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_format_helper.h>
16 #include <drm/drm_framebuffer.h>
17 #include <drm/drm_fourcc.h>
18 #include <drm/drm_rect.h>
19 
20 static unsigned int clip_offset(struct drm_rect *clip,
21 				unsigned int pitch, unsigned int cpp)
22 {
23 	return clip->y1 * pitch + clip->x1 * cpp;
24 }
25 
26 /**
27  * drm_fb_memcpy - Copy clip buffer
28  * @dst: Destination buffer
29  * @vaddr: Source buffer
30  * @fb: DRM framebuffer
31  * @clip: Clip rectangle area to copy
32  *
33  * This function does not apply clipping on dst, i.e. the destination
34  * is a small buffer containing the clip rect only.
35  */
36 void drm_fb_memcpy(void *dst, void *vaddr, struct drm_framebuffer *fb,
37 		   struct drm_rect *clip)
38 {
39 	unsigned int cpp = fb->format->cpp[0];
40 	size_t len = (clip->x2 - clip->x1) * cpp;
41 	unsigned int y, lines = clip->y2 - clip->y1;
42 
43 	vaddr += clip_offset(clip, fb->pitches[0], cpp);
44 	for (y = 0; y < lines; y++) {
45 		memcpy(dst, vaddr, len);
46 		vaddr += fb->pitches[0];
47 		dst += len;
48 	}
49 }
50 EXPORT_SYMBOL(drm_fb_memcpy);
51 
52 /**
53  * drm_fb_memcpy_dstclip - Copy clip buffer
54  * @dst: Destination buffer (iomem)
55  * @dst_pitch: Number of bytes between two consecutive scanlines within dst
56  * @vaddr: Source buffer
57  * @fb: DRM framebuffer
58  * @clip: Clip rectangle area to copy
59  *
60  * This function applies clipping on dst, i.e. the destination is a
61  * full (iomem) framebuffer but only the clip rect content is copied over.
62  */
63 void drm_fb_memcpy_dstclip(void __iomem *dst, unsigned int dst_pitch,
64 			   void *vaddr, struct drm_framebuffer *fb,
65 			   struct drm_rect *clip)
66 {
67 	unsigned int cpp = fb->format->cpp[0];
68 	unsigned int offset = clip_offset(clip, dst_pitch, cpp);
69 	size_t len = (clip->x2 - clip->x1) * cpp;
70 	unsigned int y, lines = clip->y2 - clip->y1;
71 
72 	vaddr += offset;
73 	dst += offset;
74 	for (y = 0; y < lines; y++) {
75 		memcpy_toio(dst, vaddr, len);
76 		vaddr += fb->pitches[0];
77 		dst += dst_pitch;
78 	}
79 }
80 EXPORT_SYMBOL(drm_fb_memcpy_dstclip);
81 
82 /**
83  * drm_fb_swab - Swap bytes into clip buffer
84  * @dst: Destination buffer
85  * @src: Source buffer
86  * @fb: DRM framebuffer
87  * @clip: Clip rectangle area to copy
88  * @cached: Source buffer is mapped cached (eg. not write-combined)
89  *
90  * If @cached is false a temporary buffer is used to cache one pixel line at a
91  * time to speed up slow uncached reads.
92  *
93  * This function does not apply clipping on dst, i.e. the destination
94  * is a small buffer containing the clip rect only.
