xref: /netbsd-src/sys/dev/ic/hd44780_subr.c (revision 5bacd30de624b391051ebfdfb140b0addcf51e89)
1 /* $NetBSD: hd44780_subr.c,v 1.24 2023/08/08 17:31:13 nat Exp $ */
2 
3 /*
4  * Copyright (c) 2002 Dennis I. Chernoivanov
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 /*
31  * Subroutines for Hitachi HD44870 style displays
32  */
33 
34 #include <sys/cdefs.h>
35 __KERNEL_RCSID(0, "$NetBSD: hd44780_subr.c,v 1.24 2023/08/08 17:31:13 nat Exp $");
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/conf.h>
40 #include <sys/kernel.h>
41 #include <sys/malloc.h>
42 #include <sys/types.h>
43 #include <sys/ioccom.h>
44 
45 #include <machine/autoconf.h>
46 #include <sys/intr.h>
47 #include <sys/bus.h>
48 
49 #include <dev/wscons/wsdisplayvar.h>
50 #include <dev/wscons/wsconsio.h>
51 #include <dev/wscons/wscons_callbacks.h>
52 
53 #include <dev/ic/hd44780reg.h>
54 #include <dev/ic/hd44780var.h>
55 
56 #define COORD_TO_IDX(x, y)	((y) * sc->sc_cols + (x))
57 #define COORD_TO_DADDR(x, y)	((y) * HD_ROW2_ADDR + (x))
58 #define IDX_TO_ROW(idx)		((idx) / sc->sc_cols)
59 #define IDX_TO_COL(idx)		((idx) % sc->sc_cols)
60 #define IDX_TO_DADDR(idx)	(IDX_TO_ROW((idx)) * HD_ROW2_ADDR + \
61 				IDX_TO_COL((idx)))
62 #define DADDR_TO_ROW(daddr)	((daddr) / HD_ROW2_ADDR)
63 #define DADDR_TO_COL(daddr)	((daddr) % HD_ROW2_ADDR)
64 #define DADDR_TO_CHIPDADDR(daddr)	((daddr) % (HD_ROW2_ADDR * 2))
65 #define DADDR_TO_CHIPNO(daddr)	((daddr) / (HD_ROW2_ADDR * 2))
66 
67 static void	hlcd_cursor(void *, int, int, int);
68 static int	hlcd_mapchar(void *, int, unsigned int *);
69 static void	hlcd_putchar(void *, int, int, u_int, long);
70 static void	hlcd_copycols(void *, int, int, int,int);
71 static void	hlcd_erasecols(void *, int, int, int, long);
72 static void	hlcd_copyrows(void *, int, int, int);
73 static void	hlcd_eraserows(void *, int, int, long);
74 static int	hlcd_allocattr(void *, int, int, int, long *);
75 static void	hlcd_updatechar(struct hd44780_chip *, int, int);
76 static void	hlcd_redraw(void *);
77 
78 const struct wsdisplay_emulops hlcd_emulops = {
79 	hlcd_cursor,
80 	hlcd_mapchar,
81 	hlcd_putchar,
82 	hlcd_copycols,
83 	hlcd_erasecols,
84 	hlcd_copyrows,
85 	hlcd_eraserows,
86 	hlcd_allocattr
87 };
88 
89 static int	hlcd_ioctl(void *, void *, u_long, void *, int, struct lwp *);
90 static paddr_t	hlcd_mmap(void *, void *, off_t, int);
91 static int	hlcd_alloc_screen(void *, const struct wsscreen_descr *,
92 		    void **, int *, int *, long *);
93 static void	hlcd_free_screen(void *, void *);
94 static int	hlcd_show_screen(void *, void *, int,
95 		    void (*) (void *, int, int), void *);
96 
97 const struct wsdisplay_accessops hlcd_accessops = {
98 	hlcd_ioctl,
99 	hlcd_mmap,
100 	hlcd_alloc_screen,
101 	hlcd_free_screen,
102 	hlcd_show_screen,
103 	0 /* load_font */
104 };
105 
106 static void
hlcd_cursor(void * id,int on,int row,int col)107 hlcd_cursor(void *id, int on, int row, int col)
108 {
109 	struct hlcd_screen *hdscr = id;
110 
111 	hdscr->hlcd_curon = on;
112 	hdscr->hlcd_curx = col;
113 	hdscr->hlcd_cury = row;
114 }
115 
116 static int
hlcd_mapchar(void * id,int uni,unsigned int * index)117 hlcd_mapchar(void *id, int uni, unsigned int *index)
118 {
119 
120 	if (uni < 256) {
121 		*index = uni;
122 		return 5;
123 	}
124 	*index = ' ';
125 	return 0;
126 }
127 
128 static void
hlcd_putchar(void * id,int row,int col,u_int c,long attr)129 hlcd_putchar(void *id, int row, int col, u_int c, long attr)
130 {
131 	struct hlcd_screen *hdscr = id;
132 
133 	c &= 0xff;
134 	if (row > 0 && (hdscr->hlcd_sc->sc_flags & (HD_MULTILINE|HD_MULTICHIP)))
135 		hdscr->image[hdscr->hlcd_sc->sc_cols * row + col] = c;
136 	else
137 		hdscr->image[col] = c;
138 }
139 
140 /*
141  * copies columns inside a row.
