1 /*
2  * Copyright (c) 2016 Google, Inc
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 #include <common.h>
8 #include <dm.h>
9 #include <video.h>
10 #include <video_console.h>
11 
12 /* Functions needed by stb_truetype.h */
13 static int tt_floor(double val)
14 {
15 	if (val < 0)
16 		return (int)(val - 0.999);
17 
18 	return (int)val;
19 }
20 
21 static int tt_ceil(double val)
22 {
23 	if (val < 0)
24 		return (int)val;
25 
26 	return (int)(val + 0.999);
27 }
28 
29 static double frac(double val)
30 {
31 	return val - tt_floor(val);
32 }
33 
34 static double tt_fabs(double x)
35 {
36 	return x < 0 ? -x : x;
37 }
38 
39  /*
40   * Simple square root algorithm. This is from:
41   * http://stackoverflow.com/questions/1623375/writing-your-own-square-root-function
42   * Written by Chihung Yu
43   * Creative Commons license
44   * http://creativecommons.org/licenses/by-sa/3.0/legalcode
45   * It has been modified to compile correctly, and for U-Boot style.
46   */
47 static double tt_sqrt(double value)
48 {
49 	double lo = 1.0;
50 	double hi = value;
51 
52 	while (hi - lo > 0.00001) {
53 		double mid = lo + (hi - lo) / 2;
54 
55 		if (mid * mid - value > 0.00001)
56 			hi = mid;
57 		else
58 			lo = mid;
59 	}
60 
61 	return lo;
62 }
63 
64 #define STBTT_ifloor		tt_floor
65 #define STBTT_iceil		tt_ceil
66 #define STBTT_fabs		tt_fabs
67 #define STBTT_sqrt		tt_sqrt
68 #define STBTT_malloc(size, u)	((void)(u), malloc(size))
69 #define STBTT_free(size, u)	((void)(u), free(size))
70 #define STBTT_assert(x)
71 #define STBTT_strlen(x)		strlen(x)
72 #define STBTT_memcpy		memcpy
73 #define STBTT_memset		memset
74 
75 #define STB_TRUETYPE_IMPLEMENTATION
76 #include "stb_truetype.h"
77 
78 /**
79  * struct pos_info - Records a cursor position
80  *
81  * @xpos_frac:	Fractional X position in pixels (multiplied by VID_FRAC_DIV)
82  * @ypos:	Y position (pixels from the top)
83  */
84 struct pos_info {
85 	int xpos_frac;
86 	int ypos;
87 };
88 
89 /*
90  * Allow one for each character on the command line plus one for each newline.
91  * This is just an estimate, but it should not be exceeded.
92  */
93 #define POS_HISTORY_SIZE	(CONFIG_SYS_CBSIZE * 11 / 10)
94 
95 /**
96  * struct console_tt_priv - Private data for this driver
97  *
98  * @font_size:	Vertical font size in pixels
99  * @font_data:	Pointer to TrueType font file contents
100  * @font:	TrueType font information for the current font
101  * @pos:	List of cursor positions for each character written. This is
102  *		used to handle backspace. We clear the frame buffer between
103  *		the last position and the current position, thus erasing the
104  *		last character. We record enough characters to go back to the
105  *		start of the current command line.
106  * @pos_ptr:	Current position in the position history
107  * @baseline:	Pixel offset of the font's baseline from the cursor position.
108  *		This is the 'ascent' of the font, scaled to pixel coordinates.
109  *		It measures the distance from the baseline to the top of the
110  *		font.
111  * @scale:	Scale of the font. This is calculated from the pixel height
112  *		of the font. It is used by the STB library to generate images
113  *		of the correct size.
