xref: /linux/drivers/gpu/drm/drm_modes.c (revision 27258e448eb301cf89e351df87aa8cb916653bf2)
1 /*
2  * The list_sort function is (presumably) licensed under the GPL (see the
3  * top level "COPYING" file for details).
4  *
5  * The remainder of this file is:
6  *
7  * Copyright © 1997-2003 by The XFree86 Project, Inc.
8  * Copyright © 2007 Dave Airlie
9  * Copyright © 2007-2008 Intel Corporation
10  *   Jesse Barnes <jesse.barnes@intel.com>
11  * Copyright 2005-2006 Luc Verhaegen
12  * Copyright (c) 2001, Andy Ritger  aritger@nvidia.com
13  *
14  * Permission is hereby granted, free of charge, to any person obtaining a
15  * copy of this software and associated documentation files (the "Software"),
16  * to deal in the Software without restriction, including without limitation
17  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
18  * and/or sell copies of the Software, and to permit persons to whom the
19  * Software is furnished to do so, subject to the following conditions:
20  *
21  * The above copyright notice and this permission notice shall be included in
22  * all copies or substantial portions of the Software.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
25  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
26  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
27  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
28  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
29  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
30  * OTHER DEALINGS IN THE SOFTWARE.
31  *
32  * Except as contained in this notice, the name of the copyright holder(s)
33  * and author(s) shall not be used in advertising or otherwise to promote
34  * the sale, use or other dealings in this Software without prior written
35  * authorization from the copyright holder(s) and author(s).
36  */
37 
38 #include <linux/list.h>
39 #include "drmP.h"
40 #include "drm.h"
41 #include "drm_crtc.h"
42 
43 /**
44  * drm_mode_debug_printmodeline - debug print a mode
45  * @dev: DRM device
46  * @mode: mode to print
47  *
48  * LOCKING:
49  * None.
50  *
51  * Describe @mode using DRM_DEBUG.
52  */
53 void drm_mode_debug_printmodeline(struct drm_display_mode *mode)
54 {
55 	DRM_DEBUG_KMS("Modeline %d:\"%s\" %d %d %d %d %d %d %d %d %d %d "
56 			"0x%x 0x%x\n",
57 		mode->base.id, mode->name, mode->vrefresh, mode->clock,
58 		mode->hdisplay, mode->hsync_start,
59 		mode->hsync_end, mode->htotal,
60 		mode->vdisplay, mode->vsync_start,
61 		mode->vsync_end, mode->vtotal, mode->type, mode->flags);
62 }
63 EXPORT_SYMBOL(drm_mode_debug_printmodeline);
64 
65 /**
66  * drm_cvt_mode -create a modeline based on CVT algorithm
67  * @dev: DRM device
68  * @hdisplay: hdisplay size
69  * @vdisplay: vdisplay size
70  * @vrefresh  : vrefresh rate
71  * @reduced : Whether the GTF calculation is simplified
72  * @interlaced:Whether the interlace is supported
73  *
74  * LOCKING:
75  * none.
76  *
77  * return the modeline based on CVT algorithm
78  *
79  * This function is called to generate the modeline based on CVT algorithm
80  * according to the hdisplay, vdisplay, vrefresh.
81  * It is based from the VESA(TM) Coordinated Video Timing Generator by
82  * Graham Loveridge April 9, 2003 available at
83  * http://www.vesa.org/public/CVT/CVTd6r1.xls
84  *
85  * And it is copied from xf86CVTmode in xserver/hw/xfree86/modes/xf86cvt.c.
86  * What I have done is to translate it by using integer calculation.
87  */
88 #define HV_FACTOR			1000
89 struct drm_display_mode *drm_cvt_mode(struct drm_device *dev, int hdisplay,
90 				      int vdisplay, int vrefresh,
91 				      bool reduced, bool interlaced)
92 {
93 	/* 1) top/bottom margin size (% of height) - default: 1.8, */
94 #define	CVT_MARGIN_PERCENTAGE		18
95 	/* 2) character cell horizontal granularity (pixels) - default 8 */
96 #define	CVT_H_GRANULARITY		8