142  */
143 static void
hlcd_copycols(void * id,int row,int srccol,int dstcol,int ncols)144 hlcd_copycols(void *id, int row, int srccol, int dstcol, int ncols)
145 {
146 	struct hlcd_screen *hdscr = id;
147 
148 	if ((dstcol + ncols - 1) > hdscr->hlcd_sc->sc_cols)
149 		ncols = hdscr->hlcd_sc->sc_cols - srccol;
150 
151 	if (row > 0 && (hdscr->hlcd_sc->sc_flags & (HD_MULTILINE|HD_MULTICHIP)))
152 		memmove(&hdscr->image[hdscr->hlcd_sc->sc_cols * row + dstcol],
153 		    &hdscr->image[hdscr->hlcd_sc->sc_cols * row + srccol],
154 		    ncols);
155 	else
156 		memmove(&hdscr->image[dstcol], &hdscr->image[srccol], ncols);
157 }
158 
159 
160 /*
161  * Erases a bunch of chars inside one row.
162  */
163 static void
hlcd_erasecols(void * id,int row,int startcol,int ncols,long fillattr)164 hlcd_erasecols(void *id, int row, int startcol, int ncols, long fillattr)
165 {
166 	struct hlcd_screen *hdscr = id;
167 
168 	if ((startcol + ncols) > hdscr->hlcd_sc->sc_cols)
169 		ncols = hdscr->hlcd_sc->sc_cols - startcol;
170 
171 	if (row > 0 && (hdscr->hlcd_sc->sc_flags & (HD_MULTILINE|HD_MULTICHIP)))
172 		memset(&hdscr->image[hdscr->hlcd_sc->sc_cols * row + startcol],
173 		    ' ', ncols);
174 	else
175 		memset(&hdscr->image[startcol], ' ', ncols);
176 }
177 
178 
179 static void
hlcd_copyrows(void * id,int srcrow,int dstrow,int nrows)180 hlcd_copyrows(void *id, int srcrow, int dstrow, int nrows)
181 {
182 	struct hlcd_screen *hdscr = id;
183 	int ncols = hdscr->hlcd_sc->sc_cols;
184 
185 	if (!(hdscr->hlcd_sc->sc_flags & (HD_MULTILINE|HD_MULTICHIP)))
186 		return;
187 	memmove(&hdscr->image[dstrow * ncols], &hdscr->image[srcrow * ncols],
188 	    nrows * ncols);
189 }
190 
191 static void
hlcd_eraserows(void * id,int startrow,int nrows,long fillattr)192 hlcd_eraserows(void *id, int startrow, int nrows, long fillattr)
193 {
194 	struct hlcd_screen *hdscr = id;
195 	int ncols = hdscr->hlcd_sc->sc_cols;
196 
197 	memset(&hdscr->image[startrow * ncols], ' ', ncols * nrows);
198 }
199 
200 
201 static int
hlcd_allocattr(void * id,int fg,int bg,int flags,long * attrp)202 hlcd_allocattr(void *id, int fg, int bg, int flags, long *attrp)
203 {
204 
205         *attrp = flags;
206         return 0;
207 }
208 
209 static int
