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Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
[deliverable/linux.git] / drivers / media / v4l2-core / v4l2-dv-timings.c
1 /*
2 * v4l2-dv-timings - dv-timings helper functions
3 *
4 * Copyright 2013 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
5 *
6 * This program is free software; you may redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 of the License.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
11 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
12 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
13 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
14 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
15 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
16 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
17 * SOFTWARE.
18 *
19 */
20
21 #include <linux/module.h>
22 #include <linux/types.h>
23 #include <linux/kernel.h>
24 #include <linux/errno.h>
25 #include <linux/videodev2.h>
26 #include <linux/v4l2-dv-timings.h>
27 #include <media/v4l2-dv-timings.h>
28
29 MODULE_AUTHOR("Hans Verkuil");
30 MODULE_DESCRIPTION("V4L2 DV Timings Helper Functions");
31 MODULE_LICENSE("GPL");
32
33 const struct v4l2_dv_timings v4l2_dv_timings_presets[] = {
34 V4L2_DV_BT_CEA_640X480P59_94,
35 V4L2_DV_BT_CEA_720X480I59_94,
36 V4L2_DV_BT_CEA_720X480P59_94,
37 V4L2_DV_BT_CEA_720X576I50,
38 V4L2_DV_BT_CEA_720X576P50,
39 V4L2_DV_BT_CEA_1280X720P24,
40 V4L2_DV_BT_CEA_1280X720P25,
41 V4L2_DV_BT_CEA_1280X720P30,
42 V4L2_DV_BT_CEA_1280X720P50,
43 V4L2_DV_BT_CEA_1280X720P60,
44 V4L2_DV_BT_CEA_1920X1080P24,
45 V4L2_DV_BT_CEA_1920X1080P25,
46 V4L2_DV_BT_CEA_1920X1080P30,
47 V4L2_DV_BT_CEA_1920X1080I50,
48 V4L2_DV_BT_CEA_1920X1080P50,
49 V4L2_DV_BT_CEA_1920X1080I60,
50 V4L2_DV_BT_CEA_1920X1080P60,
51 V4L2_DV_BT_DMT_640X350P85,
52 V4L2_DV_BT_DMT_640X400P85,
53 V4L2_DV_BT_DMT_720X400P85,
54 V4L2_DV_BT_DMT_640X480P72,
55 V4L2_DV_BT_DMT_640X480P75,
56 V4L2_DV_BT_DMT_640X480P85,
57 V4L2_DV_BT_DMT_800X600P56,
58 V4L2_DV_BT_DMT_800X600P60,
59 V4L2_DV_BT_DMT_800X600P72,
60 V4L2_DV_BT_DMT_800X600P75,
61 V4L2_DV_BT_DMT_800X600P85,
62 V4L2_DV_BT_DMT_800X600P120_RB,
63 V4L2_DV_BT_DMT_848X480P60,
64 V4L2_DV_BT_DMT_1024X768I43,
65 V4L2_DV_BT_DMT_1024X768P60,
66 V4L2_DV_BT_DMT_1024X768P70,
67 V4L2_DV_BT_DMT_1024X768P75,
68 V4L2_DV_BT_DMT_1024X768P85,
69 V4L2_DV_BT_DMT_1024X768P120_RB,
70 V4L2_DV_BT_DMT_1152X864P75,
71 V4L2_DV_BT_DMT_1280X768P60_RB,
72 V4L2_DV_BT_DMT_1280X768P60,
