1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * v4l2-dv-timings - dv-timings helper functions
4  *
5  * Copyright 2013 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
6  */
7 
8 #include <linux/module.h>
9 #include <linux/types.h>
10 #include <linux/kernel.h>
11 #include <linux/errno.h>
12 #include <linux/rational.h>
13 #include <linux/videodev2.h>
14 #include <linux/v4l2-dv-timings.h>
15 #include <media/v4l2-dv-timings.h>
16 #include <linux/math64.h>
17 #include <linux/hdmi.h>
18 #include <media/cec.h>
19 
20 MODULE_AUTHOR("Hans Verkuil");
21 MODULE_DESCRIPTION("V4L2 DV Timings Helper Functions");
22 MODULE_LICENSE("GPL");
23 
24 const struct v4l2_dv_timings v4l2_dv_timings_presets[] = {
25 	V4L2_DV_BT_CEA_640X480P59_94,
26 	V4L2_DV_BT_CEA_720X480I59_94,
27 	V4L2_DV_BT_CEA_720X480P59_94,
28 	V4L2_DV_BT_CEA_720X576I50,
29 	V4L2_DV_BT_CEA_720X576P50,
30 	V4L2_DV_BT_CEA_1280X720P24,
31 	V4L2_DV_BT_CEA_1280X720P25,
32 	V4L2_DV_BT_CEA_1280X720P30,
33 	V4L2_DV_BT_CEA_1280X720P50,
34 	V4L2_DV_BT_CEA_1280X720P60,
35 	V4L2_DV_BT_CEA_1920X1080P24,
36 	V4L2_DV_BT_CEA_1920X1080P25,
37 	V4L2_DV_BT_CEA_1920X1080P30,
38 	V4L2_DV_BT_CEA_1920X1080I50,
39 	V4L2_DV_BT_CEA_1920X1080P50,
40 	V4L2_DV_BT_CEA_1920X1080I60,
41 	V4L2_DV_BT_CEA_1920X1080P60,
42 	V4L2_DV_BT_DMT_640X350P85,
43 	V4L2_DV_BT_DMT_640X400P85,
44 	V4L2_DV_BT_DMT_720X400P85,
45 	V4L2_DV_BT_DMT_640X480P72,
46 	V4L2_DV_BT_DMT_640X480P75,
47 	V4L2_DV_BT_DMT_640X480P85,
48 	V4L2_DV_BT_DMT_800X600P56,
49 	V4L2_DV_BT_DMT_800X600P60,
50 	V4L2_DV_BT_DMT_800X600P72,
51 	V4L2_DV_BT_DMT_800X600P75,
52 	V4L2_DV_BT_DMT_800X600P85,
53 	V4L2_DV_BT_DMT_800X600P120_RB,
54 	V4L2_DV_BT_DMT_848X480P60,
55 	V4L2_DV_BT_DMT_1024X768I43,
56 	V4L2_DV_BT_DMT_1024X768P60,
57 	V4L2_DV_BT_DMT_1024X768P70,
58 	V4L2_DV_BT_DMT_1024X768P75,
59 	V4L2_DV_BT_DMT_1024X768P85,
60 	V4L2_DV_BT_DMT_1024X768P120_RB,
61 	V4L2_DV_BT_DMT_1152X864P75,
62 	V4L2_DV_BT_DMT_1280X768P60_RB,
63 	V4L2_DV_BT_DMT_1280X768P60,
64 	V4L2_DV_BT_DMT_1280X768P75,
65 	V4L2_DV_BT_DMT_1280X768P85,
66 	V4L2_DV_BT_DMT_1280X768P120_RB,
67 	V4L2_DV_BT_DMT_1280X800P60_RB,
68 	V4L2_DV_BT_DMT_1280X800P60,
69 	V4L2_DV_BT_DMT_1280X800P75,
70 	V4L2_DV_BT_DMT_1280X800P85,
71 	V4L2_DV_BT_DMT_1280X800P120_RB,
72 	V4L2_DV_BT_DMT_1280X960P60,
73 	V4L2_DV_BT_DMT_1280X960P85,
74 	V4L2_DV_BT_DMT_1280X960P120_RB,
75 	V4L2_DV_BT_DMT_1280X1024P60,
76 	V4L2_DV_BT_DMT_1280X1024P75,
77 	V4L2_DV_BT_DMT_1280X1024P85,
78 	V4L2_DV_BT_DMT_1280X1024P120_RB,
79 	V4L2_DV_BT_DMT_1360X768P60,
80 	V4L2_DV_BT_DMT_1360X768P120_RB,
81 	V4L2_DV_BT_DMT_1366X768P60,
82 	V4L2_DV_BT_DMT_1366X768P60_RB,
83 	V4L2_DV_BT_DMT_1400X1050P60_RB,
84 	V4L2_DV_BT_DMT_1400X1050P60,
85 	V4L2_DV_BT_DMT_1400X1050P75,
86 	V4L2_DV_BT_DMT_1400X1050P85,
87 	V4L2_DV_BT_DMT_1400X1050P120_RB,
88 	V4L2_DV_BT_DMT_1440X900P60_RB,
89 	V4L2_DV_BT_DMT_1440X900P60,
90 	V4L2_DV_BT_DMT_1440X900P75,
91 	V4L2_DV_BT_DMT_1440X900P85,
92 	V4L2_DV_BT_DMT_1440X900P120_RB,
93 	V4L2_DV_BT_DMT_1600X900P60_RB,
94 	V4L2_DV_BT_DMT_1600X1200P60,
95 	V4L2_DV_BT_DMT_1600X1200P65,
96 	V4L2_DV_BT_DMT_1600X1200P70,
97 	V4L2_DV_BT_DMT_1600X1200P75,
98 	V4L2_DV_BT_DMT_1600X1200P85,
99 	V4L2_DV_BT_DMT_1600X1200P120_RB,
100 	V4L2_DV_BT_DMT_1680X1050P60_RB,
101 	V4L2_DV_BT_DMT_1680X1050P60,
102 	V4L2_DV_BT_DMT_1680X1050P75,
103 	V4L2_DV_BT_DMT_1680X1050P85,
104 	V4L2_DV_BT_DMT_1680X1050P120_RB,
105 	V4L2_DV_BT_DMT_1792X1344P60,
106 	V4L2_DV_BT_DMT_1792X1344P75,
107 	V4L2_DV_BT_DMT_1792X1344P120_RB,
108 	V4L2_DV_BT_DMT_1856X1392P60,
109 	V4L2_DV_BT_DMT_1856X1392P75,
110 	V4L2_DV_BT_DMT_1856X1392P120_RB,
111 	V4L2_DV_BT_DMT_1920X1200P60_RB,
112 	V4L2_DV_BT_DMT_1920X1200P60,
113 	V4L2_DV_BT_DMT_1920X1200P75,
114 	V4L2_DV_BT_DMT_1920X1200P85,
115 	V4L2_DV_BT_DMT_1920X1200P120_RB,
116 	V4L2_DV_BT_DMT_1920X1440P60,
117 	V4L2_DV_BT_DMT_1920X1440P75,
118 	V4L2_DV_BT_DMT_1920X1440P120_RB,
119 	V4L2_DV_BT_DMT_2048X1152P60_RB,
120 	V4L2_DV_BT_DMT_2560X1600P60_RB,
121 	V4L2_DV_BT_DMT_2560X1600P60,
122 	V4L2_DV_BT_DMT_2560X1600P75,