hlcd_ioctl(void * v,void * vs,u_long cmd,void * data,int flag,struct lwp * l)210 hlcd_ioctl(void *v, void *vs, u_long cmd, void *data, int flag, struct lwp *l)
211 {
212 
213 	switch (cmd) {
214 	case WSDISPLAYIO_GTYPE:
215 		*(u_int *)data = WSDISPLAY_TYPE_HDLCD;
216 		break;
217 
218 	case WSDISPLAYIO_SVIDEO:
219 		break;
220 
221 	case WSDISPLAYIO_GVIDEO:
222 		*(u_int *)data = WSDISPLAYIO_VIDEO_ON;
223 		break;
224 
225 	default:
226 		return EPASSTHROUGH;
227 	}
228 	return 0;
229 }
230 
231 static paddr_t
hlcd_mmap(void * v,void * vs,off_t offset,int prot)232 hlcd_mmap(void *v, void *vs, off_t offset, int prot)
233 {
234 
235 	return -1;
236 }
237 
238 static int
hlcd_alloc_screen(void * v,const struct wsscreen_descr * type,void ** cookiep,int * curxp,int * curyp,long * defattrp)239 hlcd_alloc_screen(void *v, const struct wsscreen_descr *type, void **cookiep,
240     int *curxp, int *curyp, long *defattrp)
241 {
242 	struct hlcd_screen *hdscr = v, *new;
243 
244 	new = *cookiep = malloc(sizeof(struct hlcd_screen),
245 				M_DEVBUF, M_WAITOK|M_ZERO);
246 	new->hlcd_sc = hdscr->hlcd_sc;
247 	new->image = malloc(PAGE_SIZE, M_DEVBUF, M_WAITOK);
248 	memset(new->image, ' ', PAGE_SIZE);
249 	*curxp = *curyp = *defattrp = 0;
250 	return 0;
251 }
252 
253 static void
hlcd_free_screen(void * v,void * cookie)254 hlcd_free_screen(void *v, void *cookie)
255 {
256 }
257 
258 static int
hlcd_show_screen(void * v,void * cookie,int waitok,void (* cb)(void *,int,int),void * cbarg)259 hlcd_show_screen(void *v, void *cookie, int waitok,
260     void (*cb)(void *, int, int), void *cbarg)
261 {
262 	struct hlcd_screen *hdscr = v;
263 
264 	hdscr->hlcd_sc->sc_curscr = cookie;
265 	callout_schedule(&hdscr->hlcd_sc->redraw, 1);
266 	return 0;
267 }
268 
269 static void
hlcd_updatechar(struct hd44780_chip * sc,int daddr,int c)270 hlcd_updatechar(struct hd44780_chip *sc, int daddr, int c)
271 {
272 	int curdaddr, en, chipdaddr;
273 
274 	curdaddr = COORD_TO_DADDR(sc->sc_screen.hlcd_curx,
275 	    sc->sc_screen.hlcd_cury);
276 	en = DADDR_TO_CHIPNO(daddr);
277 	chipdaddr = DADDR_TO_CHIPDADDR(daddr);
278 	if (daddr != curdaddr)
279 		hd44780_ir_write(sc, en, cmd_ddramset(chipdaddr));
280 
281 	hd44780_dr_write(sc, en, c);
282 
283 	daddr++;
284 	sc->sc_screen.hlcd_curx = DADDR_TO_COL(daddr);
