1 // SPDX-License-Identifier: GPL-2.0 or MIT
2 /*
3  * Copyright (C) 2016 Noralf Trønnes
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  */
10 
11 #include <linux/module.h>
12 #include <linux/slab.h>
13 #include <linux/io.h>
14 
15 #include <drm/drm_device.h>
16 #include <drm/drm_format_helper.h>
17 #include <drm/drm_framebuffer.h>
18 #include <drm/drm_fourcc.h>
19 #include <drm/drm_print.h>
20 #include <drm/drm_rect.h>
21 
22 static unsigned int clip_offset(const struct drm_rect *clip, unsigned int pitch, unsigned int cpp)
23 {
24 	return clip->y1 * pitch + clip->x1 * cpp;
25 }
26 
27 /**
28  * drm_fb_clip_offset - Returns the clipping rectangles byte-offset in a framebuffer
29  * @pitch: Framebuffer line pitch in byte
30  * @format: Framebuffer format
31  * @clip: Clip rectangle
32  *
33  * Returns:
34  * The byte offset of the clip rectangle's top-left corner within the framebuffer.
35  */
36 unsigned int drm_fb_clip_offset(unsigned int pitch, const struct drm_format_info *format,
37 				const struct drm_rect *clip)
38 {
39 	return clip_offset(clip, pitch, format->cpp[0]);
40 }
41 EXPORT_SYMBOL(drm_fb_clip_offset);
42 
43 /* TODO: Make this functon work with multi-plane formats. */
44 static int drm_fb_xfrm(void *dst, unsigned long dst_pitch, unsigned long dst_pixsize,
45 		       const void *vaddr, const struct drm_framebuffer *fb,
46 		       const struct drm_rect *clip, bool vaddr_cached_hint,
47 		       void (*xfrm_line)(void *dbuf, const void *sbuf, unsigned int npixels))
48 {
49 	unsigned long linepixels = drm_rect_width(clip);
50 	unsigned long lines = drm_rect_height(clip);
51 	size_t sbuf_len = linepixels * fb->format->cpp[0];
52 	void *stmp = NULL;
53 	unsigned long i;
54 	const void *sbuf;
55 
56 	/*
57 	 * Some source buffers, such as CMA memory, use write-combine
58 	 * caching, so reads are uncached. Speed up access by fetching
59 	 * one line at a time.
60 	 */
61 	if (!vaddr_cached_hint) {
62 		stmp = kmalloc(sbuf_len, GFP_KERNEL);
63 		if (!stmp)
64 			return -ENOMEM;
65 	}
66 
67 	if (!dst_pitch)
68 		dst_pitch = drm_rect_width(clip) * dst_pixsize;
69 	vaddr += clip_offset(clip, fb->pitches[0], fb->format->cpp[0]);
70 
71 	for (i = 0; i < lines; ++i) {
72 		if (stmp)
73 			sbuf = memcpy(stmp, vaddr, sbuf_len);
74 		else
75 			sbuf = vaddr;
76 		xfrm_line(dst, sbuf, linepixels);
77 		vaddr += fb->pitches[0];
78 		dst += dst_pitch;
79 	}
80 
81 	kfree(stmp);
82 
83 	return 0;
84 }
85 
86 /* TODO: Make this functon work with multi-plane formats. */
87 static int drm_fb_xfrm_toio(void __iomem *dst, unsigned long dst_pitch, unsigned long dst_pixsize,