95  */
96 void drm_fb_swab(void *dst, void *src, struct drm_framebuffer *fb,
97 		 struct drm_rect *clip, bool cached)
98 {
99 	u8 cpp = fb->format->cpp[0];
100 	size_t len = drm_rect_width(clip) * cpp;
101 	u16 *src16, *dst16 = dst;
102 	u32 *src32, *dst32 = dst;
103 	unsigned int x, y;
104 	void *buf = NULL;
105 
106 	if (WARN_ON_ONCE(cpp != 2 && cpp != 4))
107 		return;
108 
109 	if (!cached)
110 		buf = kmalloc(len, GFP_KERNEL);
111 
112 	src += clip_offset(clip, fb->pitches[0], cpp);
113 
114 	for (y = clip->y1; y < clip->y2; y++) {
115 		if (buf) {
116 			memcpy(buf, src, len);
117 			src16 = buf;
118 			src32 = buf;
119 		} else {
120 			src16 = src;
121 			src32 = src;
122 		}
123 
124 		for (x = clip->x1; x < clip->x2; x++) {
125 			if (cpp == 4)
126 				*dst32++ = swab32(*src32++);
127 			else
128 				*dst16++ = swab16(*src16++);
129 		}
130 
131 		src += fb->pitches[0];
132 	}
133 
134 	kfree(buf);
135 }
136 EXPORT_SYMBOL(drm_fb_swab);
137 
138 static void drm_fb_xrgb8888_to_rgb565_line(u16 *dbuf, u32 *sbuf,
139 					   unsigned int pixels,
140 					   bool swab)
141 {
142 	unsigned int x;
143 	u16 val16;
144 
145 	for (x = 0; x < pixels; x++) {
146 		val16 = ((sbuf[x] & 0x00F80000) >> 8) |
147 			((sbuf[x] & 0x0000FC00) >> 5) |
148 			((sbuf[x] & 0x000000F8) >> 3);
149 		if (swab)
150 			dbuf[x] = swab16(val16);
151 		else
152 			dbuf[x] = val16;
153 	}
154 }
155 
156 /**
157  * drm_fb_xrgb8888_to_rgb565 - Convert XRGB8888 to RGB565 clip buffer
158  * @dst: RGB565 destination buffer
159  * @vaddr: XRGB8888 source buffer
160  * @fb: DRM framebuffer
161  * @clip: Clip rectangle area to copy
162  * @swab: Swap bytes
163  *
164  * Drivers can use this function for RGB565 devices that don't natively
165  * support XRGB8888.
166  *
167  * This function does not apply clipping on dst, i.e. the destination
168  * is a small buffer containing the clip rect only.
169  */
170 void drm_fb_xrgb8888_to_rgb565(void *dst, void *vaddr,
171 			       struct drm_framebuffer *fb,
172 			       struct drm_rect *clip, bool swab)
173 {
174 	size_t linepixels = clip->x2 - clip->x1;
175 	size_t src_len = linepixels * sizeof(u32);
176 	size_t dst_len = linepixels * sizeof(u16);
177 	unsigned y, lines = clip->y2 - clip->y1;
178 	void *sbuf;
179 
180 	/*
181 	 * The cma memory is write-combined so reads are uncached.
182 	 * Speed up by fetching one line at a time.
183 	 */
184 	sbuf = kmalloc(src_len, GFP_KERNEL);
185 	if (!sbuf)
186 		return;
187 
188 	vaddr += clip_offset(clip, fb->pitches[0], sizeof(u32));
189 	for (y = 0; y < lines; y++) {
190 		memcpy(sbuf, vaddr, src_len);
191 		drm_fb_xrgb8888_to_rgb565_line(dst, sbuf, linepixels, swab);
192 		vaddr += fb->pitches[0];
193 		dst += dst_len;
194 	}
195 
196 	kfree(sbuf);
197 }
198 EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb565);
199 
200 /**
201  * drm_fb_xrgb8888_to_rgb565_dstclip - Convert XRGB8888 to RGB565 clip buffer
202  * @dst: RGB565 destination buffer (iomem)
203  * @dst_pitch: destination buffer pitch
204  * @vaddr: XRGB8888 source buffer
205  * @fb: DRM framebuffer
206  * @clip: Clip rectangle area to copy
207  * @swab: Swap bytes
208  *
209  * Drivers can use this function for RGB565 devices that don't natively
210  * support XRGB8888.
211  *
212  * This function applies clipping on dst, i.e. the destination is a
213  * full (iomem) framebuffer but only the clip rect content is copied over.