123 	V4L2_DV_BT_DMT_2560X1600P85,
124 	V4L2_DV_BT_DMT_2560X1600P120_RB,
125 	V4L2_DV_BT_CEA_3840X2160P24,
126 	V4L2_DV_BT_CEA_3840X2160P25,
127 	V4L2_DV_BT_CEA_3840X2160P30,
128 	V4L2_DV_BT_CEA_3840X2160P50,
129 	V4L2_DV_BT_CEA_3840X2160P60,
130 	V4L2_DV_BT_CEA_4096X2160P24,
131 	V4L2_DV_BT_CEA_4096X2160P25,
132 	V4L2_DV_BT_CEA_4096X2160P30,
133 	V4L2_DV_BT_CEA_4096X2160P50,
134 	V4L2_DV_BT_DMT_4096X2160P59_94_RB,
135 	V4L2_DV_BT_CEA_4096X2160P60,
136 	{ }
137 };
138 EXPORT_SYMBOL_GPL(v4l2_dv_timings_presets);
139 
140 bool v4l2_valid_dv_timings(const struct v4l2_dv_timings *t,
141 			   const struct v4l2_dv_timings_cap *dvcap,
142 			   v4l2_check_dv_timings_fnc fnc,
143 			   void *fnc_handle)
144 {
145 	const struct v4l2_bt_timings *bt = &t->bt;
146 	const struct v4l2_bt_timings_cap *cap = &dvcap->bt;
147 	u32 caps = cap->capabilities;
148 
149 	if (t->type != V4L2_DV_BT_656_1120)
150 		return false;
151 	if (t->type != dvcap->type ||
152 	    bt->height < cap->min_height ||
153 	    bt->height > cap->max_height ||
154 	    bt->width < cap->min_width ||
155 	    bt->width > cap->max_width ||
156 	    bt->pixelclock < cap->min_pixelclock ||
157 	    bt->pixelclock > cap->max_pixelclock ||
158 	    (!(caps & V4L2_DV_BT_CAP_CUSTOM) &&
159 	     cap->standards && bt->standards &&
160 	     !(bt->standards & cap->standards)) ||
161 	    (bt->interlaced && !(caps & V4L2_DV_BT_CAP_INTERLACED)) ||
162 	    (!bt->interlaced && !(caps & V4L2_DV_BT_CAP_PROGRESSIVE)))
163 		return false;
164 	return fnc == NULL || fnc(t, fnc_handle);
165 }
166 EXPORT_SYMBOL_GPL(v4l2_valid_dv_timings);
167 
168 int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t,
169 			     const struct v4l2_dv_timings_cap *cap,
170 			     v4l2_check_dv_timings_fnc fnc,
171 			     void *fnc_handle)
172 {
173 	u32 i, idx;
174 
175 	memset(t->reserved, 0, sizeof(t->reserved));
176 	for (i = idx = 0; v4l2_dv_timings_presets[i].bt.width; i++) {
177 		if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap,
178 					  fnc, fnc_handle) &&
179 		    idx++ == t->index) {
180 			t->timings = v4l2_dv_timings_presets[i];
181 			return 0;
182 		}
183 	}
184 	return -EINVAL;
185 }
186 EXPORT_SYMBOL_GPL(v4l2_enum_dv_timings_cap);
187 
188 bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t,
189 			      const struct v4l2_dv_timings_cap *cap,
190 			      unsigned pclock_delta,
191 			      v4l2_check_dv_timings_fnc fnc,
192 			      void *fnc_handle)
193 {
194 	int i;
195 
196 	if (!v4l2_valid_dv_timings(t, cap, fnc, fnc_handle))
197 		return false;
198 
199 	for (i = 0; i < v4l2_dv_timings_presets[i].bt.width; i++) {
200 		if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap,
201 					  fnc, fnc_handle) &&
202 		    v4l2_match_dv_timings(t, v4l2_dv_timings_presets + i,
203 					  pclock_delta, false)) {
204 			u32 flags = t->bt.flags & V4L2_DV_FL_REDUCED_FPS;
205 
206 			*t = v4l2_dv_timings_presets[i];
207 			if (can_reduce_fps(&t->bt))
208 				t->bt.flags |= flags;
209 
210 			return true;
211 		}
212 	}
213 	return false;
214 }
215 EXPORT_SYMBOL_GPL(v4l2_find_dv_timings_cap);
216 
217 bool v4l2_find_dv_timings_cea861_vic(struct v4l2_dv_timings *t, u8 vic)
218 {
219 	unsigned int i;
220 
221 	for (i = 0; i < v4l2_dv_timings_presets[i].bt.width; i++) {
222 		const struct v4l2_bt_timings *bt =
223 			&v4l2_dv_timings_presets[i].bt;
224 
225 		if ((bt->flags & V4L2_DV_FL_HAS_CEA861_VIC) &&
226 		    bt->cea861_vic == vic) {
227 			*t = v4l2_dv_timings_presets[i];
228 			return true;
229 		}
230 	}
231 	return false;
232 }
233 EXPORT_SYMBOL_GPL(v4l2_find_dv_timings_cea861_vic);
234 
235 /**
236  * v4l2_match_dv_timings - check if two timings match
237  * @t1: compare this v4l2_dv_timings struct...
238  * @t2: with this struct.
239  * @pclock_delta: the allowed pixelclock deviation.
240  * @match_reduced_fps: if true, then fail if V4L2_DV_FL_REDUCED_FPS does not
241  *	match.
242  *
243  * Compare t1 with t2 with a given margin of error for the pixelclock.