73 V4L2_DV_BT_DMT_1280X768P75,
74 V4L2_DV_BT_DMT_1280X768P85,
75 V4L2_DV_BT_DMT_1280X768P120_RB,
76 V4L2_DV_BT_DMT_1280X800P60_RB,
77 V4L2_DV_BT_DMT_1280X800P60,
78 V4L2_DV_BT_DMT_1280X800P75,
79 V4L2_DV_BT_DMT_1280X800P85,
80 V4L2_DV_BT_DMT_1280X800P120_RB,
81 V4L2_DV_BT_DMT_1280X960P60,
82 V4L2_DV_BT_DMT_1280X960P85,
83 V4L2_DV_BT_DMT_1280X960P120_RB,
84 V4L2_DV_BT_DMT_1280X1024P60,
85 V4L2_DV_BT_DMT_1280X1024P75,
86 V4L2_DV_BT_DMT_1280X1024P85,
87 V4L2_DV_BT_DMT_1280X1024P120_RB,
88 V4L2_DV_BT_DMT_1360X768P60,
89 V4L2_DV_BT_DMT_1360X768P120_RB,
90 V4L2_DV_BT_DMT_1366X768P60,
91 V4L2_DV_BT_DMT_1366X768P60_RB,
92 V4L2_DV_BT_DMT_1400X1050P60_RB,
93 V4L2_DV_BT_DMT_1400X1050P60,
94 V4L2_DV_BT_DMT_1400X1050P75,
95 V4L2_DV_BT_DMT_1400X1050P85,
96 V4L2_DV_BT_DMT_1400X1050P120_RB,
97 V4L2_DV_BT_DMT_1440X900P60_RB,
98 V4L2_DV_BT_DMT_1440X900P60,
99 V4L2_DV_BT_DMT_1440X900P75,
100 V4L2_DV_BT_DMT_1440X900P85,
101 V4L2_DV_BT_DMT_1440X900P120_RB,
102 V4L2_DV_BT_DMT_1600X900P60_RB,
103 V4L2_DV_BT_DMT_1600X1200P60,
104 V4L2_DV_BT_DMT_1600X1200P65,
105 V4L2_DV_BT_DMT_1600X1200P70,
106 V4L2_DV_BT_DMT_1600X1200P75,
107 V4L2_DV_BT_DMT_1600X1200P85,
108 V4L2_DV_BT_DMT_1600X1200P120_RB,
109 V4L2_DV_BT_DMT_1680X1050P60_RB,
110 V4L2_DV_BT_DMT_1680X1050P60,
111 V4L2_DV_BT_DMT_1680X1050P75,
112 V4L2_DV_BT_DMT_1680X1050P85,
113 V4L2_DV_BT_DMT_1680X1050P120_RB,
114 V4L2_DV_BT_DMT_1792X1344P60,
115 V4L2_DV_BT_DMT_1792X1344P75,
116 V4L2_DV_BT_DMT_1792X1344P120_RB,
117 V4L2_DV_BT_DMT_1856X1392P60,
118 V4L2_DV_BT_DMT_1856X1392P75,
119 V4L2_DV_BT_DMT_1856X1392P120_RB,
120 V4L2_DV_BT_DMT_1920X1200P60_RB,
121 V4L2_DV_BT_DMT_1920X1200P60,
122 V4L2_DV_BT_DMT_1920X1200P75,
123 V4L2_DV_BT_DMT_1920X1200P85,
124 V4L2_DV_BT_DMT_1920X1200P120_RB,
125 V4L2_DV_BT_DMT_1920X1440P60,
126 V4L2_DV_BT_DMT_1920X1440P75,
127 V4L2_DV_BT_DMT_1920X1440P120_RB,
128 V4L2_DV_BT_DMT_2048X1152P60_RB,
129 V4L2_DV_BT_DMT_2560X1600P60_RB,
130 V4L2_DV_BT_DMT_2560X1600P60,
131 V4L2_DV_BT_DMT_2560X1600P75,
132 V4L2_DV_BT_DMT_2560X1600P85,
133 V4L2_DV_BT_DMT_2560X1600P120_RB,
134 V4L2_DV_BT_CEA_3840X2160P24,
135 V4L2_DV_BT_CEA_3840X2160P25,
136 V4L2_DV_BT_CEA_3840X2160P30,
137 V4L2_DV_BT_CEA_3840X2160P50,
138 V4L2_DV_BT_CEA_3840X2160P60,
139 V4L2_DV_BT_CEA_4096X2160P24,
140 V4L2_DV_BT_CEA_4096X2160P25,
141 V4L2_DV_BT_CEA_4096X2160P30,
142 V4L2_DV_BT_CEA_4096X2160P50,
143 V4L2_DV_BT_DMT_4096X2160P59_94_RB,
144 V4L2_DV_BT_CEA_4096X2160P60,
145 { }
146 };
147 EXPORT_SYMBOL_GPL(v4l2_dv_timings_presets);