88 			    const void *vaddr, const struct drm_framebuffer *fb,
89 			    const struct drm_rect *clip, bool vaddr_cached_hint,
90 			    void (*xfrm_line)(void *dbuf, const void *sbuf, unsigned int npixels))
91 {
92 	unsigned long linepixels = drm_rect_width(clip);
93 	unsigned long lines = drm_rect_height(clip);
94 	size_t dbuf_len = linepixels * dst_pixsize;
95 	size_t stmp_off = round_up(dbuf_len, ARCH_KMALLOC_MINALIGN); /* for sbuf alignment */
96 	size_t sbuf_len = linepixels * fb->format->cpp[0];
97 	void *stmp = NULL;
98 	unsigned long i;
99 	const void *sbuf;
100 	void *dbuf;
101 
102 	if (vaddr_cached_hint) {
103 		dbuf = kmalloc(dbuf_len, GFP_KERNEL);
104 	} else {
105 		dbuf = kmalloc(stmp_off + sbuf_len, GFP_KERNEL);
106 		stmp = dbuf + stmp_off;
107 	}
108 	if (!dbuf)
109 		return -ENOMEM;
110 
111 	if (!dst_pitch)
112 		dst_pitch = linepixels * dst_pixsize;
113 	vaddr += clip_offset(clip, fb->pitches[0], fb->format->cpp[0]);
114 
115 	for (i = 0; i < lines; ++i) {
116 		if (stmp)
117 			sbuf = memcpy(stmp, vaddr, sbuf_len);
118 		else
119 			sbuf = vaddr;
120 		xfrm_line(dbuf, sbuf, linepixels);
121 		memcpy_toio(dst, dbuf, dbuf_len);
122 		vaddr += fb->pitches[0];
123 		dst += dst_pitch;
124 	}
125 
126 	kfree(dbuf);
127 
128 	return 0;
129 }
130 
131 /**
132  * drm_fb_memcpy - Copy clip buffer
133  * @dst: Destination buffer
134  * @dst_pitch: Number of bytes between two consecutive scanlines within dst
135  * @vaddr: Source buffer
136  * @fb: DRM framebuffer
137  * @clip: Clip rectangle area to copy
138  *
139  * This function does not apply clipping on dst, i.e. the destination
140  * is at the top-left corner.
141  */
142 void drm_fb_memcpy(void *dst, unsigned int dst_pitch, const void *vaddr,
143 		   const struct drm_framebuffer *fb, const struct drm_rect *clip)
144 {
145 	unsigned int cpp = fb->format->cpp[0];
146 	size_t len = (clip->x2 - clip->x1) * cpp;
147 	unsigned int y, lines = clip->y2 - clip->y1;
148 
149 	if (!dst_pitch)
150 		dst_pitch = len;
151 
152 	vaddr += clip_offset(clip, fb->pitches[0], cpp);
153 	for (y = 0; y < lines; y++) {
154 		memcpy(dst, vaddr, len);
155 		vaddr += fb->pitches[0];
156 		dst += dst_pitch;
157 	}
158 }
159 EXPORT_SYMBOL(drm_fb_memcpy);
160 
161 /**
162  * drm_fb_memcpy_toio - Copy clip buffer
163  * @dst: Destination buffer (iomem)
164  * @dst_pitch: Number of bytes between two consecutive scanlines within dst
165  * @vaddr: Source buffer
166  * @fb: DRM framebuffer
167  * @clip: Clip rectangle area to copy
168  *
169  * This function does not apply clipping on dst, i.e. the destination
170  * is at the top-left corner.
