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cg4.c revision 1.21.4.3
      1 /*	$NetBSD: cg4.c,v 1.21.4.3 2002/06/28 08:22:32 jdolecek Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1992, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This software was developed by the Computer Systems Engineering group
      8  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
      9  * contributed to Berkeley.
     10  *
     11  * All advertising materials mentioning features or use of this software
     12  * must display the following acknowledgement:
     13  *	This product includes software developed by the University of
     14  *	California, Lawrence Berkeley Laboratory.
     15  *
     16  * Redistribution and use in source and binary forms, with or without
     17  * modification, are permitted provided that the following conditions
     18  * are met:
     19  * 1. Redistributions of source code must retain the above copyright
     20  *    notice, this list of conditions and the following disclaimer.
     21  * 2. Redistributions in binary form must reproduce the above copyright
     22  *    notice, this list of conditions and the following disclaimer in the
     23  *    documentation and/or other materials provided with the distribution.
     24  * 3. All advertising materials mentioning features or use of this software
     25  *    must display the following acknowledgement:
     26  *	This product includes software developed by the University of
     27  *	California, Berkeley and its contributors.
     28  * 4. Neither the name of the University nor the names of its contributors
     29  *    may be used to endorse or promote products derived from this software
     30  *    without specific prior written permission.
     31  *
     32  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     33  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     34  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     35  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     36  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     40  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     41  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     42  * SUCH DAMAGE.
     43  *
     44  *	from: @(#)cgthree.c	8.2 (Berkeley) 10/30/93
     45  */
     46 
     47 /*
     48  * color display (cg4) driver.
     49  *
     50  * Credits, history:
     51  * Gordon Ross created this driver based on the cg3 driver from
     52  * the sparc port as distributed in BSD 4.4 Lite, but included
     53  * support for only the "type B" adapter (Brooktree DACs).
     54  * Ezra Story added support for the "type A" (AMD DACs).
     55  *
     56  * Todo:
     57  * Make this driver handle video interrupts.
     58  * Defer colormap updates to vertical retrace interrupts.
     59  */
     60 
     61 #include <sys/param.h>
     62 #include <sys/systm.h>
     63 #include <sys/conf.h>
     64 #include <sys/device.h>
     65 #include <sys/ioctl.h>
     66 #include <sys/malloc.h>
     67 #include <sys/mman.h>
     68 #include <sys/proc.h>
     69 #include <sys/tty.h>
     70 
     71 #include <uvm/uvm_extern.h>
     72 
     73 #include <machine/autoconf.h>
     74 #include <machine/cpu.h>
     75 #include <dev/sun/fbio.h>
     76 #include <machine/idprom.h>
     77 #include <machine/pmap.h>
     78 
     79 #include <sun3/dev/fbvar.h>
     80 #include <sun3/dev/btreg.h>
     81 #include <sun3/dev/cg4reg.h>
     82 #include <sun3/dev/p4reg.h>
     83 
     84 union bt_cmap_u {
     85 	u_char  btcm_char[256 * 3];		/* raw data */
     86 	u_char  btcm_rgb[256][3];		/* 256 R/G/B entries */
     87 	u_int   btcm_int[256 * 3 / 4];	/* the way the chip gets loaded */
     88 };
     89 