148
149 bool v4l2_valid_dv_timings(const struct v4l2_dv_timings *t,
150 const struct v4l2_dv_timings_cap *dvcap,
151 v4l2_check_dv_timings_fnc fnc,
152 void *fnc_handle)
153 {
154 const struct v4l2_bt_timings *bt = &t->bt;
155 const struct v4l2_bt_timings_cap *cap = &dvcap->bt;
156 u32 caps = cap->capabilities;
157
158 if (t->type != V4L2_DV_BT_656_1120)
159 return false;
160 if (t->type != dvcap->type ||
161 bt->height < cap->min_height ||
162 bt->height > cap->max_height ||
163 bt->width < cap->min_width ||
164 bt->width > cap->max_width ||
165 bt->pixelclock < cap->min_pixelclock ||
166 bt->pixelclock > cap->max_pixelclock ||
167 (cap->standards && !(bt->standards & cap->standards)) ||
168 (bt->interlaced && !(caps & V4L2_DV_BT_CAP_INTERLACED)) ||
169 (!bt->interlaced && !(caps & V4L2_DV_BT_CAP_PROGRESSIVE)))
170 return false;
171 return fnc == NULL || fnc(t, fnc_handle);
172 }
173 EXPORT_SYMBOL_GPL(v4l2_valid_dv_timings);
174
175 int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t,
176 const struct v4l2_dv_timings_cap *cap,
177 v4l2_check_dv_timings_fnc fnc,
178 void *fnc_handle)
179 {
180 u32 i, idx;
181
182 memset(t->reserved, 0, sizeof(t->reserved));
183 for (i = idx = 0; v4l2_dv_timings_presets[i].bt.width; i++) {
184 if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap,
185 fnc, fnc_handle) &&
186 idx++ == t->index) {
187 t->timings = v4l2_dv_timings_presets[i];
188 return 0;
189 }
190 }
191 return -EINVAL;
192 }
193 EXPORT_SYMBOL_GPL(v4l2_enum_dv_timings_cap);
194
195 bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t,
196 const struct v4l2_dv_timings_cap *cap,
197 unsigned pclock_delta,
198 v4l2_check_dv_timings_fnc fnc,
199 void *fnc_handle)
200 {
201 int i;
202
203 if (!v4l2_valid_dv_timings(t, cap, fnc, fnc_handle))
204 return false;
205
206 for (i = 0; i < v4l2_dv_timings_presets[i].bt.width; i++) {
207 if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap,
208 fnc, fnc_handle) &&
209 v4l2_match_dv_timings(t, v4l2_dv_timings_presets + i,
210 pclock_delta)) {
211 *t = v4l2_dv_timings_presets[i];
212 return true;
213 }
214 }
215 return false;
216 }
217 EXPORT_SYMBOL_GPL(v4l2_find_dv_timings_cap);
218
219 /**
220 * v4l2_match_dv_timings - check if two timings match
221 * @t1 - compare this v4l2_dv_timings struct...
222 * @t2 - with this struct.
223 * @pclock_delta - the allowed pixelclock deviation.
224 *
225 * Compare t1 with t2 with a given margin of error for the pixelclock.
