projects / deliverable / linux.git / blob
? search:


5792192bce6ccd3c14cf9ec01cdced4fbeb0dcc3
[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 #include <linux/math64.h>
29
30 MODULE_AUTHOR("Hans Verkuil");
31 MODULE_DESCRIPTION("V4L2 DV Timings Helper Functions");
32 MODULE_LICENSE("GPL");
33
34 const struct v4l2_dv_timings v4l2_dv_timings_presets[] = {
35 V4L2_DV_BT_CEA_640X480P59_94,
36 V4L2_DV_BT_CEA_720X480I59_94,
37 V4L2_DV_BT_CEA_720X480P59_94,
38 V4L2_DV_BT_CEA_720X576I50,
39 V4L2_DV_BT_CEA_720X576P50,
40 V4L2_DV_BT_CEA_1280X720P24,
41 V4L2_DV_BT_CEA_1280X720P25,
42 V4L2_DV_BT_CEA_1280X720P30,
43 V4L2_DV_BT_CEA_1280X720P50,
44 V4L2_DV_BT_CEA_1280X720P60,
45 V4L2_DV_BT_CEA_1920X1080P24,
46 V4L2_DV_BT_CEA_1920X1080P25,
47 V4L2_DV_BT_CEA_1920X1080P30,
48 V4L2_DV_BT_CEA_1920X1080I50,
49 V4L2_DV_BT_CEA_1920X1080P50,
50 V4L2_DV_BT_CEA_1920X1080I60,
51 V4L2_DV_BT_CEA_1920X1080P60,
52 V4L2_DV_BT_DMT_640X350P85,
53 V4L2_DV_BT_DMT_640X400P85,
54 V4L2_DV_BT_DMT_720X400P85,
55 V4L2_DV_BT_DMT_640X480P72,
56 V4L2_DV_BT_DMT_640X480P75,
57 V4L2_DV_BT_DMT_640X480P85,
58 V4L2_DV_BT_DMT_800X600P56,
59 V4L2_DV_BT_DMT_800X600P60,
60 V4L2_DV_BT_DMT_800X600P72,
61 V4L2_DV_BT_DMT_800X600P75,
62 V4L2_DV_BT_DMT_800X600P85,
63 V4L2_DV_BT_DMT_800X600P120_RB,
64 V4L2_DV_BT_DMT_848X480P60,
65 V4L2_DV_BT_DMT_1024X768I43,
66 V4L2_DV_BT_DMT_1024X768P60,
67 V4L2_DV_BT_DMT_1024X768P70,
68 V4L2_DV_BT_DMT_1024X768P75,
69 V4L2_DV_BT_DMT_1024X768P85,
70 V4L2_DV_BT_DMT_1024X768P120_RB,
71 V4L2_DV_BT_DMT_1152X864P75,
72 V4L2_DV_BT_DMT_1280X768P60_RB,
73 V4L2_DV_BT_DMT_1280X768P60,
74 V4L2_DV_BT_DMT_1280X768P75,
75 V4L2_DV_BT_DMT_1280X768P85,
76 V4L2_DV_BT_DMT_1280X768P120_RB,
77 V4L2_DV_BT_DMT_1280X800P60_RB,
78 V4L2_DV_BT_DMT_1280X800P60,
79 V4L2_DV_BT_DMT_1280X800P75,
80 V4L2_DV_BT_DMT_1280X800P85,
81 V4L2_DV_BT_DMT_1280X800P120_RB,
82 V4L2_DV_BT_DMT_1280X960P60,
83 V4L2_DV_BT_DMT_1280X960P85,
84 V4L2_DV_BT_DMT_1280X960P120_RB,
85 V4L2_DV_BT_DMT_1280X1024P60,
86 V4L2_DV_BT_DMT_1280X1024P75,
87 V4L2_DV_BT_DMT_1280X1024P85,
88 V4L2_DV_BT_DMT_1280X1024P120_RB,
89 V4L2_DV_BT_DMT_1360X768P60,
90 V4L2_DV_BT_DMT_1360X768P120_RB,
91 V4L2_DV_BT_DMT_1366X768P60,
92 V4L2_DV_BT_DMT_1366X768P60_RB,
93 V4L2_DV_BT_DMT_1400X1050P60_RB,
94 V4L2_DV_BT_DMT_1400X1050P60,
95 V4L2_DV_BT_DMT_1400X1050P75,
96 V4L2_DV_BT_DMT_1400X1050P85,
97 V4L2_DV_BT_DMT_1400X1050P120_RB,
98 V4L2_DV_BT_DMT_1440X900P60_RB,
99 V4L2_DV_BT_DMT_1440X900P60,
100 V4L2_DV_BT_DMT_1440X900P75,
101 V4L2_DV_BT_DMT_1440X900P85,
102 V4L2_DV_BT_DMT_1440X900P120_RB,
103 V4L2_DV_BT_DMT_1600X900P60_RB,
104 V4L2_DV_BT_DMT_1600X1200P60,
105 V4L2_DV_BT_DMT_1600X1200P65,
106 V4L2_DV_BT_DMT_1600X1200P70,
