xref: /openbmc/linux/drivers/gpu/drm/drm_edid.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
1 /*
2  * Copyright (c) 2006 Luc Verhaegen (quirks list)
3  * Copyright (c) 2007-2008 Intel Corporation
4  *   Jesse Barnes <jesse.barnes@intel.com>
5  *
6  * DDC probing routines (drm_ddc_read & drm_do_probe_ddc_edid) originally from
7  * FB layer.
8  *   Copyright (C) 2006 Dennis Munsie <dmunsie@cecropia.com>
9  *
10  * Permission is hereby granted, free of charge, to any person obtaining a
11  * copy of this software and associated documentation files (the "Software"),
12  * to deal in the Software without restriction, including without limitation
13  * the rights to use, copy, modify, merge, publish, distribute, sub license,
14  * and/or sell copies of the Software, and to permit persons to whom the
15  * Software is furnished to do so, subject to the following conditions:
16  *
17  * The above copyright notice and this permission notice (including the
18  * next paragraph) shall be included in all copies or substantial portions
19  * of the Software.
20  *
21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
22  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
23  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
24  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
25  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
26  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
27  * DEALINGS IN THE SOFTWARE.
28  */
29 #include <linux/kernel.h>
30 #include <linux/i2c.h>
31 #include <linux/i2c-algo-bit.h>
32 #include "drmP.h"
33 #include "drm_edid.h"
34 
35 /*
36  * TODO:
37  *   - support EDID 1.4 (incl. CE blocks)
38  */
39 
40 /*
41  * EDID blocks out in the wild have a variety of bugs, try to collect
42  * them here (note that userspace may work around broken monitors first,
43  * but fixes should make their way here so that the kernel "just works"
44  * on as many displays as possible).
45  */
46 
47 /* First detailed mode wrong, use largest 60Hz mode */
48 #define EDID_QUIRK_PREFER_LARGE_60		(1 << 0)
49 /* Reported 135MHz pixel clock is too high, needs adjustment */
50 #define EDID_QUIRK_135_CLOCK_TOO_HIGH		(1 << 1)
51 /* Prefer the largest mode at 75 Hz */
52 #define EDID_QUIRK_PREFER_LARGE_75		(1 << 2)
53 /* Detail timing is in cm not mm */
54 #define EDID_QUIRK_DETAILED_IN_CM		(1 << 3)
55 /* Detailed timing descriptors have bogus size values, so just take the
56  * maximum size and use that.
57  */
58 #define EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE	(1 << 4)
59 /* Monitor forgot to set the first detailed is preferred bit. */
60 #define EDID_QUIRK_FIRST_DETAILED_PREFERRED	(1 << 5)
61 /* use +hsync +vsync for detailed mode */
62 #define EDID_QUIRK_DETAILED_SYNC_PP		(1 << 6)
63 
64 static struct edid_quirk {
65 	char *vendor;
66 	int product_id;
67 	u32 quirks;
68 } edid_quirk_list[] = {
69 	/* Acer AL1706 */
70 	{ "ACR", 44358, EDID_QUIRK_PREFER_LARGE_60 },
71 	/* Acer F51 */
72 	{ "API", 0x7602, EDID_QUIRK_PREFER_LARGE_60 },
73 	/* Unknown Acer */
74 	{ "ACR", 2423, EDID_QUIRK_FIRST_DETAILED_PREFERRED },
75 
76 	/* Belinea 10 15 55 */
77 	{ "MAX", 1516, EDID_QUIRK_PREFER_LARGE_60 },
78 	{ "MAX", 0x77e, EDID_QUIRK_PREFER_LARGE_60 },
79 
80 	/* Envision Peripherals, Inc. EN-7100e */
81 	{ "EPI", 59264, EDID_QUIRK_135_CLOCK_TOO_HIGH },
82 
83 	/* Funai Electronics PM36B */
84 	{ "FCM", 13600, EDID_QUIRK_PREFER_LARGE_75 |
85 	  EDID_QUIRK_DETAILED_IN_CM },
86 
87 	/* LG Philips LCD LP154W01-A5 */
88 	{ "LPL", 0, EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE },
89 	{ "LPL", 0x2a00, EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE },
90 
91 	/* Philips 107p5 CRT */
92 	{ "PHL", 57364, EDID_QUIRK_FIRST_DETAILED_PREFERRED },
93 
94 	/* Proview AY765C */
95 	{ "PTS", 765, EDID_QUIRK_FIRST_DETAILED_PREFERRED },
96 
97 	/* Samsung SyncMaster 205BW.  Note: irony */
98 	{ "SAM", 541, EDID_QUIRK_DETAILED_SYNC_PP },
99 	/* Samsung SyncMaster 22[5-6]BW */
100 	{ "SAM", 596, EDID_QUIRK_PREFER_LARGE_60 },
101 	{ "SAM", 638, EDID_QUIRK_PREFER_LARGE_60 },
102 };
103 
104 
105 /* Valid EDID header has these bytes */
106 static u8 edid_header[] = { 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00 };
107 
108 /**
109  * edid_is_valid - sanity check EDID data
110  * @edid: EDID data
111  *
112  * Sanity check the EDID block by looking at the header, the version number
113  * and the checksum.  Return 0 if the EDID doesn't check out, or 1 if it's
114  * valid.