285 	sc->sc_screen.hlcd_cury = DADDR_TO_ROW(daddr);
286 }
287 
288 static void
hlcd_redraw(void * arg)289 hlcd_redraw(void *arg)
290 {
291 	struct hd44780_chip *sc = arg;
292 	int len, crsridx, startidx, x, y;
293 	int old_en, new_en;
294 	uint8_t *img, *curimg;
295 
296 	if (sc->sc_curscr == NULL)
297 		return;
298 
299 	if (sc->sc_flags & HD_MULTILINE)
300 		len = 2 * sc->sc_cols;
301 	else
302 		len = sc->sc_cols;
303 
304 	if (sc->sc_flags & HD_MULTICHIP)
305 		len = len * 2;
306 
307 	x = sc->sc_screen.hlcd_curx;
308 	y = sc->sc_screen.hlcd_cury;
309 	old_en = DADDR_TO_CHIPNO(COORD_TO_DADDR(x, y));
310 
311 	img = sc->sc_screen.image;
312 	curimg = sc->sc_curscr->image;
313 	startidx = crsridx =
314 	    COORD_TO_IDX(sc->sc_screen.hlcd_curx, sc->sc_screen.hlcd_cury);
315 	do {
316 		if (img[crsridx] != curimg[crsridx]) {
317 			hlcd_updatechar(sc, IDX_TO_DADDR(crsridx),
318 			    curimg[crsridx]);
319 			img[crsridx] = curimg[crsridx];
320 		}
321 		crsridx++;
322 		if (crsridx == len)
323 			crsridx = 0;
324 	} while (crsridx != startidx);
325 
326 	x = sc->sc_curscr->hlcd_curx;
327 	y = sc->sc_curscr->hlcd_cury;
328 	new_en = DADDR_TO_CHIPNO(COORD_TO_DADDR(x, y));
329 
330 	if (sc->sc_screen.hlcd_curx != sc->sc_curscr->hlcd_curx ||
331 	    sc->sc_screen.hlcd_cury != sc->sc_curscr->hlcd_cury) {
332 
333 		x = sc->sc_screen.hlcd_curx = sc->sc_curscr->hlcd_curx;
334 		y = sc->sc_screen.hlcd_cury = sc->sc_curscr->hlcd_cury;
335 
336 		hd44780_ir_write(sc, new_en, cmd_ddramset(
337 		    DADDR_TO_CHIPDADDR(COORD_TO_DADDR(x, y))));
338 
339 	}
340 
341 	/* visible cursor switched to other chip */
342 	if (old_en != new_en && sc->sc_screen.hlcd_curon) {
343 		hd44780_ir_write(sc, old_en, cmd_dispctl(1, 0, 0));
344 		hd44780_ir_write(sc, new_en, cmd_dispctl(1, 1, 1));
345 	}
346 
347 	if (sc->sc_screen.hlcd_curon != sc->sc_curscr->hlcd_curon) {
348 		sc->sc_screen.hlcd_curon = sc->sc_curscr->hlcd_curon;
349 		if (sc->sc_screen.hlcd_curon)
350 			hd44780_ir_write(sc, new_en, cmd_dispctl(1, 1, 1));
351 		else
352 			hd44780_ir_write(sc, new_en, cmd_dispctl(1, 0, 0));
353 	}
354 
355 	callout_schedule(&sc->redraw, 1);
356 }
357 
358 
359 /*
360  * Finish device attach. sc_writereg, sc_readreg and sc_flags must be properly
361  * initialized prior to this call.
