADMODE |
    240 	    REX_OP_FLG_BLOCK | REX_OP_FLG_STOPONX | REX_OP_FLG_STOPONY);
    241 	rex_write(dc, REX_PAGE0_GO, REX_P0REG_XYMOVE,
    242 	    ((dx << 16) & 0xffff0000) | (dy & 0x0000ffff));
    243 }
    244 
    245 static void
    246 rex_fill_rect(struct light_devconfig *dc, int from_x, int from_y, int to_x,
    247     int to_y, long attr)
    248 {
    249 
    250 	rex_wait(dc);
    251 
    252 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_YSTARTI, from_y);
    253 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_YENDI, to_y);
    254 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_XSTARTI, from_x);
    255 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_XENDI, to_x);
    256 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_COLORREDI, LIGHT_ATTR_BG(attr));
    257 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_COMMAND, REX_OP_DRAW |
    258 	    REX_LOGICOP_SRC | REX_OP_FLG_QUADMODE | REX_OP_FLG_BLOCK |
    259 	    REX_OP_FLG_STOPONX | REX_OP_FLG_STOPONY);
    260 	rex_read(dc, REX_PAGE0_GO, REX_P0REG_COMMAND);
    261 }
    262 
    263 /*******************************************************************************
    264  * match/attach functions
    265  ******************************************************************************/
    266 
    267 static int
    268 light_match(struct device *parent, struct cfdata *self, void *aux)
    269 {
    270 	struct gio_attach_args *ga = aux;
    271 
    272 	if (ga->ga_addr != LIGHT_ADDR_0 && ga->ga_addr != LIGHT_ADDR_1)
    273 		return (0);
    274 
    275 	if (platform.badaddr(
    276 	    (void *)(ga->ga_ioh + REX_PAGE1_SET + REX_P1REG_XYOFFSET),
    277 	    sizeof(uint32_t)))
    278 		return (0);
    279 
    280 	if (bus_space_read_4(ga->ga_iot, ga->ga_ioh,
    281 	    REX_PAGE1_SET + REX_P1REG_XYOFFSET) != 0x08000800)
    282 		return (0);
    283 
    284 	return (1);
    285 }
    286 
    287 static void
    288 light_attach_common(struct light_devconfig *dc, struct gio_attach_args *ga)
    289 {
    290 
    291 	dc->dc_addr = ga->ga_addr;
    292 	dc->dc_st = ga->ga_iot;
    293 	dc->dc_sh = ga->ga_ioh;
    294 
    295 	dc->dc_boardrev = rex_revision(dc);
    296 
    297 	wsfont_init();
    298 
    299 	dc->dc_font = wsfont_find(NULL, 8, 16, 0, WSDISPLAY_FONTORDER_L2R,
    300 	    WSDISPLAY_FONTORDER_L2R);
    301 
    302 	if (dc->dc_font < 0)
    303 		panic("light_attach_common: no suitable fonts");
    304 
    305 	if (wsfont_lock(dc->dc_font, &dc->dc_fontdata))
    306 		panic("light_attach_common: unable to lock font data");
    307 
    308 	rex_vc1_write(dc, rex_vc1_read(dc) & ~(VC1_SYSCTL_CURSOR |
    309 	    VC1_SYSCTL_CURSOR_ON));
    310 	rex_fill_rect(dc, 0, 0, LIGHT_XRES - 1, LIGHT_YRES - 1, 0);
    311 }
    312 
    313 static void
    314 light_attach(struct device *parent, struct device *self, void *aux)
    315 {
    316 	struct gio_attach_args *ga = aux;
    317 	struct light_softc *sc = (void *)self;
    318 	struct wsemuldisplaydev_attach_args wa;
    319 
    320 	if (light_is_console && ga->ga_addr == light_console_dc.dc_addr) {
    321 		wa.console = 1;
    322 		sc->sc_dc = &light_console_dc;
    323 	} else {
    324 		wa.console = 0;
    325 		sc->sc_dc = malloc(sizeof(struct light_devconfig), M_DEVBUF,
    326 		    M_WAITOK | M_ZERO);
    327 		if (sc->sc_dc == NULL)
    328 			panic("light_attach: out of memory");
    329 
    330 		light_attach_common(sc->sc_dc, ga);
    331 	}
    332 
    333 	aprint_naive(": Display adapter\n");
    334 
    335 	aprint_normal(": SGI LG%d (board revision %d)\n",
    336 	    LIGHT_IS_LG1(sc->sc_dc->dc_boardrev) ? 1 : 2,
    337 	    sc->sc_dc->dc_boardrev);
    338 
    339 	wa.scrdata = &light_screenlist;
    340 	wa.accessops = &light_accessops;
    341 	wa.accesscookie = sc->sc_dc;
    342 
    343 	config_found(&sc->sc_dev, &wa, wsemuldisplaydevprint);
    344 }
    345 
    346 int
    347 light_cnattach(struct gio_attach_args *ga)
    348 {
    349 
    350 	if (!light_match(NULL, NULL, ga))
    351 		return (ENXIO);
    352 
    353 	light_attach_common(&light_console_dc, ga);