171  */
172 void drm_fb_memcpy_toio(void __iomem *dst, unsigned int dst_pitch, const void *vaddr,
173 			const struct drm_framebuffer *fb, const struct drm_rect *clip)
174 {
175 	unsigned int cpp = fb->format->cpp[0];
176 	size_t len = (clip->x2 - clip->x1) * cpp;
177 	unsigned int y, lines = clip->y2 - clip->y1;
178 
179 	if (!dst_pitch)
180 		dst_pitch = len;
181 
182 	vaddr += clip_offset(clip, fb->pitches[0], cpp);
183 	for (y = 0; y < lines; y++) {
184 		memcpy_toio(dst, vaddr, len);
185 		vaddr += fb->pitches[0];
186 		dst += dst_pitch;
187 	}
188 }
189 EXPORT_SYMBOL(drm_fb_memcpy_toio);
190 
191 static void drm_fb_swab16_line(void *dbuf, const void *sbuf, unsigned int pixels)
192 {
193 	u16 *dbuf16 = dbuf;
194 	const u16 *sbuf16 = sbuf;
195 	const u16 *send16 = sbuf16 + pixels;
196 
197 	while (sbuf16 < send16)
198 		*dbuf16++ = swab16(*sbuf16++);
199 }
200 
201 static void drm_fb_swab32_line(void *dbuf, const void *sbuf, unsigned int pixels)
202 {
203 	u32 *dbuf32 = dbuf;
204 	const u32 *sbuf32 = sbuf;
205 	const u32 *send32 = sbuf32 + pixels;
206 
207 	while (sbuf32 < send32)
208 		*dbuf32++ = swab32(*sbuf32++);
209 }
210 
211 /**
212  * drm_fb_swab - Swap bytes into clip buffer
213  * @dst: Destination buffer
214  * @dst_pitch: Number of bytes between two consecutive scanlines within dst
215  * @src: Source buffer
216  * @fb: DRM framebuffer
217  * @clip: Clip rectangle area to copy
218  * @cached: Source buffer is mapped cached (eg. not write-combined)
219  *
220  * If @cached is false a temporary buffer is used to cache one pixel line at a
221  * time to speed up slow uncached reads.
222  *
223  * This function does not apply clipping on dst, i.e. the destination
224  * is at the top-left corner.
225  */
226 void drm_fb_swab(void *dst, unsigned int dst_pitch, const void *src,
227 		 const struct drm_framebuffer *fb, const struct drm_rect *clip,
228 		 bool cached)
229 {
230 	u8 cpp = fb->format->cpp[0];
231 
232 	switch (cpp) {
233 	case 4:
234 		drm_fb_xfrm(dst, dst_pitch, cpp, src, fb, clip, cached, drm_fb_swab32_line);
235 		break;
236 	case 2:
237 		drm_fb_xfrm(dst, dst_pitch, cpp, src, fb, clip, cached, drm_fb_swab16_line);
238 		break;
239 	default:
240 		drm_warn_once(fb->dev, "Format %p4cc has unsupported pixel size.\n",
241 			      &fb->format->format);
242 		break;
243 	}
244 }
245 EXPORT_SYMBOL(drm_fb_swab);
246 
247 static void drm_fb_xrgb8888_to_rgb332_line(void *dbuf, const void *sbuf, unsigned int pixels)
248 {
249 	u8 *dbuf8 = dbuf;
250 	const __le32 *sbuf32 = sbuf;
251 	unsigned int x;
252 	u32 pix;
253 
254 	for (x = 0; x < pixels; x++) {
255 		pix = le32_to_cpu(sbuf32[x]);
256 		dbuf8[x] = ((pix & 0x00e00000) >> 16) |
257 			   ((pix & 0x0000e000) >> 11) |
258 			   ((pix & 0x000000c0) >> 6);
259 	}
260 }
261 
262 /**
263  * drm_fb_xrgb8888_to_rgb332 - Convert XRGB8888 to RGB332 clip buffer
264  * @dst: RGB332 destination buffer
265  * @dst_pitch: Number of bytes between two consecutive scanlines within dst
266  * @src: XRGB8888 source buffer
267  * @fb: DRM framebuffer
268  * @clip: Clip rectangle area to copy
269  *
270  * Drivers can use this function for RGB332 devices that don't natively support XRGB8888.