     90 #define CG4_TYPE_A 0	/* AMD DACs */
     91 #define CG4_TYPE_B 1	/* Brooktree DACs */
     92 
     93 cdev_decl(cg4);
     94 
     95 #define	CG4_MMAP_SIZE (CG4_OVERLAY_SIZE + CG4_ENABLE_SIZE + CG4_PIXMAP_SIZE)
     96 
     97 #define CMAP_SIZE 256
     98 struct soft_cmap {
     99 	u_char r[CMAP_SIZE];
    100 	u_char g[CMAP_SIZE];
    101 	u_char b[CMAP_SIZE];
    102 };
    103 
    104 /* per-display variables */
    105 struct cg4_softc {
    106 	struct	device sc_dev;		/* base device */
    107 	struct	fbdevice sc_fb;		/* frame buffer device */
    108 	int 	sc_cg4type;		/* A or B */
    109 	int 	sc_pa_overlay;		/* phys. addr. of overlay plane */
    110 	int 	sc_pa_enable;		/* phys. addr. of enable plane */
    111 	int 	sc_pa_pixmap;		/* phys. addr. of color plane */
    112 	int 	sc_video_on;		/* zero if blanked */
    113 	void	*sc_va_cmap;		/* Colormap h/w (mapped KVA) */
    114 	void	*sc_btcm;		/* Soft cmap, Brooktree format */
    115 	void	(*sc_ldcmap) __P((struct cg4_softc *));
    116 	struct soft_cmap sc_cmap;	/* Soft cmap, user format */
    117 };
    118 
    119 /* autoconfiguration driver */
    120 static void	cg4attach __P((struct device *, struct device *, void *));
    121 static int	cg4match __P((struct device *, struct cfdata *, void *));
    122 
    123 struct cfattach cgfour_ca = {
    124 	sizeof(struct cg4_softc), cg4match, cg4attach
    125 };
    126 
    127 extern struct cfdriver cgfour_cd;
    128 
    129 static int	cg4gattr   __P((struct fbdevice *, void *));
    130 static int	cg4gvideo  __P((struct fbdevice *, void *));
    131 static int	cg4svideo  __P((struct fbdevice *, void *));
    132 static int	cg4getcmap __P((struct fbdevice *, void *));
    133 static int	cg4putcmap __P((struct fbdevice *, void *));
    134 
    135 #ifdef	_SUN3_
    136 static void	cg4a_init   __P((struct cg4_softc *));
    137 static void	cg4a_ldcmap __P((struct cg4_softc *));
    138 #endif	/* SUN3 */
    139 
    140 static void	cg4b_init   __P((struct cg4_softc *));
    141 static void	cg4b_ldcmap __P((struct cg4_softc *));
    142 
    143 static struct fbdriver cg4_fbdriver = {
    144 	cg4open, cg4close, cg4mmap, cg4kqfilter, cg4gattr,
    145 	cg4gvideo, cg4svideo,
    146 	cg4getcmap, cg4putcmap };
    147 
    148 /*
    149  * Match a cg4.
    150  */
    151 static int
    152 cg4match(parent, cf, args)
    153 	struct device *parent;
    154 	struct cfdata *cf;
    155 	void *args;
    156 {
    157 	struct confargs *ca = args;
    158 	int mid, p4id, peekval, tmp;
    159 	void *p4reg;
    160 
    161 	/* No default address support. */
    162 	if (ca->ca_paddr == -1)
    163 		return (0);
    164 
    165 	/*
    166 	 * Slight hack here:  The low four bits of the
    167 	 * config flags, if set, restrict the match to
    168 	 * that machine "implementation" only.
    169 	 */
    170 	mid = cf->cf_flags & IDM_IMPL_MASK;
    171 	if (mid && (mid != (cpu_machine_id & IDM_IMPL_MASK)))
    172 		return (0);
    173 
    174 	/*
    175 	 * The config flag 0x10 if set means we are
    176 	 * looking for a Type A board (3/110).
    177 	 */
    178 	if (cf->cf_flags & 0x10) {
    179 #ifdef	_SUN3_
    180 		/* Type A: Check for AMD RAMDACs in control space. */
    181 		if (bus_peek(BUS_OBIO, CG4A_OBIO_CMAP, 1) == -1)
    182 			return (0);
    183 		/* Check for the overlay plane. */
    184 		tmp = ca->ca_paddr + CG4A_OFF_OVERLAY;
    185 		if (bus_peek(ca->ca_bustype, tmp, 1) == -1)
    186 			return (0);
    187 		/* OK, it looks like a Type A. */
    188 		return (1);
    189 #else	/* SUN3 */
    190 		/* Only the Sun3/110 ever has a type A. */
    191 		return (0);
    192 #endif	/* SUN3 */
    193 	}
    194 
    195 	/*
    196 	 * From here on, it is a type B or nothing.