362  */
363 void
hd44780_attach_subr(struct hd44780_chip * sc)364 hd44780_attach_subr(struct hd44780_chip *sc)
365 {
366 	int err = 0;
367 
368 	/* Putc/getc are supposed to be set by platform-dependent code. */
369 	if ((sc->sc_writereg == NULL) || (sc->sc_readreg == NULL))
370 		sc->sc_dev_ok = 0;
371 
372 	/* Make sure that HD_MAX_CHARS is enough. */
373 	if ((sc->sc_flags & HD_MULTILINE) && (2 * sc->sc_cols > HD_MAX_CHARS))
374 		sc->sc_dev_ok = 0;
375 	else if (sc->sc_cols > HD_MAX_CHARS)
376 		sc->sc_dev_ok = 0;
377 
378 	if (sc->sc_dev_ok) {
379 		if ((sc->sc_flags & HD_UP) == 0)
380 			err = hd44780_init(sc);
381 		if (err != 0)
382 			aprint_error_dev(sc->sc_dev,
383 			    "LCD not responding or unconnected\n");
384 	}
385 
386 	sc->sc_screen.hlcd_sc = sc;
387 
388 	sc->sc_screen.image = malloc(PAGE_SIZE, M_DEVBUF, M_WAITOK);
389 	memset(sc->sc_screen.image, ' ', PAGE_SIZE);
390 	sc->sc_curscr = NULL;
391 	sc->sc_curchip = 0;
392 	callout_init(&sc->redraw, 0);
393 	callout_setfunc(&sc->redraw, hlcd_redraw, sc);
394 }
395 
hd44780_detach(struct hd44780_chip * sc)396 void hd44780_detach(struct hd44780_chip *sc)
397 {
398 	callout_stop(&sc->redraw);
399 	callout_destroy(&sc->redraw);
400 
401 	if (sc->sc_screen.image)
402 		free(sc->sc_screen.image, M_DEVBUF);
403 }
404 
hd44780_init(struct hd44780_chip * sc)405 int hd44780_init(struct hd44780_chip *sc)
406 {
407 	int ret;
408 
409 	ret = hd44780_chipinit(sc, 0);
410 	if (ret != 0 || !(sc->sc_flags & HD_MULTICHIP))
411 		return ret;
412 	else
413 		return hd44780_chipinit(sc, 1);
414 }
415 
416 /*
417  * Initialize 4-bit or 8-bit connected device.
418  */
419 int
hd44780_chipinit(struct hd44780_chip * sc,uint32_t en)420 hd44780_chipinit(struct hd44780_chip *sc, uint32_t en)
421 {
422 	uint8_t cmd, dat;
423 
424 	sc->sc_flags &= ~(HD_TIMEDOUT|HD_UP);
425 	sc->sc_dev_ok = 1;
426 
427 	cmd = cmd_init(sc->sc_flags & HD_8BIT);
428 	hd44780_ir_write(sc, en, cmd);
429 	delay(HD_TIMEOUT_LONG);
430 	hd44780_ir_write(sc, en, cmd);
431 	hd44780_ir_write(sc, en, cmd);
432 
433 	cmd = cmd_funcset(
434 			sc->sc_flags & HD_8BIT,
435 			sc->sc_flags & HD_MULTILINE,
436 			sc->sc_flags & HD_BIGFONT);
437 
438 	if ((sc->sc_flags & HD_8BIT) == 0)
439 		hd44780_ir_write(sc, en, cmd);
440 
441 	sc->sc_flags |= HD_UP;
442 
443 	hd44780_ir_write(sc, en, cmd);
444 	hd44780_ir_write(sc, en, cmd_dispctl(0, 0, 0));
445 	hd44780_ir_write(sc, en, cmd_clear());
446 	hd44780_ir_write(sc, en, cmd_modset(1, 0));
447 
448 	if (sc->sc_flags & HD_TIMEDOUT) {
449 		sc->sc_flags &= ~HD_UP;
450 		return EIO;
451 	}
452 
453 	/* Turn display on and clear it. */
454 	hd44780_ir_write(sc, en, cmd_clear());
455 	hd44780_ir_write(sc, en, cmd_dispctl(1, 0, 0));
456 
457 	/* Attempt a simple probe for presence */
458 	hd44780_ir_write(sc, en, cmd_ddramset(0x5));
459 	hd44780_ir_write(sc, en, cmd_shift(0, 1));
460 	hd44780_busy_wait(sc, en);
461 	if (!(sc->sc_flags & HD_WRITEONLY) &&
462 	    (dat = hd44780_ir_read(sc, en) & 0x7f) != 0x6) {
463 		sc->sc_dev_ok = 0;
464 		sc->sc_flags &= ~HD_UP;
465 		return EIO;
466 	}
467 	hd44780_ir_write(sc, en, cmd_ddramset(0));
468 
469 	return 0;
470 }
471 
472 /*
473  * Standard hd44780 ioctl() functions.