114  */
115 struct console_tt_priv {
116 	int font_size;
117 	u8 *font_data;
118 	stbtt_fontinfo font;
119 	struct pos_info pos[POS_HISTORY_SIZE];
120 	int pos_ptr;
121 	int baseline;
122 	double scale;
123 };
124 
125 static int console_truetype_set_row(struct udevice *dev, uint row, int clr)
126 {
127 	struct video_priv *vid_priv = dev_get_uclass_priv(dev->parent);
128 	struct console_tt_priv *priv = dev_get_priv(dev);
129 	void *line;
130 	int pixels = priv->font_size * vid_priv->line_length;
131 	int i;
132 
133 	line = vid_priv->fb + row * priv->font_size * vid_priv->line_length;
134 	switch (vid_priv->bpix) {
135 #ifdef CONFIG_VIDEO_BPP8
136 	case VIDEO_BPP8: {
137 		uint8_t *dst = line;
138 
139 		for (i = 0; i < pixels; i++)
140 			*dst++ = clr;
141 		break;
142 	}
143 #endif
144 #ifdef CONFIG_VIDEO_BPP16
145 	case VIDEO_BPP16: {
146 		uint16_t *dst = line;
147 
148 		for (i = 0; i < pixels; i++)
149 			*dst++ = clr;
150 		break;
151 	}
152 #endif
153 #ifdef CONFIG_VIDEO_BPP32
154 	case VIDEO_BPP32: {
155 		uint32_t *dst = line;
156 
157 		for (i = 0; i < pixels; i++)
158 			*dst++ = clr;
159 		break;
160 	}
161 #endif
162 	default:
163 		return -ENOSYS;
164 	}
165 
166 	return 0;
167 }
168 
169 static int console_truetype_move_rows(struct udevice *dev, uint rowdst,
170 				     uint rowsrc, uint count)
171 {
172 	struct video_priv *vid_priv = dev_get_uclass_priv(dev->parent);
173 	struct console_tt_priv *priv = dev_get_priv(dev);
174 	void *dst;
175 	void *src;
176 	int i, diff;
177 
178 	dst = vid_priv->fb + rowdst * priv->font_size * vid_priv->line_length;
179 	src = vid_priv->fb + rowsrc * priv->font_size * vid_priv->line_length;
180 	memmove(dst, src, priv->font_size * vid_priv->line_length * count);
181 
182 	/* Scroll up our position history */
183 	diff = (rowsrc - rowdst) * priv->font_size;
184 	for (i = 0; i < priv->pos_ptr; i++)
185 		priv->pos[i].ypos -= diff;
186 
187 	return 0;
188 }
189 
190 static int console_truetype_putc_xy(struct udevice *dev, uint x, uint y,
191 				    char ch)
192 {
193 	struct vidconsole_priv *vc_priv = dev_get_uclass_priv(dev);
194 	struct udevice *vid = dev->parent;
195 	struct video_priv *vid_priv = dev_get_uclass_priv(vid);
196 	struct console_tt_priv *priv = dev_get_priv(dev);
197 	stbtt_fontinfo *font = &priv->font;
198 	int width, height, xoff, yoff;
199 	double xpos, x_shift;
200 	int lsb;
201 	int width_frac, linenum;
202 	struct pos_info *pos;
203 	u8 *bits, *data;
204 	int advance;
205 	void *line;
206 	int row;
207 
208 	/* First get some basic metrics about this character */
209 	stbtt_GetCodepointHMetrics(font, ch, &advance, &lsb);
210 
211 	/*
212 	 * First out our current X position in fractional pixels. If we wrote
213 	 * a character previously, using kerning to fine-tune the position of
214 	 * this character */
215 	xpos = frac(VID_TO_PIXEL((double)x));
216 	if (vc_priv->last_ch) {
217 		xpos += priv->scale * stbtt_GetCodepointKernAdvance(font,
218 							vc_priv->last_ch, ch);
219 	}
220 
221 	/*
222 	 * Figure out where the cursor will move to after this character, and
223 	 * abort if we are out of space on this line. Also calculate the
224 	 * effective width of this character, which will be our return value:
225 	 * it dictates how much the cursor will move forward on the line.