107 V4L2_DV_BT_DMT_1600X1200P75,
108 V4L2_DV_BT_DMT_1600X1200P85,
109 V4L2_DV_BT_DMT_1600X1200P120_RB,
110 V4L2_DV_BT_DMT_1680X1050P60_RB,
111 V4L2_DV_BT_DMT_1680X1050P60,
112 V4L2_DV_BT_DMT_1680X1050P75,
113 V4L2_DV_BT_DMT_1680X1050P85,
114 V4L2_DV_BT_DMT_1680X1050P120_RB,
115 V4L2_DV_BT_DMT_1792X1344P60,
116 V4L2_DV_BT_DMT_1792X1344P75,
117 V4L2_DV_BT_DMT_1792X1344P120_RB,
118 V4L2_DV_BT_DMT_1856X1392P60,
119 V4L2_DV_BT_DMT_1856X1392P75,
120 V4L2_DV_BT_DMT_1856X1392P120_RB,
121 V4L2_DV_BT_DMT_1920X1200P60_RB,
122 V4L2_DV_BT_DMT_1920X1200P60,
123 V4L2_DV_BT_DMT_1920X1200P75,
124 V4L2_DV_BT_DMT_1920X1200P85,
125 V4L2_DV_BT_DMT_1920X1200P120_RB,
126 V4L2_DV_BT_DMT_1920X1440P60,
127 V4L2_DV_BT_DMT_1920X1440P75,
128 V4L2_DV_BT_DMT_1920X1440P120_RB,
129 V4L2_DV_BT_DMT_2048X1152P60_RB,
130 V4L2_DV_BT_DMT_2560X1600P60_RB,
131 V4L2_DV_BT_DMT_2560X1600P60,
132 V4L2_DV_BT_DMT_2560X1600P75,
133 V4L2_DV_BT_DMT_2560X1600P85,
134 V4L2_DV_BT_DMT_2560X1600P120_RB,
135 V4L2_DV_BT_CEA_3840X2160P24,
136 V4L2_DV_BT_CEA_3840X2160P25,
137 V4L2_DV_BT_CEA_3840X2160P30,
138 V4L2_DV_BT_CEA_3840X2160P50,
139 V4L2_DV_BT_CEA_3840X2160P60,
140 V4L2_DV_BT_CEA_4096X2160P24,
141 V4L2_DV_BT_CEA_4096X2160P25,
142 V4L2_DV_BT_CEA_4096X2160P30,
143 V4L2_DV_BT_CEA_4096X2160P50,
144 V4L2_DV_BT_DMT_4096X2160P59_94_RB,
145 V4L2_DV_BT_CEA_4096X2160P60,
146 { }
147 };
148 EXPORT_SYMBOL_GPL(v4l2_dv_timings_presets);
149
150 bool v4l2_valid_dv_timings(const struct v4l2_dv_timings *t,
151 const struct v4l2_dv_timings_cap *dvcap,
152 v4l2_check_dv_timings_fnc fnc,
153 void *fnc_handle)
154 {
155 const struct v4l2_bt_timings *bt = &t->bt;
156 const struct v4l2_bt_timings_cap *cap = &dvcap->bt;
157 u32 caps = cap->capabilities;
158
159 if (t->type != V4L2_DV_BT_656_1120)
160 return false;
161 if (t->type != dvcap->type ||
162 bt->height < cap->min_height ||
163 bt->height > cap->max_height ||
164 bt->width < cap->min_width ||
165 bt->width > cap->max_width ||
166 bt->pixelclock < cap->min_pixelclock ||
167 bt->pixelclock > cap->max_pixelclock ||
168 (cap->standards && bt->standards &&
169 !(bt->standards & cap->standards)) ||
170 (bt->interlaced && !(caps & V4L2_DV_BT_CAP_INTERLACED)) ||
171 (!bt->interlaced && !(caps & V4L2_DV_BT_CAP_PROGRESSIVE)))
172 return false;
173 return fnc == NULL || fnc(t, fnc_handle);
174 }
175 EXPORT_SYMBOL_GPL(v4l2_valid_dv_timings);
176
177 int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t,
178 const struct v4l2_dv_timings_cap *cap,
179 v4l2_check_dv_timings_fnc fnc,
180 void *fnc_handle)
181 {
182 u32 i, idx;
183
184 memset(t->reserved, 0, sizeof(t->reserved));
185 for (i = idx = 0; v4l2_dv_timings_presets[i].bt.width; i++) {
186 if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap,