271  */
272 void drm_fb_xrgb8888_to_rgb332(void *dst, unsigned int dst_pitch, const void *src,
273 			       const struct drm_framebuffer *fb, const struct drm_rect *clip)
274 {
275 	drm_fb_xfrm(dst, dst_pitch, 1, src, fb, clip, false, drm_fb_xrgb8888_to_rgb332_line);
276 }
277 EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb332);
278 
279 static void drm_fb_xrgb8888_to_rgb565_line(void *dbuf, const void *sbuf, unsigned int pixels)
280 {
281 	u16 *dbuf16 = dbuf;
282 	const u32 *sbuf32 = sbuf;
283 	unsigned int x;
284 	u16 val16;
285 
286 	for (x = 0; x < pixels; x++) {
287 		val16 = ((sbuf32[x] & 0x00F80000) >> 8) |
288 			((sbuf32[x] & 0x0000FC00) >> 5) |
289 			((sbuf32[x] & 0x000000F8) >> 3);
290 		dbuf16[x] = val16;
291 	}
292 }
293 
294 static void drm_fb_xrgb8888_to_rgb565_swab_line(void *dbuf, const void *sbuf,
295 						unsigned int pixels)
296 {
297 	u16 *dbuf16 = dbuf;
298 	const u32 *sbuf32 = sbuf;
299 	unsigned int x;
300 	u16 val16;
301 
302 	for (x = 0; x < pixels; x++) {
303 		val16 = ((sbuf32[x] & 0x00F80000) >> 8) |
304 			((sbuf32[x] & 0x0000FC00) >> 5) |
305 			((sbuf32[x] & 0x000000F8) >> 3);
306 		dbuf16[x] = swab16(val16);
307 	}
308 }
309 
310 /**
311  * drm_fb_xrgb8888_to_rgb565 - Convert XRGB8888 to RGB565 clip buffer
312  * @dst: RGB565 destination buffer
313  * @dst_pitch: Number of bytes between two consecutive scanlines within dst
314  * @vaddr: XRGB8888 source buffer
315  * @fb: DRM framebuffer
316  * @clip: Clip rectangle area to copy
317  * @swab: Swap bytes
318  *
319  * Drivers can use this function for RGB565 devices that don't natively
320  * support XRGB8888.
321  */
322 void drm_fb_xrgb8888_to_rgb565(void *dst, unsigned int dst_pitch, const void *vaddr,
323 			       const struct drm_framebuffer *fb, const struct drm_rect *clip,
324 			       bool swab)
325 {
326 	if (swab)
327 		drm_fb_xfrm(dst, dst_pitch, 2, vaddr, fb, clip, false,
328 			    drm_fb_xrgb8888_to_rgb565_swab_line);
329 	else
330 		drm_fb_xfrm(dst, dst_pitch, 2, vaddr, fb, clip, false,
331 			    drm_fb_xrgb8888_to_rgb565_line);
332 }
333 EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb565);
334 
335 /**
336  * drm_fb_xrgb8888_to_rgb565_toio - Convert XRGB8888 to RGB565 clip buffer
337  * @dst: RGB565 destination buffer (iomem)
338  * @dst_pitch: Number of bytes between two consecutive scanlines within dst
339  * @vaddr: XRGB8888 source buffer
340  * @fb: DRM framebuffer
341  * @clip: Clip rectangle area to copy
342  * @swab: Swap bytes
343  *
344  * Drivers can use this function for RGB565 devices that don't natively
345  * support XRGB8888.
346  */
347 void drm_fb_xrgb8888_to_rgb565_toio(void __iomem *dst, unsigned int dst_pitch,
348 				    const void *vaddr, const struct drm_framebuffer *fb,
349 				    const struct drm_rect *clip, bool swab)
350 {
351 	if (swab)
352 		drm_fb_xfrm_toio(dst, dst_pitch, 2, vaddr, fb, clip, false,
353 				 drm_fb_xrgb8888_to_rgb565_swab_line);
354 	else
355 		drm_fb_xfrm_toio(dst, dst_pitch, 2, vaddr, fb, clip, false,
356 				 drm_fb_xrgb8888_to_rgb565_line);
357 }
358 EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb565_toio);
359 
360 static void drm_fb_xrgb8888_to_rgb888_line(void *dbuf, const void *sbuf, unsigned int pixels)
361 {
362 	u8 *dbuf8 = dbuf;
363 	const u32 *sbuf32 = sbuf;
364 	unsigned int x;
365 
366 	for (x = 0; x < pixels; x++) {
367 		*dbuf8++ = (sbuf32[x] & 0x000000FF) >>  0;
368 		*dbuf8++ = (sbuf32[x] & 0x0000FF00) >>  8;
369 		*dbuf8++ = (sbuf32[x] & 0x00FF0000) >> 16;
370 	}
371 }
372 
373 /**
374  * drm_fb_xrgb8888_to_rgb888 - Convert XRGB8888 to RGB888 clip buffer
375  * @dst: RGB888 destination buffer
376  * @dst_pitch: Number of bytes between two consecutive scanlines within dst
377  * @src: XRGB8888 source buffer
378  * @fb: DRM framebuffer
379  * @clip: Clip rectangle area to copy
380  *
381  * Drivers can use this function for RGB888 devices that don't natively
382  * support XRGB8888.