226 	 */
227 	x_shift = xpos - (double)tt_floor(xpos);
228 	xpos += advance * priv->scale;
229 	width_frac = (int)VID_TO_POS(xpos);
230 	if (x + width_frac >= vc_priv->xsize_frac)
231 		return -EAGAIN;
232 
233 	/* Write the current cursor position into history */
234 	if (priv->pos_ptr < POS_HISTORY_SIZE) {
235 		pos = &priv->pos[priv->pos_ptr];
236 		pos->xpos_frac = vc_priv->xcur_frac;
237 		pos->ypos = vc_priv->ycur;
238 		priv->pos_ptr++;
239 	}
240 
241 	/*
242 	 * Figure out how much past the start of a pixel we are, and pass this
243 	 * information into the render, which will return a 8-bit-per-pixel
244 	 * image of the character. For empty characters, like ' ', data will
245 	 * return NULL;
246 	 */
247 	data = stbtt_GetCodepointBitmapSubpixel(font, priv->scale, priv->scale,
248 						x_shift, 0, ch, &width, &height,
249 						&xoff, &yoff);
250 	if (!data)
251 		return width_frac;
252 
253 	/* Figure out where to write the character in the frame buffer */
254 	bits = data;
255 	line = vid_priv->fb + y * vid_priv->line_length +
256 		VID_TO_PIXEL(x) * VNBYTES(vid_priv->bpix);
257 	linenum = priv->baseline + yoff;
258 	if (linenum > 0)
259 		line += linenum * vid_priv->line_length;
260 
261 	/*
262 	 * Write a row at a time, converting the 8bpp image into the colour
263 	 * depth of the display. We only expect white-on-black or the reverse
264 	 * so the code only handles this simple case.
265 	 */
266 	for (row = 0; row < height; row++) {
267 		switch (vid_priv->bpix) {
268 #ifdef CONFIG_VIDEO_BPP16
269 		case VIDEO_BPP16: {
270 			uint16_t *dst = (uint16_t *)line + xoff;
271 			int i;
272 
273 			for (i = 0; i < width; i++) {
274 				int val = *bits;
275 				int out;
276 
277 				if (vid_priv->colour_bg)
278 					val = 255 - val;
279 				out = val >> 3 |
280 					(val >> 2) << 5 |
281 					(val >> 3) << 11;
282 				if (vid_priv->colour_fg)
283 					*dst++ |= out;
284 				else
285 					*dst++ &= out;
286 				bits++;
287 			}
288 			break;
289 		}
290 #endif
291 		default:
292 			return -ENOSYS;
293 		}
294 
295 		line += vid_priv->line_length;
296 	}
297 	free(data);
298 
299 	return width_frac;
300 }
301 
302 /**
303  * console_truetype_erase() - Erase a character
304  *
305  * This is used for backspace. We erase a square of the display within the
306  * given bounds.
307  *
308  * @dev:	Device to update
309  * @xstart:	X start position in pixels from the left
310  * @ystart:	Y start position in pixels from the top
311  * @xend:	X end position in pixels from the left
312  * @yend:	Y end position  in pixels from the top
313  * @clr:	Value to write
314  * @return 0 if OK, -ENOSYS if the display depth is not supported
315  */
316 static int console_truetype_erase(struct udevice *dev, int xstart, int ystart,
317 				  int xend, int yend, int clr)
318 {
319 	struct video_priv *vid_priv = dev_get_uclass_priv(dev->parent);
320 	void *line;
321 	int pixels = xend - xstart;
322 	int row, i;
323 
324 	line = vid_priv->fb + ystart * vid_priv->line_length;
325 	line += xstart * VNBYTES(vid_priv->bpix);
326 	for (row = ystart; row < yend; row++) {
327 		switch (vid_priv->bpix) {
328 #ifdef CONFIG_VIDEO_BPP8
329 		case VIDEO_BPP8: {
330 			uint8_t *dst = line;
331 
332 			for (i = 0; i < pixels; i++)
333 				*dst++ = clr;
334 			break;
335 		}
336 #endif
337 #ifdef CONFIG_VIDEO_BPP16
338 		case VIDEO_BPP16: {
339 			uint16_t *dst = line;
340 
341 			for (i = 0; i < pixels; i++)
342 				*dst++ = clr;
343 			break;
344 		}
345 #endif
346 #ifdef CONFIG_VIDEO_BPP32
347 		case VIDEO_BPP32: {
348 			uint32_t *dst = line;
349 
350 			for (i = 0; i < pixels; i++)
351 				*dst++ = clr;
352 			break;
353 		}
354 #endif
355 		default:
356 			return -ENOSYS;
357 		}
358 		line += vid_priv->line_length;
359 	}
360 
361 	return 0;
362 }
363 
364 /**
365  * console_truetype_backspace() - Handle a backspace operation
366  *
367  * This clears the previous character so that the console looks as if it had
368  * not been entered.