244  */
245 bool v4l2_match_dv_timings(const struct v4l2_dv_timings *t1,
246 			   const struct v4l2_dv_timings *t2,
247 			   unsigned pclock_delta, bool match_reduced_fps)
248 {
249 	if (t1->type != t2->type || t1->type != V4L2_DV_BT_656_1120)
250 		return false;
251 	if (t1->bt.width == t2->bt.width &&
252 	    t1->bt.height == t2->bt.height &&
253 	    t1->bt.interlaced == t2->bt.interlaced &&
254 	    t1->bt.polarities == t2->bt.polarities &&
255 	    t1->bt.pixelclock >= t2->bt.pixelclock - pclock_delta &&
256 	    t1->bt.pixelclock <= t2->bt.pixelclock + pclock_delta &&
257 	    t1->bt.hfrontporch == t2->bt.hfrontporch &&
258 	    t1->bt.hsync == t2->bt.hsync &&
259 	    t1->bt.hbackporch == t2->bt.hbackporch &&
260 	    t1->bt.vfrontporch == t2->bt.vfrontporch &&
261 	    t1->bt.vsync == t2->bt.vsync &&
262 	    t1->bt.vbackporch == t2->bt.vbackporch &&
263 	    (!match_reduced_fps ||
264 	     (t1->bt.flags & V4L2_DV_FL_REDUCED_FPS) ==
265 		(t2->bt.flags & V4L2_DV_FL_REDUCED_FPS)) &&
266 	    (!t1->bt.interlaced ||
267 		(t1->bt.il_vfrontporch == t2->bt.il_vfrontporch &&
268 		 t1->bt.il_vsync == t2->bt.il_vsync &&
269 		 t1->bt.il_vbackporch == t2->bt.il_vbackporch)))
270 		return true;
271 	return false;
272 }
273 EXPORT_SYMBOL_GPL(v4l2_match_dv_timings);
274 
275 void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix,
276 			   const struct v4l2_dv_timings *t, bool detailed)
277 {
278 	const struct v4l2_bt_timings *bt = &t->bt;
279 	u32 htot, vtot;
280 	u32 fps;
281 
282 	if (t->type != V4L2_DV_BT_656_1120)
283 		return;
284 
285 	htot = V4L2_DV_BT_FRAME_WIDTH(bt);
286 	vtot = V4L2_DV_BT_FRAME_HEIGHT(bt);
287 	if (bt->interlaced)
288 		vtot /= 2;
289 
290 	fps = (htot * vtot) > 0 ? div_u64((100 * (u64)bt->pixelclock),
291 				  (htot * vtot)) : 0;
292 
293 	if (prefix == NULL)
294 		prefix = "";
295 
296 	pr_info("%s: %s%ux%u%s%u.%u (%ux%u)\n", dev_prefix, prefix,
297 		bt->width, bt->height, bt->interlaced ? "i" : "p",
298 		fps / 100, fps % 100, htot, vtot);
299 
300 	if (!detailed)
301 		return;
302 
303 	pr_info("%s: horizontal: fp = %u, %ssync = %u, bp = %u\n",
304 			dev_prefix, bt->hfrontporch,
305 			(bt->polarities & V4L2_DV_HSYNC_POS_POL) ? "+" : "-",
306 			bt->hsync, bt->hbackporch);
307 	pr_info("%s: vertical: fp = %u, %ssync = %u, bp = %u\n",
308 			dev_prefix, bt->vfrontporch,
309 			(bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-",
310 			bt->vsync, bt->vbackporch);
311 	if (bt->interlaced)
312 		pr_info("%s: vertical bottom field: fp = %u, %ssync = %u, bp = %u\n",
313 			dev_prefix, bt->il_vfrontporch,
314 			(bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-",
315 			bt->il_vsync, bt->il_vbackporch);
316 	pr_info("%s: pixelclock: %llu\n", dev_prefix, bt->pixelclock);
317 	pr_info("%s: flags (0x%x):%s%s%s%s%s%s%s%s%s%s\n",
318 			dev_prefix, bt->flags,
319 			(bt->flags & V4L2_DV_FL_REDUCED_BLANKING) ?
320 			" REDUCED_BLANKING" : "",
321 			((bt->flags & V4L2_DV_FL_REDUCED_BLANKING) &&
322 			 bt->vsync == 8) ? " (V2)" : "",
323 			(bt->flags & V4L2_DV_FL_CAN_REDUCE_FPS) ?
324 			" CAN_REDUCE_FPS" : "",
325 			(bt->flags & V4L2_DV_FL_REDUCED_FPS) ?
326 			" REDUCED_FPS" : "",
327 			(bt->flags & V4L2_DV_FL_HALF_LINE) ?
328 			" HALF_LINE" : "",
329 			(bt->flags & V4L2_DV_FL_IS_CE_VIDEO) ?
330 			" CE_VIDEO" : "",
331 			(bt->flags & V4L2_DV_FL_FIRST_FIELD_EXTRA_LINE) ?
332 			" FIRST_FIELD_EXTRA_LINE" : "",
333 			(bt->flags & V4L2_DV_FL_HAS_PICTURE_ASPECT) ?
334 			" HAS_PICTURE_ASPECT" : "",
335 			(bt->flags & V4L2_DV_FL_HAS_CEA861_VIC) ?
336 			" HAS_CEA861_VIC" : "",
337 			(bt->flags & V4L2_DV_FL_HAS_HDMI_VIC) ?
338 			" HAS_HDMI_VIC" : "");
339 	pr_info("%s: standards (0x%x):%s%s%s%s%s\n", dev_prefix, bt->standards,
340 			(bt->standards & V4L2_DV_BT_STD_CEA861) ?  " CEA" : "",
341 			(bt->standards & V4L2_DV_BT_STD_DMT) ?  " DMT" : "",
342 			(bt->standards & V4L2_DV_BT_STD_CVT) ?  " CVT" : "",
343 			(bt->standards & V4L2_DV_BT_STD_GTF) ?  " GTF" : "",
344 			(bt->standards & V4L2_DV_BT_STD_SDI) ?  " SDI" : "");
345 	if (bt->flags & V4L2_DV_FL_HAS_PICTURE_ASPECT)
346 		pr_info("%s: picture aspect (hor:vert): %u:%u\n", dev_prefix,
347 			bt->picture_aspect.numerator,
348 			bt->picture_aspect.denominator);
349 	if (bt->flags & V4L2_DV_FL_HAS_CEA861_VIC)
350 		pr_info("%s: CEA-861 VIC: %u\n", dev_prefix, bt->cea861_vic);
351 	if (bt->flags & V4L2_DV_FL_HAS_HDMI_VIC)
352 		pr_info("%s: HDMI VIC: %u\n", dev_prefix, bt->hdmi_vic);
353 }
354 EXPORT_SYMBOL_GPL(v4l2_print_dv_timings);
355 
356 struct v4l2_fract v4l2_dv_timings_aspect_ratio(const struct v4l2_dv_timings *t)
357 {
358 	struct v4l2_fract ratio = { 1, 1 };
359 	unsigned long n, d;
360 
361 	if (t->type != V4L2_DV_BT_656_1120)
362 		return ratio;
363 	if (!(t->bt.flags & V4L2_DV_FL_HAS_PICTURE_ASPECT))
364 		return ratio;
365 
366 	ratio.numerator = t->bt.width * t->bt.picture_aspect.denominator;
367 	ratio.denominator = t->bt.height * t->bt.picture_aspect.numerator;
368 
369 	rational_best_approximation(ratio.numerator, ratio.denominator,
370 				    ratio.numerator, ratio.denominator, &n, &d);
371 	ratio.numerator = n;
372 	ratio.denominator = d;
373 	return ratio;
374 }
375 EXPORT_SYMBOL_GPL(v4l2_dv_timings_aspect_ratio);
376 
377 /** v4l2_calc_timeperframe - helper function to calculate timeperframe based
378  *	v4l2_dv_timings fields.