115  */
116 static bool edid_is_valid(struct edid *edid)
117 {
118 	int i;
119 	u8 csum = 0;
120 	u8 *raw_edid = (u8 *)edid;
121 
122 	if (memcmp(edid->header, edid_header, sizeof(edid_header)))
123 		goto bad;
124 	if (edid->version != 1) {
125 		DRM_ERROR("EDID has major version %d, instead of 1\n", edid->version);
126 		goto bad;
127 	}
128 	if (edid->revision > 3) {
129 		DRM_ERROR("EDID has minor version %d, which is not between 0-3\n", edid->revision);
130 		goto bad;
131 	}
132 
133 	for (i = 0; i < EDID_LENGTH; i++)
134 		csum += raw_edid[i];
135 	if (csum) {
136 		DRM_ERROR("EDID checksum is invalid, remainder is %d\n", csum);
137 		goto bad;
138 	}
139 
140 	return 1;
141 
142 bad:
143 	if (raw_edid) {
144 		DRM_ERROR("Raw EDID:\n");
145 		print_hex_dump_bytes(KERN_ERR, DUMP_PREFIX_NONE, raw_edid, EDID_LENGTH);
146 		printk("\n");
147 	}
148 	return 0;
149 }
150 
151 /**
152  * edid_vendor - match a string against EDID's obfuscated vendor field
153  * @edid: EDID to match
154  * @vendor: vendor string
155  *
156  * Returns true if @vendor is in @edid, false otherwise
157  */
158 static bool edid_vendor(struct edid *edid, char *vendor)
159 {
160 	char edid_vendor[3];
161 
162 	edid_vendor[0] = ((edid->mfg_id[0] & 0x7c) >> 2) + '@';
163 	edid_vendor[1] = (((edid->mfg_id[0] & 0x3) << 3) |
164 			  ((edid->mfg_id[1] & 0xe0) >> 5)) + '@';
165 	edid_vendor[2] = (edid->mfg_id[2] & 0x1f) + '@';
166 
167 	return !strncmp(edid_vendor, vendor, 3);
168 }
169 
170 /**
171  * edid_get_quirks - return quirk flags for a given EDID
172  * @edid: EDID to process
173  *
174  * This tells subsequent routines what fixes they need to apply.
175  */
176 static u32 edid_get_quirks(struct edid *edid)
177 {
178 	struct edid_quirk *quirk;
179 	int i;
180 
181 	for (i = 0; i < ARRAY_SIZE(edid_quirk_list); i++) {
182 		quirk = &edid_quirk_list[i];
183 
184 		if (edid_vendor(edid, quirk->vendor) &&
185 		    (EDID_PRODUCT_ID(edid) == quirk->product_id))
186 			return quirk->quirks;
187 	}
188 
189 	return 0;
190 }
191 
192 #define MODE_SIZE(m) ((m)->hdisplay * (m)->vdisplay)
193 #define MODE_REFRESH_DIFF(m,r) (abs((m)->vrefresh - target_refresh))
194 
195 
196 /**
197  * edid_fixup_preferred - set preferred modes based on quirk list
198  * @connector: has mode list to fix up
199  * @quirks: quirks list
200  *
201  * Walk the mode list for @connector, clearing the preferred status
202  * on existing modes and setting it anew for the right mode ala @quirks.