97 	/* 3) Minimum vertical porch (lines) - default 3 */
98 #define	CVT_MIN_V_PORCH			3
99 	/* 4) Minimum number of vertical back porch lines - default 6 */
100 #define	CVT_MIN_V_BPORCH		6
101 	/* Pixel Clock step (kHz) */
102 #define CVT_CLOCK_STEP			250
103 	struct drm_display_mode *drm_mode;
104 	bool margins = false;
105 	unsigned int vfieldrate, hperiod;
106 	int hdisplay_rnd, hmargin, vdisplay_rnd, vmargin, vsync;
107 	int interlace;
108 
109 	/* allocate the drm_display_mode structure. If failure, we will
110 	 * return directly
111 	 */
112 	drm_mode = drm_mode_create(dev);
113 	if (!drm_mode)
114 		return NULL;
115 
116 	/* the CVT default refresh rate is 60Hz */
117 	if (!vrefresh)
118 		vrefresh = 60;
119 
120 	/* the required field fresh rate */
121 	if (interlaced)
122 		vfieldrate = vrefresh * 2;
123 	else
124 		vfieldrate = vrefresh;
125 
126 	/* horizontal pixels */
127 	hdisplay_rnd = hdisplay - (hdisplay % CVT_H_GRANULARITY);
128 
129 	/* determine the left&right borders */
130 	hmargin = 0;
131 	if (margins) {
132 		hmargin = hdisplay_rnd * CVT_MARGIN_PERCENTAGE / 1000;
133 		hmargin -= hmargin % CVT_H_GRANULARITY;
134 	}
135 	/* find the total active pixels */
136 	drm_mode->hdisplay = hdisplay_rnd + 2 * hmargin;
137 
138 	/* find the number of lines per field */
139 	if (interlaced)
140 		vdisplay_rnd = vdisplay / 2;
141 	else
142 		vdisplay_rnd = vdisplay;
143 
144 	/* find the top & bottom borders */
145 	vmargin = 0;
146 	if (margins)
147 		vmargin = vdisplay_rnd * CVT_MARGIN_PERCENTAGE / 1000;
148 
149 	drm_mode->vdisplay = vdisplay + 2 * vmargin;
150 
151 	/* Interlaced */
152 	if (interlaced)
153 		interlace = 1;
154 	else
155 		interlace = 0;
156 
157 	/* Determine VSync Width from aspect ratio */
158 	if (!(vdisplay % 3) && ((vdisplay * 4 / 3) == hdisplay))
159 		vsync = 4;
160 	else if (!(vdisplay % 9) && ((vdisplay * 16 / 9) == hdisplay))
161 		vsync = 5;
162 	else if (!(vdisplay % 10) && ((vdisplay * 16 / 10) == hdisplay))
163 		vsync = 6;
164 	else if (!(vdisplay % 4) && ((vdisplay * 5 / 4) == hdisplay))
165 		vsync = 7;
166 	else if (!(vdisplay % 9) && ((vdisplay * 15 / 9) == hdisplay))
167 		vsync = 7;
168 	else /* custom */
169 		vsync = 10;
170 
171 	if (!reduced) {
172 		/* simplify the GTF calculation */
173 		/* 4) Minimum time of vertical sync + back porch interval (µs)
174 		 * default 550.0
175 		 */
176 		int tmp1, tmp2;
177 #define CVT_MIN_VSYNC_BP	550
178 		/* 3) Nominal HSync width (% of line period) - default 8 */
179 #define CVT_HSYNC_PERCENTAGE	8
180 		unsigned int hblank_percentage;
181 		int vsyncandback_porch, vback_porch, hblank;
182 
183 		/* estimated the horizontal period */
184 		tmp1 = HV_FACTOR * 1000000  -
185 				CVT_MIN_VSYNC_BP * HV_FACTOR * vfieldrate;
186 		tmp2 = (vdisplay_rnd + 2 * vmargin + CVT_MIN_V_PORCH) * 2 +
187 				interlace;
188 		hperiod = tmp1 * 2 / (tmp2 * vfieldrate);
189 
190 		tmp1 = CVT_MIN_VSYNC_BP * HV_FACTOR / hperiod + 1;
191 		/* 9. Find number of lines in sync + backporch */
192 		if (tmp1 < (vsync + CVT_MIN_V_PORCH))
193 			vsyncandback_porch = vsync + CVT_MIN_V_PORCH;
194 		else
195 			vsyncandback_porch = tmp1;
196 		/* 10. Find number of lines in back porch */
197 		vback_porch = vsyncandback_porch - vsync;
198 		drm_mode->vtotal = vdisplay_rnd + 2 * vmargin +
199 				vsyncandback_porch + CVT_MIN_V_PORCH;
200 		/* 5) Definition of Horizontal blanking time limitation */
201 		/* Gradient (%/kHz) - default 600 */
202 #define CVT_M_FACTOR	600
203 		/* Offset (%) - default 40 */
204 #define CVT_C_FACTOR	40
205 		/* Blanking time scaling factor - default 128 */
206 #define CVT_K_FACTOR	128
207 		/* Scaling factor weighting - default 20 */
208 #define CVT_J_FACTOR	20
209 #define CVT_M_PRIME	(CVT_M_FACTOR * CVT_K_FACTOR / 256)
210 #define CVT_C_PRIME	((CVT_C_FACTOR - CVT_J_FACTOR) * CVT_K_FACTOR / 256 + \
211 			 CVT_J_FACTOR)
