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[linux/fpc-iii.git] / drivers / media / v4l2-core / v4l2-dv-timings.c
blobf7902fe8a5267972aa7d2e9daa0b66e81d6727e3
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 const struct v4l2_dv_timings v4l2_dv_timings_presets[] = {
30 V4L2_DV_BT_CEA_640X480P59_94,
31 V4L2_DV_BT_CEA_720X480I59_94,
32 V4L2_DV_BT_CEA_720X480P59_94,
33 V4L2_DV_BT_CEA_720X576I50,
34 V4L2_DV_BT_CEA_720X576P50,
35 V4L2_DV_BT_CEA_1280X720P24,
36 V4L2_DV_BT_CEA_1280X720P25,
37 V4L2_DV_BT_CEA_1280X720P30,
38 V4L2_DV_BT_CEA_1280X720P50,
39 V4L2_DV_BT_CEA_1280X720P60,
40 V4L2_DV_BT_CEA_1920X1080P24,
41 V4L2_DV_BT_CEA_1920X1080P25,
42 V4L2_DV_BT_CEA_1920X1080P30,
43 V4L2_DV_BT_CEA_1920X1080I50,
44 V4L2_DV_BT_CEA_1920X1080P50,
45 V4L2_DV_BT_CEA_1920X1080I60,
46 V4L2_DV_BT_CEA_1920X1080P60,
47 V4L2_DV_BT_DMT_640X350P85,
48 V4L2_DV_BT_DMT_640X400P85,
49 V4L2_DV_BT_DMT_720X400P85,
50 V4L2_DV_BT_DMT_640X480P72,
51 V4L2_DV_BT_DMT_640X480P75,
52 V4L2_DV_BT_DMT_640X480P85,
53 V4L2_DV_BT_DMT_800X600P56,
54 V4L2_DV_BT_DMT_800X600P60,
55 V4L2_DV_BT_DMT_800X600P72,
56 V4L2_DV_BT_DMT_800X600P75,
57 V4L2_DV_BT_DMT_800X600P85,
58 V4L2_DV_BT_DMT_800X600P120_RB,
59 V4L2_DV_BT_DMT_848X480P60,
60 V4L2_DV_BT_DMT_1024X768I43,
61 V4L2_DV_BT_DMT_1024X768P60,
62 V4L2_DV_BT_DMT_1024X768P70,
63 V4L2_DV_BT_DMT_1024X768P75,
64 V4L2_DV_BT_DMT_1024X768P85,
65 V4L2_DV_BT_DMT_1024X768P120_RB,
66 V4L2_DV_BT_DMT_1152X864P75,
67 V4L2_DV_BT_DMT_1280X768P60_RB,
68 V4L2_DV_BT_DMT_1280X768P60,
69 V4L2_DV_BT_DMT_1280X768P75,
70 V4L2_DV_BT_DMT_1280X768P85,
71 V4L2_DV_BT_DMT_1280X768P120_RB,
72 V4L2_DV_BT_DMT_1280X800P60_RB,
73 V4L2_DV_BT_DMT_1280X800P60,
74 V4L2_DV_BT_DMT_1280X800P75,
75 V4L2_DV_BT_DMT_1280X800P85,
76 V4L2_DV_BT_DMT_1280X800P120_RB,
77 V4L2_DV_BT_DMT_1280X960P60,
78 V4L2_DV_BT_DMT_1280X960P85,
79 V4L2_DV_BT_DMT_1280X960P120_RB,
80 V4L2_DV_BT_DMT_1280X1024P60,
81 V4L2_DV_BT_DMT_1280X1024P75,
82 V4L2_DV_BT_DMT_1280X1024P85,
83 V4L2_DV_BT_DMT_1280X1024P120_RB,
84 V4L2_DV_BT_DMT_1360X768P60,
85 V4L2_DV_BT_DMT_1360X768P120_RB,
86 V4L2_DV_BT_DMT_1366X768P60,
87 V4L2_DV_BT_DMT_1366X768P60_RB,
88 V4L2_DV_BT_DMT_1400X1050P60_RB,
89 V4L2_DV_BT_DMT_1400X1050P60,
90 V4L2_DV_BT_DMT_1400X1050P75,
91 V4L2_DV_BT_DMT_1400X1050P85,
92 V4L2_DV_BT_DMT_1400X1050P120_RB,
93 V4L2_DV_BT_DMT_1440X900P60_RB,
94 V4L2_DV_BT_DMT_1440X900P60,
95 V4L2_DV_BT_DMT_1440X900P75,
96 V4L2_DV_BT_DMT_1440X900P85,
97 V4L2_DV_BT_DMT_1440X900P120_RB,
98 V4L2_DV_BT_DMT_1600X900P60_RB,
99 V4L2_DV_BT_DMT_1600X1200P60,