    197 	 * The config flag 0x20 if set means there
    198 	 * is no P4 register.  (bus error)
    199 	 */
    200 	if ((cf->cf_flags & 0x20) == 0) {
    201 		p4reg = bus_tmapin(ca->ca_bustype, ca->ca_paddr);
    202 		peekval = peek_long(p4reg);
    203 		p4id = (peekval == -1) ?
    204 			P4_NOTFOUND : fb_pfour_id(p4reg);
    205 		bus_tmapout(p4reg);
    206 		if (peekval == -1)
    207 			return (0);
    208 		if (p4id != P4_ID_COLOR8P1) {
    209 #ifdef	DEBUG
    210 			printf("cgfour at 0x%x match p4id=0x%x fails\n",
    211 				   ca->ca_paddr, p4id & 0xFF);
    212 #endif
    213 			return (0);
    214 		}
    215 	}
    216 
    217 	/*
    218 	 * Check for CMAP hardware and overlay plane.
    219 	 */
    220 	tmp = ca->ca_paddr + CG4B_OFF_CMAP;
    221 	if (bus_peek(ca->ca_bustype, tmp, 4) == -1)
    222 		return (0);
    223 	tmp = ca->ca_paddr + CG4B_OFF_OVERLAY;
    224 	if (bus_peek(ca->ca_bustype, tmp, 1) == -1)
    225 		return (0);
    226 
    227 	return (1);
    228 }
    229 
    230 /*
    231  * Attach a display.  We need to notice if it is the console, too.
    232  */
    233 static void
    234 cg4attach(parent, self, args)
    235 	struct device *parent, *self;
    236 	void *args;
    237 {
    238 	struct cg4_softc *sc = (struct cg4_softc *)self;
    239 	struct fbdevice *fb = &sc->sc_fb;
    240 	struct confargs *ca = args;
    241 	struct fbtype *fbt;
    242 	int tmp;
    243 
    244 	fbt = &fb->fb_fbtype;
    245 	fbt->fb_type = FBTYPE_SUN4COLOR;
    246 	fbt->fb_width = 1152;	/* default - see below */
    247 	fbt->fb_height = 900;	/* default - see below */
    248 	fbt->fb_depth = 8;
    249 	fbt->fb_cmsize = 256;
    250 	fbt->fb_size = CG4_MMAP_SIZE;
    251 	fb->fb_driver = &cg4_fbdriver;
    252 	fb->fb_private = sc;
    253 	fb->fb_name  = sc->sc_dev.dv_xname;
    254 	fb->fb_flags = sc->sc_dev.dv_cfdata->cf_flags;
    255 
    256 	/*
    257 	 * The config flag 0x10 if set means we are
    258 	 * attaching a Type A (3/110) which has the
    259 	 * AMD RAMDACs in control space, and no P4.
    260 	 */
    261 	if (fb->fb_flags & 0x10) {
    262 #ifdef	_SUN3_
    263 		sc->sc_cg4type = CG4_TYPE_A;
    264 		sc->sc_ldcmap  = cg4a_ldcmap;
    265 		sc->sc_pa_overlay = ca->ca_paddr + CG4A_OFF_OVERLAY;
    266 		sc->sc_pa_enable  = ca->ca_paddr + CG4A_OFF_ENABLE;
    267 		sc->sc_pa_pixmap  = ca->ca_paddr + CG4A_OFF_PIXMAP;
    268 		sc->sc_va_cmap = bus_mapin(BUS_OBIO, CG4A_OBIO_CMAP,
    269 		                           sizeof(struct amd_regs));
    270 		cg4a_init(sc);
    271 #else	/* SUN3 */
    272 		panic("cgfour flags 0x10");
    273 #endif	/* SUN3 */
    274 	} else {
    275 		sc->sc_cg4type = CG4_TYPE_B;
    276 		sc->sc_ldcmap  = cg4b_ldcmap;
    277 		sc->sc_pa_overlay = ca->ca_paddr + CG4B_OFF_OVERLAY;
    278 		sc->sc_pa_enable  = ca->ca_paddr + CG4B_OFF_ENABLE;
    279 		sc->sc_pa_pixmap  = ca->ca_paddr + CG4B_OFF_PIXMAP;
    280 		tmp               = ca->ca_paddr + CG4B_OFF_CMAP;
    281 		sc->sc_va_cmap = bus_mapin(ca->ca_bustype, tmp,
    282 		                           sizeof(struct bt_regs));
    283 		cg4b_init(sc);
    284 	}
    285 
    286 	if ((fb->fb_flags & 0x20) == 0) {
    287 		/* It is supposed to have a P4 register. */
    288 		fb->fb_pfour = bus_mapin(ca->ca_bustype, ca->ca_paddr, 4);
    289 	}
    290 
    291 	/*
    292 	 * Determine width and height as follows:
    293 	 * If it has a P4 register, use that;
    294 	 * else if unit==0, use the EEPROM size,
    295 	 * else make our best guess.