212 		/* 12. Find ideal blanking duty cycle from formula */
213 		hblank_percentage = CVT_C_PRIME * HV_FACTOR - CVT_M_PRIME *
214 					hperiod / 1000;
215 		/* 13. Blanking time */
216 		if (hblank_percentage < 20 * HV_FACTOR)
217 			hblank_percentage = 20 * HV_FACTOR;
218 		hblank = drm_mode->hdisplay * hblank_percentage /
219 			 (100 * HV_FACTOR - hblank_percentage);
220 		hblank -= hblank % (2 * CVT_H_GRANULARITY);
221 		/* 14. find the total pixes per line */
222 		drm_mode->htotal = drm_mode->hdisplay + hblank;
223 		drm_mode->hsync_end = drm_mode->hdisplay + hblank / 2;
224 		drm_mode->hsync_start = drm_mode->hsync_end -
225 			(drm_mode->htotal * CVT_HSYNC_PERCENTAGE) / 100;
226 		drm_mode->hsync_start += CVT_H_GRANULARITY -
227 			drm_mode->hsync_start % CVT_H_GRANULARITY;
228 		/* fill the Vsync values */
229 		drm_mode->vsync_start = drm_mode->vdisplay + CVT_MIN_V_PORCH;
230 		drm_mode->vsync_end = drm_mode->vsync_start + vsync;
231 	} else {
232 		/* Reduced blanking */
233 		/* Minimum vertical blanking interval time (µs)- default 460 */
234 #define CVT_RB_MIN_VBLANK	460
235 		/* Fixed number of clocks for horizontal sync */
236 #define CVT_RB_H_SYNC		32
237 		/* Fixed number of clocks for horizontal blanking */
238 #define CVT_RB_H_BLANK		160
239 		/* Fixed number of lines for vertical front porch - default 3*/
240 #define CVT_RB_VFPORCH		3
241 		int vbilines;
242 		int tmp1, tmp2;
243 		/* 8. Estimate Horizontal period. */
244 		tmp1 = HV_FACTOR * 1000000 -
245 			CVT_RB_MIN_VBLANK * HV_FACTOR * vfieldrate;
246 		tmp2 = vdisplay_rnd + 2 * vmargin;
247 		hperiod = tmp1 / (tmp2 * vfieldrate);
248 		/* 9. Find number of lines in vertical blanking */
249 		vbilines = CVT_RB_MIN_VBLANK * HV_FACTOR / hperiod + 1;
250 		/* 10. Check if vertical blanking is sufficient */
251 		if (vbilines < (CVT_RB_VFPORCH + vsync + CVT_MIN_V_BPORCH))
252 			vbilines = CVT_RB_VFPORCH + vsync + CVT_MIN_V_BPORCH;
253 		/* 11. Find total number of lines in vertical field */
254 		drm_mode->vtotal = vdisplay_rnd + 2 * vmargin + vbilines;
255 		/* 12. Find total number of pixels in a line */
256 		drm_mode->htotal = drm_mode->hdisplay + CVT_RB_H_BLANK;
257 		/* Fill in HSync values */
258 		drm_mode->hsync_end = drm_mode->hdisplay + CVT_RB_H_BLANK / 2;
259 		drm_mode->hsync_start = drm_mode->hsync_end = CVT_RB_H_SYNC;
260 	}
261 	/* 15/13. Find pixel clock frequency (kHz for xf86) */
262 	drm_mode->clock = drm_mode->htotal * HV_FACTOR * 1000 / hperiod;
263 	drm_mode->clock -= drm_mode->clock % CVT_CLOCK_STEP;
264 	/* 18/16. Find actual vertical frame frequency */
265 	/* ignore - just set the mode flag for interlaced */
266 	if (interlaced)
267 		drm_mode->vtotal *= 2;
268 	/* Fill the mode line name */
269 	drm_mode_set_name(drm_mode);
270 	if (reduced)
271 		drm_mode->flags |= (DRM_MODE_FLAG_PHSYNC |
272 					DRM_MODE_FLAG_NVSYNC);
273 	else
274 		drm_mode->flags |= (DRM_MODE_FLAG_PVSYNC |
275 					DRM_MODE_FLAG_NHSYNC);
276 	if (interlaced)
277 		drm_mode->flags |= DRM_MODE_FLAG_INTERLACE;
278 
279     return drm_mode;
280 }
281 EXPORT_SYMBOL(drm_cvt_mode);
282 
283 /**
284  * drm_gtf_mode - create the modeline based on GTF algorithm
285  *
286  * @dev		:drm device
287  * @hdisplay	:hdisplay size
288  * @vdisplay	:vdisplay size
289  * @vrefresh	:vrefresh rate.
290  * @interlaced	:whether the interlace is supported
291  * @margins	:whether the margin is supported
292  *
293  * LOCKING.
294  * none.
295  *
296  * return the modeline based on GTF algorithm
297  *
298  * This function is to create the modeline based on the GTF algorithm.
299  * Generalized Timing Formula is derived from:
300  *	GTF Spreadsheet by Andy Morrish (1/5/97)
301  *	available at http://www.vesa.org
302  *
303  * And it is copied from the file of xserver/hw/xfree86/modes/xf86gtf.c.
304  * What I have done is to translate it by using integer calculation.