203  */
204 static void edid_fixup_preferred(struct drm_connector *connector,
205 				 u32 quirks)
206 {
207 	struct drm_display_mode *t, *cur_mode, *preferred_mode;
208 	int target_refresh = 0;
209 
210 	if (list_empty(&connector->probed_modes))
211 		return;
212 
213 	if (quirks & EDID_QUIRK_PREFER_LARGE_60)
214 		target_refresh = 60;
215 	if (quirks & EDID_QUIRK_PREFER_LARGE_75)
216 		target_refresh = 75;
217 
218 	preferred_mode = list_first_entry(&connector->probed_modes,
219 					  struct drm_display_mode, head);
220 
221 	list_for_each_entry_safe(cur_mode, t, &connector->probed_modes, head) {
222 		cur_mode->type &= ~DRM_MODE_TYPE_PREFERRED;
223 
224 		if (cur_mode == preferred_mode)
225 			continue;
226 
227 		/* Largest mode is preferred */
228 		if (MODE_SIZE(cur_mode) > MODE_SIZE(preferred_mode))
229 			preferred_mode = cur_mode;
230 
231 		/* At a given size, try to get closest to target refresh */
232 		if ((MODE_SIZE(cur_mode) == MODE_SIZE(preferred_mode)) &&
233 		    MODE_REFRESH_DIFF(cur_mode, target_refresh) <
234 		    MODE_REFRESH_DIFF(preferred_mode, target_refresh)) {
235 			preferred_mode = cur_mode;
236 		}
237 	}
238 
239 	preferred_mode->type |= DRM_MODE_TYPE_PREFERRED;
240 }
241 
242 /**
243  * drm_mode_std - convert standard mode info (width, height, refresh) into mode
244  * @t: standard timing params
245  *
246  * Take the standard timing params (in this case width, aspect, and refresh)
247  * and convert them into a real mode using CVT.
248  *
249  * Punts for now, but should eventually use the FB layer's CVT based mode
250  * generation code.
251  */
252 struct drm_display_mode *drm_mode_std(struct drm_device *dev,
253 				      struct std_timing *t)
254 {
255 	struct drm_display_mode *mode;
256 	int hsize = t->hsize * 8 + 248, vsize;
257 
258 	mode = drm_mode_create(dev);
259 	if (!mode)
260 		return NULL;
261 
262 	if (t->aspect_ratio == 0)
263 		vsize = (hsize * 10) / 16;
264 	else if (t->aspect_ratio == 1)
265 		vsize = (hsize * 3) / 4;
266 	else if (t->aspect_ratio == 2)
267 		vsize = (hsize * 4) / 5;
268 	else
269 		vsize = (hsize * 9) / 16;
270 
271 	drm_mode_set_name(mode);
272 
273 	return mode;
274 }
275 
276 /**
277  * drm_mode_detailed - create a new mode from an EDID detailed timing section
278  * @dev: DRM device (needed to create new mode)
279  * @edid: EDID block
280  * @timing: EDID detailed timing info
281  * @quirks: quirks to apply
282  *
283  * An EDID detailed timing block contains enough info for us to create and
284  * return a new struct drm_display_mode.
285  */
286 static struct drm_display_mode *drm_mode_detailed(struct drm_device *dev,
287 						  struct edid *edid,
288 						  struct detailed_timing *timing,
289 						  u32 quirks)
290 {
291 	struct drm_display_mode *mode;
292 	struct detailed_pixel_timing *pt = &timing->data.pixel_data;
293 
294 	if (pt->stereo) {
295 		printk(KERN_WARNING "stereo mode not supported\n");
296 		return NULL;
297 	}
298 	if (!pt->separate_sync) {
299 		printk(KERN_WARNING "integrated sync not supported\n");
300 		return NULL;
301 	}
302 
303 	mode = drm_mode_create(dev);
304 	if (!mode)
305 		return NULL;
306 
307 	mode->type = DRM_MODE_TYPE_DRIVER;
308 
309 	if (quirks & EDID_QUIRK_135_CLOCK_TOO_HIGH)
310 		timing->pixel_clock = 1088;
311 
312 	mode->clock = timing->pixel_clock * 10;
313 
314 	mode->hdisplay = (pt->hactive_hi << 8) | pt->hactive_lo;
315 	mode->hsync_start = mode->hdisplay + ((pt->hsync_offset_hi << 8) |
316 					      pt->hsync_offset_lo);
317 	mode->hsync_end = mode->hsync_start +
318 		((pt->hsync_pulse_width_hi << 8) |