226 */
227 bool v4l2_match_dv_timings(const struct v4l2_dv_timings *t1,
228 const struct v4l2_dv_timings *t2,
229 unsigned pclock_delta)
230 {
231 if (t1->type != t2->type || t1->type != V4L2_DV_BT_656_1120)
232 return false;
233 if (t1->bt.width == t2->bt.width &&
234 t1->bt.height == t2->bt.height &&
235 t1->bt.interlaced == t2->bt.interlaced &&
236 t1->bt.polarities == t2->bt.polarities &&
237 t1->bt.pixelclock >= t2->bt.pixelclock - pclock_delta &&
238 t1->bt.pixelclock <= t2->bt.pixelclock + pclock_delta &&
239 t1->bt.hfrontporch == t2->bt.hfrontporch &&
240 t1->bt.vfrontporch == t2->bt.vfrontporch &&
241 t1->bt.vsync == t2->bt.vsync &&
242 t1->bt.vbackporch == t2->bt.vbackporch &&
243 (!t1->bt.interlaced ||
244 (t1->bt.il_vfrontporch == t2->bt.il_vfrontporch &&
245 t1->bt.il_vsync == t2->bt.il_vsync &&
246 t1->bt.il_vbackporch == t2->bt.il_vbackporch)))
247 return true;
248 return false;
249 }
250 EXPORT_SYMBOL_GPL(v4l2_match_dv_timings);
251
252 void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix,
253 const struct v4l2_dv_timings *t, bool detailed)
254 {
255 const struct v4l2_bt_timings *bt = &t->bt;
256 u32 htot, vtot;
257
258 if (t->type != V4L2_DV_BT_656_1120)
259 return;
260
261 htot = V4L2_DV_BT_FRAME_WIDTH(bt);
262 vtot = V4L2_DV_BT_FRAME_HEIGHT(bt);
263
264 if (prefix == NULL)
265 prefix = "";
266
267 pr_info("%s: %s%ux%u%s%u (%ux%u)\n", dev_prefix, prefix,
268 bt->width, bt->height, bt->interlaced ? "i" : "p",
269 (htot * vtot) > 0 ? ((u32)bt->pixelclock / (htot * vtot)) : 0,
270 htot, vtot);
271
272 if (!detailed)
273 return;
274
275 pr_info("%s: horizontal: fp = %u, %ssync = %u, bp = %u\n",
276 dev_prefix, bt->hfrontporch,
277 (bt->polarities & V4L2_DV_HSYNC_POS_POL) ? "+" : "-",
278 bt->hsync, bt->hbackporch);
279 pr_info("%s: vertical: fp = %u, %ssync = %u, bp = %u\n",
280 dev_prefix, bt->vfrontporch,
281 (bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-",
282 bt->vsync, bt->vbackporch);
283 pr_info("%s: pixelclock: %llu\n", dev_prefix, bt->pixelclock);
284 pr_info("%s: flags (0x%x):%s%s%s%s\n", dev_prefix, bt->flags,
285 (bt->flags & V4L2_DV_FL_REDUCED_BLANKING) ?
286 " REDUCED_BLANKING" : "",
287 (bt->flags & V4L2_DV_FL_CAN_REDUCE_FPS) ?
288 " CAN_REDUCE_FPS" : "",
289 (bt->flags & V4L2_DV_FL_REDUCED_FPS) ?
290 " REDUCED_FPS" : "",
291 (bt->flags & V4L2_DV_FL_HALF_LINE) ?
292 " HALF_LINE" : "");
293 pr_info("%s: standards (0x%x):%s%s%s%s\n", dev_prefix, bt->standards,
294 (bt->standards & V4L2_DV_BT_STD_CEA861) ? " CEA" : "",
295 (bt->standards & V4L2_DV_BT_STD_DMT) ? " DMT" : "",
296 (bt->standards & V4L2_DV_BT_STD_CVT) ? " CVT" : "",
297 (bt->standards & V4L2_DV_BT_STD_GTF) ? " GTF" : "");
298 }
299 EXPORT_SYMBOL_GPL(v4l2_print_dv_timings);
300
301 /*
302 * CVT defines
303 * Based on Coordinated Video Timings Standard
304 * version 1.1 September 10, 2003
305 */
306
307 #define CVT_PXL_CLK_GRAN 250000 /* pixel clock granularity */
308
309 /* Normal blanking */
310 #define CVT_MIN_V_BPORCH 7 /* lines */
311 #define CVT_MIN_V_PORCH_RND 3 /* lines */
312 #define CVT_MIN_VSYNC_BP 550 /* min time of vsync + back porch (us) */
313
314 /* Normal blanking for CVT uses GTF to calculate horizontal blanking */
315 #define CVT_CELL_GRAN 8 /* character cell granularity */
316 #define CVT_M 600 /* blanking formula gradient */
317 #define CVT_C 40 /* blanking formula offset */
318 #define CVT_K 128 /* blanking formula scaling factor */
319 #define CVT_J 20 /* blanking formula scaling factor */
320 #define CVT_C_PRIME (((CVT_C - CVT_J) * CVT_K / 256) + CVT_J)
321 #define CVT_M_PRIME (CVT_K * CVT_M / 256)
322
323 /* Reduced Blanking */
324 #define CVT_RB_MIN_V_BPORCH 7 /* lines */
325 #define CVT_RB_V_FPORCH 3 /* lines */
326 #define CVT_RB_MIN_V_BLANK 460 /* us */
327 #define CVT_RB_H_SYNC 32 /* pixels */
328 #define CVT_RB_H_BPORCH 80 /* pixels */
329 #define CVT_RB_H_BLANK 160 /* pixels */
330
331 /** v4l2_detect_cvt - detect if the given timings follow the CVT standard
332 * @frame_height - the total height of the frame (including blanking) in lines.