305  * I also refer to the function of fb_get_mode in the file of
306  * drivers/video/fbmon.c
307  */
308 struct drm_display_mode *drm_gtf_mode(struct drm_device *dev, int hdisplay,
309 				      int vdisplay, int vrefresh,
310 				      bool interlaced, int margins)
311 {
312 	/* 1) top/bottom margin size (% of height) - default: 1.8, */
313 #define	GTF_MARGIN_PERCENTAGE		18
314 	/* 2) character cell horizontal granularity (pixels) - default 8 */
315 #define	GTF_CELL_GRAN			8
316 	/* 3) Minimum vertical porch (lines) - default 3 */
317 #define	GTF_MIN_V_PORCH			1
318 	/* width of vsync in lines */
319 #define V_SYNC_RQD			3
320 	/* width of hsync as % of total line */
321 #define H_SYNC_PERCENT			8
322 	/* min time of vsync + back porch (microsec) */
323 #define MIN_VSYNC_PLUS_BP		550
324 	/* blanking formula gradient */
325 #define GTF_M				600
326 	/* blanking formula offset */
327 #define GTF_C				40
328 	/* blanking formula scaling factor */
329 #define GTF_K				128
330 	/* blanking formula scaling factor */
331 #define GTF_J				20
332 	/* C' and M' are part of the Blanking Duty Cycle computation */
333 #define GTF_C_PRIME		(((GTF_C - GTF_J) * GTF_K / 256) + GTF_J)
334 #define GTF_M_PRIME		(GTF_K * GTF_M / 256)
335 	struct drm_display_mode *drm_mode;
336 	unsigned int hdisplay_rnd, vdisplay_rnd, vfieldrate_rqd;
337 	int top_margin, bottom_margin;
338 	int interlace;
339 	unsigned int hfreq_est;
340 	int vsync_plus_bp, vback_porch;
341 	unsigned int vtotal_lines, vfieldrate_est, hperiod;
342 	unsigned int vfield_rate, vframe_rate;
343 	int left_margin, right_margin;
344 	unsigned int total_active_pixels, ideal_duty_cycle;
345 	unsigned int hblank, total_pixels, pixel_freq;
346 	int hsync, hfront_porch, vodd_front_porch_lines;
347 	unsigned int tmp1, tmp2;
348 
349 	drm_mode = drm_mode_create(dev);
350 	if (!drm_mode)
351 		return NULL;
352 
353 	/* 1. In order to give correct results, the number of horizontal
354 	 * pixels requested is first processed to ensure that it is divisible
355 	 * by the character size, by rounding it to the nearest character
356 	 * cell boundary:
357 	 */
358 	hdisplay_rnd = (hdisplay + GTF_CELL_GRAN / 2) / GTF_CELL_GRAN;
359 	hdisplay_rnd = hdisplay_rnd * GTF_CELL_GRAN;
360 
361 	/* 2. If interlace is requested, the number of vertical lines assumed
362 	 * by the calculation must be halved, as the computation calculates
363 	 * the number of vertical lines per field.
364 	 */
365 	if (interlaced)
366 		vdisplay_rnd = vdisplay / 2;
367 	else
368 		vdisplay_rnd = vdisplay;
369 
370 	/* 3. Find the frame rate required: */
371 	if (interlaced)
372 		vfieldrate_rqd = vrefresh * 2;
373 	else
374 		vfieldrate_rqd = vrefresh;
375 
376 	/* 4. Find number of lines in Top margin: */
377 	top_margin = 0;
378 	if (margins)
379 		top_margin = (vdisplay_rnd * GTF_MARGIN_PERCENTAGE + 500) /
380 				1000;
381 	/* 5. Find number of lines in bottom margin: */
382 	bottom_margin = top_margin;
383 
384 	/* 6. If interlace is required, then set variable interlace: */
385 	if (interlaced)
386 		interlace = 1;
387 	else
388 		interlace = 0;
389 
390 	/* 7. Estimate the Horizontal frequency */
391 	{
392 		tmp1 = (1000000  - MIN_VSYNC_PLUS_BP * vfieldrate_rqd) / 500;
393 		tmp2 = (vdisplay_rnd + 2 * top_margin + GTF_MIN_V_PORCH) *
394 				2 + interlace;
395 		hfreq_est = (tmp2 * 1000 * vfieldrate_rqd) / tmp1;
396 	}
397 
398 	/* 8. Find the number of lines in V sync + back porch */
399 	/* [V SYNC+BP] = RINT(([MIN VSYNC+BP] * hfreq_est / 1000000)) */
400 	vsync_plus_bp = MIN_VSYNC_PLUS_BP * hfreq_est / 1000;
401 	vsync_plus_bp = (vsync_plus_bp + 500) / 1000;
402 	/*  9. Find the number of lines in V back porch alone: */
403 	vback_porch = vsync_plus_bp - V_SYNC_RQD;
404 	/*  10. Find the total number of lines in Vertical field period: */
405 	vtotal_lines = vdisplay_rnd + top_margin + bottom_margin +
406 			vsync_plus_bp + GTF_MIN_V_PORCH;
407 	/*  11. Estimate the Vertical field frequency: */
408 	vfieldrate_est = hfreq_est / vtotal_lines;
409 	/*  12. Find the actual horizontal period: */
410 	hperiod = 1000000 / (vfieldrate_rqd * vtotal_lines);
411 
412 	/*  13. Find the actual Vertical field frequency: */
413 	vfield_rate = hfreq_est / vtotal_lines;
414 	/*  14. Find the Vertical frame frequency: */
415 	if (interlaced)
416 		vframe_rate = vfield_rate / 2;
417 	else
418 		vframe_rate = vfield_rate;
419 	/*  15. Find number of pixels in left margin: */