319 		 pt->hsync_pulse_width_lo);
320 	mode->htotal = mode->hdisplay + ((pt->hblank_hi << 8) | pt->hblank_lo);
321 
322 	mode->vdisplay = (pt->vactive_hi << 8) | pt->vactive_lo;
323 	mode->vsync_start = mode->vdisplay + ((pt->vsync_offset_hi << 4) |
324 					      pt->vsync_offset_lo);
325 	mode->vsync_end = mode->vsync_start +
326 		((pt->vsync_pulse_width_hi << 4) |
327 		 pt->vsync_pulse_width_lo);
328 	mode->vtotal = mode->vdisplay + ((pt->vblank_hi << 8) | pt->vblank_lo);
329 
330 	drm_mode_set_name(mode);
331 
332 	if (pt->interlaced)
333 		mode->flags |= DRM_MODE_FLAG_INTERLACE;
334 
335 	if (quirks & EDID_QUIRK_DETAILED_SYNC_PP) {
336 		pt->hsync_positive = 1;
337 		pt->vsync_positive = 1;
338 	}
339 
340 	mode->flags |= pt->hsync_positive ? DRM_MODE_FLAG_PHSYNC : DRM_MODE_FLAG_NHSYNC;
341 	mode->flags |= pt->vsync_positive ? DRM_MODE_FLAG_PVSYNC : DRM_MODE_FLAG_NVSYNC;
342 
343 	mode->width_mm = pt->width_mm_lo | (pt->width_mm_hi << 8);
344 	mode->height_mm = pt->height_mm_lo | (pt->height_mm_hi << 8);
345 
346 	if (quirks & EDID_QUIRK_DETAILED_IN_CM) {
347 		mode->width_mm *= 10;
348 		mode->height_mm *= 10;
349 	}
350 
351 	if (quirks & EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE) {
352 		mode->width_mm = edid->width_cm * 10;
353 		mode->height_mm = edid->height_cm * 10;
354 	}
355 
356 	return mode;
357 }
358 
359 /*
360  * Detailed mode info for the EDID "established modes" data to use.
361  */
362 static struct drm_display_mode edid_est_modes[] = {
363 	{ DRM_MODE("800x600", DRM_MODE_TYPE_DRIVER, 40000, 800, 840,
364 		   968, 1056, 0, 600, 601, 605, 628, 0,
365 		   DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC) }, /* 800x600@60Hz */
366 	{ DRM_MODE("800x600", DRM_MODE_TYPE_DRIVER, 36000, 800, 824,
367 		   896, 1024, 0, 600, 601, 603,  625, 0,
368 		   DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC) }, /* 800x600@56Hz */
369 	{ DRM_MODE("640x480", DRM_MODE_TYPE_DRIVER, 31500, 640, 656,
370 		   720, 840, 0, 480, 481, 484, 500, 0,
371 		   DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC) }, /* 640x480@75Hz */
372 	{ DRM_MODE("640x480", DRM_MODE_TYPE_DRIVER, 31500, 640, 664,
373 		   704,  832, 0, 480, 489, 491, 520, 0,
374 		   DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC) }, /* 640x480@72Hz */
375 	{ DRM_MODE("640x480", DRM_MODE_TYPE_DRIVER, 30240, 640, 704,
376 		   768,  864, 0, 480, 483, 486, 525, 0,
377 		   DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC) }, /* 640x480@67Hz */
378 	{ DRM_MODE("640x480", DRM_MODE_TYPE_DRIVER, 25200, 640, 656,
379 		   752, 800, 0, 480, 490, 492, 525, 0,
380 		   DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC) }, /* 640x480@60Hz */
381 	{ DRM_MODE("720x400", DRM_MODE_TYPE_DRIVER, 35500, 720, 738,
382 		   846, 900, 0, 400, 421, 423,  449, 0,
383 		   DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC) }, /* 720x400@88Hz */
384 	{ DRM_MODE("720x400", DRM_MODE_TYPE_DRIVER, 28320, 720, 738,
385 		   846,  900, 0, 400, 412, 414, 449, 0,
386 		   DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_PVSYNC) }, /* 720x400@70Hz */
387 	{ DRM_MODE("1280x1024", DRM_MODE_TYPE_DRIVER, 135000, 1280, 1296,
388 		   1440, 1688, 0, 1024, 1025, 1028, 1066, 0,
389 		   DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC) }, /* 1280x1024@75Hz */
390 	{ DRM_MODE("1024x768", DRM_MODE_TYPE_DRIVER, 78800, 1024, 1040,
391 		   1136, 1312, 0,  768, 769, 772, 800, 0,
392 		   DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC) }, /* 1024x768@75Hz */
393 	{ DRM_MODE("1024x768", DRM_MODE_TYPE_DRIVER, 75000, 1024, 1048,
394 		   1184, 1328, 0,  768, 771, 777, 806, 0,