383  */
384 void drm_fb_xrgb8888_to_rgb888(void *dst, unsigned int dst_pitch, const void *src,
385 			       const struct drm_framebuffer *fb, const struct drm_rect *clip)
386 {
387 	drm_fb_xfrm(dst, dst_pitch, 3, src, fb, clip, false, drm_fb_xrgb8888_to_rgb888_line);
388 }
389 EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb888);
390 
391 /**
392  * drm_fb_xrgb8888_to_rgb888_toio - Convert XRGB8888 to RGB888 clip buffer
393  * @dst: RGB565 destination buffer (iomem)
394  * @dst_pitch: Number of bytes between two consecutive scanlines within dst
395  * @vaddr: XRGB8888 source buffer
396  * @fb: DRM framebuffer
397  * @clip: Clip rectangle area to copy
398  *
399  * Drivers can use this function for RGB888 devices that don't natively
400  * support XRGB8888.
401  */
402 void drm_fb_xrgb8888_to_rgb888_toio(void __iomem *dst, unsigned int dst_pitch,
403 				    const void *vaddr, const struct drm_framebuffer *fb,
404 				    const struct drm_rect *clip)
405 {
406 	drm_fb_xfrm_toio(dst, dst_pitch, 3, vaddr, fb, clip, false,
407 			 drm_fb_xrgb8888_to_rgb888_line);
408 }
409 EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb888_toio);
410 
411 static void drm_fb_rgb565_to_xrgb8888_line(void *dbuf, const void *sbuf, unsigned int pixels)
412 {
413 	u32 *dbuf32 = dbuf;
414 	const u16 *sbuf16 = sbuf;
415 	unsigned int x;
416 
417 	for (x = 0; x < pixels; x++, ++sbuf16, ++dbuf32) {
418 		u32 val32 = ((*sbuf16 & 0xf800) << 8) |
419 			    ((*sbuf16 & 0x07e0) << 5) |
420 			    ((*sbuf16 & 0x001f) << 3);
421 		*dbuf32 = 0xff000000 | val32 |
422 			  ((val32 >> 3) & 0x00070007) |
423 			  ((val32 >> 2) & 0x00000300);
424 	}
425 }
426 
427 static void drm_fb_rgb565_to_xrgb8888_toio(void __iomem *dst, unsigned int dst_pitch,
428 					   const void *vaddr, const struct drm_framebuffer *fb,
429 					   const struct drm_rect *clip)
430 {
431 	drm_fb_xfrm_toio(dst, dst_pitch, 4, vaddr, fb, clip, false,
432 			 drm_fb_rgb565_to_xrgb8888_line);
433 }
434 
435 static void drm_fb_rgb888_to_xrgb8888_line(void *dbuf, const void *sbuf, unsigned int pixels)
436 {
437 	u32 *dbuf32 = dbuf;
438 	const u8 *sbuf8 = sbuf;
439 	unsigned int x;
440 
441 	for (x = 0; x < pixels; x++) {
442 		u8 r = *sbuf8++;
443 		u8 g = *sbuf8++;
444 		u8 b = *sbuf8++;
445 		*dbuf32++ = 0xff000000 | (r << 16) | (g << 8) | b;
446 	}
447 }
448 
449 static void drm_fb_rgb888_to_xrgb8888_toio(void __iomem *dst, unsigned int dst_pitch,
450 					   const void *vaddr, const struct drm_framebuffer *fb,
451 					   const struct drm_rect *clip)
452 {
453 	drm_fb_xfrm_toio(dst, dst_pitch, 4, vaddr, fb, clip, false,