420 	if (margins)
421 		left_margin = (hdisplay_rnd * GTF_MARGIN_PERCENTAGE + 500) /
422 				1000;
423 	else
424 		left_margin = 0;
425 
426 	/* 16.Find number of pixels in right margin: */
427 	right_margin = left_margin;
428 	/* 17.Find total number of active pixels in image and left and right */
429 	total_active_pixels = hdisplay_rnd + left_margin + right_margin;
430 	/* 18.Find the ideal blanking duty cycle from blanking duty cycle */
431 	ideal_duty_cycle = GTF_C_PRIME * 1000 -
432 				(GTF_M_PRIME * 1000000 / hfreq_est);
433 	/* 19.Find the number of pixels in the blanking time to the nearest
434 	 * double character cell: */
435 	hblank = total_active_pixels * ideal_duty_cycle /
436 			(100000 - ideal_duty_cycle);
437 	hblank = (hblank + GTF_CELL_GRAN) / (2 * GTF_CELL_GRAN);
438 	hblank = hblank * 2 * GTF_CELL_GRAN;
439 	/* 20.Find total number of pixels: */
440 	total_pixels = total_active_pixels + hblank;
441 	/* 21.Find pixel clock frequency: */
442 	pixel_freq = total_pixels * hfreq_est / 1000;
443 	/* Stage 1 computations are now complete; I should really pass
444 	 * the results to another function and do the Stage 2 computations,
445 	 * but I only need a few more values so I'll just append the
446 	 * computations here for now */
447 	/* 17. Find the number of pixels in the horizontal sync period: */
448 	hsync = H_SYNC_PERCENT * total_pixels / 100;
449 	hsync = (hsync + GTF_CELL_GRAN / 2) / GTF_CELL_GRAN;
450 	hsync = hsync * GTF_CELL_GRAN;
451 	/* 18. Find the number of pixels in horizontal front porch period */
452 	hfront_porch = hblank / 2 - hsync;
453 	/*  36. Find the number of lines in the odd front porch period: */
454 	vodd_front_porch_lines = GTF_MIN_V_PORCH ;
455 
456 	/* finally, pack the results in the mode struct */
457 	drm_mode->hdisplay = hdisplay_rnd;
458 	drm_mode->hsync_start = hdisplay_rnd + hfront_porch;
459 	drm_mode->hsync_end = drm_mode->hsync_start + hsync;
460 	drm_mode->htotal = total_pixels;
461 	drm_mode->vdisplay = vdisplay_rnd;
462 	drm_mode->vsync_start = vdisplay_rnd + vodd_front_porch_lines;
463 	drm_mode->vsync_end = drm_mode->vsync_start + V_SYNC_RQD;
464 	drm_mode->vtotal = vtotal_lines;
465 
466 	drm_mode->clock = pixel_freq;
467 
468 	drm_mode_set_name(drm_mode);
469 	drm_mode->flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_PVSYNC;
470 
471 	if (interlaced) {
472 		drm_mode->vtotal *= 2;
473 		drm_mode->flags |= DRM_MODE_FLAG_INTERLACE;
474 	}
475 
476 	return drm_mode;
477 }
478 EXPORT_SYMBOL(drm_gtf_mode);
479 /**
480  * drm_mode_set_name - set the name on a mode
481  * @mode: name will be set in this mode
482  *
483  * LOCKING:
484  * None.
485  *
486  * Set the name of @mode to a standard format.
487  */
488 void drm_mode_set_name(struct drm_display_mode *mode)
489 {
490 	snprintf(mode->name, DRM_DISPLAY_MODE_LEN, "%dx%d", mode->hdisplay,
491 		 mode->vdisplay);
492 }
493 EXPORT_SYMBOL(drm_mode_set_name);
494 
495 /**
496  * drm_mode_list_concat - move modes from one list to another
497  * @head: source list
498  * @new: dst list
499  *
500  * LOCKING:
501  * Caller must ensure both lists are locked.
502  *
503  * Move all the modes from @head to @new.
504  */
505 void drm_mode_list_concat(struct list_head *head, struct list_head *new)
506 {
507 
508 	struct list_head *entry, *tmp;
509 
510 	list_for_each_safe(entry, tmp, head) {
511 		list_move_tail(entry, new);
512 	}
513 }
514 EXPORT_SYMBOL(drm_mode_list_concat);
515 
516 /**
517  * drm_mode_width - get the width of a mode
518  * @mode: mode
519  *
520  * LOCKING:
521  * None.
522  *
523  * Return @mode's width (hdisplay) value.
524  *
525  * FIXME: is this needed?
526  *
527  * RETURNS:
528  * @mode->hdisplay
529  */
530 int drm_mode_width(struct drm_display_mode *mode)
531 {
532 	return mode->hdisplay;
533 
534 }
535 EXPORT_SYMBOL(drm_mode_width);
536 
537 /**
538  * drm_mode_height - get the height of a mode
539  * @mode: mode
540  *
541  * LOCKING:
542  * None.
543  *
544  * Return @mode's height (vdisplay) value.
545  *
546  * FIXME: is this needed?
547  *
548  * RETURNS:
549  * @mode->vdisplay
550  */
551 int drm_mode_height(struct drm_display_mode *mode)
552 {
553 	return mode->vdisplay;
554 }
555 EXPORT_SYMBOL(drm_mode_height);
556 
557 /**
558  * drm_mode_vrefresh - get the vrefresh of a mode
559  * @mode: mode
560  *
561  * LOCKING:
562  * None.
563  *
564  * Return @mode's vrefresh rate or calculate it if necessary.