100 V4L2_DV_BT_DMT_1600X1200P65,
101 V4L2_DV_BT_DMT_1600X1200P70,
102 V4L2_DV_BT_DMT_1600X1200P75,
103 V4L2_DV_BT_DMT_1600X1200P85,
104 V4L2_DV_BT_DMT_1600X1200P120_RB,
105 V4L2_DV_BT_DMT_1680X1050P60_RB,
106 V4L2_DV_BT_DMT_1680X1050P60,
107 V4L2_DV_BT_DMT_1680X1050P75,
108 V4L2_DV_BT_DMT_1680X1050P85,
109 V4L2_DV_BT_DMT_1680X1050P120_RB,
110 V4L2_DV_BT_DMT_1792X1344P60,
111 V4L2_DV_BT_DMT_1792X1344P75,
112 V4L2_DV_BT_DMT_1792X1344P120_RB,
113 V4L2_DV_BT_DMT_1856X1392P60,
114 V4L2_DV_BT_DMT_1856X1392P75,
115 V4L2_DV_BT_DMT_1856X1392P120_RB,
116 V4L2_DV_BT_DMT_1920X1200P60_RB,
117 V4L2_DV_BT_DMT_1920X1200P60,
118 V4L2_DV_BT_DMT_1920X1200P75,
119 V4L2_DV_BT_DMT_1920X1200P85,
120 V4L2_DV_BT_DMT_1920X1200P120_RB,
121 V4L2_DV_BT_DMT_1920X1440P60,
122 V4L2_DV_BT_DMT_1920X1440P75,
123 V4L2_DV_BT_DMT_1920X1440P120_RB,
124 V4L2_DV_BT_DMT_2048X1152P60_RB,
125 V4L2_DV_BT_DMT_2560X1600P60_RB,
126 V4L2_DV_BT_DMT_2560X1600P60,
127 V4L2_DV_BT_DMT_2560X1600P75,
128 V4L2_DV_BT_DMT_2560X1600P85,
129 V4L2_DV_BT_DMT_2560X1600P120_RB,
130 { }
131 };
132 EXPORT_SYMBOL_GPL(v4l2_dv_timings_presets);
133
134 bool v4l2_valid_dv_timings(const struct v4l2_dv_timings *t,
135 const struct v4l2_dv_timings_cap *dvcap,
136 v4l2_check_dv_timings_fnc fnc,
137 void *fnc_handle)
138 {
139 const struct v4l2_bt_timings *bt = &t->bt;
140 const struct v4l2_bt_timings_cap *cap = &dvcap->bt;
141 u32 caps = cap->capabilities;
142
143 if (t->type != V4L2_DV_BT_656_1120)
144 return false;
145 if (t->type != dvcap->type ||
146 bt->height < cap->min_height ||
147 bt->height > cap->max_height ||
148 bt->width < cap->min_width ||
149 bt->width > cap->max_width ||
150 bt->pixelclock < cap->min_pixelclock ||
151 bt->pixelclock > cap->max_pixelclock ||
152 (cap->standards && !(bt->standards & cap->standards)) ||
153 (bt->interlaced && !(caps & V4L2_DV_BT_CAP_INTERLACED)) ||
154 (!bt->interlaced && !(caps & V4L2_DV_BT_CAP_PROGRESSIVE)))
155 return false;
156 return fnc == NULL || fnc(t, fnc_handle);
157 }
158 EXPORT_SYMBOL_GPL(v4l2_valid_dv_timings);
159
160 int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t,
161 const struct v4l2_dv_timings_cap *cap,
162 v4l2_check_dv_timings_fnc fnc,
163 void *fnc_handle)
164 {
165 u32 i, idx;
166
167 memset(t->reserved, 0, sizeof(t->reserved));
168 for (i = idx = 0; v4l2_dv_timings_presets[i].bt.width; i++) {
169 if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap,
170 fnc, fnc_handle) &&
171 idx++ == t->index) {
172 t->timings = v4l2_dv_timings_presets[i];
173 return 0;
174 }
175 }
176 return -EINVAL;