    296 	 */
    297 	if (fb->fb_pfour)
    298 		fb_pfour_setsize(fb);
    299 	else if (sc->sc_dev.dv_unit == 0)
    300 		fb_eeprom_setsize(fb);
    301 	else {
    302 		/* Guess based on machine ID. */
    303 		switch (cpu_machine_id) {
    304 		default:
    305 			/* Leave the defaults set above. */
    306 			break;
    307 		}
    308 	}
    309 	printf(" (%dx%d)\n", fbt->fb_width, fbt->fb_height);
    310 
    311 	/*
    312 	 * Make sure video is on.  This driver uses a
    313 	 * black colormap to blank the screen, so if
    314 	 * there is any global enable, set it here.
    315 	 */
    316 	tmp = 1;
    317 	cg4svideo(fb, &tmp);
    318 	if (fb->fb_pfour)
    319 		fb_pfour_set_video(fb, 1);
    320 	else
    321 		enable_video(1);
    322 
    323 	/* Let /dev/fb know we are here. */
    324 	fb_attach(fb, 4);
    325 }
    326 
    327 int
    328 cg4open(dev, flags, mode, p)
    329 	dev_t dev;
    330 	int flags, mode;
    331 	struct proc *p;
    332 {
    333 	int unit = minor(dev);
    334 
    335 	if (unit >= cgfour_cd.cd_ndevs || cgfour_cd.cd_devs[unit] == NULL)
    336 		return (ENXIO);
    337 	return (0);
    338 }
    339 
    340 int
    341 cg4close(dev, flags, mode, p)
    342 	dev_t dev;
    343 	int flags, mode;
    344 	struct proc *p;
    345 {
    346 
    347 	return (0);
    348 }
    349 
    350 int
    351 cg4ioctl(dev, cmd, data, flags, p)
    352 	dev_t dev;
    353 	u_long cmd;
    354 	caddr_t data;
    355 	int flags;
    356 	struct proc *p;
    357 {
    358 	struct cg4_softc *sc = cgfour_cd.cd_devs[minor(dev)];
    359 
    360 	return (fbioctlfb(&sc->sc_fb, cmd, data));
    361 }
    362 
    363 /*
    364  * Return the address that would map the given device at the given
    365  * offset, allowing for the given protection, or return -1 for error.
    366  *
    367  * X11 expects its mmap'd region to look like this:
    368  * 	128k overlay data memory
    369  * 	128k overlay enable bitmap
    370  * 	1024k color memory
    371  *
    372  * The hardware looks completely different.
    373  */
    374 paddr_t
    375 cg4mmap(dev, off, prot)
    376 	dev_t dev;
    377 	off_t off;
    378 	int prot;
    379 {
    380 	struct cg4_softc *sc = cgfour_cd.cd_devs[minor(dev)];
    381 	int physbase;
    382 
    383 	if (off & PGOFSET)
    384 		panic("cg4mmap");
    385 
    386 	if ((off < 0) || (off >= CG4_MMAP_SIZE))
    387 		return (-1);
    388 
    389 	if (off < 0x40000) {
    390 		if (off < 0x20000) {
    391 			physbase = sc->sc_pa_overlay;
    392 		} else {
    393 			/* enable plane */
    394 			off -= 0x20000;
    395 			physbase = sc->sc_pa_enable;
    396 		}
    397 	} else {
    398 		/* pixel map */
    399 		off -= 0x40000;
    400 		physbase = sc->sc_pa_pixmap;
    401 	}
    402 
    403 	/*
    404 	 * I turned on PMAP_NC here to disable the cache as I was
    405 	 * getting horribly broken behaviour without it.