187 fnc, fnc_handle) &&
188 idx++ == t->index) {
189 t->timings = v4l2_dv_timings_presets[i];
190 return 0;
191 }
192 }
193 return -EINVAL;
194 }
195 EXPORT_SYMBOL_GPL(v4l2_enum_dv_timings_cap);
196
197 bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t,
198 const struct v4l2_dv_timings_cap *cap,
199 unsigned pclock_delta,
200 v4l2_check_dv_timings_fnc fnc,
201 void *fnc_handle)
202 {
203 int i;
204
205 if (!v4l2_valid_dv_timings(t, cap, fnc, fnc_handle))
206 return false;
207
208 for (i = 0; i < v4l2_dv_timings_presets[i].bt.width; i++) {
209 if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap,
210 fnc, fnc_handle) &&
211 v4l2_match_dv_timings(t, v4l2_dv_timings_presets + i,
212 pclock_delta)) {
213 *t = v4l2_dv_timings_presets[i];
214 return true;
215 }
216 }
217 return false;
218 }
219 EXPORT_SYMBOL_GPL(v4l2_find_dv_timings_cap);
220
221 /**
222 * v4l2_match_dv_timings - check if two timings match
223 * @t1 - compare this v4l2_dv_timings struct...
224 * @t2 - with this struct.
225 * @pclock_delta - the allowed pixelclock deviation.
226 *
227 * Compare t1 with t2 with a given margin of error for the pixelclock.
228 */
229 bool v4l2_match_dv_timings(const struct v4l2_dv_timings *t1,
230 const struct v4l2_dv_timings *t2,
231 unsigned pclock_delta)
232 {
233 if (t1->type != t2->type || t1->type != V4L2_DV_BT_656_1120)
234 return false;
235 if (t1->bt.width == t2->bt.width &&
236 t1->bt.height == t2->bt.height &&
237 t1->bt.interlaced == t2->bt.interlaced &&
238 t1->bt.polarities == t2->bt.polarities &&
239 t1->bt.pixelclock >= t2->bt.pixelclock - pclock_delta &&
240 t1->bt.pixelclock <= t2->bt.pixelclock + pclock_delta &&
241 t1->bt.hfrontporch == t2->bt.hfrontporch &&
242 t1->bt.vfrontporch == t2->bt.vfrontporch &&
243 t1->bt.vsync == t2->bt.vsync &&
244 t1->bt.vbackporch == t2->bt.vbackporch &&
245 (!t1->bt.interlaced ||
246 (t1->bt.il_vfrontporch == t2->bt.il_vfrontporch &&
247 t1->bt.il_vsync == t2->bt.il_vsync &&
248 t1->bt.il_vbackporch == t2->bt.il_vbackporch)))
249 return true;
250 return false;
251 }
252 EXPORT_SYMBOL_GPL(v4l2_match_dv_timings);
253
254 void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix,
255 const struct v4l2_dv_timings *t, bool detailed)
256 {
257 const struct v4l2_bt_timings *bt = &t->bt;
258 u32 htot, vtot;
259
260 if (t->type != V4L2_DV_BT_656_1120)
261 return;
262
263 htot = V4L2_DV_BT_FRAME_WIDTH(bt);
264 vtot = V4L2_DV_BT_FRAME_HEIGHT(bt);
265
266 if (prefix == NULL)
267 prefix = "";
268
269 pr_info("%s: %s%ux%u%s%u (%ux%u)\n", dev_prefix, prefix,
270 bt->width, bt->height, bt->interlaced ? "i" : "p",
271 (htot * vtot) > 0 ? ((u32)bt->pixelclock / (htot * vtot)) : 0,