214  */
215 void drm_fb_xrgb8888_to_rgb565_dstclip(void __iomem *dst, unsigned int dst_pitch,
216 				       void *vaddr, struct drm_framebuffer *fb,
217 				       struct drm_rect *clip, bool swab)
218 {
219 	size_t linepixels = clip->x2 - clip->x1;
220 	size_t dst_len = linepixels * sizeof(u16);
221 	unsigned y, lines = clip->y2 - clip->y1;
222 	void *dbuf;
223 
224 	dbuf = kmalloc(dst_len, GFP_KERNEL);
225 	if (!dbuf)
226 		return;
227 
228 	vaddr += clip_offset(clip, fb->pitches[0], sizeof(u32));
229 	dst += clip_offset(clip, dst_pitch, sizeof(u16));
230 	for (y = 0; y < lines; y++) {
231 		drm_fb_xrgb8888_to_rgb565_line(dbuf, vaddr, linepixels, swab);
232 		memcpy_toio(dst, dbuf, dst_len);
233 		vaddr += fb->pitches[0];
234 		dst += dst_len;
235 	}
236 
237 	kfree(dbuf);
238 }
239 EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb565_dstclip);
240 
241 static void drm_fb_xrgb8888_to_rgb888_line(u8 *dbuf, u32 *sbuf,
242 					   unsigned int pixels)
243 {
244 	unsigned int x;
245 
246 	for (x = 0; x < pixels; x++) {
247 		*dbuf++ = (sbuf[x] & 0x000000FF) >>  0;
248 		*dbuf++ = (sbuf[x] & 0x0000FF00) >>  8;
249 		*dbuf++ = (sbuf[x] & 0x00FF0000) >> 16;
250 	}
251 }
252 
253 /**
254  * drm_fb_xrgb8888_to_rgb888_dstclip - Convert XRGB8888 to RGB888 clip buffer
255  * @dst: RGB565 destination buffer (iomem)
256  * @dst_pitch: destination buffer pitch
257  * @vaddr: XRGB8888 source buffer
258  * @fb: DRM framebuffer
259  * @clip: Clip rectangle area to copy
260  *
261  * Drivers can use this function for RGB888 devices that don't natively
262  * support XRGB8888.
263  *
264  * This function applies clipping on dst, i.e. the destination is a
265  * full (iomem) framebuffer but only the clip rect content is copied over.
266  */
267 void drm_fb_xrgb8888_to_rgb888_dstclip(void __iomem *dst, unsigned int dst_pitch,
268 				       void *vaddr, struct drm_framebuffer *fb,
269 				       struct drm_rect *clip)
270 {
271 	size_t linepixels = clip->x2 - clip->x1;
272 	size_t dst_len = linepixels * 3;
273 	unsigned y, lines = clip->y2 - clip->y1;
274 	void *dbuf;
275 
276 	dbuf = kmalloc(dst_len, GFP_KERNEL);
277 	if (!dbuf)
278 		return;
279 
280 	vaddr += clip_offset(clip, fb->pitches[0], sizeof(u32));
281 	dst += clip_offset(clip, dst_pitch, sizeof(u16));
282 	for (y = 0; y < lines; y++) {
283 		drm_fb_xrgb8888_to_rgb888_line(dbuf, vaddr, linepixels);
284 		memcpy_toio(dst, dbuf, dst_len);
285 		vaddr += fb->pitches[0];
286 		dst += dst_len;
287 	}
288 
289 	kfree(dbuf);
290 }
291 EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb888_dstclip);
292 
293 /**
294  * drm_fb_xrgb8888_to_gray8 - Convert XRGB8888 to grayscale
295  * @dst: 8-bit grayscale destination buffer
296  * @vaddr: XRGB8888 source buffer
297  * @fb: DRM framebuffer
298  * @clip: Clip rectangle area to copy
299  *
300  * Drm doesn't have native monochrome or grayscale support.
301  * Such drivers can announce the commonly supported XR24 format to userspace
302  * and use this function to convert to the native format.
303  *
304  * Monochrome drivers will use the most significant bit,
305  * where 1 means foreground color and 0 background color.
306  *
307  * ITU BT.601 is used for the RGB -> luma (brightness) conversion.
308  */
309 void drm_fb_xrgb8888_to_gray8(u8 *dst, void *vaddr, struct drm_framebuffer *fb,
310 			       struct drm_rect *clip)
311 {
312 	unsigned int len = (clip->x2 - clip->x1) * sizeof(u32);
313 	unsigned int x, y;
314 	void *buf;
315 	u32 *src;
316 
317 	if (WARN_ON(fb->format->format != DRM_FORMAT_XRGB8888))
318 		return;
319 	/*
320 	 * The cma memory is write-combined so reads are uncached.
321 	 * Speed up by fetching one line at a time.