177 }
178 EXPORT_SYMBOL_GPL(v4l2_enum_dv_timings_cap);
179
180 bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t,
181 const struct v4l2_dv_timings_cap *cap,
182 unsigned pclock_delta,
183 v4l2_check_dv_timings_fnc fnc,
184 void *fnc_handle)
185 {
186 int i;
187
188 if (!v4l2_valid_dv_timings(t, cap, fnc, fnc_handle))
189 return false;
190
191 for (i = 0; i < v4l2_dv_timings_presets[i].bt.width; i++) {
192 if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap,
193 fnc, fnc_handle) &&
194 v4l2_match_dv_timings(t, v4l2_dv_timings_presets + i,
195 pclock_delta)) {
196 *t = v4l2_dv_timings_presets[i];
197 return true;
198 }
199 }
200 return false;
201 }
202 EXPORT_SYMBOL_GPL(v4l2_find_dv_timings_cap);
203
204 /**
205 * v4l2_match_dv_timings - check if two timings match
206 * @t1 - compare this v4l2_dv_timings struct...
207 * @t2 - with this struct.
208 * @pclock_delta - the allowed pixelclock deviation.
209 *
210 * Compare t1 with t2 with a given margin of error for the pixelclock.
211 */
212 bool v4l2_match_dv_timings(const struct v4l2_dv_timings *t1,
213 const struct v4l2_dv_timings *t2,
214 unsigned pclock_delta)
215 {
216 if (t1->type != t2->type || t1->type != V4L2_DV_BT_656_1120)
217 return false;
218 if (t1->bt.width == t2->bt.width &&
219 t1->bt.height == t2->bt.height &&
220 t1->bt.interlaced == t2->bt.interlaced &&
221 t1->bt.polarities == t2->bt.polarities &&
222 t1->bt.pixelclock >= t2->bt.pixelclock - pclock_delta &&
223 t1->bt.pixelclock <= t2->bt.pixelclock + pclock_delta &&
224 t1->bt.hfrontporch == t2->bt.hfrontporch &&
225 t1->bt.vfrontporch == t2->bt.vfrontporch &&
226 t1->bt.vsync == t2->bt.vsync &&
227 t1->bt.vbackporch == t2->bt.vbackporch &&
228 (!t1->bt.interlaced ||
229 (t1->bt.il_vfrontporch == t2->bt.il_vfrontporch &&
230 t1->bt.il_vsync == t2->bt.il_vsync &&
231 t1->bt.il_vbackporch == t2->bt.il_vbackporch)))
232 return true;
233 return false;
234 }
235 EXPORT_SYMBOL_GPL(v4l2_match_dv_timings);
236
237 void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix,
238 const struct v4l2_dv_timings *t, bool detailed)
239 {
240 const struct v4l2_bt_timings *bt = &t->bt;
241 u32 htot, vtot;
242
243 if (t->type != V4L2_DV_BT_656_1120)
244 return;
245
246 htot = V4L2_DV_BT_FRAME_WIDTH(bt);
247 vtot = V4L2_DV_BT_FRAME_HEIGHT(bt);
248
249 if (prefix == NULL)
250 prefix = "";
251
252 pr_info("%s: %s%ux%u%s%u (%ux%u)\n", dev_prefix, prefix,
253 bt->width, bt->height, bt->interlaced ? "i" : "p",
254 (htot * vtot) > 0 ? ((u32)bt->pixelclock / (htot * vtot)) : 0,