454 			 drm_fb_rgb888_to_xrgb8888_line);
455 }
456 
457 static void drm_fb_xrgb8888_to_xrgb2101010_line(void *dbuf, const void *sbuf, unsigned int pixels)
458 {
459 	u32 *dbuf32 = dbuf;
460 	const u32 *sbuf32 = sbuf;
461 	unsigned int x;
462 	u32 val32;
463 
464 	for (x = 0; x < pixels; x++) {
465 		val32 = ((sbuf32[x] & 0x000000FF) << 2) |
466 			((sbuf32[x] & 0x0000FF00) << 4) |
467 			((sbuf32[x] & 0x00FF0000) << 6);
468 		*dbuf32++ = val32 | ((val32 >> 8) & 0x00300C03);
469 	}
470 }
471 
472 /**
473  * drm_fb_xrgb8888_to_xrgb2101010_toio - Convert XRGB8888 to XRGB2101010 clip
474  * buffer
475  * @dst: XRGB2101010 destination buffer (iomem)
476  * @dst_pitch: Number of bytes between two consecutive scanlines within dst
477  * @vaddr: XRGB8888 source buffer
478  * @fb: DRM framebuffer
479  * @clip: Clip rectangle area to copy
480  *
481  * Drivers can use this function for XRGB2101010 devices that don't natively
482  * support XRGB8888.
483  */
484 void drm_fb_xrgb8888_to_xrgb2101010_toio(void __iomem *dst,
485 					 unsigned int dst_pitch, const void *vaddr,
486 					 const struct drm_framebuffer *fb,
487 					 const struct drm_rect *clip)
488 {
489 	drm_fb_xfrm_toio(dst, dst_pitch, 4, vaddr, fb, clip, false,
490 			 drm_fb_xrgb8888_to_xrgb2101010_line);
491 }
492 EXPORT_SYMBOL(drm_fb_xrgb8888_to_xrgb2101010_toio);
493 
494 static void drm_fb_xrgb8888_to_gray8_line(void *dbuf, const void *sbuf, unsigned int pixels)
495 {
496 	u8 *dbuf8 = dbuf;
497 	const u32 *sbuf32 = sbuf;
498 	unsigned int x;
499 
500 	for (x = 0; x < pixels; x++) {
501 		u8 r = (*sbuf32 & 0x00ff0000) >> 16;
502 		u8 g = (*sbuf32 & 0x0000ff00) >> 8;
503 		u8 b =  *sbuf32 & 0x000000ff;
504 
505 		/* ITU BT.601: Y = 0.299 R + 0.587 G + 0.114 B */
506 		*dbuf8++ = (3 * r + 6 * g + b) / 10;
507 		sbuf32++;
508 	}
509 }
510 
511 /**
512  * drm_fb_xrgb8888_to_gray8 - Convert XRGB8888 to grayscale
513  * @dst: 8-bit grayscale destination buffer
514  * @dst_pitch: Number of bytes between two consecutive scanlines within dst
515  * @vaddr: XRGB8888 source buffer
516  * @fb: DRM framebuffer
517  * @clip: Clip rectangle area to copy
518  *
519  * Drm doesn't have native monochrome or grayscale support.
520  * Such drivers can announce the commonly supported XR24 format to userspace
521  * and use this function to convert to the native format.
522  *
523  * Monochrome drivers will use the most significant bit,
524  * where 1 means foreground color and 0 background color.
525  *
526  * ITU BT.601 is used for the RGB -> luma (brightness) conversion.