474  */
475 int
hd44780_ioctl_subr(struct hd44780_chip * sc,u_long cmd,void * data)476 hd44780_ioctl_subr(struct hd44780_chip *sc, u_long cmd, void *data)
477 {
478 	uint8_t tmp;
479 	int error = 0;
480 	uint32_t en = sc->sc_curchip;
481 
482 #define hd44780_io()	((struct hd44780_io *)data)
483 #define hd44780_info()	((struct hd44780_info *)data)
484 #define hd44780_ctrl()	((struct hd44780_dispctl *)data)
485 
486 	switch (cmd) {
487 	case HLCD_CLEAR:
488 		/* Clear the LCD. */
489 		hd44780_ir_write(sc, en, cmd_clear());
490 		break;
491 
492 	case HLCD_CURSOR_LEFT:
493 		/* Move the cursor one position to the left. */
494 		hd44780_ir_write(sc, en, cmd_shift(0, 0));
495 			break;
496 
497 	case HLCD_CURSOR_RIGHT:
498 		/* Move the cursor one position to the right. */
499 		hd44780_ir_write(sc, en, cmd_shift(0, 1));
500 		break;
501 
502 	case HLCD_DISPCTL:
503 		/* Control the LCD. */
504 		hd44780_ir_write(sc, en, cmd_dispctl(
505 					hd44780_ctrl()->display_on,
506 					hd44780_ctrl()->cursor_on,
507 					hd44780_ctrl()->blink_on));
508 		break;
509 
510 	case HLCD_GET_INFO:
511 		/* Get LCD configuration. */
512 		hd44780_info()->lines
513 			= (sc->sc_flags & HD_MULTILINE) ? 2 : 1;
514 		if (sc->sc_flags & HD_MULTICHIP)
515 			hd44780_info()->lines *= 2;
516 		hd44780_info()->phys_rows = sc->sc_cols;
517 		hd44780_info()->virt_rows = sc->sc_vcols;
518 		hd44780_info()->is_wide = sc->sc_flags & HD_8BIT;
519 		hd44780_info()->is_bigfont = sc->sc_flags & HD_BIGFONT;
520 		hd44780_info()->kp_present = sc->sc_flags & HD_KEYPAD;
521 		break;
522 
523 
524 	case HLCD_RESET:
525 		/* Reset the LCD. */
526 		error = hd44780_init(sc);
527 		break;
528 
529 	case HLCD_GET_CURSOR_POS:
530 		/* Get the current cursor position. */
531 		hd44780_io()->dat = (hd44780_ir_read(sc, en) & 0x7f);
532 		break;
533 
534 	case HLCD_SET_CURSOR_POS:
535 		/* Set the cursor position. */
536 		hd44780_ir_write(sc, en, cmd_ddramset(hd44780_io()->dat));
537 		break;
538 
539 	case HLCD_GETC:
540 		/* Get the value at the current cursor position. */
541 		tmp = (hd44780_ir_read(sc, en) & 0x7f);
542 		hd44780_ir_write(sc, en, cmd_ddramset(tmp));
543 		hd44780_io()->dat = hd44780_dr_read(sc, en);
544 		break;
545 
546 	case HLCD_PUTC:
547 		/* Set the character at the cursor position + advance cursor. */
548 		hd44780_dr_write(sc, en, hd44780_io()->dat);
549 		break;
550 
551 	case HLCD_SHIFT_LEFT:
552 		/* Shift display left. */
553 		hd44780_ir_write(sc, en, cmd_shift(1, 0));
554 		break;
555 
556 	case HLCD_SHIFT_RIGHT:
557 		/* Shift display right. */
558 		hd44780_ir_write(sc, en, cmd_shift(1, 1));
559 		break;
560 
561 	case HLCD_HOME:
562 		/* Return home. */
563 		hd44780_ir_write(sc, en, cmd_rethome());
564 		break;
565 
566 	case HLCD_WRITE:
567 		/* Write a string to the LCD virtual area. */
568 		error = hd44780_ddram_io(sc, en, hd44780_io(), HD_DDRAM_WRITE);
569 		break;
570 
571 	case HLCD_READ:
572 		/* Read LCD virtual area. */
573 		error = hd44780_ddram_io(sc, en, hd44780_io(), HD_DDRAM_READ);
574 		break;
575 
576 	case HLCD_REDRAW:
577 		/* Write to the LCD visible area. */
578 		hd44780_ddram_redraw(sc, en, hd44780_io());
579 		break;
580 
581 	case HLCD_WRITE_INST:
582 		/* Write raw instruction. */
583 		hd44780_ir_write(sc, en, hd44780_io()->dat);
584 		break;
585 
586 	case HLCD_WRITE_DATA:
587 		/* Write raw data. */
588 		hd44780_dr_write(sc, en, hd44780_io()->dat);
589 		break;
590 
591 	case HLCD_GET_CHIPNO:
592 		/* Get current chip 0 or 1 (top or bottom) */
593 		*(uint8_t *)data = sc->sc_curchip;
594 		break;
595 
596 	case HLCD_SET_CHIPNO:
597 		/* Set current chip 0 or 1 (top or bottom) */
598 		sc->sc_curchip = *(uint8_t *)data;
599 		break;
600 
601 	default:
602 		error = EINVAL;
603 	}
604 
605 	if (sc->sc_flags & HD_TIMEDOUT)
606 		error = EIO;
607 
608 	return error;
609 }
610 
611 /*
612  * Read/write particular area of the LCD screen.