255 htot, vtot);
256
257 if (!detailed)
258 return;
259
260 pr_info("%s: horizontal: fp = %u, %ssync = %u, bp = %u\n",
261 dev_prefix, bt->hfrontporch,
262 (bt->polarities & V4L2_DV_HSYNC_POS_POL) ? "+" : "-",
263 bt->hsync, bt->hbackporch);
264 pr_info("%s: vertical: fp = %u, %ssync = %u, bp = %u\n",
265 dev_prefix, bt->vfrontporch,
266 (bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-",
267 bt->vsync, bt->vbackporch);
268 pr_info("%s: pixelclock: %llu\n", dev_prefix, bt->pixelclock);
269 pr_info("%s: flags (0x%x):%s%s%s%s\n", dev_prefix, bt->flags,
270 (bt->flags & V4L2_DV_FL_REDUCED_BLANKING) ?
271 " REDUCED_BLANKING" : "",
272 (bt->flags & V4L2_DV_FL_CAN_REDUCE_FPS) ?
273 " CAN_REDUCE_FPS" : "",
274 (bt->flags & V4L2_DV_FL_REDUCED_FPS) ?
275 " REDUCED_FPS" : "",
276 (bt->flags & V4L2_DV_FL_HALF_LINE) ?
277 " HALF_LINE" : "");
278 pr_info("%s: standards (0x%x):%s%s%s%s\n", dev_prefix, bt->standards,
279 (bt->standards & V4L2_DV_BT_STD_CEA861) ? " CEA" : "",
280 (bt->standards & V4L2_DV_BT_STD_DMT) ? " DMT" : "",
281 (bt->standards & V4L2_DV_BT_STD_CVT) ? " CVT" : "",
282 (bt->standards & V4L2_DV_BT_STD_GTF) ? " GTF" : "");
283 }
284 EXPORT_SYMBOL_GPL(v4l2_print_dv_timings);
285
286 /*
287 * CVT defines
288 * Based on Coordinated Video Timings Standard
289 * version 1.1 September 10, 2003
290 */
291
292 #define CVT_PXL_CLK_GRAN 250000 /* pixel clock granularity */
293
294 /* Normal blanking */
295 #define CVT_MIN_V_BPORCH 7 /* lines */
296 #define CVT_MIN_V_PORCH_RND 3 /* lines */
297 #define CVT_MIN_VSYNC_BP 550 /* min time of vsync + back porch (us) */
298
299 /* Normal blanking for CVT uses GTF to calculate horizontal blanking */
300 #define CVT_CELL_GRAN 8 /* character cell granularity */
301 #define CVT_M 600 /* blanking formula gradient */
302 #define CVT_C 40 /* blanking formula offset */
303 #define CVT_K 128 /* blanking formula scaling factor */
304 #define CVT_J 20 /* blanking formula scaling factor */
305 #define CVT_C_PRIME (((CVT_C - CVT_J) * CVT_K / 256) + CVT_J)
306 #define CVT_M_PRIME (CVT_K * CVT_M / 256)
307
308 /* Reduced Blanking */
309 #define CVT_RB_MIN_V_BPORCH 7 /* lines */
310 #define CVT_RB_V_FPORCH 3 /* lines */
311 #define CVT_RB_MIN_V_BLANK 460 /* us */
312 #define CVT_RB_H_SYNC 32 /* pixels */
313 #define CVT_RB_H_BPORCH 80 /* pixels */
314 #define CVT_RB_H_BLANK 160 /* pixels */
315
316 /** v4l2_detect_cvt - detect if the given timings follow the CVT standard
317 * @frame_height - the total height of the frame (including blanking) in lines.