369  *
370  * @dev:	Device to update
371  * @return 0 if OK, -ENOSYS if not supported
372  */
373 static int console_truetype_backspace(struct udevice *dev)
374 {
375 	struct vidconsole_priv *vc_priv = dev_get_uclass_priv(dev);
376 	struct console_tt_priv *priv = dev_get_priv(dev);
377 	struct udevice *vid_dev = dev->parent;
378 	struct video_priv *vid_priv = dev_get_uclass_priv(vid_dev);
379 	struct pos_info *pos;
380 	int xend;
381 
382 	/*
383 	 * This indicates a very strange error higher in the stack. The caller
384 	 * has sent out n character and n + 1 backspaces.
385 	 */
386 	if (!priv->pos_ptr)
387 		return -ENOSYS;
388 
389 	/* Pop the last cursor position off the stack */
390 	pos = &priv->pos[--priv->pos_ptr];
391 
392 	/*
393 	 * Figure out the end position for clearing. Normlly it is the current
394 	 * cursor position, but if we are clearing a character on the previous
395 	 * line, we clear from the end of the line.
396 	 */
397 	if (pos->ypos == vc_priv->ycur)
398 		xend = VID_TO_PIXEL(vc_priv->xcur_frac);
399 	else
400 		xend = vid_priv->xsize;
401 
402 	console_truetype_erase(dev, VID_TO_PIXEL(pos->xpos_frac), pos->ypos,
403 			       xend, pos->ypos + vc_priv->y_charsize,
404 			       vid_priv->colour_bg);
405 
406 	/* Move the cursor back to where it was when we pushed this record */
407 	vc_priv->xcur_frac = pos->xpos_frac;
408 	vc_priv->ycur = pos->ypos;
409 
410 	return 0;
411 }
412 
413 static int console_truetype_entry_start(struct udevice *dev)
414 {
415 	struct console_tt_priv *priv = dev_get_priv(dev);
416 
417 	/* A new input line has start, so clear our history */
418 	priv->pos_ptr = 0;
419 
420 	return 0;
421 }
422 
423 /*
424  * Provides a list of fonts which can be obtained at run-time in U-Boot. These
425  * are compiled in by the Makefile.
426  *
427  * At present there is no mechanism to select a particular font - the first
428  * one found is the one that is used. But the build system and the code here
429  * supports multiple fonts, which may be useful for certain firmware screens.
430  */
431 struct font_info {
432 	char *name;
433 	u8 *begin;
434 	u8 *end;
435 };
436 
437 #define FONT_DECL(_name) \
438 	extern u8 __ttf_ ## _name ## _begin[]; \
439 	extern u8 __ttf_ ## _name ## _end[];
440 
441 #define FONT_ENTRY(_name)		{ \
442 	.name = #_name, \
443 	.begin = __ttf_ ## _name ## _begin, \
444 	.end = __ttf_ ## _name ## _end, \
445 	}
446 
447 FONT_DECL(nimbus_sans_l_regular);
448 FONT_DECL(ankacoder_c75_r);
449 FONT_DECL(rufscript010);
450 FONT_DECL(cantoraone_regular);
451 
452 static struct font_info font_table[] = {
453 #ifdef CONFIG_CONSOLE_TRUETYPE_NIMBUS
454 	FONT_ENTRY(nimbus_sans_l_regular),
455 #endif
456 #ifdef CONFIG_CONSOLE_TRUETYPE_ANKACODER
457 	FONT_ENTRY(ankacoder_c75_r),
458 #endif
459 #ifdef CONFIG_CONSOLE_TRUETYPE_RUFSCRIPT
460 	FONT_ENTRY(rufscript010),
461 #endif
462 #ifdef CONFIG_CONSOLE_TRUETYPE_CANTORAONE
463 	FONT_ENTRY(cantoraone_regular),
464 #endif
465 	{} /* sentinel */
466 };
467 
468 #define FONT_BEGIN(name)	__ttf_ ## name ## _begin
469 #define FONT_END(name)		__ttf_ ## name ## _end
470 #define FONT_IS_VALID(name)	(abs(FONT_END(name) - FONT_BEGIN) > 4)
471 
472 /**
473  * console_truetype_find_font() - Find a suitable font
474  *
475  * This searched for the first available font.