379  * @t - Timings for the video mode.
380  *
381  * Calculates the expected timeperframe using the pixel clock value and
382  * horizontal/vertical measures. This means that v4l2_dv_timings structure
383  * must be correctly and fully filled.
384  */
385 struct v4l2_fract v4l2_calc_timeperframe(const struct v4l2_dv_timings *t)
386 {
387 	const struct v4l2_bt_timings *bt = &t->bt;
388 	struct v4l2_fract fps_fract = { 1, 1 };
389 	unsigned long n, d;
390 	u32 htot, vtot, fps;
391 	u64 pclk;
392 
393 	if (t->type != V4L2_DV_BT_656_1120)
394 		return fps_fract;
395 
396 	htot = V4L2_DV_BT_FRAME_WIDTH(bt);
397 	vtot = V4L2_DV_BT_FRAME_HEIGHT(bt);
398 	pclk = bt->pixelclock;
399 
400 	if ((bt->flags & V4L2_DV_FL_CAN_DETECT_REDUCED_FPS) &&
401 	    (bt->flags & V4L2_DV_FL_REDUCED_FPS))
402 		pclk = div_u64(pclk * 1000ULL, 1001);
403 
404 	fps = (htot * vtot) > 0 ? div_u64((100 * pclk), (htot * vtot)) : 0;
405 	if (!fps)
406 		return fps_fract;
407 
408 	rational_best_approximation(fps, 100, fps, 100, &n, &d);
409 
410 	fps_fract.numerator = d;
411 	fps_fract.denominator = n;
412 	return fps_fract;
413 }
414 EXPORT_SYMBOL_GPL(v4l2_calc_timeperframe);
415 
416 /*
417  * CVT defines
418  * Based on Coordinated Video Timings Standard
419  * version 1.1 September 10, 2003
420  */
421 
422 #define CVT_PXL_CLK_GRAN	250000	/* pixel clock granularity */
423 #define CVT_PXL_CLK_GRAN_RB_V2 1000	/* granularity for reduced blanking v2*/
424 
425 /* Normal blanking */
426 #define CVT_MIN_V_BPORCH	7	/* lines */
427 #define CVT_MIN_V_PORCH_RND	3	/* lines */
428 #define CVT_MIN_VSYNC_BP	550	/* min time of vsync + back porch (us) */
429 #define CVT_HSYNC_PERCENT       8       /* nominal hsync as percentage of line */
430 
431 /* Normal blanking for CVT uses GTF to calculate horizontal blanking */
432 #define CVT_CELL_GRAN		8	/* character cell granularity */
433 #define CVT_M			600	/* blanking formula gradient */
434 #define CVT_C			40	/* blanking formula offset */
435 #define CVT_K			128	/* blanking formula scaling factor */
436 #define CVT_J			20	/* blanking formula scaling factor */
437 #define CVT_C_PRIME (((CVT_C - CVT_J) * CVT_K / 256) + CVT_J)
438 #define CVT_M_PRIME (CVT_K * CVT_M / 256)
439 
440 /* Reduced Blanking */
441 #define CVT_RB_MIN_V_BPORCH    7       /* lines  */
442 #define CVT_RB_V_FPORCH        3       /* lines  */
443 #define CVT_RB_MIN_V_BLANK   460       /* us     */
444 #define CVT_RB_H_SYNC         32       /* pixels */
445 #define CVT_RB_H_BLANK       160       /* pixels */
446 /* Reduce blanking Version 2 */
447 #define CVT_RB_V2_H_BLANK     80       /* pixels */
448 #define CVT_RB_MIN_V_FPORCH    3       /* lines  */
449 #define CVT_RB_V2_MIN_V_FPORCH 1       /* lines  */
450 #define CVT_RB_V_BPORCH        6       /* lines  */
451 
452 /** v4l2_detect_cvt - detect if the given timings follow the CVT standard
453  * @frame_height - the total height of the frame (including blanking) in lines.
454  * @hfreq - the horizontal frequency in Hz.
455  * @vsync - the height of the vertical sync in lines.
456  * @active_width - active width of image (does not include blanking). This
457  * information is needed only in case of version 2 of reduced blanking.
458  * In other cases, this parameter does not have any effect on timings.
459  * @polarities - the horizontal and vertical polarities (same as struct
460  *		v4l2_bt_timings polarities).
461  * @interlaced - if this flag is true, it indicates interlaced format
462  * @fmt - the resulting timings.
463  *
464  * This function will attempt to detect if the given values correspond to a
465  * valid CVT format. If so, then it will return true, and fmt will be filled
466  * in with the found CVT timings.