272 htot, vtot);
273
274 if (!detailed)
275 return;
276
277 pr_info("%s: horizontal: fp = %u, %ssync = %u, bp = %u\n",
278 dev_prefix, bt->hfrontporch,
279 (bt->polarities & V4L2_DV_HSYNC_POS_POL) ? "+" : "-",
280 bt->hsync, bt->hbackporch);
281 pr_info("%s: vertical: fp = %u, %ssync = %u, bp = %u\n",
282 dev_prefix, bt->vfrontporch,
283 (bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-",
284 bt->vsync, bt->vbackporch);
285 pr_info("%s: pixelclock: %llu\n", dev_prefix, bt->pixelclock);
286 pr_info("%s: flags (0x%x):%s%s%s%s%s\n", dev_prefix, bt->flags,
287 (bt->flags & V4L2_DV_FL_REDUCED_BLANKING) ?
288 " REDUCED_BLANKING" : "",
289 (bt->flags & V4L2_DV_FL_CAN_REDUCE_FPS) ?
290 " CAN_REDUCE_FPS" : "",
291 (bt->flags & V4L2_DV_FL_REDUCED_FPS) ?
292 " REDUCED_FPS" : "",
293 (bt->flags & V4L2_DV_FL_HALF_LINE) ?
294 " HALF_LINE" : "",
295 (bt->flags & V4L2_DV_FL_IS_CE_VIDEO) ?
296 " CE_VIDEO" : "");
297 pr_info("%s: standards (0x%x):%s%s%s%s\n", dev_prefix, bt->standards,
298 (bt->standards & V4L2_DV_BT_STD_CEA861) ? " CEA" : "",
299 (bt->standards & V4L2_DV_BT_STD_DMT) ? " DMT" : "",
300 (bt->standards & V4L2_DV_BT_STD_CVT) ? " CVT" : "",
301 (bt->standards & V4L2_DV_BT_STD_GTF) ? " GTF" : "");
302 }
303 EXPORT_SYMBOL_GPL(v4l2_print_dv_timings);
304
305 /*
306 * CVT defines
307 * Based on Coordinated Video Timings Standard
308 * version 1.1 September 10, 2003
309 */
310
311 #define CVT_PXL_CLK_GRAN 250000 /* pixel clock granularity */
312
313 /* Normal blanking */
314 #define CVT_MIN_V_BPORCH 7 /* lines */
315 #define CVT_MIN_V_PORCH_RND 3 /* lines */
316 #define CVT_MIN_VSYNC_BP 550 /* min time of vsync + back porch (us) */
317 #define CVT_HSYNC_PERCENT 8 /* nominal hsync as percentage of line */
318
319 /* Normal blanking for CVT uses GTF to calculate horizontal blanking */
320 #define CVT_CELL_GRAN 8 /* character cell granularity */
321 #define CVT_M 600 /* blanking formula gradient */
322 #define CVT_C 40 /* blanking formula offset */
323 #define CVT_K 128 /* blanking formula scaling factor */
324 #define CVT_J 20 /* blanking formula scaling factor */
325 #define CVT_C_PRIME (((CVT_C - CVT_J) * CVT_K / 256) + CVT_J)
326 #define CVT_M_PRIME (CVT_K * CVT_M / 256)
327
328 /* Reduced Blanking */
329 #define CVT_RB_MIN_V_BPORCH 7 /* lines */
330 #define CVT_RB_V_FPORCH 3 /* lines */
331 #define CVT_RB_MIN_V_BLANK 460 /* us */
332 #define CVT_RB_H_SYNC 32 /* pixels */
333 #define CVT_RB_H_BPORCH 80 /* pixels */
334 #define CVT_RB_H_BLANK 160 /* pixels */
335
336 /** v4l2_detect_cvt - detect if the given timings follow the CVT standard
337 * @frame_height - the total height of the frame (including blanking) in lines.
