text: /*
   * Copyright © 1997-2003 by The XFree86 Project, Inc.
   * Copyright © 2007 Dave Airlie
   * Copyright © 2007-2008 Intel Corporation
   *   Jesse Barnes <jesse.barnes@intel.com>
   * Copyright 2005-2006 Luc Verhaegen
   * Copyright (c) 2001, Andy Ritger  aritger@nvidia.com
   *
   * Permission is hereby granted, free of charge, to any person obtaining a
   * copy of this software and associated documentation files (the "Software"),
   * to deal in the Software without restriction, including without limitation
   * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   * and/or sell copies of the Software, and to permit persons to whom the
   * Software is furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
   * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
   * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
   * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
   * OTHER DEALINGS IN THE SOFTWARE.
   *
   * Except as contained in this notice, the name of the copyright holder(s)
   * and author(s) shall not be used in advertising or otherwise to promote
   * the sale, use or other dealings in this Software without prior written
   * authorization from the copyright holder(s) and author(s).
   */
  
  #include <linux/list.h>
  #include <linux/list_sort.h>
  #include <linux/export.h>
  #include <drm/drmP.h>
  #include <drm/drm_crtc.h>
  #include <video/of_videomode.h>
  #include <video/videomode.h>
  #include <drm/drm_modes.h>
  
  #include "drm_crtc_internal.h"
  
  /**
   * drm_mode_debug_printmodeline - print a mode to dmesg
   * @mode: mode to print
   *
   * Describe @mode using DRM_DEBUG.
   */
  void drm_mode_debug_printmodeline(const struct drm_display_mode *mode)
  {
  	DRM_DEBUG_KMS("Modeline %d:\"%s\" %d %d %d %d %d %d %d %d %d %d "
  			"0x%x 0x%x\n",
  		mode->base.id, mode->name, mode->vrefresh, mode->clock,
  		mode->hdisplay, mode->hsync_start,
  		mode->hsync_end, mode->htotal,
  		mode->vdisplay, mode->vsync_start,
  		mode->vsync_end, mode->vtotal, mode->type, mode->flags);
  }
  EXPORT_SYMBOL(drm_mode_debug_printmodeline);
  
  /**
   * drm_mode_create - create a new display mode
   * @dev: DRM device
   *
   * Create a new, cleared drm_display_mode with kzalloc, allocate an ID for it
   * and return it.
   *
   * Returns:
   * Pointer to new mode on success, NULL on error.
   */
  struct drm_display_mode *drm_mode_create(struct drm_device *dev)
  {
  	struct drm_display_mode *nmode;
  
  	nmode = kzalloc(sizeof(struct drm_display_mode), GFP_KERNEL);
  	if (!nmode)
  		return NULL;
  
  	if (drm_mode_object_get(dev, &nmode->base, DRM_MODE_OBJECT_MODE)) {
  		kfree(nmode);
  		return NULL;
  	}
  
  	return nmode;
  }
  EXPORT_SYMBOL(drm_mode_create);
  
  /**
   * drm_mode_destroy - remove a mode
   * @dev: DRM device
   * @mode: mode to remove
   *
   * Release @mode's unique ID, then free it @mode structure itself using kfree.
   */
  void drm_mode_destroy(struct drm_device *dev, struct drm_display_mode *mode)
  {
  	if (!mode)
  		return;
  
  	drm_mode_object_put(dev, &mode->base);
  
  	kfree(mode);
  }
  EXPORT_SYMBOL(drm_mode_destroy);
  
  /**
   * drm_mode_probed_add - add a mode to a connector's probed_mode list
   * @connector: connector the new mode
   * @mode: mode data
   *
   * Add @mode to @connector's probed_mode list for later use. This list should
   * then in a second step get filtered and all the modes actually supported by
   * the hardware moved to the @connector's modes list.
   */
  void drm_mode_probed_add(struct drm_connector *connector,
  			 struct drm_display_mode *mode)
  {
  	WARN_ON(!mutex_is_locked(&connector->dev->mode_config.mutex));
  
  	list_add_tail(&mode->head, &connector->probed_modes);
  }
  EXPORT_SYMBOL(drm_mode_probed_add);
  
  /**
   * drm_cvt_mode -create a modeline based on the CVT algorithm
   * @dev: drm device
   * @hdisplay: hdisplay size
   * @vdisplay: vdisplay size
   * @vrefresh: vrefresh rate
   * @reduced: whether to use reduced blanking
   * @interlaced: whether to compute an interlaced mode
   * @margins: whether to add margins (borders)
   *
   * This function is called to generate the modeline based on CVT algorithm
   * according to the hdisplay, vdisplay, vrefresh.
   * It is based from the VESA(TM) Coordinated Video Timing Generator by
   * Graham Loveridge April 9, 2003 available at
   * http://www.elo.utfsm.cl/~elo212/docs/CVTd6r1.xls 
   *
   * And it is copied from xf86CVTmode in xserver/hw/xfree86/modes/xf86cvt.c.
   * What I have done is to translate it by using integer calculation.
   *
   * Returns:
   * The modeline based on the CVT algorithm stored in a drm_display_mode object.
   * The display mode object is allocated with drm_mode_create(). Returns NULL
   * when no mode could be allocated.
   */
  struct drm_display_mode *drm_cvt_mode(struct drm_device *dev, int hdisplay,
  				      int vdisplay, int vrefresh,
  				      bool reduced, bool interlaced, bool margins)
  {
  #define HV_FACTOR			1000
  	/* 1) top/bottom margin size (% of height) - default: 1.8, */
  #define	CVT_MARGIN_PERCENTAGE		18
  	/* 2) character cell horizontal granularity (pixels) - default 8 */
  #define	CVT_H_GRANULARITY		8
  	/* 3) Minimum vertical porch (lines) - default 3 */
  #define	CVT_MIN_V_PORCH			3
  	/* 4) Minimum number of vertical back porch lines - default 6 */
  #define	CVT_MIN_V_BPORCH		6
  	/* Pixel Clock step (kHz) */
  #define CVT_CLOCK_STEP			250
  	struct drm_display_mode *drm_mode;
  	unsigned int vfieldrate, hperiod;
  	int hdisplay_rnd, hmargin, vdisplay_rnd, vmargin, vsync;
  	int interlace;
  