467  */
468 bool v4l2_detect_cvt(unsigned frame_height,
469 		     unsigned hfreq,
470 		     unsigned vsync,
471 		     unsigned active_width,
472 		     u32 polarities,
473 		     bool interlaced,
474 		     struct v4l2_dv_timings *fmt)
475 {
476 	int  v_fp, v_bp, h_fp, h_bp, hsync;
477 	int  frame_width, image_height, image_width;
478 	bool reduced_blanking;
479 	bool rb_v2 = false;
480 	unsigned pix_clk;
481 
482 	if (vsync < 4 || vsync > 8)
483 		return false;
484 
485 	if (polarities == V4L2_DV_VSYNC_POS_POL)
486 		reduced_blanking = false;
487 	else if (polarities == V4L2_DV_HSYNC_POS_POL)
488 		reduced_blanking = true;
489 	else
490 		return false;
491 
492 	if (reduced_blanking && vsync == 8)
493 		rb_v2 = true;
494 
495 	if (rb_v2 && active_width == 0)
496 		return false;
497 
498 	if (!rb_v2 && vsync > 7)
499 		return false;
500 
501 	if (hfreq == 0)
502 		return false;
503 
504 	/* Vertical */
505 	if (reduced_blanking) {
506 		if (rb_v2) {
507 			v_bp = CVT_RB_V_BPORCH;
508 			v_fp = (CVT_RB_MIN_V_BLANK * hfreq) / 1000000 + 1;
509 			v_fp -= vsync + v_bp;
510 
511 			if (v_fp < CVT_RB_V2_MIN_V_FPORCH)
512 				v_fp = CVT_RB_V2_MIN_V_FPORCH;
513 		} else {
514 			v_fp = CVT_RB_V_FPORCH;
515 			v_bp = (CVT_RB_MIN_V_BLANK * hfreq) / 1000000 + 1;
516 			v_bp -= vsync + v_fp;
517 
518 			if (v_bp < CVT_RB_MIN_V_BPORCH)
519 				v_bp = CVT_RB_MIN_V_BPORCH;
520 		}
521 	} else {
522 		v_fp = CVT_MIN_V_PORCH_RND;
523 		v_bp = (CVT_MIN_VSYNC_BP * hfreq) / 1000000 + 1 - vsync;
524 
525 		if (v_bp < CVT_MIN_V_BPORCH)
526 			v_bp = CVT_MIN_V_BPORCH;
527 	}
528 
529 	if (interlaced)
530 		image_height = (frame_height - 2 * v_fp - 2 * vsync - 2 * v_bp) & ~0x1;
531 	else
532 		image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
533 
534 	if (image_height < 0)
535 		return false;
536 
537 	/* Aspect ratio based on vsync */
538 	switch (vsync) {
539 	case 4:
540 		image_width = (image_height * 4) / 3;
541 		break;
542 	case 5:
543 		image_width = (image_height * 16) / 9;
544 		break;
545 	case 6:
546 		image_width = (image_height * 16) / 10;
547 		break;
548 	case 7:
549 		/* special case */
550 		if (image_height == 1024)
551 			image_width = (image_height * 5) / 4;
552 		else if (image_height == 768)
553 			image_width = (image_height * 15) / 9;
554 		else
555 			return false;
556 		break;
557 	case 8:
558 		image_width = active_width;
559 		break;
560 	default:
561 		return false;
562 	}
563 
564 	if (!rb_v2)
565 		image_width = image_width & ~7;
566 
567 	/* Horizontal */
568 	if (reduced_blanking) {
569 		int h_blank;
570 		int clk_gran;
571 
572 		h_blank = rb_v2 ? CVT_RB_V2_H_BLANK : CVT_RB_H_BLANK;
573 		clk_gran = rb_v2 ? CVT_PXL_CLK_GRAN_RB_V2 : CVT_PXL_CLK_GRAN;
574 
575 		pix_clk = (image_width + h_blank) * hfreq;
576 		pix_clk = (pix_clk / clk_gran) * clk_gran;
577 
578 		h_bp  = h_blank / 2;
579 		hsync = CVT_RB_H_SYNC;
580 		h_fp  = h_blank - h_bp - hsync;
581 
582 		frame_width = image_width + h_blank;
583 	} else {
584 		unsigned ideal_duty_cycle_per_myriad =
585 			100 * CVT_C_PRIME - (CVT_M_PRIME * 100000) / hfreq;
586 		int h_blank;
587 
588 		if (ideal_duty_cycle_per_myriad < 2000)
589 			ideal_duty_cycle_per_myriad = 2000;
590 
591 		h_blank = image_width * ideal_duty_cycle_per_myriad /
592 					(10000 - ideal_duty_cycle_per_myriad);
593 		h_blank = (h_blank / (2 * CVT_CELL_GRAN)) * 2 * CVT_CELL_GRAN;
594 
595 		pix_clk = (image_width + h_blank) * hfreq;
596 		pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN;
597 
598 		h_bp = h_blank / 2;
599 		frame_width = image_width + h_blank;
600 
601 		hsync = frame_width * CVT_HSYNC_PERCENT / 100;
602 		hsync = (hsync / CVT_CELL_GRAN) * CVT_CELL_GRAN;
603 		h_fp = h_blank - hsync - h_bp;
604 	}
605 
606 	fmt->type = V4L2_DV_BT_656_1120;
607 	fmt->bt.polarities = polarities;
608 	fmt->bt.width = image_width;
609 	fmt->bt.height = image_height;
610 	fmt->bt.hfrontporch = h_fp;
611 	fmt->bt.vfrontporch = v_fp;
612 	fmt->bt.hsync = hsync;
613 	fmt->bt.vsync = vsync;
614 	fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
615 
616 	if (!interlaced) {
617 		fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
618 		fmt->bt.interlaced = V4L2_DV_PROGRESSIVE;
619 	} else {
620 		fmt->bt.vbackporch = (frame_height - image_height - 2 * v_fp -
621 				      2 * vsync) / 2;
622 		fmt->bt.il_vbackporch = frame_height - image_height - 2 * v_fp -
623 					2 * vsync - fmt->bt.vbackporch;
624 		fmt->bt.il_vfrontporch = v_fp;
625 		fmt->bt.il_vsync = vsync;
626 		fmt->bt.flags |= V4L2_DV_FL_HALF_LINE;
627 		fmt->bt.interlaced = V4L2_DV_INTERLACED;
628 	}
629 
630 	fmt->bt.pixelclock = pix_clk;
631 	fmt->bt.standards = V4L2_DV_BT_STD_CVT;
632 
633 	if (reduced_blanking)
634 		fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
635 
636 	return true;
637 }
638 EXPORT_SYMBOL_GPL(v4l2_detect_cvt);
639 
640 /*
641  * GTF defines
642  * Based on Generalized Timing Formula Standard
643  * Version 1.1 September 2, 1999
644  */
645 
646 #define GTF_PXL_CLK_GRAN	250000	/* pixel clock granularity */
647 
648 #define GTF_MIN_VSYNC_BP	550	/* min time of vsync + back porch (us) */
649 #define GTF_V_FP		1	/* vertical front porch (lines) */
650 #define GTF_CELL_GRAN		8	/* character cell granularity */
651 
652 /* Default */
653 #define GTF_D_M			600	/* blanking formula gradient */
654 #define GTF_D_C			40	/* blanking formula offset */
655 #define GTF_D_K			128	/* blanking formula scaling factor */
656 #define GTF_D_J			20	/* blanking formula scaling factor */
657 #define GTF_D_C_PRIME ((((GTF_D_C - GTF_D_J) * GTF_D_K) / 256) + GTF_D_J)
658 #define GTF_D_M_PRIME ((GTF_D_K * GTF_D_M) / 256)
659 
660 /* Secondary */
661 #define GTF_S_M			3600	/* blanking formula gradient */
662 #define GTF_S_C			40	/* blanking formula offset */
663 #define GTF_S_K			128	/* blanking formula scaling factor */
664 #define GTF_S_J			35	/* blanking formula scaling factor */
665 #define GTF_S_C_PRIME ((((GTF_S_C - GTF_S_J) * GTF_S_K) / 256) + GTF_S_J)
666 #define GTF_S_M_PRIME ((GTF_S_K * GTF_S_M) / 256)
667 
668 /** v4l2_detect_gtf - detect if the given timings follow the GTF standard
669  * @frame_height - the total height of the frame (including blanking) in lines.