338 * @hfreq - the horizontal frequency in Hz.
339 * @vsync - the height of the vertical sync in lines.
340 * @polarities - the horizontal and vertical polarities (same as struct
341 * v4l2_bt_timings polarities).
342 * @fmt - the resulting timings.
343 *
344 * This function will attempt to detect if the given values correspond to a
345 * valid CVT format. If so, then it will return true, and fmt will be filled
346 * in with the found CVT timings.
347 *
348 * TODO: VESA defined a new version 2 of their reduced blanking
349 * formula. Support for that is currently missing in this CVT
350 * detection function.
351 */
352 bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync,
353 u32 polarities, struct v4l2_dv_timings *fmt)
354 {
355 int v_fp, v_bp, h_fp, h_bp, hsync;
356 int frame_width, image_height, image_width;
357 bool reduced_blanking;
358 unsigned pix_clk;
359
360 if (vsync < 4 || vsync > 7)
361 return false;
362
363 if (polarities == V4L2_DV_VSYNC_POS_POL)
364 reduced_blanking = false;
365 else if (polarities == V4L2_DV_HSYNC_POS_POL)
366 reduced_blanking = true;
367 else
368 return false;
369
370 if (hfreq == 0)
371 return false;
372
373 /* Vertical */
374 if (reduced_blanking) {
375 v_fp = CVT_RB_V_FPORCH;
376 v_bp = (CVT_RB_MIN_V_BLANK * hfreq) / 1000000 + 1;
377 v_bp -= vsync + v_fp;
378
379 if (v_bp < CVT_RB_MIN_V_BPORCH)
380 v_bp = CVT_RB_MIN_V_BPORCH;
381 } else {
382 v_fp = CVT_MIN_V_PORCH_RND;
383 v_bp = (CVT_MIN_VSYNC_BP * hfreq) / 1000000 + 1 - vsync;
384
385 if (v_bp < CVT_MIN_V_BPORCH)
386 v_bp = CVT_MIN_V_BPORCH;
387 }
388 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
389
390 if (image_height < 0)
391 return false;
392
393 /* Aspect ratio based on vsync */
394 switch (vsync) {
395 case 4:
396 image_width = (image_height * 4) / 3;
397 break;
398 case 5:
399 image_width = (image_height * 16) / 9;
400 break;
401 case 6:
402 image_width = (image_height * 16) / 10;
403 break;
404 case 7:
405 /* special case */
406 if (image_height == 1024)
407 image_width = (image_height * 5) / 4;
408 else if (image_height == 768)
409 image_width = (image_height * 15) / 9;
410 else
411 return false;
412 break;
413 default:
414 return false;
415 }
416
417 image_width = image_width & ~7;
418
419 /* Horizontal */
420 if (reduced_blanking) {
421 pix_clk = (image_width + CVT_RB_H_BLANK) * hfreq;
422 pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN;
423
424 h_bp = CVT_RB_H_BPORCH;
425 hsync = CVT_RB_H_SYNC;
426 h_fp = CVT_RB_H_BLANK - h_bp - hsync;
427
428 frame_width = image_width + CVT_RB_H_BLANK;
429 } else {
430 unsigned ideal_duty_cycle_per_myriad =
431 100 * CVT_C_PRIME - (CVT_M_PRIME * 100000) / hfreq;
432 int h_blank;
433
434 if (ideal_duty_cycle_per_myriad < 2000)
435 ideal_duty_cycle_per_myriad = 2000;
436
437 h_blank = image_width * ideal_duty_cycle_per_myriad /
438 (10000 - ideal_duty_cycle_per_myriad);
439 h_blank = (h_blank / (2 * CVT_CELL_GRAN)) * 2 * CVT_CELL_GRAN;
440
441 pix_clk = (image_width + h_blank) * hfreq;