565  *
566  * FIXME: why is this needed?  shouldn't vrefresh be set already?
567  *
568  * RETURNS:
569  * Vertical refresh rate. It will be the result of actual value plus 0.5.
570  * If it is 70.288, it will return 70Hz.
571  * If it is 59.6, it will return 60Hz.
572  */
573 int drm_mode_vrefresh(struct drm_display_mode *mode)
574 {
575 	int refresh = 0;
576 	unsigned int calc_val;
577 
578 	if (mode->vrefresh > 0)
579 		refresh = mode->vrefresh;
580 	else if (mode->htotal > 0 && mode->vtotal > 0) {
581 		int vtotal;
582 		vtotal = mode->vtotal;
583 		/* work out vrefresh the value will be x1000 */
584 		calc_val = (mode->clock * 1000);
585 		calc_val /= mode->htotal;
586 		refresh = (calc_val + vtotal / 2) / vtotal;
587 
588 		if (mode->flags & DRM_MODE_FLAG_INTERLACE)
589 			refresh *= 2;
590 		if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
591 			refresh /= 2;
592 		if (mode->vscan > 1)
593 			refresh /= mode->vscan;
594 	}
595 	return refresh;
596 }
597 EXPORT_SYMBOL(drm_mode_vrefresh);
598 
599 /**
600  * drm_mode_set_crtcinfo - set CRTC modesetting parameters
601  * @p: mode
602  * @adjust_flags: unused? (FIXME)
603  *
604  * LOCKING:
605  * None.
606  *
607  * Setup the CRTC modesetting parameters for @p, adjusting if necessary.
608  */
609 void drm_mode_set_crtcinfo(struct drm_display_mode *p, int adjust_flags)
610 {
611 	if ((p == NULL) || ((p->type & DRM_MODE_TYPE_CRTC_C) == DRM_MODE_TYPE_BUILTIN))
612 		return;
613 
614 	p->crtc_hdisplay = p->hdisplay;
615 	p->crtc_hsync_start = p->hsync_start;
616 	p->crtc_hsync_end = p->hsync_end;
617 	p->crtc_htotal = p->htotal;
618 	p->crtc_hskew = p->hskew;
619 	p->crtc_vdisplay = p->vdisplay;
620 	p->crtc_vsync_start = p->vsync_start;
621 	p->crtc_vsync_end = p->vsync_end;
622 	p->crtc_vtotal = p->vtotal;
623 
624 	if (p->flags & DRM_MODE_FLAG_INTERLACE) {
625 		if (adjust_flags & CRTC_INTERLACE_HALVE_V) {
626 			p->crtc_vdisplay /= 2;
627 			p->crtc_vsync_start /= 2;
628 			p->crtc_vsync_end /= 2;
629 			p->crtc_vtotal /= 2;
630 		}
631 
632 		p->crtc_vtotal |= 1;
633 	}
634 
635 	if (p->flags & DRM_MODE_FLAG_DBLSCAN) {
636 		p->crtc_vdisplay *= 2;
637 		p->crtc_vsync_start *= 2;
638 		p->crtc_vsync_end *= 2;
639 		p->crtc_vtotal *= 2;
640 	}
641 
642 	if (p->vscan > 1) {
643 		p->crtc_vdisplay *= p->vscan;
644 		p->crtc_vsync_start *= p->vscan;
645 		p->crtc_vsync_end *= p->vscan;
646 		p->crtc_vtotal *= p->vscan;
647 	}
648 
649 	p->crtc_vblank_start = min(p->crtc_vsync_start, p->crtc_vdisplay);
650 	p->crtc_vblank_end = max(p->crtc_vsync_end, p->crtc_vtotal);
651 	p->crtc_hblank_start = min(p->crtc_hsync_start, p->crtc_hdisplay);
652 	p->crtc_hblank_end = max(p->crtc_hsync_end, p->crtc_htotal);
653 
654 	p->crtc_hadjusted = false;
655 	p->crtc_vadjusted = false;
656 }
657 EXPORT_SYMBOL(drm_mode_set_crtcinfo);
658 
659 
660 /**
661  * drm_mode_duplicate - allocate and duplicate an existing mode
662  * @m: mode to duplicate
663  *
664  * LOCKING:
665  * None.
666  *
667  * Just allocate a new mode, copy the existing mode into it, and return
668  * a pointer to it.  Used to create new instances of established modes.
669  */
670 struct drm_display_mode *drm_mode_duplicate(struct drm_device *dev,
671 					    struct drm_display_mode *mode)
672 {
673 	struct drm_display_mode *nmode;
674 	int new_id;
675 
676 	nmode = drm_mode_create(dev);
677 	if (!nmode)
678 		return NULL;
679 
680 	new_id = nmode->base.id;
681 	*nmode = *mode;
682 	nmode->base.id = new_id;
683 	INIT_LIST_HEAD(&nmode->head);
684 	return nmode;
685 }
686 EXPORT_SYMBOL(drm_mode_duplicate);
687 
688 /**
689  * drm_mode_equal - test modes for equality
690  * @mode1: first mode
691  * @mode2: second mode
692  *
693  * LOCKING:
694  * None.
695  *
696  * Check to see if @mode1 and @mode2 are equivalent.