670  * @hfreq - the horizontal frequency in Hz.
671  * @vsync - the height of the vertical sync in lines.
672  * @polarities - the horizontal and vertical polarities (same as struct
673  *		v4l2_bt_timings polarities).
674  * @interlaced - if this flag is true, it indicates interlaced format
675  * @aspect - preferred aspect ratio. GTF has no method of determining the
676  *		aspect ratio in order to derive the image width from the
677  *		image height, so it has to be passed explicitly. Usually
678  *		the native screen aspect ratio is used for this. If it
679  *		is not filled in correctly, then 16:9 will be assumed.
680  * @fmt - the resulting timings.
681  *
682  * This function will attempt to detect if the given values correspond to a
683  * valid GTF format. If so, then it will return true, and fmt will be filled
684  * in with the found GTF timings.
685  */
686 bool v4l2_detect_gtf(unsigned frame_height,
687 		unsigned hfreq,
688 		unsigned vsync,
689 		u32 polarities,
690 		bool interlaced,
691 		struct v4l2_fract aspect,
692 		struct v4l2_dv_timings *fmt)
693 {
694 	int pix_clk;
695 	int  v_fp, v_bp, h_fp, hsync;
696 	int frame_width, image_height, image_width;
697 	bool default_gtf;
698 	int h_blank;
699 
700 	if (vsync != 3)
701 		return false;
702 
703 	if (polarities == V4L2_DV_VSYNC_POS_POL)
704 		default_gtf = true;
705 	else if (polarities == V4L2_DV_HSYNC_POS_POL)
706 		default_gtf = false;
707 	else
708 		return false;
709 
710 	if (hfreq == 0)
711 		return false;
712 
713 	/* Vertical */
714 	v_fp = GTF_V_FP;
715 	v_bp = (GTF_MIN_VSYNC_BP * hfreq + 500000) / 1000000 - vsync;
716 	if (interlaced)
717 		image_height = (frame_height - 2 * v_fp - 2 * vsync - 2 * v_bp) & ~0x1;
718 	else
719 		image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
720 
721 	if (image_height < 0)
722 		return false;
723 
724 	if (aspect.numerator == 0 || aspect.denominator == 0) {
725 		aspect.numerator = 16;
726 		aspect.denominator = 9;
727 	}
728 	image_width = ((image_height * aspect.numerator) / aspect.denominator);
729 	image_width = (image_width + GTF_CELL_GRAN/2) & ~(GTF_CELL_GRAN - 1);
730 
731 	/* Horizontal */
732 	if (default_gtf) {
733 		u64 num;
734 		u32 den;
735 
736 		num = ((image_width * GTF_D_C_PRIME * (u64)hfreq) -
737 		      ((u64)image_width * GTF_D_M_PRIME * 1000));
738 		den = (hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000) *
739 		      (2 * GTF_CELL_GRAN);
740 		h_blank = div_u64((num + (den >> 1)), den);
741 		h_blank *= (2 * GTF_CELL_GRAN);
742 	} else {
743 		u64 num;
744 		u32 den;
745 
746 		num = ((image_width * GTF_S_C_PRIME * (u64)hfreq) -
747 		      ((u64)image_width * GTF_S_M_PRIME * 1000));
748 		den = (hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000) *
749 		      (2 * GTF_CELL_GRAN);
750 		h_blank = div_u64((num + (den >> 1)), den);
751 		h_blank *= (2 * GTF_CELL_GRAN);
752 	}
753 
754 	frame_width = image_width + h_blank;
755 
756 	pix_clk = (image_width + h_blank) * hfreq;
757 	pix_clk = pix_clk / GTF_PXL_CLK_GRAN * GTF_PXL_CLK_GRAN;
758 
759 	hsync = (frame_width * 8 + 50) / 100;
760 	hsync = ((hsync + GTF_CELL_GRAN / 2) / GTF_CELL_GRAN) * GTF_CELL_GRAN;
761 
762 	h_fp = h_blank / 2 - hsync;
763 
764 	fmt->type = V4L2_DV_BT_656_1120;
765 	fmt->bt.polarities = polarities;
766 	fmt->bt.width = image_width;
767 	fmt->bt.height = image_height;
768 	fmt->bt.hfrontporch = h_fp;
769 	fmt->bt.vfrontporch = v_fp;
770 	fmt->bt.hsync = hsync;
771 	fmt->bt.vsync = vsync;
772 	fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
773 
774 	if (!interlaced) {
775 		fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
776 		fmt->bt.interlaced = V4L2_DV_PROGRESSIVE;
777 	} else {
778 		fmt->bt.vbackporch = (frame_height - image_height - 2 * v_fp -
779 				      2 * vsync) / 2;
780 		fmt->bt.il_vbackporch = frame_height - image_height - 2 * v_fp -
781 					2 * vsync - fmt->bt.vbackporch;
782 		fmt->bt.il_vfrontporch = v_fp;
783 		fmt->bt.il_vsync = vsync;
784 		fmt->bt.flags |= V4L2_DV_FL_HALF_LINE;
785 		fmt->bt.interlaced = V4L2_DV_INTERLACED;
786 	}
787 
788 	fmt->bt.pixelclock = pix_clk;
789 	fmt->bt.standards = V4L2_DV_BT_STD_GTF;
790 
791 	if (!default_gtf)
792 		fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
793 
794 	return true;
795 }
796 EXPORT_SYMBOL_GPL(v4l2_detect_gtf);
797 
798 /** v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes
799  *	0x15 and 0x16 from the EDID.
800  * @hor_landscape - byte 0x15 from the EDID.
801  * @vert_portrait - byte 0x16 from the EDID.
802  *
803  * Determines the aspect ratio from the EDID.
804  * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2:
805  * "Horizontal and Vertical Screen Size or Aspect Ratio"
806  */
807 struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait)
808 {
809 	struct v4l2_fract aspect = { 16, 9 };
810 	u8 ratio;
811 
812 	/* Nothing filled in, fallback to 16:9 */
813 	if (!hor_landscape && !vert_portrait)
814 		return aspect;
815 	/* Both filled in, so they are interpreted as the screen size in cm */
816 	if (hor_landscape && vert_portrait) {
817 		aspect.numerator = hor_landscape;
818 		aspect.denominator = vert_portrait;
819 		return aspect;
820 	}
821 	/* Only one is filled in, so interpret them as a ratio:
822 	   (val + 99) / 100 */
823 	ratio = hor_landscape | vert_portrait;
824 	/* Change some rounded values into the exact aspect ratio */
825 	if (ratio == 79) {
826 		aspect.numerator = 16;
827 		aspect.denominator = 9;
828 	} else if (ratio == 34) {
829 		aspect.numerator = 4;
830 		aspect.denominator = 3;
831 	} else if (ratio == 68) {
832 		aspect.numerator = 15;
833 		aspect.denominator = 9;
834 	} else {
835 		aspect.numerator = hor_landscape + 99;
836 		aspect.denominator = 100;
837 	}
838 	if (hor_landscape)
839 		return aspect;
840 	/* The aspect ratio is for portrait, so swap numerator and denominator */
841 	swap(aspect.denominator, aspect.numerator);
842 	return aspect;
843 }
844 EXPORT_SYMBOL_GPL(v4l2_calc_aspect_ratio);
845 
846 /** v4l2_hdmi_rx_colorimetry - determine HDMI colorimetry information
847  *	based on various InfoFrames.