442 pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN;
443
444 h_bp = h_blank / 2;
445 frame_width = image_width + h_blank;
446
447 hsync = frame_width * CVT_HSYNC_PERCENT / 100;
448 hsync = (hsync / CVT_CELL_GRAN) * CVT_CELL_GRAN;
449 h_fp = h_blank - hsync - h_bp;
450 }
451
452 fmt->type = V4L2_DV_BT_656_1120;
453 fmt->bt.polarities = polarities;
454 fmt->bt.width = image_width;
455 fmt->bt.height = image_height;
456 fmt->bt.hfrontporch = h_fp;
457 fmt->bt.vfrontporch = v_fp;
458 fmt->bt.hsync = hsync;
459 fmt->bt.vsync = vsync;
460 fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
461 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
462 fmt->bt.pixelclock = pix_clk;
463 fmt->bt.standards = V4L2_DV_BT_STD_CVT;
464 if (reduced_blanking)
465 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
466 return true;
467 }
468 EXPORT_SYMBOL_GPL(v4l2_detect_cvt);
469
470 /*
471 * GTF defines
472 * Based on Generalized Timing Formula Standard
473 * Version 1.1 September 2, 1999
474 */
475
476 #define GTF_PXL_CLK_GRAN 250000 /* pixel clock granularity */
477
478 #define GTF_MIN_VSYNC_BP 550 /* min time of vsync + back porch (us) */
479 #define GTF_V_FP 1 /* vertical front porch (lines) */
480 #define GTF_CELL_GRAN 8 /* character cell granularity */
481
482 /* Default */
483 #define GTF_D_M 600 /* blanking formula gradient */
484 #define GTF_D_C 40 /* blanking formula offset */
485 #define GTF_D_K 128 /* blanking formula scaling factor */
486 #define GTF_D_J 20 /* blanking formula scaling factor */
487 #define GTF_D_C_PRIME ((((GTF_D_C - GTF_D_J) * GTF_D_K) / 256) + GTF_D_J)
488 #define GTF_D_M_PRIME ((GTF_D_K * GTF_D_M) / 256)
489
490 /* Secondary */
491 #define GTF_S_M 3600 /* blanking formula gradient */
492 #define GTF_S_C 40 /* blanking formula offset */
493 #define GTF_S_K 128 /* blanking formula scaling factor */
494 #define GTF_S_J 35 /* blanking formula scaling factor */
495 #define GTF_S_C_PRIME ((((GTF_S_C - GTF_S_J) * GTF_S_K) / 256) + GTF_S_J)
496 #define GTF_S_M_PRIME ((GTF_S_K * GTF_S_M) / 256)
497
498 /** v4l2_detect_gtf - detect if the given timings follow the GTF standard
499 * @frame_height - the total height of the frame (including blanking) in lines.
500 * @hfreq - the horizontal frequency in Hz.
501 * @vsync - the height of the vertical sync in lines.
502 * @polarities - the horizontal and vertical polarities (same as struct
503 * v4l2_bt_timings polarities).
504 * @aspect - preferred aspect ratio. GTF has no method of determining the
505 * aspect ratio in order to derive the image width from the
506 * image height, so it has to be passed explicitly. Usually
507 * the native screen aspect ratio is used for this. If it
508 * is not filled in correctly, then 16:9 will be assumed.
509 * @fmt - the resulting timings.
510 *
511 * This function will attempt to detect if the given values correspond to a
512 * valid GTF format. If so, then it will return true, and fmt will be filled
513 * in with the found GTF timings.