322 	 */
323 	buf = kmalloc(len, GFP_KERNEL);
324 	if (!buf)
325 		return;
326 
327 	for (y = clip->y1; y < clip->y2; y++) {
328 		src = vaddr + (y * fb->pitches[0]);
329 		src += clip->x1;
330 		memcpy(buf, src, len);
331 		src = buf;
332 		for (x = clip->x1; x < clip->x2; x++) {
333 			u8 r = (*src & 0x00ff0000) >> 16;
334 			u8 g = (*src & 0x0000ff00) >> 8;
335 			u8 b =  *src & 0x000000ff;
336 
337 			/* ITU BT.601: Y = 0.299 R + 0.587 G + 0.114 B */
338 			*dst++ = (3 * r + 6 * g + b) / 10;
339 			src++;
340 		}
341 	}
342 
343 	kfree(buf);
344 }
345 EXPORT_SYMBOL(drm_fb_xrgb8888_to_gray8);
346 
347 /**
348  * drm_fb_blit_rect_dstclip - Copy parts of a framebuffer to display memory
349  * @dst:	The display memory to copy to
350  * @dst_pitch:	Number of bytes between two consecutive scanlines within dst
351  * @dst_format:	FOURCC code of the display's color format
352  * @vmap:	The framebuffer memory to copy from
353  * @fb:		The framebuffer to copy from
354  * @clip:	Clip rectangle area to copy
355  *
356  * This function copies parts of a framebuffer to display memory. If the
357  * formats of the display and the framebuffer mismatch, the blit function
358  * will attempt to convert between them.
359  *
360  * Use drm_fb_blit_dstclip() to copy the full framebuffer.
361  *
362  * Returns:
363  * 0 on success, or
364  * -EINVAL if the color-format conversion failed, or
365  * a negative error code otherwise.
366  */
367 int drm_fb_blit_rect_dstclip(void __iomem *dst, unsigned int dst_pitch,
368 			     uint32_t dst_format, void *vmap,
369 			     struct drm_framebuffer *fb,
370 			     struct drm_rect *clip)
371 {
372 	uint32_t fb_format = fb->format->format;
373 
374 	/* treat alpha channel like filler bits */
375 	if (fb_format == DRM_FORMAT_ARGB8888)
376 		fb_format = DRM_FORMAT_XRGB8888;
377 	if (dst_format == DRM_FORMAT_ARGB8888)
378 		dst_format = DRM_FORMAT_XRGB8888;
379 
380 	if (dst_format == fb_format) {
381 		drm_fb_memcpy_dstclip(dst, dst_pitch, vmap, fb, clip);
382 		return 0;
383 
384 	} else if (dst_format == DRM_FORMAT_RGB565) {
385 		if (fb_format == DRM_FORMAT_XRGB8888) {
386 			drm_fb_xrgb8888_to_rgb565_dstclip(dst, dst_pitch,
387 							  vmap, fb, clip,
388 							  false);
389 			return 0;
390 		}
391 	} else if (dst_format == DRM_FORMAT_RGB888) {
392 		if (fb_format == DRM_FORMAT_XRGB8888) {
393 			drm_fb_xrgb8888_to_rgb888_dstclip(dst, dst_pitch,
394 							  vmap, fb, clip);
395 			return 0;
396 		}
397 	}
398 
399 	return -EINVAL;
400 }
401 EXPORT_SYMBOL(drm_fb_blit_rect_dstclip);
402 
403 /**
404  * drm_fb_blit_dstclip - Copy framebuffer to display memory
405  * @dst:	The display memory to copy to
406  * @dst_pitch:	Number of bytes between two consecutive scanlines within dst
407  * @dst_format:	FOURCC code of the display's color format
408  * @vmap:	The framebuffer memory to copy from
409  * @fb:		The framebuffer to copy from
410  *
411  * This function copies a full framebuffer to display memory. If the formats
412  * of the display and the framebuffer mismatch, the copy function will
413  * attempt to convert between them.
414  *
415  * See drm_fb_blit_rect_dstclip() for more information.
416  *
417  * Returns:
418  * 0 on success, or a negative error code otherwise.
419  */
420 int drm_fb_blit_dstclip(void __iomem *dst, unsigned int dst_pitch,
421 			uint32_t dst_format, void *vmap,
422 			struct drm_framebuffer *fb)
423 {
424 	struct drm_rect fullscreen = {
425 		.x1 = 0,
426 		.x2 = fb->width,
427 		.y1 = 0,
428 		.y2 = fb->height,
429 	};
430 	return drm_fb_blit_rect_dstclip(dst, dst_pitch, dst_format, vmap, fb,
431 					&fullscreen);
432 }
433 EXPORT_SYMBOL(drm_fb_blit_dstclip);
434