848  * @avi: the AVI InfoFrame
849  * @hdmi: the HDMI Vendor InfoFrame, may be NULL
850  * @height: the frame height
851  *
852  * Determines the HDMI colorimetry information, i.e. how the HDMI
853  * pixel color data should be interpreted.
854  *
855  * Note that some of the newer features (DCI-P3, HDR) are not yet
856  * implemented: the hdmi.h header needs to be updated to the HDMI 2.0
857  * and CTA-861-G standards.
858  */
859 struct v4l2_hdmi_colorimetry
860 v4l2_hdmi_rx_colorimetry(const struct hdmi_avi_infoframe *avi,
861 			 const struct hdmi_vendor_infoframe *hdmi,
862 			 unsigned int height)
863 {
864 	struct v4l2_hdmi_colorimetry c = {
865 		V4L2_COLORSPACE_SRGB,
866 		V4L2_YCBCR_ENC_DEFAULT,
867 		V4L2_QUANTIZATION_FULL_RANGE,
868 		V4L2_XFER_FUNC_SRGB
869 	};
870 	bool is_ce = avi->video_code || (hdmi && hdmi->vic);
871 	bool is_sdtv = height <= 576;
872 	bool default_is_lim_range_rgb = avi->video_code > 1;
873 
874 	switch (avi->colorspace) {
875 	case HDMI_COLORSPACE_RGB:
876 		/* RGB pixel encoding */
877 		switch (avi->colorimetry) {
878 		case HDMI_COLORIMETRY_EXTENDED:
879 			switch (avi->extended_colorimetry) {
880 			case HDMI_EXTENDED_COLORIMETRY_OPRGB:
881 				c.colorspace = V4L2_COLORSPACE_OPRGB;
882 				c.xfer_func = V4L2_XFER_FUNC_OPRGB;
883 				break;
884 			case HDMI_EXTENDED_COLORIMETRY_BT2020:
885 				c.colorspace = V4L2_COLORSPACE_BT2020;
886 				c.xfer_func = V4L2_XFER_FUNC_709;
887 				break;
888 			default:
889 				break;
890 			}
891 			break;
892 		default:
893 			break;
894 		}
895 		switch (avi->quantization_range) {
896 		case HDMI_QUANTIZATION_RANGE_LIMITED:
897 			c.quantization = V4L2_QUANTIZATION_LIM_RANGE;
898 			break;
899 		case HDMI_QUANTIZATION_RANGE_FULL:
900 			break;
901 		default:
902 			if (default_is_lim_range_rgb)
903 				c.quantization = V4L2_QUANTIZATION_LIM_RANGE;
904 			break;
905 		}
906 		break;
907 
908 	default:
909 		/* YCbCr pixel encoding */
910 		c.quantization = V4L2_QUANTIZATION_LIM_RANGE;
911 		switch (avi->colorimetry) {
912 		case HDMI_COLORIMETRY_NONE:
913 			if (!is_ce)
914 				break;
915 			if (is_sdtv) {
916 				c.colorspace = V4L2_COLORSPACE_SMPTE170M;
917 				c.ycbcr_enc = V4L2_YCBCR_ENC_601;
918 			} else {
919 				c.colorspace = V4L2_COLORSPACE_REC709;
920 				c.ycbcr_enc = V4L2_YCBCR_ENC_709;
921 			}
922 			c.xfer_func = V4L2_XFER_FUNC_709;
923 			break;
924 		case HDMI_COLORIMETRY_ITU_601:
925 			c.colorspace = V4L2_COLORSPACE_SMPTE170M;
926 			c.ycbcr_enc = V4L2_YCBCR_ENC_601;
927 			c.xfer_func = V4L2_XFER_FUNC_709;
928 			break;
929 		case HDMI_COLORIMETRY_ITU_709:
930 			c.colorspace = V4L2_COLORSPACE_REC709;
931 			c.ycbcr_enc = V4L2_YCBCR_ENC_709;
932 			c.xfer_func = V4L2_XFER_FUNC_709;
933 			break;
934 		case HDMI_COLORIMETRY_EXTENDED:
935 			switch (avi->extended_colorimetry) {
936 			case HDMI_EXTENDED_COLORIMETRY_XV_YCC_601:
937 				c.colorspace = V4L2_COLORSPACE_REC709;
938 				c.ycbcr_enc = V4L2_YCBCR_ENC_XV709;
939 				c.xfer_func = V4L2_XFER_FUNC_709;
940 				break;
941 			case HDMI_EXTENDED_COLORIMETRY_XV_YCC_709:
942 				c.colorspace = V4L2_COLORSPACE_REC709;
943 				c.ycbcr_enc = V4L2_YCBCR_ENC_XV601;
944 				c.xfer_func = V4L2_XFER_FUNC_709;
945 				break;
946 			case HDMI_EXTENDED_COLORIMETRY_S_YCC_601:
947 				c.colorspace = V4L2_COLORSPACE_SRGB;
948 				c.ycbcr_enc = V4L2_YCBCR_ENC_601;
949 				c.xfer_func = V4L2_XFER_FUNC_SRGB;
950 				break;
951 			case HDMI_EXTENDED_COLORIMETRY_OPYCC_601:
952 				c.colorspace = V4L2_COLORSPACE_OPRGB;
953 				c.ycbcr_enc = V4L2_YCBCR_ENC_601;
954 				c.xfer_func = V4L2_XFER_FUNC_OPRGB;
955 				break;
956 			case HDMI_EXTENDED_COLORIMETRY_BT2020:
957 				c.colorspace = V4L2_COLORSPACE_BT2020;
958 				c.ycbcr_enc = V4L2_YCBCR_ENC_BT2020;
959 				c.xfer_func = V4L2_XFER_FUNC_709;
960 				break;
961 			case HDMI_EXTENDED_COLORIMETRY_BT2020_CONST_LUM:
962 				c.colorspace = V4L2_COLORSPACE_BT2020;
963 				c.ycbcr_enc = V4L2_YCBCR_ENC_BT2020_CONST_LUM;
964 				c.xfer_func = V4L2_XFER_FUNC_709;
965 				break;
966 			default: /* fall back to ITU_709 */
967 				c.colorspace = V4L2_COLORSPACE_REC709;
968 				c.ycbcr_enc = V4L2_YCBCR_ENC_709;
969 				c.xfer_func = V4L2_XFER_FUNC_709;
970 				break;
971 			}
972 			break;
973 		default:
974 			break;
975 		}
976 		/*
977 		 * YCC Quantization Range signaling is more-or-less broken,
978 		 * let's just ignore this.