395 		   DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC) }, /* 1024x768@70Hz */
396 	{ DRM_MODE("1024x768", DRM_MODE_TYPE_DRIVER, 65000, 1024, 1048,
397 		   1184, 1344, 0,  768, 771, 777, 806, 0,
398 		   DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC) }, /* 1024x768@60Hz */
399 	{ DRM_MODE("1024x768", DRM_MODE_TYPE_DRIVER,44900, 1024, 1032,
400 		   1208, 1264, 0, 768, 768, 776, 817, 0,
401 		   DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC | DRM_MODE_FLAG_INTERLACE) }, /* 1024x768@43Hz */
402 	{ DRM_MODE("832x624", DRM_MODE_TYPE_DRIVER, 57284, 832, 864,
403 		   928, 1152, 0, 624, 625, 628, 667, 0,
404 		   DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC) }, /* 832x624@75Hz */
405 	{ DRM_MODE("800x600", DRM_MODE_TYPE_DRIVER, 49500, 800, 816,
406 		   896, 1056, 0, 600, 601, 604,  625, 0,
407 		   DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC) }, /* 800x600@75Hz */
408 	{ DRM_MODE("800x600", DRM_MODE_TYPE_DRIVER, 50000, 800, 856,
409 		   976, 1040, 0, 600, 637, 643, 666, 0,
410 		   DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC) }, /* 800x600@72Hz */
411 	{ DRM_MODE("1152x864", DRM_MODE_TYPE_DRIVER, 108000, 1152, 1216,
412 		   1344, 1600, 0,  864, 865, 868, 900, 0,
413 		   DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC) }, /* 1152x864@75Hz */
414 };
415 
416 #define EDID_EST_TIMINGS 16
417 #define EDID_STD_TIMINGS 8
418 #define EDID_DETAILED_TIMINGS 4
419 
420 /**
421  * add_established_modes - get est. modes from EDID and add them
422  * @edid: EDID block to scan
423  *
424  * Each EDID block contains a bitmap of the supported "established modes" list
425  * (defined above).  Tease them out and add them to the global modes list.
426  */
427 static int add_established_modes(struct drm_connector *connector, struct edid *edid)
428 {
429 	struct drm_device *dev = connector->dev;
430 	unsigned long est_bits = edid->established_timings.t1 |
431 		(edid->established_timings.t2 << 8) |
432 		((edid->established_timings.mfg_rsvd & 0x80) << 9);
433 	int i, modes = 0;
434 
435 	for (i = 0; i <= EDID_EST_TIMINGS; i++)
436 		if (est_bits & (1<<i)) {
437 			struct drm_display_mode *newmode;
438 			newmode = drm_mode_duplicate(dev, &edid_est_modes[i]);
439 			if (newmode) {
440 				drm_mode_probed_add(connector, newmode);
441 				modes++;
442 			}
443 		}
444 
445 	return modes;
446 }
447 
448 /**
449  * add_standard_modes - get std. modes from EDID and add them
450  * @edid: EDID block to scan
451  *
452  * Standard modes can be calculated using the CVT standard.  Grab them from
453  * @edid, calculate them, and add them to the list.
454  */
455 static int add_standard_modes(struct drm_connector *connector, struct edid *edid)
456 {
457 	struct drm_device *dev = connector->dev;
458 	int i, modes = 0;
459 
460 	for (i = 0; i < EDID_STD_TIMINGS; i++) {
461 		struct std_timing *t = &edid->standard_timings[i];
462 		struct drm_display_mode *newmode;
463 
464 		/* If std timings bytes are 1, 1 it's empty */
465 		if (t->hsize == 1 && (t->aspect_ratio | t->vfreq) == 1)
466 			continue;
467 
468 		newmode = drm_mode_std(dev, &edid->standard_timings[i]);
469 		if (newmode) {
470 			drm_mode_probed_add(connector, newmode);
471 			modes++;
472 		}
473 	}
474 
475 	return modes;
476 }
477 
478 /**
479  * add_detailed_modes - get detailed mode info from EDID data
480  * @connector: attached connector
481  * @edid: EDID block to scan
482  * @quirks: quirks to apply
483  *
484  * Some of the detailed timing sections may contain mode information.  Grab
485  * it and add it to the list.