    406 	 */
    407 	return ((physbase + off) | PMAP_NC);
    408 }
    409 
    410 static void
    411 filt_cg4detach(struct knote *kn)
    412 {
    413 	/* Nothing to do */
    414 }
    415 
    416 static const struct filterops cg4_filtops =
    417 	{ 1, NULL, filt_cg4detach, filt_seltrue };
    418 
    419 int
    420 cg4kqfilter(dev_t dev, struct knote *kn)
    421 {
    422 	switch (kn->kn_filter) {
    423 	case EVFILT_READ:
    424 	case EVFILT_WRITE:
    425 		kn->kn_fop = &cg4_filtops;
    426 		break;
    427 	default:
    428 		return (1);
    429 	}
    430 
    431 	/* Nothing more to do */
    432 	return (0);
    433 }
    434 
    435 /*
    436  * Internal ioctl functions.
    437  */
    438 
    439 /* FBIOGATTR: */
    440 static int  cg4gattr(fb, data)
    441 	struct fbdevice *fb;
    442 	void *data;
    443 {
    444 	struct fbgattr *fba = data;
    445 
    446 	fba->real_type = fb->fb_fbtype.fb_type;
    447 	fba->owner = 0;		/* XXX - TIOCCONS stuff? */
    448 	fba->fbtype = fb->fb_fbtype;
    449 	fba->sattr.flags = 0;
    450 	fba->sattr.emu_type = fb->fb_fbtype.fb_type;
    451 	fba->sattr.dev_specific[0] = -1;
    452 	fba->emu_types[0] = fb->fb_fbtype.fb_type;
    453 	fba->emu_types[1] = -1;
    454 	return (0);
    455 }
    456 
    457 /* FBIOGVIDEO: */
    458 static int  cg4gvideo(fb, data)
    459 	struct fbdevice *fb;
    460 	void *data;
    461 {
    462 	struct cg4_softc *sc = fb->fb_private;
    463 	int *on = data;
    464 
    465 	*on = sc->sc_video_on;
    466 	return (0);
    467 }
    468 
    469 /* FBIOSVIDEO: */
    470 static int cg4svideo(fb, data)
    471 	struct fbdevice *fb;
    472 	void *data;
    473 {
    474 	struct cg4_softc *sc = fb->fb_private;
    475 	int *on = data;
    476 
    477 	if (sc->sc_video_on == *on)
    478 		return (0);
    479 	sc->sc_video_on = *on;
    480 
    481 	(*sc->sc_ldcmap)(sc);
    482 	return (0);
    483 }
    484 
    485 /*
    486  * FBIOGETCMAP:
    487  * Copy current colormap out to user space.
    488  */
    489 static int cg4getcmap(fb, data)
    490 	struct fbdevice *fb;
    491 	void *data;
    492 {
    493 	struct cg4_softc *sc = fb->fb_private;
    494 	struct soft_cmap *cm = &sc->sc_cmap;
    495 	struct fbcmap *fbcm = data;
    496 	int error, start, count;
    497 
    498 	start = fbcm->index;
    499 	count = fbcm->count;
    500 	if ((start < 0) || (start >= CMAP_SIZE) ||
    501 	    (count < 0) || (start + count > CMAP_SIZE) )
    502 		return (EINVAL);
    503 
    504 	if ((error = copyout(&cm->r[start], fbcm->red, count)) != 0)
    505 		return (error);
    506 
    507 	if ((error = copyout(&cm->g[start], fbcm->green, count)) != 0)
    508 		return (error);
    509 
    510 	if ((error = copyout(&cm->b[start], fbcm->blue, count)) != 0)
    511 		return (error);
    512 
    513 	return (0);
    514 }
    515 
    516 /*
    517  * FBIOPUTCMAP:
    518  * Copy new colormap from user space and load.