613  */
614 int
hd44780_ddram_io(struct hd44780_chip * sc,uint32_t en,struct hd44780_io * io,uint8_t dir)615 hd44780_ddram_io(struct hd44780_chip *sc, uint32_t en, struct hd44780_io *io,
616     uint8_t dir)
617 {
618 	uint8_t hi;
619 	uint8_t addr;
620 	int error = 0;
621 	uint8_t i = 0;
622 
623 	if (io->dat < sc->sc_vcols) {
624 		hi = HD_ROW1_ADDR + sc->sc_vcols;
625 		addr = HD_ROW1_ADDR + io->dat;
626 		for (; (addr < hi) && (i < io->len); addr++, i++) {
627 			hd44780_ir_write(sc, en, cmd_ddramset(addr));
628 			if (dir == HD_DDRAM_READ)
629 				io->buf[i] = hd44780_dr_read(sc, en);
630 			else
631 				hd44780_dr_write(sc, en, io->buf[i]);
632 		}
633 	}
634 	if (io->dat < 2 * sc->sc_vcols) {
635 		hi = HD_ROW2_ADDR + sc->sc_vcols;
636 		if (io->dat >= sc->sc_vcols)
637 			addr = HD_ROW2_ADDR + io->dat - sc->sc_vcols;
638 		else
639 			addr = HD_ROW2_ADDR;
640 		for (; (addr < hi) && (i < io->len); addr++, i++) {
641 			hd44780_ir_write(sc, en, cmd_ddramset(addr));
642 			if (dir == HD_DDRAM_READ)
643 				io->buf[i] = hd44780_dr_read(sc, en);
644 			else
645 				hd44780_dr_write(sc, en, io->buf[i]);
646 		}
647 		if (i < io->len)
648 			io->len = i;
649 	} else {
650 		error = EINVAL;
651 	}
652 	return error;
653 }
654 
655 /*
656  * Write to the visible area of the display.