486  */
487 static int add_detailed_info(struct drm_connector *connector,
488 			     struct edid *edid, u32 quirks)
489 {
490 	struct drm_device *dev = connector->dev;
491 	int i, j, modes = 0;
492 
493 	for (i = 0; i < EDID_DETAILED_TIMINGS; i++) {
494 		struct detailed_timing *timing = &edid->detailed_timings[i];
495 		struct detailed_non_pixel *data = &timing->data.other_data;
496 		struct drm_display_mode *newmode;
497 
498 		/* EDID up to and including 1.2 may put monitor info here */
499 		if (edid->version == 1 && edid->revision < 3)
500 			continue;
501 
502 		/* Detailed mode timing */
503 		if (timing->pixel_clock) {
504 			newmode = drm_mode_detailed(dev, edid, timing, quirks);
505 			if (!newmode)
506 				continue;
507 
508 			/* First detailed mode is preferred */
509 			if (i == 0 && edid->preferred_timing)
510 				newmode->type |= DRM_MODE_TYPE_PREFERRED;
511 			drm_mode_probed_add(connector, newmode);
512 
513 			modes++;
514 			continue;
515 		}
516 
517 		/* Other timing or info */
518 		switch (data->type) {
519 		case EDID_DETAIL_MONITOR_SERIAL:
520 			break;
521 		case EDID_DETAIL_MONITOR_STRING:
522 			break;
523 		case EDID_DETAIL_MONITOR_RANGE:
524 			/* Get monitor range data */
525 			break;
526 		case EDID_DETAIL_MONITOR_NAME:
527 			break;
528 		case EDID_DETAIL_MONITOR_CPDATA:
529 			break;
530 		case EDID_DETAIL_STD_MODES:
531 			/* Five modes per detailed section */
532 			for (j = 0; j < 5; i++) {
533 				struct std_timing *std;
534 				struct drm_display_mode *newmode;
535 
536 				std = &data->data.timings[j];
537 				newmode = drm_mode_std(dev, std);
538 				if (newmode) {
539 					drm_mode_probed_add(connector, newmode);
540 					modes++;
541 				}
542 			}
543 			break;
544 		default:
545 			break;
546 		}
547 	}
548 
549 	return modes;
550 }
551 
552 #define DDC_ADDR 0x50
553 /**
554  * Get EDID information via I2C.
555  *
556  * \param adapter : i2c device adaptor
557  * \param buf     : EDID data buffer to be filled
558  * \param len     : EDID data buffer length
559  * \return 0 on success or -1 on failure.
560  *
561  * Try to fetch EDID information by calling i2c driver function.
562  */
563 int drm_do_probe_ddc_edid(struct i2c_adapter *adapter,
564 			  unsigned char *buf, int len)
565 {
566 	unsigned char start = 0x0;
567 	struct i2c_msg msgs[] = {
568 		{
569 			.addr	= DDC_ADDR,
570 			.flags	= 0,
571 			.len	= 1,
572 			.buf	= &start,
573 		}, {
574 			.addr	= DDC_ADDR,
575 			.flags	= I2C_M_RD,
576 			.len	= len,
577 			.buf	= buf,
578 		}
579 	};
580 
581 	if (i2c_transfer(adapter, msgs, 2) == 2)
582 		return 0;
583 
584 	dev_info(&adapter->dev, "unable to read EDID block.\n");
585 	return -1;
586 }
587 EXPORT_SYMBOL(drm_do_probe_ddc_edid);
588 
589 /**
590  * Get EDID information.
591  *
592  * \param adapter : i2c device adaptor.
593  * \param buf     : EDID data buffer to be filled
594  * \param len     : EDID data buffer length
595  * \return 0 on success or -1 on failure.
596  *
597  * Initialize DDC, then fetch EDID information
598  * by calling drm_do_probe_ddc_edid function.