333 * @hfreq - the horizontal frequency in Hz.
334 * @vsync - the height of the vertical sync in lines.
335 * @polarities - the horizontal and vertical polarities (same as struct
336 * v4l2_bt_timings polarities).
337 * @fmt - the resulting timings.
338 *
339 * This function will attempt to detect if the given values correspond to a
340 * valid CVT format. If so, then it will return true, and fmt will be filled
341 * in with the found CVT timings.
342 *
343 * TODO: VESA defined a new version 2 of their reduced blanking
344 * formula. Support for that is currently missing in this CVT
345 * detection function.
346 */
347 bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync,
348 u32 polarities, struct v4l2_dv_timings *fmt)
349 {
350 int v_fp, v_bp, h_fp, h_bp, hsync;
351 int frame_width, image_height, image_width;
352 bool reduced_blanking;
353 unsigned pix_clk;
354
355 if (vsync < 4 || vsync > 7)
356 return false;
357
358 if (polarities == V4L2_DV_VSYNC_POS_POL)
359 reduced_blanking = false;
360 else if (polarities == V4L2_DV_HSYNC_POS_POL)
361 reduced_blanking = true;
362 else
363 return false;
364
365 /* Vertical */
366 if (reduced_blanking) {
367 v_fp = CVT_RB_V_FPORCH;
368 v_bp = (CVT_RB_MIN_V_BLANK * hfreq + 1999999) / 1000000;
369 v_bp -= vsync + v_fp;
370
371 if (v_bp < CVT_RB_MIN_V_BPORCH)
372 v_bp = CVT_RB_MIN_V_BPORCH;
373 } else {
374 v_fp = CVT_MIN_V_PORCH_RND;
375 v_bp = (CVT_MIN_VSYNC_BP * hfreq + 1999999) / 1000000 - vsync;
376
377 if (v_bp < CVT_MIN_V_BPORCH)
378 v_bp = CVT_MIN_V_BPORCH;
379 }
380 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
381
382 /* Aspect ratio based on vsync */
383 switch (vsync) {
384 case 4:
385 image_width = (image_height * 4) / 3;
386 break;
387 case 5:
388 image_width = (image_height * 16) / 9;
389 break;
390 case 6:
391 image_width = (image_height * 16) / 10;
392 break;
393 case 7:
394 /* special case */
395 if (image_height == 1024)
396 image_width = (image_height * 5) / 4;
397 else if (image_height == 768)
398 image_width = (image_height * 15) / 9;
399 else
400 return false;
401 break;
402 default:
403 return false;
404 }
405
406 image_width = image_width & ~7;
407
408 /* Horizontal */
409 if (reduced_blanking) {
410 pix_clk = (image_width + CVT_RB_H_BLANK) * hfreq;
411 pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN;
412
413 h_bp = CVT_RB_H_BPORCH;
414 hsync = CVT_RB_H_SYNC;
415 h_fp = CVT_RB_H_BLANK - h_bp - hsync;
416
417 frame_width = image_width + CVT_RB_H_BLANK;
418 } else {
419 unsigned ideal_duty_cycle_per_myriad =
420 100 * CVT_C_PRIME - (CVT_M_PRIME * 100000) / hfreq;
421 int h_blank;
422
423 if (ideal_duty_cycle_per_myriad < 2000)
424 ideal_duty_cycle_per_myriad = 2000;
425
426 h_blank = image_width * ideal_duty_cycle_per_myriad /
427 (10000 - ideal_duty_cycle_per_myriad);
428 h_blank = (h_blank / (2 * CVT_CELL_GRAN)) * 2 * CVT_CELL_GRAN;
429
430 pix_clk = (image_width + h_blank) * hfreq;