318 * @hfreq - the horizontal frequency in Hz.
319 * @vsync - the height of the vertical sync in lines.
320 * @polarities - the horizontal and vertical polarities (same as struct
321 * v4l2_bt_timings polarities).
322 * @fmt - the resulting timings.
323 *
324 * This function will attempt to detect if the given values correspond to a
325 * valid CVT format. If so, then it will return true, and fmt will be filled
326 * in with the found CVT timings.
327 */
328 bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync,
329 u32 polarities, struct v4l2_dv_timings *fmt)
330 {
331 int v_fp, v_bp, h_fp, h_bp, hsync;
332 int frame_width, image_height, image_width;
333 bool reduced_blanking;
334 unsigned pix_clk;
335
336 if (vsync < 4 || vsync > 7)
337 return false;
338
339 if (polarities == V4L2_DV_VSYNC_POS_POL)
340 reduced_blanking = false;
341 else if (polarities == V4L2_DV_HSYNC_POS_POL)
342 reduced_blanking = true;
343 else
344 return false;
345
346 /* Vertical */
347 if (reduced_blanking) {
348 v_fp = CVT_RB_V_FPORCH;
349 v_bp = (CVT_RB_MIN_V_BLANK * hfreq + 1999999) / 1000000;
350 v_bp -= vsync + v_fp;
351
352 if (v_bp < CVT_RB_MIN_V_BPORCH)
353 v_bp = CVT_RB_MIN_V_BPORCH;
354 } else {
355 v_fp = CVT_MIN_V_PORCH_RND;
356 v_bp = (CVT_MIN_VSYNC_BP * hfreq + 1999999) / 1000000 - vsync;
357
358 if (v_bp < CVT_MIN_V_BPORCH)
359 v_bp = CVT_MIN_V_BPORCH;
360 }
361 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
362
363 /* Aspect ratio based on vsync */
364 switch (vsync) {
365 case 4:
366 image_width = (image_height * 4) / 3;
367 break;
368 case 5:
369 image_width = (image_height * 16) / 9;
370 break;
371 case 6:
372 image_width = (image_height * 16) / 10;
373 break;
374 case 7:
375 /* special case */
376 if (image_height == 1024)
377 image_width = (image_height * 5) / 4;
378 else if (image_height == 768)
379 image_width = (image_height * 15) / 9;
380 else
381 return false;
382 break;
383 default:
384 return false;
385 }
386
387 image_width = image_width & ~7;
388
389 /* Horizontal */
390 if (reduced_blanking) {
391 pix_clk = (image_width + CVT_RB_H_BLANK) * hfreq;
392 pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN;
393
394 h_bp = CVT_RB_H_BPORCH;
395 hsync = CVT_RB_H_SYNC;
396 h_fp = CVT_RB_H_BLANK - h_bp - hsync;
397
398 frame_width = image_width + CVT_RB_H_BLANK;
399 } else {
400 unsigned ideal_duty_cycle_per_myriad =
401 100 * CVT_C_PRIME - (CVT_M_PRIME * 100000) / hfreq;
402 int h_blank;
403
404 if (ideal_duty_cycle_per_myriad < 2000)
405 ideal_duty_cycle_per_myriad = 2000;
406
407 h_blank = image_width * ideal_duty_cycle_per_myriad /
408 (10000 - ideal_duty_cycle_per_myriad);
409 h_blank = (h_blank / (2 * CVT_CELL_GRAN)) * 2 * CVT_CELL_GRAN;
410
411 pix_clk = (image_width + h_blank) * hfreq;
412 pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN;
413
414 h_bp = h_blank / 2;
415 frame_width = image_width + h_blank;