979 		 */
980 		break;
981 	}
982 	return c;
983 }
984 EXPORT_SYMBOL_GPL(v4l2_hdmi_rx_colorimetry);
985 
986 /**
987  * v4l2_get_edid_phys_addr() - find and return the physical address
988  *
989  * @edid:	pointer to the EDID data
990  * @size:	size in bytes of the EDID data
991  * @offset:	If not %NULL then the location of the physical address
992  *		bytes in the EDID will be returned here. This is set to 0
993  *		if there is no physical address found.
994  *
995  * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none.
996  */
997 u16 v4l2_get_edid_phys_addr(const u8 *edid, unsigned int size,
998 			    unsigned int *offset)
999 {
1000 	unsigned int loc = cec_get_edid_spa_location(edid, size);
1001 
1002 	if (offset)
1003 		*offset = loc;
1004 	if (loc == 0)
1005 		return CEC_PHYS_ADDR_INVALID;
1006 	return (edid[loc] << 8) | edid[loc + 1];
1007 }
1008 EXPORT_SYMBOL_GPL(v4l2_get_edid_phys_addr);
1009 
1010 /**
1011  * v4l2_set_edid_phys_addr() - find and set the physical address
1012  *
1013  * @edid:	pointer to the EDID data
1014  * @size:	size in bytes of the EDID data
1015  * @phys_addr:	the new physical address
1016  *
1017  * This function finds the location of the physical address in the EDID
1018  * and fills in the given physical address and updates the checksum
1019  * at the end of the EDID block. It does nothing if the EDID doesn't
1020  * contain a physical address.
1021  */
1022 void v4l2_set_edid_phys_addr(u8 *edid, unsigned int size, u16 phys_addr)
1023 {
1024 	unsigned int loc = cec_get_edid_spa_location(edid, size);
1025 	u8 sum = 0;
1026 	unsigned int i;
1027 
1028 	if (loc == 0)
1029 		return;
1030 	edid[loc] = phys_addr >> 8;
1031 	edid[loc + 1] = phys_addr & 0xff;
1032 	loc &= ~0x7f;
1033 
1034 	/* update the checksum */
1035 	for (i = loc; i < loc + 127; i++)
1036 		sum += edid[i];
1037 	edid[i] = 256 - sum;
1038 }
1039 EXPORT_SYMBOL_GPL(v4l2_set_edid_phys_addr);
1040 
1041 /**
1042  * v4l2_phys_addr_for_input() - calculate the PA for an input
1043  *
1044  * @phys_addr:	the physical address of the parent
1045  * @input:	the number of the input port, must be between 1 and 15
1046  *
1047  * This function calculates a new physical address based on the input
1048  * port number. For example:
1049  *
1050  * PA = 0.0.0.0 and input = 2 becomes 2.0.0.0
1051  *
1052  * PA = 3.0.0.0 and input = 1 becomes 3.1.0.0
1053  *
1054  * PA = 3.2.1.0 and input = 5 becomes 3.2.1.5
1055  *
1056  * PA = 3.2.1.3 and input = 5 becomes f.f.f.f since it maxed out the depth.
1057  *
1058  * Return: the new physical address or CEC_PHYS_ADDR_INVALID.
1059  */
1060 u16 v4l2_phys_addr_for_input(u16 phys_addr, u8 input)
1061 {
1062 	/* Check if input is sane */
1063 	if (WARN_ON(input == 0 || input > 0xf))
1064 		return CEC_PHYS_ADDR_INVALID;
1065 
1066 	if (phys_addr == 0)
1067 		return input << 12;
1068 
1069 	if ((phys_addr & 0x0fff) == 0)
1070 		return phys_addr | (input << 8);
1071 
1072 	if ((phys_addr & 0x00ff) == 0)
1073 		return phys_addr | (input << 4);
1074 
1075 	if ((phys_addr & 0x000f) == 0)
1076 		return phys_addr | input;
1077 
1078 	/*
1079 	 * All nibbles are used so no valid physical addresses can be assigned
1080 	 * to the input.
1081 	 */
1082 	return CEC_PHYS_ADDR_INVALID;
1083 }
1084 EXPORT_SYMBOL_GPL(v4l2_phys_addr_for_input);
1085 
1086 /**
1087  * v4l2_phys_addr_validate() - validate a physical address from an EDID
1088  *
1089  * @phys_addr:	the physical address to validate
1090  * @parent:	if not %NULL, then this is filled with the parents PA.
1091  * @port:	if not %NULL, then this is filled with the input port.
1092  *
1093  * This validates a physical address as read from an EDID. If the
1094  * PA is invalid (such as 1.0.1.0 since '0' is only allowed at the end),
1095  * then it will return -EINVAL.
1096  *
1097  * The parent PA is passed into %parent and the input port is passed into
1098  * %port. For example:
1099  *
1100  * PA = 0.0.0.0: has parent 0.0.0.0 and input port 0.
1101  *
1102  * PA = 1.0.0.0: has parent 0.0.0.0 and input port 1.
1103  *
1104  * PA = 3.2.0.0: has parent 3.0.0.0 and input port 2.
1105  *
1106  * PA = f.f.f.f: has parent f.f.f.f and input port 0.
1107  *
1108  * Return: 0 if the PA is valid, -EINVAL if not.
1109  */
1110 int v4l2_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port)
1111 {
1112 	int i;
1113 
1114 	if (parent)
1115 		*parent = phys_addr;
1116 	if (port)
1117 		*port = 0;
1118 	if (phys_addr == CEC_PHYS_ADDR_INVALID)
1119 		return 0;
1120 	for (i = 0; i < 16; i += 4)
1121 		if (phys_addr & (0xf << i))
1122 			break;
1123 	if (i == 16)
1124 		return 0;
1125 	if (parent)
1126 		*parent = phys_addr & (0xfff0 << i);
1127 	if (port)
1128 		*port = (phys_addr >> i) & 0xf;
1129 	for (i += 4; i < 16; i += 4)
1130 		if ((phys_addr & (0xf << i)) == 0)
1131 			return -EINVAL;
1132 	return 0;
1133 }
1134 EXPORT_SYMBOL_GPL(v4l2_phys_addr_validate);
1135