697  *
698  * RETURNS:
699  * True if the modes are equal, false otherwise.
700  */
701 bool drm_mode_equal(struct drm_display_mode *mode1, struct drm_display_mode *mode2)
702 {
703 	/* do clock check convert to PICOS so fb modes get matched
704 	 * the same */
705 	if (mode1->clock && mode2->clock) {
706 		if (KHZ2PICOS(mode1->clock) != KHZ2PICOS(mode2->clock))
707 			return false;
708 	} else if (mode1->clock != mode2->clock)
709 		return false;
710 
711 	if (mode1->hdisplay == mode2->hdisplay &&
712 	    mode1->hsync_start == mode2->hsync_start &&
713 	    mode1->hsync_end == mode2->hsync_end &&
714 	    mode1->htotal == mode2->htotal &&
715 	    mode1->hskew == mode2->hskew &&
716 	    mode1->vdisplay == mode2->vdisplay &&
717 	    mode1->vsync_start == mode2->vsync_start &&
718 	    mode1->vsync_end == mode2->vsync_end &&
719 	    mode1->vtotal == mode2->vtotal &&
720 	    mode1->vscan == mode2->vscan &&
721 	    mode1->flags == mode2->flags)
722 		return true;
723 
724 	return false;
725 }
726 EXPORT_SYMBOL(drm_mode_equal);
727 
728 /**
729  * drm_mode_validate_size - make sure modes adhere to size constraints
730  * @dev: DRM device
731  * @mode_list: list of modes to check
732  * @maxX: maximum width
733  * @maxY: maximum height
734  * @maxPitch: max pitch
735  *
736  * LOCKING:
737  * Caller must hold a lock protecting @mode_list.
738  *
739  * The DRM device (@dev) has size and pitch limits.  Here we validate the
740  * modes we probed for @dev against those limits and set their status as
741  * necessary.
742  */
743 void drm_mode_validate_size(struct drm_device *dev,
744 			    struct list_head *mode_list,
745 			    int maxX, int maxY, int maxPitch)
746 {
747 	struct drm_display_mode *mode;
748 
749 	list_for_each_entry(mode, mode_list, head) {
750 		if (maxPitch > 0 && mode->hdisplay > maxPitch)
751 			mode->status = MODE_BAD_WIDTH;
752 
753 		if (maxX > 0 && mode->hdisplay > maxX)
754 			mode->status = MODE_VIRTUAL_X;
755 
756 		if (maxY > 0 && mode->vdisplay > maxY)
757 			mode->status = MODE_VIRTUAL_Y;
758 	}
759 }
760 EXPORT_SYMBOL(drm_mode_validate_size);
761 
762 /**
763  * drm_mode_validate_clocks - validate modes against clock limits
764  * @dev: DRM device
765  * @mode_list: list of modes to check
766  * @min: minimum clock rate array
767  * @max: maximum clock rate array
768  * @n_ranges: number of clock ranges (size of arrays)
769  *
770  * LOCKING:
771  * Caller must hold a lock protecting @mode_list.
772  *
773  * Some code may need to check a mode list against the clock limits of the
774  * device in question.  This function walks the mode list, testing to make
775  * sure each mode falls within a given range (defined by @min and @max
776  * arrays) and sets @mode->status as needed.
777  */
778 void drm_mode_validate_clocks(struct drm_device *dev,
779 			      struct list_head *mode_list,
780 			      int *min, int *max, int n_ranges)
781 {
782 	struct drm_display_mode *mode;
783 	int i;
784 
785 	list_for_each_entry(mode, mode_list, head) {
786 		bool good = false;
787 		for (i = 0; i < n_ranges; i++) {
788 			if (mode->clock >= min[i] && mode->clock <= max[i]) {
789 				good = true;
790 				break;
791 			}
792 		}
793 		if (!good)
794 			mode->status = MODE_CLOCK_RANGE;
795 	}
796 }
797 EXPORT_SYMBOL(drm_mode_validate_clocks);
798 
799 /**
800  * drm_mode_prune_invalid - remove invalid modes from mode list
801  * @dev: DRM device
802  * @mode_list: list of modes to check
803  * @verbose: be verbose about it
804  *
805  * LOCKING:
806  * Caller must hold a lock protecting @mode_list.
807  *
808  * Once mode list generation is complete, a caller can use this routine to
809  * remove invalid modes from a mode list.  If any of the modes have a
810  * status other than %MODE_OK, they are removed from @mode_list and freed.
811  */
812 void drm_mode_prune_invalid(struct drm_device *dev,
813 			    struct list_head *mode_list, bool verbose)
814 {
815 	struct drm_display_mode *mode, *t;
816 
817 	list_for_each_entry_safe(mode, t, mode_list, head) {
818 		if (mode->status != MODE_OK) {
819 			list_del(&mode->head);
820 			if (verbose) {
821 				drm_mode_debug_printmodeline(mode);
822 				DRM_DEBUG_KMS("Not using %s mode %d\n",
823 					mode->name, mode->status);
824 			}
825 			drm_mode_destroy(dev, mode);
826 		}
827 	}
828 }
829 EXPORT_SYMBOL(drm_mode_prune_invalid);
830 
831 /**
832  * drm_mode_compare - compare modes for favorability
833  * @lh_a: list_head for first mode
834  * @lh_b: list_head for second mode
835  *
836  * LOCKING:
837  * None.