    354 
    355 	wsdisplay_cnattach(&light_screen, &light_console_dc, 0, 0,
    356 	    LIGHT_ATTR_ENCODE(WSCOL_WHITE, WSCOL_BLACK));
    357 
    358 	light_is_console = 1;
    359 
    360 	return (0);
    361 }
    362 
    363 /*******************************************************************************
    364  * wsdisplay_emulops
    365  ******************************************************************************/
    366 
    367 static void
    368 light_cursor(void *c, int on, int row, int col)
    369 {
    370 	/* XXX */
    371 }
    372 
    373 static int
    374 light_mapchar(void *c, int ch, unsigned int *cp)
    375 {
    376 	struct light_devconfig *dc = (void *)c;
    377 
    378 	if (dc->dc_fontdata->encoding != WSDISPLAY_FONTENC_ISO) {
    379 		ch = wsfont_map_unichar(dc->dc_fontdata, ch);
    380 
    381 		if (ch < 0)
    382 			goto fail;
    383 	}
    384 
    385 	if (ch < dc->dc_fontdata->firstchar ||
    386 	    ch >= dc->dc_fontdata->firstchar + dc->dc_fontdata->numchars)
    387 		goto fail;
    388 
    389 	*cp = ch;
    390 	return 5;
    391 
    392 fail:
    393 	*cp = ' ';
    394 	return 0;
    395 }
    396 
    397 static void
    398 light_putchar(void *c, int row, int col, u_int ch, long attr)
    399 {
    400         struct light_devconfig *dc = c;
    401 	struct wsdisplay_font *font = dc->dc_fontdata;
    402 	uint8_t *bitmap;
    403 	uint32_t pattern;
    404 	int i, x, y;
    405 
    406 	bitmap = (u_int8_t *)font->data +
    407 	    ((ch - font->firstchar) * font->fontheight * font->stride);
    408 	x = col * font->fontwidth;
    409 	y = row * font->fontheight;
    410 
    411 	rex_wait(dc);
    412 
    413 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_YSTARTI, y);
    414 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_YENDI, y + font->fontheight - 1);
    415 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_XSTARTI, x);
    416 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_XENDI, x + font->fontwidth - 1);
    417 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_COLORREDI, LIGHT_ATTR_FG(attr));
    418 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_COLORBACK, LIGHT_ATTR_BG(attr));
    419 	rex_write(dc, REX_PAGE0_GO,  REX_P0REG_COMMAND, REX_OP_NOP);
    420 
    421 	rex_wait(dc);
    422 
    423 	rex_write(dc, REX_PAGE0_SET, REX_P0REG_COMMAND, REX_OP_DRAW |
    424 	    REX_LOGICOP_SRC | REX_OP_FLG_ENZPATTERN | REX_OP_FLG_QUADMODE |
    425 	    REX_OP_FLG_XYCONTINUE | REX_OP_FLG_STOPONX | REX_OP_FLG_BLOCK |
    426 	    REX_OP_FLG_LENGTH32 | REX_OP_FLG_ZOPAQUE);
    427 
    428 	for (i = 0; i < font->fontheight; i++) {
    429 		/* XXX assumes font->fontwidth == 8 */
    430 		pattern = *bitmap << 24;
    431 		rex_write(dc, REX_PAGE0_GO, REX_P0REG_ZPATTERN, pattern);
    432 		bitmap += font->stride;
    433 	}
    434 }
    435 
    436 /* copy set of columns within the same line */
    437 static void
    438 light_copycols(void *c, int row, int srccol, int dstcol, int ncols)
    439 {
    440 	struct light_devconfig *dc = c;
    441 	struct wsdisplay_font *font = dc->dc_fontdata;
    442 	int from_x, from_y, to_x, to_y, width, height;
    443 
    444 	from_x	= srccol * font->fontwidth;
    445 	from_y	= row * font->fontheight;
    446 	to_x	= dstcol * font->fontwidth;
    447 	to_y	= from_y;
    448 	width	= ncols * font->fontwidth;
    449 	height	= font->fontheight;
    450 
    451 	rex_copy_rect(c, from_x, from_y, to_x, to_y, width, height);
    452 }
    453 
    454 /* erase a set of columns in the same line */
    455 static void
    456 light_erasecols(void *c, int row, int startcol, int ncols, long attr)
    457 {
    458 	struct light_devconfig *dc = c;
    459 	struct wsdisplay_font *font = dc->dc_fontdata;
    460 	int from_x, from_y, to_x, to_y;
    461 
    462 	from_x	= startcol * font->fontwidth;
    463 	from_y	= row * font->fontheight;
    464 	to_x	= from_x + (ncols * font->fontwidth) - 1;
    465 	to_y	= from_y + font->fontheight - 1;
    466 
    467 	rex_fill_rect(c, from_x, from_y, to_x, to_y, attr);