    519  */
    520 static int cg4putcmap(fb, data)
    521 	struct fbdevice *fb;
    522 	void *data;
    523 {
    524 	struct cg4_softc *sc = fb->fb_private;
    525 	struct soft_cmap *cm = &sc->sc_cmap;
    526 	struct fbcmap *fbcm = data;
    527 	int error, start, count;
    528 
    529 	start = fbcm->index;
    530 	count = fbcm->count;
    531 	if ((start < 0) || (start >= CMAP_SIZE) ||
    532 	    (count < 0) || (start + count > CMAP_SIZE) )
    533 		return (EINVAL);
    534 
    535 	if ((error = copyin(fbcm->red, &cm->r[start], count)) != 0)
    536 		return (error);
    537 
    538 	if ((error = copyin(fbcm->green, &cm->g[start], count)) != 0)
    539 		return (error);
    540 
    541 	if ((error = copyin(fbcm->blue, &cm->b[start], count)) != 0)
    542 		return (error);
    543 
    544 	(*sc->sc_ldcmap)(sc);
    545 	return (0);
    546 }
    547 
    548 /****************************************************************
    549  * Routines for the "Type A" hardware
    550  ****************************************************************/
    551 #ifdef	_SUN3_
    552 
    553 static void
    554 cg4a_init(sc)
    555 	struct cg4_softc *sc;
    556 {
    557 	volatile struct amd_regs *ar = sc->sc_va_cmap;
    558 	struct soft_cmap *cm = &sc->sc_cmap;
    559 	int i;
    560 
    561 	/* Grab initial (current) color map. */
    562 	for(i = 0; i < 256; i++) {
    563 		cm->r[i] = ar->r[i];
    564 		cm->g[i] = ar->g[i];
    565 		cm->b[i] = ar->b[i];
    566 	}
    567 }
    568 
    569 static void
    570 cg4a_ldcmap(sc)
    571 	struct cg4_softc *sc;
    572 {
    573 	volatile struct amd_regs *ar = sc->sc_va_cmap;
    574 	struct soft_cmap *cm = &sc->sc_cmap;
    575 	int i;
    576 
    577 	/*
    578 	 * Now blast them into the chip!
    579 	 * XXX Should use retrace interrupt!
    580 	 * Just set a "need load" bit and let the
    581 	 * retrace interrupt handler do the work.
    582 	 */
    583 	if (sc->sc_video_on) {
    584 		/* Update H/W colormap. */
    585 		for (i = 0; i < 256; i++) {
    586 			ar->r[i] = cm->r[i];
    587 			ar->g[i] = cm->g[i];
    588 			ar->b[i] = cm->b[i];
    589 		}
    590 	} else {
    591 		/* Clear H/W colormap. */
    592 		for (i = 0; i < 256; i++) {
    593 			ar->r[i] = 0;
    594 			ar->g[i] = 0;
    595 			ar->b[i] = 0;
    596 		}
    597 	}
    598 }
    599 #endif	/* SUN3 */
    600 
    601 /****************************************************************
    602  * Routines for the "Type B" hardware
    603  ****************************************************************/
    604 
    605 static void
    606 cg4b_init(sc)
    607 	struct cg4_softc *sc;
    608 {
    609 	volatile struct bt_regs *bt = sc->sc_va_cmap;
    610 	struct soft_cmap *cm = &sc->sc_cmap;
    611 	union bt_cmap_u *btcm;
    612 	int i;
    613 
    614 	/* Need a buffer for colormap format translation. */
    615 	btcm = malloc(sizeof(*btcm), M_DEVBUF, M_WAITOK);
    616 	sc->sc_btcm = btcm;
    617 
    618 	/*
    619 	 * BT458 chip initialization as described in Brooktree's
    620 	 * 1993 Graphics and Imaging Product Databook (DB004-1/93).