476  *
477  * @return pointer to the font, or NULL if none is found
478  */
479 static u8 *console_truetype_find_font(void)
480 {
481 	struct font_info *tab;
482 
483 	for (tab = font_table; tab->begin; tab++) {
484 		if (abs(tab->begin - tab->end) > 4) {
485 			debug("%s: Font '%s', at %p, size %lx\n", __func__,
486 			      tab->name, tab->begin,
487 			      (ulong)(tab->end - tab->begin));
488 			return tab->begin;
489 		}
490 	}
491 
492 	return NULL;
493 }
494 
495 static int console_truetype_probe(struct udevice *dev)
496 {
497 	struct vidconsole_priv *vc_priv = dev_get_uclass_priv(dev);
498 	struct console_tt_priv *priv = dev_get_priv(dev);
499 	struct udevice *vid_dev = dev->parent;
500 	struct video_priv *vid_priv = dev_get_uclass_priv(vid_dev);
501 	stbtt_fontinfo *font = &priv->font;
502 	int ascent;
503 
504 	debug("%s: start\n", __func__);
505 	if (vid_priv->font_size)
506 		priv->font_size = vid_priv->font_size;
507 	else
508 		priv->font_size = CONFIG_CONSOLE_TRUETYPE_SIZE;
509 	priv->font_data = console_truetype_find_font();
510 	if (!priv->font_data) {
511 		debug("%s: Could not find any fonts\n", __func__);
512 		return -EBFONT;
513 	}
514 
515 	vc_priv->x_charsize = priv->font_size;
516 	vc_priv->y_charsize = priv->font_size;
517 	vc_priv->xstart_frac = VID_TO_POS(2);
518 	vc_priv->cols = vid_priv->xsize / priv->font_size;
519 	vc_priv->rows = vid_priv->ysize / priv->font_size;
520 	vc_priv->tab_width_frac = VID_TO_POS(priv->font_size) * 8 / 2;
521 
522 	if (!stbtt_InitFont(font, priv->font_data, 0)) {
523 		debug("%s: Font init failed\n", __func__);
524 		return -EPERM;
525 	}
526 
527 	/* Pre-calculate some things we will need regularly */
528 	priv->scale = stbtt_ScaleForPixelHeight(font, priv->font_size);
529 	stbtt_GetFontVMetrics(font, &ascent, 0, 0);
530 	priv->baseline = (int)(ascent * priv->scale);
531 	debug("%s: ready\n", __func__);
532 
533 	return 0;
534 }
535 
536 struct vidconsole_ops console_truetype_ops = {
537 	.putc_xy	= console_truetype_putc_xy,
538 	.move_rows	= console_truetype_move_rows,
539 	.set_row	= console_truetype_set_row,
540 	.backspace	= console_truetype_backspace,
541 	.entry_start	= console_truetype_entry_start,
542 };
543 
544 U_BOOT_DRIVER(vidconsole_truetype) = {
545 	.name	= "vidconsole_tt",
546 	.id	= UCLASS_VIDEO_CONSOLE,
547 	.ops	= &console_truetype_ops,
548 	.probe	= console_truetype_probe,
549 	.priv_auto_alloc_size	= sizeof(struct console_tt_priv),
550 };
551