599  */
600 static int drm_ddc_read(struct i2c_adapter *adapter,
601 			unsigned char *buf, int len)
602 {
603 	struct i2c_algo_bit_data *algo_data = adapter->algo_data;
604 	int i, j;
605 	int ret = -1;
606 
607 	algo_data->setscl(algo_data->data, 1);
608 
609 	for (i = 0; i < 1; i++) {
610 		/* For some old monitors we need the
611 		 * following process to initialize/stop DDC
612 		 */
613 		algo_data->setsda(algo_data->data, 1);
614 		msleep(13);
615 
616 		algo_data->setscl(algo_data->data, 1);
617 		for (j = 0; j < 5; j++) {
618 			msleep(10);
619 			if (algo_data->getscl(algo_data->data))
620 				break;
621 		}
622 		if (j == 5)
623 			continue;
624 
625 		algo_data->setsda(algo_data->data, 0);
626 		msleep(15);
627 		algo_data->setscl(algo_data->data, 0);
628 		msleep(15);
629 		algo_data->setsda(algo_data->data, 1);
630 		msleep(15);
631 
632 		/* Do the real work */
633 		ret = drm_do_probe_ddc_edid(adapter, buf, len);
634 		algo_data->setsda(algo_data->data, 0);
635 		algo_data->setscl(algo_data->data, 0);
636 		msleep(15);
637 
638 		algo_data->setscl(algo_data->data, 1);
639 		for (j = 0; j < 10; j++) {
640 			msleep(10);
641 			if (algo_data->getscl(algo_data->data))
642 				break;
643 		}
644 
645 		algo_data->setsda(algo_data->data, 1);
646 		msleep(15);
647 		algo_data->setscl(algo_data->data, 0);
648 		algo_data->setsda(algo_data->data, 0);
649 		if (ret == 0)
650 			break;
651 	}
652 	/* Release the DDC lines when done or the Apple Cinema HD display
653 	 * will switch off
654 	 */
655 	algo_data->setsda(algo_data->data, 1);
656 	algo_data->setscl(algo_data->data, 1);
657 
658 	return ret;
659 }
660 
661 static int drm_ddc_read_edid(struct drm_connector *connector,
662 			     struct i2c_adapter *adapter,
663 			     char *buf, int len)
664 {
665 	int ret;
666 
667 	ret = drm_ddc_read(adapter, buf, len);
668 	if (ret != 0) {
669 		dev_info(&connector->dev->pdev->dev, "%s: no EDID data\n",
670 			 drm_get_connector_name(connector));
671 		goto end;
672 	}
673 	if (!edid_is_valid((struct edid *)buf)) {
674 		dev_warn(&connector->dev->pdev->dev, "%s: EDID invalid.\n",
675 			 drm_get_connector_name(connector));
676 		ret = -1;
677 	}
678 end:
679 	return ret;
680 }
681 
682 #define MAX_EDID_EXT_NUM 4
683 /**
684  * drm_get_edid - get EDID data, if available
685  * @connector: connector we're probing
686  * @adapter: i2c adapter to use for DDC
687  *
688  * Poke the given connector's i2c channel to grab EDID data if possible.
689  *
690  * Return edid data or NULL if we couldn't find any.
691  */
692 struct edid *drm_get_edid(struct drm_connector *connector,
693 			  struct i2c_adapter *adapter)
694 {
695 	int ret;
696 	struct edid *edid;
697 
698 	edid = kmalloc(EDID_LENGTH * (MAX_EDID_EXT_NUM + 1),
699 		       GFP_KERNEL);
700 	if (edid == NULL) {
701 		dev_warn(&connector->dev->pdev->dev,
702 			 "Failed to allocate EDID\n");
703 		goto end;
704 	}
705 
706 	/* Read first EDID block */
707 	ret = drm_ddc_read_edid(connector, adapter,
708 				(unsigned char *)edid, EDID_LENGTH);
709 	if (ret != 0)
710 		goto clean_up;
711 
712 	/* There are EDID extensions to be read */
713 	if (edid->extensions != 0) {
714 		int edid_ext_num = edid->extensions;
715 
716 		if (edid_ext_num > MAX_EDID_EXT_NUM) {
717 			dev_warn(&connector->dev->pdev->dev,
718 				 "The number of extension(%d) is "
719 				 "over max (%d), actually read number (%d)\n",
720 				 edid_ext_num, MAX_EDID_EXT_NUM,
721 				 MAX_EDID_EXT_NUM);
722 			/* Reset EDID extension number to be read */
723 			edid_ext_num = MAX_EDID_EXT_NUM;
724 		}
725 		/* Read EDID including extensions too */
726 		ret = drm_ddc_read_edid(connector, adapter, (char *)edid,
727 					EDID_LENGTH * (edid_ext_num + 1));
728 		if (ret != 0)
729 			goto clean_up;
730 
731 	}
732 
733 	connector->display_info.raw_edid = (char *)edid;
734 	goto end;
735 
736 clean_up:
737 	kfree(edid);
738 	edid = NULL;
739 end:
740 	return edid;
741 
742 }
743 EXPORT_SYMBOL(drm_get_edid);
744 
745 #define HDMI_IDENTIFIER 0x000C03
746 #define VENDOR_BLOCK    0x03
747 /**
748  * drm_detect_hdmi_monitor - detect whether monitor is hdmi.