416
417 hsync = (frame_width * 8 + 50) / 100;
418 hsync = hsync - hsync % CVT_CELL_GRAN;
419 h_fp = h_blank - hsync - h_bp;
420 }
421
422 fmt->type = V4L2_DV_BT_656_1120;
423 fmt->bt.polarities = polarities;
424 fmt->bt.width = image_width;
425 fmt->bt.height = image_height;
426 fmt->bt.hfrontporch = h_fp;
427 fmt->bt.vfrontporch = v_fp;
428 fmt->bt.hsync = hsync;
429 fmt->bt.vsync = vsync;
430 fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
431 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
432 fmt->bt.pixelclock = pix_clk;
433 fmt->bt.standards = V4L2_DV_BT_STD_CVT;
434 if (reduced_blanking)
435 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
436 return true;
437 }
438 EXPORT_SYMBOL_GPL(v4l2_detect_cvt);
439
440 /*
441 * GTF defines
442 * Based on Generalized Timing Formula Standard
443 * Version 1.1 September 2, 1999
444 */
445
446 #define GTF_PXL_CLK_GRAN 250000 /* pixel clock granularity */
447
448 #define GTF_MIN_VSYNC_BP 550 /* min time of vsync + back porch (us) */
449 #define GTF_V_FP 1 /* vertical front porch (lines) */
450 #define GTF_CELL_GRAN 8 /* character cell granularity */
451
452 /* Default */
453 #define GTF_D_M 600 /* blanking formula gradient */
454 #define GTF_D_C 40 /* blanking formula offset */
455 #define GTF_D_K 128 /* blanking formula scaling factor */
456 #define GTF_D_J 20 /* blanking formula scaling factor */
457 #define GTF_D_C_PRIME ((((GTF_D_C - GTF_D_J) * GTF_D_K) / 256) + GTF_D_J)
458 #define GTF_D_M_PRIME ((GTF_D_K * GTF_D_M) / 256)
459
460 /* Secondary */
461 #define GTF_S_M 3600 /* blanking formula gradient */
462 #define GTF_S_C 40 /* blanking formula offset */
463 #define GTF_S_K 128 /* blanking formula scaling factor */
464 #define GTF_S_J 35 /* blanking formula scaling factor */
465 #define GTF_S_C_PRIME ((((GTF_S_C - GTF_S_J) * GTF_S_K) / 256) + GTF_S_J)
466 #define GTF_S_M_PRIME ((GTF_S_K * GTF_S_M) / 256)
467
468 /** v4l2_detect_gtf - detect if the given timings follow the GTF standard
469 * @frame_height - the total height of the frame (including blanking) in lines.
470 * @hfreq - the horizontal frequency in Hz.
471 * @vsync - the height of the vertical sync in lines.
472 * @polarities - the horizontal and vertical polarities (same as struct
473 * v4l2_bt_timings polarities).
474 * @aspect - preferred aspect ratio. GTF has no method of determining the
475 * aspect ratio in order to derive the image width from the
476 * image height, so it has to be passed explicitly. Usually
477 * the native screen aspect ratio is used for this. If it
478 * is not filled in correctly, then 16:9 will be assumed.
479 * @fmt - the resulting timings.
480 *
481 * This function will attempt to detect if the given values correspond to a
482 * valid GTF format. If so, then it will return true, and fmt will be filled
483 * in with the found GTF timings.