527  */
528 void drm_fb_xrgb8888_to_gray8(void *dst, unsigned int dst_pitch, const void *vaddr,
529 			      const struct drm_framebuffer *fb, const struct drm_rect *clip)
530 {
531 	drm_fb_xfrm(dst, dst_pitch, 1, vaddr, fb, clip, false, drm_fb_xrgb8888_to_gray8_line);
532 }
533 EXPORT_SYMBOL(drm_fb_xrgb8888_to_gray8);
534 
535 /**
536  * drm_fb_blit_toio - Copy parts of a framebuffer to display memory
537  * @dst:	The display memory to copy to
538  * @dst_pitch:	Number of bytes between two consecutive scanlines within dst
539  * @dst_format:	FOURCC code of the display's color format
540  * @vmap:	The framebuffer memory to copy from
541  * @fb:		The framebuffer to copy from
542  * @clip:	Clip rectangle area to copy
543  *
544  * This function copies parts of a framebuffer to display memory. If the
545  * formats of the display and the framebuffer mismatch, the blit function
546  * will attempt to convert between them.
547  *
548  * Returns:
549  * 0 on success, or
550  * -EINVAL if the color-format conversion failed, or
551  * a negative error code otherwise.
552  */
553 int drm_fb_blit_toio(void __iomem *dst, unsigned int dst_pitch, uint32_t dst_format,
554 		     const void *vmap, const struct drm_framebuffer *fb,
555 		     const struct drm_rect *clip)
556 {
557 	uint32_t fb_format = fb->format->format;
558 
559 	/* treat alpha channel like filler bits */
560 	if (fb_format == DRM_FORMAT_ARGB8888)
561 		fb_format = DRM_FORMAT_XRGB8888;
562 	if (dst_format == DRM_FORMAT_ARGB8888)
563 		dst_format = DRM_FORMAT_XRGB8888;
564 	if (fb_format == DRM_FORMAT_ARGB2101010)
565 		fb_format = DRM_FORMAT_XRGB2101010;
566 	if (dst_format == DRM_FORMAT_ARGB2101010)
567 		dst_format = DRM_FORMAT_XRGB2101010;
568 
569 	if (dst_format == fb_format) {
570 		drm_fb_memcpy_toio(dst, dst_pitch, vmap, fb, clip);
571 		return 0;
572 
573 	} else if (dst_format == DRM_FORMAT_RGB565) {
574 		if (fb_format == DRM_FORMAT_XRGB8888) {
575 			drm_fb_xrgb8888_to_rgb565_toio(dst, dst_pitch, vmap, fb, clip, false);
576 			return 0;
577 		}
578 	} else if (dst_format == DRM_FORMAT_RGB888) {
579 		if (fb_format == DRM_FORMAT_XRGB8888) {
580 			drm_fb_xrgb8888_to_rgb888_toio(dst, dst_pitch, vmap, fb, clip);
581 			return 0;
582 		}
583 	} else if (dst_format == DRM_FORMAT_XRGB8888) {
584 		if (fb_format == DRM_FORMAT_RGB888) {
585 			drm_fb_rgb888_to_xrgb8888_toio(dst, dst_pitch, vmap, fb, clip);
586 			return 0;
587 		} else if (fb_format == DRM_FORMAT_RGB565) {
588 			drm_fb_rgb565_to_xrgb8888_toio(dst, dst_pitch, vmap, fb, clip);
589 			return 0;
590 		}
591 	} else if (dst_format == DRM_FORMAT_XRGB2101010) {
592 		if (fb_format == DRM_FORMAT_XRGB8888) {
593 			drm_fb_xrgb8888_to_xrgb2101010_toio(dst, dst_pitch, vmap, fb, clip);
594 			return 0;
595 		}
596 	}
597 
598 	drm_warn_once(fb->dev, "No conversion helper from %p4cc to %p4cc found.\n",
599 		      &fb_format, &dst_format);
600 
601 	return -EINVAL;
602 }
603 EXPORT_SYMBOL(drm_fb_blit_toio);
604 
605 
606 static void drm_fb_gray8_to_mono_line(void *dbuf, const void *sbuf, unsigned int pixels)
607 {
608 	u8 *dbuf8 = dbuf;
609 	const u8 *sbuf8 = sbuf;
610 
611 	while (pixels) {
612 		unsigned int i, bits = min(pixels, 8U);
613 		u8 byte = 0;
614 
615 		for (i = 0; i < bits; i++, pixels--) {
616 			if (*sbuf8++ >= 128)
617 				byte |= BIT(i);
618 		}
619 		*dbuf8++ = byte;
620 	}
621 }
622 
623 /**
624  * drm_fb_xrgb8888_to_mono - Convert XRGB8888 to monochrome
625  * @dst: monochrome destination buffer (0=black, 1=white)
626  * @dst_pitch: Number of bytes between two consecutive scanlines within dst
627  * @vaddr: XRGB8888 source buffer
628  * @fb: DRM framebuffer
629  * @clip: Clip rectangle area to copy
630  *
631  * DRM doesn't have native monochrome support.