514 */
515 bool v4l2_detect_gtf(unsigned frame_height,
516 unsigned hfreq,
517 unsigned vsync,
518 u32 polarities,
519 struct v4l2_fract aspect,
520 struct v4l2_dv_timings *fmt)
521 {
522 int pix_clk;
523 int v_fp, v_bp, h_fp, hsync;
524 int frame_width, image_height, image_width;
525 bool default_gtf;
526 int h_blank;
527
528 if (vsync != 3)
529 return false;
530
531 if (polarities == V4L2_DV_VSYNC_POS_POL)
532 default_gtf = true;
533 else if (polarities == V4L2_DV_HSYNC_POS_POL)
534 default_gtf = false;
535 else
536 return false;
537
538 if (hfreq == 0)
539 return false;
540
541 /* Vertical */
542 v_fp = GTF_V_FP;
543
544 v_bp = (GTF_MIN_VSYNC_BP * hfreq + 500000) / 1000000 - vsync;
545 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
546
547 if (image_height < 0)
548 return false;
549
550 if (aspect.numerator == 0 || aspect.denominator == 0) {
551 aspect.numerator = 16;
552 aspect.denominator = 9;
553 }
554 image_width = ((image_height * aspect.numerator) / aspect.denominator);
555 image_width = (image_width + GTF_CELL_GRAN/2) & ~(GTF_CELL_GRAN - 1);
556
557 /* Horizontal */
558 if (default_gtf) {
559 u64 num;
560 u32 den;
561
562 num = ((image_width * GTF_D_C_PRIME * (u64)hfreq) -
563 ((u64)image_width * GTF_D_M_PRIME * 1000));
564 den = hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000;
565 h_blank = div_u64((num + (den >> 1)), den);
566 } else {
567 u64 num;
568 u32 den;
569
570 num = ((image_width * GTF_S_C_PRIME * (u64)hfreq) -
571 ((u64)image_width * GTF_S_M_PRIME * 1000));
572 den = hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000;
573 h_blank = div_u64((num + (den >> 1)), den);
574 }
575
576 h_blank = ((h_blank + GTF_CELL_GRAN) / (2 * GTF_CELL_GRAN)) *
577 (2 * GTF_CELL_GRAN);
578 frame_width = image_width + h_blank;
579
580 pix_clk = (image_width + h_blank) * hfreq;
581 pix_clk = pix_clk / GTF_PXL_CLK_GRAN * GTF_PXL_CLK_GRAN;
582
583 hsync = (frame_width * 8 + 50) / 100;
584 hsync = ((hsync + GTF_CELL_GRAN / 2) / GTF_CELL_GRAN) * GTF_CELL_GRAN;
585
586 h_fp = h_blank / 2 - hsync;
587
588 fmt->type = V4L2_DV_BT_656_1120;
589 fmt->bt.polarities = polarities;
590 fmt->bt.width = image_width;
591 fmt->bt.height = image_height;
592 fmt->bt.hfrontporch = h_fp;
593 fmt->bt.vfrontporch = v_fp;
594 fmt->bt.hsync = hsync;
595 fmt->bt.vsync = vsync;
596 fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
597 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
598 fmt->bt.pixelclock = pix_clk;
599 fmt->bt.standards = V4L2_DV_BT_STD_GTF;
600 if (!default_gtf)
601 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
602 return true;
603 }
604 EXPORT_SYMBOL_GPL(v4l2_detect_gtf);
605
606 /** v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes
607 * 0x15 and 0x16 from the EDID.
608 * @hor_landscape - byte 0x15 from the EDID.
609 * @vert_portrait - byte 0x16 from the EDID.
610 *
611 * Determines the aspect ratio from the EDID.
612 * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2:
613 * "Horizontal and Vertical Screen Size or Aspect Ratio"
614 */
615 struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait)
616 {
617 struct v4l2_fract aspect = { 16, 9 };
618 u32 tmp;
619 u8 ratio;
620
621 /* Nothing filled in, fallback to 16:9 */
622 if (!hor_landscape && !vert_portrait)
623 return aspect;
624 /* Both filled in, so they are interpreted as the screen size in cm */
625 if (hor_landscape && vert_portrait) {
626 aspect.numerator = hor_landscape;
627 aspect.denominator = vert_portrait;
628 return aspect;
629 }
630 /* Only one is filled in, so interpret them as a ratio:
631 (val + 99) / 100 */
632 ratio = hor_landscape | vert_portrait;
633 /* Change some rounded values into the exact aspect ratio */
634 if (ratio == 79) {
635 aspect.numerator = 16;
636 aspect.denominator = 9;
637 } else if (ratio == 34) {
638 aspect.numerator = 4;
639 aspect.denominator = 3;
640 } else if (ratio == 68) {
641 aspect.numerator = 15;
642 aspect.denominator = 9;
643 } else {
644 aspect.numerator = hor_landscape + 99;
645 aspect.denominator = 100;
646 }
647 if (hor_landscape)
648 return aspect;
649 /* The aspect ratio is for portrait, so swap numerator and denominator */
650 tmp = aspect.denominator;
651 aspect.denominator = aspect.numerator;
652 aspect.numerator = tmp;
653 return aspect;
654 }
655 EXPORT_SYMBOL_GPL(v4l2_calc_aspect_ratio);
Linux kernel - Deliverables
This page took 0.04326 seconds and 4 git commands to generate.