657  */
658 void
hd44780_ddram_redraw(struct hd44780_chip * sc,uint32_t en,struct hd44780_io * io)659 hd44780_ddram_redraw(struct hd44780_chip *sc, uint32_t en,
660     struct hd44780_io *io)
661 {
662 	uint8_t i;
663 
664 	hd44780_ir_write(sc, en, cmd_clear());
665 	hd44780_ir_write(sc, en, cmd_rethome());
666 	hd44780_ir_write(sc, en, cmd_ddramset(HD_ROW1_ADDR));
667 	for (i = 0; (i < io->len) && (i < sc->sc_cols); i++) {
668 		hd44780_dr_write(sc, en, io->buf[i]);
669 	}
670 	hd44780_ir_write(sc, en, cmd_ddramset(HD_ROW2_ADDR));
671 	for (; (i < io->len); i++)
672 		hd44780_dr_write(sc, en, io->buf[i]);
673 }
674 
675 void
hd44780_busy_wait(struct hd44780_chip * sc,uint32_t en)676 hd44780_busy_wait(struct hd44780_chip *sc, uint32_t en)
677 {
678 	int nloops = 100;
679 
680 	if (sc->sc_flags & HD_TIMEDOUT)
681 		return;
682 
683 	while (nloops-- && (hd44780_ir_read(sc, en) & BUSY_FLAG) == BUSY_FLAG)
684 		continue;
685 
686 	if (nloops == 0) {
687 		sc->sc_flags |= HD_TIMEDOUT;
688 		sc->sc_dev_ok = 0;
689 	}
690 }
691 
692 #if defined(HD44780_STD_WIDE)
693 /*
694  * Standard 8-bit version of 'sc_writereg' (8-bit port, 8-bit access)
695  */
696 void
hd44780_writereg(struct hd44780_chip * sc,uint32_t en,uint32_t reg,uint8_t cmd)697 hd44780_writereg(struct hd44780_chip *sc, uint32_t en, uint32_t reg,
698     uint8_t cmd)
699 {
700 	bus_space_tag_t iot = sc->sc_iot;
701 	bus_space_handle_t ioh;
702 
703 	if (sc->sc_dev_ok == 0)
704 		return;
705 
706 	if (reg == 0)
707 		ioh = sc->sc_ioir;
708 	else
709 		ioh = sc->sc_iodr;
710 
711 	bus_space_write_1(iot, ioh, 0x00, cmd);
712 	delay(HD_TIMEOUT_NORMAL);
713 }
714 
715 /*
716  * Standard 8-bit version of 'sc_readreg' (8-bit port, 8-bit access)
717  */
718 uint8_t
hd44780_readreg(struct hd44780_chip * sc,uint32_t en,uint32_t reg)719 hd44780_readreg(struct hd44780_chip *sc, uint32_t en, uint32_t reg)
720 {
721 	bus_space_tag_t iot = sc->sc_iot;
722 	bus_space_handle_t ioh;
723 
724 	if (sc->sc_dev_ok == 0)
725 		return;
726 
727 	if (reg == 0)
728 		ioh = sc->sc_ioir;
729 	else
730 		ioh = sc->sc_iodr;
731 
732 	delay(HD_TIMEOUT_NORMAL);
733 	return bus_space_read_1(iot, ioh, 0x00);
734 }
735 #elif defined(HD44780_STD_SHORT)
736 /*
737  * Standard 4-bit version of 'sc_writereg' (4-bit port, 8-bit access)
738  */
739 void
hd44780_writereg(struct hd44780_chip * sc,uint32_t en,uint32_t reg,uint8_t cmd)740 hd44780_writereg(struct hd44780_chip *sc, uint32_t en, uint32_t reg,
741     uint8_t cmd)
742 {
743 	bus_space_tag_t iot = sc->sc_iot;
744 	bus_space_handle_t ioh;
745 
746 	if (sc->sc_dev_ok == 0)
747 		return;
748 
749 	if (reg == 0)
750 		ioh = sc->sc_ioir;
751 	else
752 		ioh = sc->sc_iodr;
753 
754 	bus_space_write_1(iot, ioh, 0x00, hi_bits(cmd));
755 	if (sc->sc_flags & HD_UP)
756 		bus_space_write_1(iot, ioh, 0x00, lo_bits(cmd));
757 	delay(HD_TIMEOUT_NORMAL);
758 }
759 
760 /*
761  * Standard 4-bit version of 'sc_readreg' (4-bit port, 8-bit access)
762  */
763 uint8_t
hd44780_readreg(struct hd44780_chip * sc,uint32_t en,uint32_t reg)764 hd44780_readreg(struct hd44780_chip *sc, uint32_t en, uint32_t reg)
765 {
766 	bus_space_tag_t iot = sc->sc_iot;
767 	bus_space_handle_t ioh;
768 	uint8_t rd, dat;
769 
770 	if (sc->sc_dev_ok == 0)
771 		return;
772 
773 	if (reg == 0)
774 		ioh = sc->sc_ioir;
775 	else
776 		ioh = sc->sc_iodr;
777 
778 	rd = bus_space_read_1(iot, ioh, 0x00);
779 	dat = (rd & 0x0f) << 4;
780 	rd = bus_space_read_1(iot, ioh, 0x00);
781 	return (dat | (rd & 0x0f));
782 }
783 #endif
784