484 */
485 bool v4l2_detect_gtf(unsigned frame_height,
486 unsigned hfreq,
487 unsigned vsync,
488 u32 polarities,
489 struct v4l2_fract aspect,
490 struct v4l2_dv_timings *fmt)
491 {
492 int pix_clk;
493 int v_fp, v_bp, h_fp, hsync;
494 int frame_width, image_height, image_width;
495 bool default_gtf;
496 int h_blank;
497
498 if (vsync != 3)
499 return false;
500
501 if (polarities == V4L2_DV_VSYNC_POS_POL)
502 default_gtf = true;
503 else if (polarities == V4L2_DV_HSYNC_POS_POL)
504 default_gtf = false;
505 else
506 return false;
507
508 /* Vertical */
509 v_fp = GTF_V_FP;
510 v_bp = (GTF_MIN_VSYNC_BP * hfreq + 999999) / 1000000 - vsync;
511 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
512
513 if (aspect.numerator == 0 || aspect.denominator == 0) {
514 aspect.numerator = 16;
515 aspect.denominator = 9;
516 }
517 image_width = ((image_height * aspect.numerator) / aspect.denominator);
518 image_width = (image_width + GTF_CELL_GRAN/2) & ~(GTF_CELL_GRAN - 1);
519
520 /* Horizontal */
521 if (default_gtf)
522 h_blank = ((image_width * GTF_D_C_PRIME * hfreq) -
523 (image_width * GTF_D_M_PRIME * 1000) +
524 (hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000) / 2) /
525 (hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000);
526 else
527 h_blank = ((image_width * GTF_S_C_PRIME * hfreq) -
528 (image_width * GTF_S_M_PRIME * 1000) +
529 (hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000) / 2) /
530 (hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000);
531
532 h_blank = h_blank - h_blank % (2 * GTF_CELL_GRAN);
533 frame_width = image_width + h_blank;
534
535 pix_clk = (image_width + h_blank) * hfreq;
536 pix_clk = pix_clk / GTF_PXL_CLK_GRAN * GTF_PXL_CLK_GRAN;
537
538 hsync = (frame_width * 8 + 50) / 100;
539 hsync = hsync - hsync % GTF_CELL_GRAN;
540
541 h_fp = h_blank / 2 - hsync;
542
543 fmt->type = V4L2_DV_BT_656_1120;
544 fmt->bt.polarities = polarities;
545 fmt->bt.width = image_width;
546 fmt->bt.height = image_height;
547 fmt->bt.hfrontporch = h_fp;
548 fmt->bt.vfrontporch = v_fp;
549 fmt->bt.hsync = hsync;
550 fmt->bt.vsync = vsync;
551 fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
552 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
553 fmt->bt.pixelclock = pix_clk;
554 fmt->bt.standards = V4L2_DV_BT_STD_GTF;
555 if (!default_gtf)
556 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
557 return true;
558 }
559 EXPORT_SYMBOL_GPL(v4l2_detect_gtf);
560
561 /** v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes
562 * 0x15 and 0x16 from the EDID.
563 * @hor_landscape - byte 0x15 from the EDID.
564 * @vert_portrait - byte 0x16 from the EDID.
565 *
566 * Determines the aspect ratio from the EDID.
567 * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2:
568 * "Horizontal and Vertical Screen Size or Aspect Ratio"
569 */
570 struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait)
571 {
572 struct v4l2_fract aspect = { 16, 9 };
573 u32 tmp;
574 u8 ratio;
575
576 /* Nothing filled in, fallback to 16:9 */
577 if (!hor_landscape && !vert_portrait)
578 return aspect;
579 /* Both filled in, so they are interpreted as the screen size in cm */
580 if (hor_landscape && vert_portrait) {
581 aspect.numerator = hor_landscape;
582 aspect.denominator = vert_portrait;
583 return aspect;
584 }
585 /* Only one is filled in, so interpret them as a ratio:
586 (val + 99) / 100 */
587 ratio = hor_landscape | vert_portrait;
588 /* Change some rounded values into the exact aspect ratio */
589 if (ratio == 79) {
590 aspect.numerator = 16;
591 aspect.denominator = 9;
592 } else if (ratio == 34) {
593 aspect.numerator = 4;
594 aspect.numerator = 3;
595 } else if (ratio == 68) {
596 aspect.numerator = 15;
597 aspect.numerator = 9;
598 } else {
599 aspect.numerator = hor_landscape + 99;
600 aspect.denominator = 100;
601 }
602 if (hor_landscape)
603 return aspect;
604 /* The aspect ratio is for portrait, so swap numerator and denominator */
605 tmp = aspect.denominator;
606 aspect.denominator = aspect.numerator;
607 aspect.numerator = tmp;
608 return aspect;
609 }
610 EXPORT_SYMBOL_GPL(v4l2_calc_aspect_ratio);
Linux with added FPC-III support