749  * @edid: monitor EDID information
750  *
751  * Parse the CEA extension according to CEA-861-B.
752  * Return true if HDMI, false if not or unknown.
753  */
754 bool drm_detect_hdmi_monitor(struct edid *edid)
755 {
756 	char *edid_ext = NULL;
757 	int i, hdmi_id, edid_ext_num;
758 	int start_offset, end_offset;
759 	bool is_hdmi = false;
760 
761 	/* No EDID or EDID extensions */
762 	if (edid == NULL || edid->extensions == 0)
763 		goto end;
764 
765 	/* Chose real EDID extension number */
766 	edid_ext_num = edid->extensions > MAX_EDID_EXT_NUM ?
767 		       MAX_EDID_EXT_NUM : edid->extensions;
768 
769 	/* Find CEA extension */
770 	for (i = 0; i < edid_ext_num; i++) {
771 		edid_ext = (char *)edid + EDID_LENGTH * (i + 1);
772 		/* This block is CEA extension */
773 		if (edid_ext[0] == 0x02)
774 			break;
775 	}
776 
777 	if (i == edid_ext_num)
778 		goto end;
779 
780 	/* Data block offset in CEA extension block */
781 	start_offset = 4;
782 	end_offset = edid_ext[2];
783 
784 	/*
785 	 * Because HDMI identifier is in Vendor Specific Block,
786 	 * search it from all data blocks of CEA extension.
787 	 */
788 	for (i = start_offset; i < end_offset;
789 		/* Increased by data block len */
790 		i += ((edid_ext[i] & 0x1f) + 1)) {
791 		/* Find vendor specific block */
792 		if ((edid_ext[i] >> 5) == VENDOR_BLOCK) {
793 			hdmi_id = edid_ext[i + 1] | (edid_ext[i + 2] << 8) |
794 				  edid_ext[i + 3] << 16;
795 			/* Find HDMI identifier */
796 			if (hdmi_id == HDMI_IDENTIFIER)
797 				is_hdmi = true;
798 			break;
799 		}
800 	}
801 
802 end:
803 	return is_hdmi;
804 }
805 EXPORT_SYMBOL(drm_detect_hdmi_monitor);
806 
807 /**
808  * drm_add_edid_modes - add modes from EDID data, if available
809  * @connector: connector we're probing
810  * @edid: edid data
811  *
812  * Add the specified modes to the connector's mode list.
813  *
814  * Return number of modes added or 0 if we couldn't find any.
815  */
816 int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
817 {
818 	int num_modes = 0;
819 	u32 quirks;
820 
821 	if (edid == NULL) {
822 		return 0;
823 	}
824 	if (!edid_is_valid(edid)) {
825 		dev_warn(&connector->dev->pdev->dev, "%s: EDID invalid.\n",
826 			 drm_get_connector_name(connector));
827 		return 0;
828 	}
829 
830 	quirks = edid_get_quirks(edid);
831 
832 	num_modes += add_established_modes(connector, edid);
833 	num_modes += add_standard_modes(connector, edid);
834 	num_modes += add_detailed_info(connector, edid, quirks);
835 
836 	if (quirks & (EDID_QUIRK_PREFER_LARGE_60 | EDID_QUIRK_PREFER_LARGE_75))
837 		edid_fixup_preferred(connector, quirks);
838 
839 	connector->display_info.serration_vsync = edid->serration_vsync;
840 	connector->display_info.sync_on_green = edid->sync_on_green;
841 	connector->display_info.composite_sync = edid->composite_sync;
842 	connector->display_info.separate_syncs = edid->separate_syncs;
843 	connector->display_info.blank_to_black = edid->blank_to_black;
844 	connector->display_info.video_level = edid->video_level;
845 	connector->display_info.digital = edid->digital;
846 	connector->display_info.width_mm = edid->width_cm * 10;
847 	connector->display_info.height_mm = edid->height_cm * 10;
848 	connector->display_info.gamma = edid->gamma;
849 	connector->display_info.gtf_supported = edid->default_gtf;
850 	connector->display_info.standard_color = edid->standard_color;
851 	connector->display_info.display_type = edid->display_type;
852 	connector->display_info.active_off_supported = edid->pm_active_off;
853 	connector->display_info.suspend_supported = edid->pm_suspend;
854 	connector->display_info.standby_supported = edid->pm_standby;
855 	connector->display_info.gamma = edid->gamma;
856 
857 	return num_modes;
858 }
859 EXPORT_SYMBOL(drm_add_edid_modes);
860