    468 }
    469 
    470 /* copy a set of complete rows */
    471 static void
    472 light_copyrows(void *c, int srcrow, int dstrow, int nrows)
    473 {
    474 	struct light_devconfig *dc = c;
    475 	struct wsdisplay_font *font = dc->dc_fontdata;
    476 	int from_x, from_y, to_x, to_y, width, height;
    477 
    478 	from_x	= 0;
    479 	from_y	= srcrow * font->fontheight;
    480 	to_x	= 0;
    481 	to_y	= dstrow * font->fontheight;
    482 	width	= LIGHT_XRES;
    483 	height	= nrows * font->fontheight;
    484 
    485 	rex_copy_rect(c, from_x, from_y, to_x, to_y, width, height);
    486 }
    487 
    488 /* erase a set of complete rows */
    489 static void
    490 light_eraserows(void *c, int row, int nrows, long attr)
    491 {
    492 	struct light_devconfig *dc = c;
    493 	struct wsdisplay_font *font = dc->dc_fontdata;
    494 	int from_x, from_y, to_x, to_y;
    495 
    496 	from_x	= 0;
    497 	from_y	= row * font->fontheight;
    498 	to_x	= LIGHT_XRES - 1;
    499 	to_y	= from_y + (nrows * font->fontheight) - 1;
    500 
    501 	rex_fill_rect(c, from_x, from_y, to_x, to_y, attr);
    502 }
    503 
    504 static int
    505 light_allocattr(void *c, int fg, int bg, int flags, long *attr)
    506 {
    507 
    508 	if (flags & ~(WSATTR_WSCOLORS | WSATTR_HILIT | WSATTR_REVERSE))
    509 		return (EINVAL);
    510 
    511 	if ((flags & WSATTR_WSCOLORS) == 0) {
    512 		fg = WSCOL_WHITE;
    513 		bg = WSCOL_BLACK;
    514 	}
    515 
    516 	if (flags & WSATTR_HILIT)
    517 		fg += 8;
    518 
    519 	if (flags & WSATTR_REVERSE) {
    520 		int tmp = fg;
    521 		fg = bg;
    522 		bg = tmp;
    523 	}
    524 
    525 	*attr = LIGHT_ATTR_ENCODE(fg, bg);
    526 	return (0);
    527 }
    528 
    529 /*******************************************************************************
    530  * wsdisplay_accessops
    531  ******************************************************************************/
    532 
    533 static int
    534 light_ioctl(void *c, void *vs, u_long cmd, void *data, int flag,
    535     struct lwp *l)
    536 {
    537 	struct wsdisplay_fbinfo *fbinfo = (struct wsdisplay_fbinfo *)data;
    538 
    539 	switch (cmd) {
    540 	case WSDISPLAYIO_GINFO:
    541 		fbinfo->width	= LIGHT_XRES;
    542 		fbinfo->height	= LIGHT_YRES;
    543 		fbinfo->depth	= LIGHT_DEPTH;
    544 		fbinfo->cmsize	= 1 << LIGHT_DEPTH;
    545 		return (0);
    546 
    547 	case WSDISPLAYIO_GMODE:
    548 		*(u_int *)data = WSDISPLAYIO_MODE_EMUL;
    549 		break;
    550 
    551 	case WSDISPLAYIO_GTYPE:
    552 		*(u_int *)data = WSDISPLAY_TYPE_LIGHT;
    553 		return (0);
    554 
    555 	case WSDISPLAYIO_SVIDEO:
    556 		/*
    557 		 * Turning off VC1 will stop refreshing the video ram (or so I
    558 		 * suspect). We'll blank the screen after bringing it back up,
    559 		 * since that's nicer than displaying garbage.
    560 		 */
    561 		if (*(u_int *)data == WSDISPLAYIO_VIDEO_OFF)
    562 			rex_vc1_write(c,rex_vc1_read(c) & ~VC1_SYSCTL_VIDEO_ON);
    563 		else {
    564 			rex_vc1_write(c, rex_vc1_read(c) | VC1_SYSCTL_VIDEO_ON);
    565 			rex_fill_rect(c, 0, 0, LIGHT_XRES-1, LIGHT_YRES-1, 0);
    566 		}
    567 		return (0);
    568 	}
    569 
    570 	return (EPASSTHROUGH);
    571 }
    572 
    573 static paddr_t
    574 light_mmap(void *c, void *vs, off_t off, int prot)
    575 {
    576         struct light_devconfig *dc = c;
    577 
    578 	if (off >= 0x7fff)
    579 		return (-1);
    580 
    581 	return (mips_btop(dc->dc_addr + off));
    582 }
    583 
    584 static int
    585 light_alloc_screen(void *c, const struct wsscreen_descr *type, void **cookiep,
    586     int *curxp, int *curyp, long *attr)
    587 {
    588 
    589 	return (ENOMEM);
    590 }
    591 
    592 static void
    593 light_free_screen(void *c, void *cookie)
    594 {
    595 
    596 	panic("light_free_screen");
    597 }
    598 
    599 static int
    600 light_show_screen(void *c, void *cookie, int waitok,
    601     void (*cb)(void *, int, int), void *cbarg)
    602 {
    603 
    604 	return (0);
    605 }
    606