431 pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN;
432
433 h_bp = h_blank / 2;
434 frame_width = image_width + h_blank;
435
436 hsync = (frame_width * 8 + 50) / 100;
437 hsync = hsync - hsync % CVT_CELL_GRAN;
438 h_fp = h_blank - hsync - h_bp;
439 }
440
441 fmt->type = V4L2_DV_BT_656_1120;
442 fmt->bt.polarities = polarities;
443 fmt->bt.width = image_width;
444 fmt->bt.height = image_height;
445 fmt->bt.hfrontporch = h_fp;
446 fmt->bt.vfrontporch = v_fp;
447 fmt->bt.hsync = hsync;
448 fmt->bt.vsync = vsync;
449 fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
450 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
451 fmt->bt.pixelclock = pix_clk;
452 fmt->bt.standards = V4L2_DV_BT_STD_CVT;
453 if (reduced_blanking)
454 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
455 return true;
456 }
457 EXPORT_SYMBOL_GPL(v4l2_detect_cvt);
458
459 /*
460 * GTF defines
461 * Based on Generalized Timing Formula Standard
462 * Version 1.1 September 2, 1999
463 */
464
465 #define GTF_PXL_CLK_GRAN 250000 /* pixel clock granularity */
466
467 #define GTF_MIN_VSYNC_BP 550 /* min time of vsync + back porch (us) */
468 #define GTF_V_FP 1 /* vertical front porch (lines) */
469 #define GTF_CELL_GRAN 8 /* character cell granularity */
470
471 /* Default */
472 #define GTF_D_M 600 /* blanking formula gradient */
473 #define GTF_D_C 40 /* blanking formula offset */
474 #define GTF_D_K 128 /* blanking formula scaling factor */
475 #define GTF_D_J 20 /* blanking formula scaling factor */
476 #define GTF_D_C_PRIME ((((GTF_D_C - GTF_D_J) * GTF_D_K) / 256) + GTF_D_J)
477 #define GTF_D_M_PRIME ((GTF_D_K * GTF_D_M) / 256)
478
479 /* Secondary */
480 #define GTF_S_M 3600 /* blanking formula gradient */
481 #define GTF_S_C 40 /* blanking formula offset */
482 #define GTF_S_K 128 /* blanking formula scaling factor */
483 #define GTF_S_J 35 /* blanking formula scaling factor */
484 #define GTF_S_C_PRIME ((((GTF_S_C - GTF_S_J) * GTF_S_K) / 256) + GTF_S_J)
485 #define GTF_S_M_PRIME ((GTF_S_K * GTF_S_M) / 256)
486
487 /** v4l2_detect_gtf - detect if the given timings follow the GTF standard
488 * @frame_height - the total height of the frame (including blanking) in lines.
489 * @hfreq - the horizontal frequency in Hz.
490 * @vsync - the height of the vertical sync in lines.
491 * @polarities - the horizontal and vertical polarities (same as struct
492 * v4l2_bt_timings polarities).
493 * @aspect - preferred aspect ratio. GTF has no method of determining the
494 * aspect ratio in order to derive the image width from the
495 * image height, so it has to be passed explicitly. Usually
496 * the native screen aspect ratio is used for this. If it
497 * is not filled in correctly, then 16:9 will be assumed.
498 * @fmt - the resulting timings.
499 *
500 * This function will attempt to detect if the given values correspond to a
501 * valid GTF format. If so, then it will return true, and fmt will be filled
502 * in with the found GTF timings.