    621 	 *
    622 	 * It appears that the 3/60 uses the low byte, and the 3/80
    623 	 * uses the high byte, while both ignore the other bytes.
    624 	 * Writing same value to all bytes works on both.
    625 	 */
    626 	bt->bt_addr = 0x04040404;	/* select read mask register */
    627 	bt->bt_ctrl = ~0;       	/* all planes on */
    628 	bt->bt_addr = 0x05050505;	/* select blink mask register */
    629 	bt->bt_ctrl = 0;        	/* all planes non-blinking */
    630 	bt->bt_addr = 0x06060606;	/* select command register */
    631 	bt->bt_ctrl = 0x43434343;	/* palette enabled, overlay planes enabled */
    632 	bt->bt_addr = 0x07070707;	/* select test register */
    633 	bt->bt_ctrl = 0;        	/* not test mode */
    634 
    635 	/* grab initial (current) color map */
    636 	bt->bt_addr = 0;
    637 #ifdef	_SUN3_
    638 	/* Sun3/60 wants 32-bit access, packed. */
    639 	for (i = 0; i < (256 * 3 / 4); i++)
    640 		btcm->btcm_int[i] = bt->bt_cmap;
    641 #else	/* SUN3 */
    642 	/* Sun3/80 wants 8-bits in the high byte. */
    643 	for (i = 0; i < (256 * 3); i++)
    644 		btcm->btcm_char[i] = bt->bt_cmap >> 24;
    645 #endif	/* SUN3 */
    646 
    647 	/* Transpose into H/W cmap into S/W form. */
    648 	for (i = 0; i < 256; i++) {
    649 		cm->r[i] = btcm->btcm_rgb[i][0];
    650 		cm->g[i] = btcm->btcm_rgb[i][1];
    651 		cm->b[i] = btcm->btcm_rgb[i][2];
    652 	}
    653 }
    654 
    655 static void
    656 cg4b_ldcmap(sc)
    657 	struct cg4_softc *sc;
    658 {
    659 	volatile struct bt_regs *bt = sc->sc_va_cmap;
    660 	struct soft_cmap *cm = &sc->sc_cmap;
    661 	union bt_cmap_u *btcm = sc->sc_btcm;
    662 	int i;
    663 
    664 	/* Transpose S/W cmap into H/W form. */
    665 	for (i = 0; i < 256; i++) {
    666 		btcm->btcm_rgb[i][0] = cm->r[i];
    667 		btcm->btcm_rgb[i][1] = cm->g[i];
    668 		btcm->btcm_rgb[i][2] = cm->b[i];
    669 	}
    670 
    671 	/*
    672 	 * Now blast them into the chip!
    673 	 * XXX Should use retrace interrupt!
    674 	 * Just set a "need load" bit and let the
    675 	 * retrace interrupt handler do the work.
    676 	 */
    677 	bt->bt_addr = 0;
    678 
    679 #ifdef	_SUN3_
    680 	/* Sun3/60 wants 32-bit access, packed. */
    681 	if (sc->sc_video_on) {
    682 		/* Update H/W colormap. */
    683 		for (i = 0; i < (256 * 3 / 4); i++)
    684 			bt->bt_cmap = btcm->btcm_int[i];
    685 	} else {
    686 		/* Clear H/W colormap. */
    687 		for (i = 0; i < (256 * 3 / 4); i++)
    688 			bt->bt_cmap = 0;
    689 	}
    690 #else	/* SUN3 */
    691 	/* Sun3/80 wants 8-bits in the high byte. */
    692 	if (sc->sc_video_on) {
    693 		/* Update H/W colormap. */
    694 		for (i = 0; i < (256 * 3); i++)
    695 			bt->bt_cmap = btcm->btcm_char[i] << 24;
    696 	} else {
    697 		/* Clear H/W colormap. */
    698 		for (i = 0; i < (256 * 3); i++)
    699 			bt->bt_cmap = 0;
    700 	}
    701 #endif	/* SUN3 */
    702 }
    703 
    704