632  * Such drivers can announce the commonly supported XR24 format to userspace
633  * and use this function to convert to the native format.
634  *
635  * This function uses drm_fb_xrgb8888_to_gray8() to convert to grayscale and
636  * then the result is converted from grayscale to monochrome.
637  *
638  * The first pixel (upper left corner of the clip rectangle) will be converted
639  * and copied to the first bit (LSB) in the first byte of the monochrome
640  * destination buffer.
641  * If the caller requires that the first pixel in a byte must be located at an
642  * x-coordinate that is a multiple of 8, then the caller must take care itself
643  * of supplying a suitable clip rectangle.
644  */
645 void drm_fb_xrgb8888_to_mono(void *dst, unsigned int dst_pitch, const void *vaddr,
646 			     const struct drm_framebuffer *fb, const struct drm_rect *clip)
647 {
648 	unsigned int linepixels = drm_rect_width(clip);
649 	unsigned int lines = drm_rect_height(clip);
650 	unsigned int cpp = fb->format->cpp[0];
651 	unsigned int len_src32 = linepixels * cpp;
652 	struct drm_device *dev = fb->dev;
653 	unsigned int y;
654 	u8 *mono = dst, *gray8;
655 	u32 *src32;
656 
657 	if (drm_WARN_ON(dev, fb->format->format != DRM_FORMAT_XRGB8888))
658 		return;
659 
660 	/*
661 	 * The mono destination buffer contains 1 bit per pixel
662 	 */
663 	if (!dst_pitch)
664 		dst_pitch = DIV_ROUND_UP(linepixels, 8);
665 
666 	/*
667 	 * The cma memory is write-combined so reads are uncached.
668 	 * Speed up by fetching one line at a time.
669 	 *
670 	 * Also, format conversion from XR24 to monochrome are done
671 	 * line-by-line but are converted to 8-bit grayscale as an
672 	 * intermediate step.
673 	 *
674 	 * Allocate a buffer to be used for both copying from the cma
675 	 * memory and to store the intermediate grayscale line pixels.
676 	 */
677 	src32 = kmalloc(len_src32 + linepixels, GFP_KERNEL);
678 	if (!src32)
679 		return;
680 
681 	gray8 = (u8 *)src32 + len_src32;
682 
683 	vaddr += clip_offset(clip, fb->pitches[0], cpp);
684 	for (y = 0; y < lines; y++) {
685 		src32 = memcpy(src32, vaddr, len_src32);
686 		drm_fb_xrgb8888_to_gray8_line(gray8, src32, linepixels);
687 		drm_fb_gray8_to_mono_line(mono, gray8, linepixels);
688 		vaddr += fb->pitches[0];
689 		mono += dst_pitch;
690 	}
691 
692 	kfree(src32);
693 }
694 EXPORT_SYMBOL(drm_fb_xrgb8888_to_mono);
695