503 */
504 bool v4l2_detect_gtf(unsigned frame_height,
505 unsigned hfreq,
506 unsigned vsync,
507 u32 polarities,
508 struct v4l2_fract aspect,
509 struct v4l2_dv_timings *fmt)
510 {
511 int pix_clk;
512 int v_fp, v_bp, h_fp, hsync;
513 int frame_width, image_height, image_width;
514 bool default_gtf;
515 int h_blank;
516
517 if (vsync != 3)
518 return false;
519
520 if (polarities == V4L2_DV_VSYNC_POS_POL)
521 default_gtf = true;
522 else if (polarities == V4L2_DV_HSYNC_POS_POL)
523 default_gtf = false;
524 else
525 return false;
526
527 /* Vertical */
528 v_fp = GTF_V_FP;
529 v_bp = (GTF_MIN_VSYNC_BP * hfreq + 999999) / 1000000 - vsync;
530 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
531
532 if (aspect.numerator == 0 || aspect.denominator == 0) {
533 aspect.numerator = 16;
534 aspect.denominator = 9;
535 }
536 image_width = ((image_height * aspect.numerator) / aspect.denominator);
537 image_width = (image_width + GTF_CELL_GRAN/2) & ~(GTF_CELL_GRAN - 1);
538
539 /* Horizontal */
540 if (default_gtf)
541 h_blank = ((image_width * GTF_D_C_PRIME * hfreq) -
542 (image_width * GTF_D_M_PRIME * 1000) +
543 (hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000) / 2) /
544 (hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000);
545 else
546 h_blank = ((image_width * GTF_S_C_PRIME * hfreq) -
547 (image_width * GTF_S_M_PRIME * 1000) +
548 (hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000) / 2) /
549 (hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000);
550
551 h_blank = h_blank - h_blank % (2 * GTF_CELL_GRAN);
552 frame_width = image_width + h_blank;
553
554 pix_clk = (image_width + h_blank) * hfreq;
555 pix_clk = pix_clk / GTF_PXL_CLK_GRAN * GTF_PXL_CLK_GRAN;
556
557 hsync = (frame_width * 8 + 50) / 100;
558 hsync = hsync - hsync % GTF_CELL_GRAN;
559
560 h_fp = h_blank / 2 - hsync;
561
562 fmt->type = V4L2_DV_BT_656_1120;
563 fmt->bt.polarities = polarities;
564 fmt->bt.width = image_width;
565 fmt->bt.height = image_height;
566 fmt->bt.hfrontporch = h_fp;
567 fmt->bt.vfrontporch = v_fp;
568 fmt->bt.hsync = hsync;
569 fmt->bt.vsync = vsync;
570 fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
571 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
572 fmt->bt.pixelclock = pix_clk;
573 fmt->bt.standards = V4L2_DV_BT_STD_GTF;
574 if (!default_gtf)
575 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
576 return true;
577 }
578 EXPORT_SYMBOL_GPL(v4l2_detect_gtf);
579
580 /** v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes
581 * 0x15 and 0x16 from the EDID.
582 * @hor_landscape - byte 0x15 from the EDID.
583 * @vert_portrait - byte 0x16 from the EDID.
584 *
585 * Determines the aspect ratio from the EDID.
586 * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2:
587 * "Horizontal and Vertical Screen Size or Aspect Ratio"
588 */
589 struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait)
590 {
591 struct v4l2_fract aspect = { 16, 9 };
592 u32 tmp;
593 u8 ratio;
594
595 /* Nothing filled in, fallback to 16:9 */
596 if (!hor_landscape && !vert_portrait)
597 return aspect;
598 /* Both filled in, so they are interpreted as the screen size in cm */
599 if (hor_landscape && vert_portrait) {
600 aspect.numerator = hor_landscape;
601 aspect.denominator = vert_portrait;
602 return aspect;
603 }
604 /* Only one is filled in, so interpret them as a ratio:
605 (val + 99) / 100 */
606 ratio = hor_landscape | vert_portrait;
607 /* Change some rounded values into the exact aspect ratio */
608 if (ratio == 79) {
609 aspect.numerator = 16;
610 aspect.denominator = 9;
611 } else if (ratio == 34) {
612 aspect.numerator = 4;
613 aspect.numerator = 3;
614 } else if (ratio == 68) {
615 aspect.numerator = 15;
616 aspect.numerator = 9;
617 } else {
618 aspect.numerator = hor_landscape + 99;
619 aspect.denominator = 100;
620 }
621 if (hor_landscape)
622 return aspect;
623 /* The aspect ratio is for portrait, so swap numerator and denominator */
624 tmp = aspect.denominator;
625 aspect.denominator = aspect.numerator;
626 aspect.numerator = tmp;
627 return aspect;
628 }
629 EXPORT_SYMBOL_GPL(v4l2_calc_aspect_ratio);
Linux kernel - Deliverables
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