838  *
839  * Compare two modes, given by @lh_a and @lh_b, returning a value indicating
840  * which is better.
841  *
842  * RETURNS:
843  * Negative if @lh_a is better than @lh_b, zero if they're equivalent, or
844  * positive if @lh_b is better than @lh_a.
845  */
846 static int drm_mode_compare(struct list_head *lh_a, struct list_head *lh_b)
847 {
848 	struct drm_display_mode *a = list_entry(lh_a, struct drm_display_mode, head);
849 	struct drm_display_mode *b = list_entry(lh_b, struct drm_display_mode, head);
850 	int diff;
851 
852 	diff = ((b->type & DRM_MODE_TYPE_PREFERRED) != 0) -
853 		((a->type & DRM_MODE_TYPE_PREFERRED) != 0);
854 	if (diff)
855 		return diff;
856 	diff = b->hdisplay * b->vdisplay - a->hdisplay * a->vdisplay;
857 	if (diff)
858 		return diff;
859 	diff = b->clock - a->clock;
860 	return diff;
861 }
862 
863 /* FIXME: what we don't have a list sort function? */
864 /* list sort from Mark J Roberts (mjr@znex.org) */
865 void list_sort(struct list_head *head,
866 	       int (*cmp)(struct list_head *a, struct list_head *b))
867 {
868 	struct list_head *p, *q, *e, *list, *tail, *oldhead;
869 	int insize, nmerges, psize, qsize, i;
870 
871 	list = head->next;
872 	list_del(head);
873 	insize = 1;
874 	for (;;) {
875 		p = oldhead = list;
876 		list = tail = NULL;
877 		nmerges = 0;
878 
879 		while (p) {
880 			nmerges++;
881 			q = p;
882 			psize = 0;
883 			for (i = 0; i < insize; i++) {
884 				psize++;
885 				q = q->next == oldhead ? NULL : q->next;
886 				if (!q)
887 					break;
888 			}
889 
890 			qsize = insize;
891 			while (psize > 0 || (qsize > 0 && q)) {
892 				if (!psize) {
893 					e = q;
894 					q = q->next;
895 					qsize--;
896 					if (q == oldhead)
897 						q = NULL;
898 				} else if (!qsize || !q) {
899 					e = p;
900 					p = p->next;
901 					psize--;
902 					if (p == oldhead)
903 						p = NULL;
904 				} else if (cmp(p, q) <= 0) {
905 					e = p;
906 					p = p->next;
907 					psize--;
908 					if (p == oldhead)
909 						p = NULL;
910 				} else {
911 					e = q;
912 					q = q->next;
913 					qsize--;
914 					if (q == oldhead)
915 						q = NULL;
916 				}
917 				if (tail)
918 					tail->next = e;
919 				else
920 					list = e;
921 				e->prev = tail;
922 				tail = e;
923 			}
924 			p = q;
925 		}
926 
927 		tail->next = list;
928 		list->prev = tail;
929 
930 		if (nmerges <= 1)
931 			break;
932 
933 		insize *= 2;
934 	}
935 
936 	head->next = list;
937 	head->prev = list->prev;
938 	list->prev->next = head;
939 	list->prev = head;
940 }
941 
942 /**
943  * drm_mode_sort - sort mode list
944  * @mode_list: list to sort
945  *
946  * LOCKING:
947  * Caller must hold a lock protecting @mode_list.
948  *
949  * Sort @mode_list by favorability, putting good modes first.
950  */
951 void drm_mode_sort(struct list_head *mode_list)
952 {
953 	list_sort(mode_list, drm_mode_compare);
954 }
955 EXPORT_SYMBOL(drm_mode_sort);
956 
957 /**
958  * drm_mode_connector_list_update - update the mode list for the connector
959  * @connector: the connector to update
960  *
961  * LOCKING:
962  * Caller must hold a lock protecting @mode_list.
963  *
964  * This moves the modes from the @connector probed_modes list
965  * to the actual mode list. It compares the probed mode against the current
966  * list and only adds different modes. All modes unverified after this point
967  * will be removed by the prune invalid modes.
968  */
969 void drm_mode_connector_list_update(struct drm_connector *connector)
970 {
971 	struct drm_display_mode *mode;
972 	struct drm_display_mode *pmode, *pt;
973 	int found_it;
974 
975 	list_for_each_entry_safe(pmode, pt, &connector->probed_modes,
976 				 head) {
977 		found_it = 0;
978 		/* go through current modes checking for the new probed mode */
979 		list_for_each_entry(mode, &connector->modes, head) {
980 			if (drm_mode_equal(pmode, mode)) {
981 				found_it = 1;
982 				/* if equal delete the probed mode */
983 				mode->status = pmode->status;
984 				/* Merge type bits together */
985 				mode->type |= pmode->type;
986 				list_del(&pmode->head);
987 				drm_mode_destroy(connector->dev, pmode);
988 				break;
989 			}
990 		}
991 
992 		if (!found_it) {
993 			list_move_tail(&pmode->head, &connector->modes);
994 		}
995 	}
996 }
997 EXPORT_SYMBOL(drm_mode_connector_list_update);
998