  	/* allocate the drm_display_mode structure. If failure, we will
  	 * return directly
  	 */
  	drm_mode = drm_mode_create(dev);
  	if (!drm_mode)
  		return NULL;
  
  	/* the CVT default refresh rate is 60Hz */
  	if (!vrefresh)
  		vrefresh = 60;
  
  	/* the required field fresh rate */
  	if (interlaced)
  		vfieldrate = vrefresh * 2;
  	else
  		vfieldrate = vrefresh;
  
  	/* horizontal pixels */
  	hdisplay_rnd = hdisplay - (hdisplay % CVT_H_GRANULARITY);
  
  	/* determine the left&right borders */
  	hmargin = 0;
  	if (margins) {
  		hmargin = hdisplay_rnd * CVT_MARGIN_PERCENTAGE / 1000;
  		hmargin -= hmargin % CVT_H_GRANULARITY;
  	}
  	/* find the total active pixels */
  	drm_mode->hdisplay = hdisplay_rnd + 2 * hmargin;
  
  	/* find the number of lines per field */
  	if (interlaced)
  		vdisplay_rnd = vdisplay / 2;
  	else
  		vdisplay_rnd = vdisplay;
  
  	/* find the top & bottom borders */
  	vmargin = 0;
  	if (margins)
  		vmargin = vdisplay_rnd * CVT_MARGIN_PERCENTAGE / 1000;
  
  	drm_mode->vdisplay = vdisplay + 2 * vmargin;
  
  	/* Interlaced */
  	if (interlaced)
  		interlace = 1;
  	else
  		interlace = 0;
  
  	/* Determine VSync Width from aspect ratio */
  	if (!(vdisplay % 3) && ((vdisplay * 4 / 3) == hdisplay))
  		vsync = 4;
  	else if (!(vdisplay % 9) && ((vdisplay * 16 / 9) == hdisplay))
  		vsync = 5;
  	else if (!(vdisplay % 10) && ((vdisplay * 16 / 10) == hdisplay))
  		vsync = 6;
  	else if (!(vdisplay % 4) && ((vdisplay * 5 / 4) == hdisplay))
  		vsync = 7;
  	else if (!(vdisplay % 9) && ((vdisplay * 15 / 9) == hdisplay))
  		vsync = 7;
  	else /* custom */
  		vsync = 10;
  
  	if (!reduced) {
  		/* simplify the GTF calculation */
  		/* 4) Minimum time of vertical sync + back porch interval (µs)
  		 * default 550.0
  		 */
  		int tmp1, tmp2;
  #define CVT_MIN_VSYNC_BP	550
  		/* 3) Nominal HSync width (% of line period) - default 8 */
  #define CVT_HSYNC_PERCENTAGE	8
  		unsigned int hblank_percentage;
  		int vsyncandback_porch, vback_porch, hblank;
  
  		/* estimated the horizontal period */
  		tmp1 = HV_FACTOR * 1000000  -
  				CVT_MIN_VSYNC_BP * HV_FACTOR * vfieldrate;
  		tmp2 = (vdisplay_rnd + 2 * vmargin + CVT_MIN_V_PORCH) * 2 +
  				interlace;
  		hperiod = tmp1 * 2 / (tmp2 * vfieldrate);
  
  		tmp1 = CVT_MIN_VSYNC_BP * HV_FACTOR / hperiod + 1;
  		/* 9. Find number of lines in sync + backporch */
  		if (tmp1 < (vsync + CVT_MIN_V_PORCH))
  			vsyncandback_porch = vsync + CVT_MIN_V_PORCH;
  		else
  			vsyncandback_porch = tmp1;
  		/* 10. Find number of lines in back porch */
  		vback_porch = vsyncandback_porch - vsync;
  		drm_mode->vtotal = vdisplay_rnd + 2 * vmargin +
  				vsyncandback_porch + CVT_MIN_V_PORCH;
  		/* 5) Definition of Horizontal blanking time limitation */
  		/* Gradient (%/kHz) - default 600 */
  #define CVT_M_FACTOR	600
  		/* Offset (%) - default 40 */
  #define CVT_C_FACTOR	40
  		/* Blanking time scaling factor - default 128 */
  #define CVT_K_FACTOR	128
  		/* Scaling factor weighting - default 20 */
  #define CVT_J_FACTOR	20
  #define CVT_M_PRIME	(CVT_M_FACTOR * CVT_K_FACTOR / 256)
  #define CVT_C_PRIME	((CVT_C_FACTOR - CVT_J_FACTOR) * CVT_K_FACTOR / 256 + \
  			 CVT_J_FACTOR)
  		/* 12. Find ideal blanking duty cycle from formula */
  		hblank_percentage = CVT_C_PRIME * HV_FACTOR - CVT_M_PRIME *
  					hperiod / 1000;
  		/* 13. Blanking time */
  		if (hblank_percentage < 20 * HV_FACTOR)
  			hblank_percentage = 20 * HV_FACTOR;
  		hblank = drm_mode->hdisplay * hblank_percentage /
  			 (100 * HV_FACTOR - hblank_percentage);
  		hblank -= hblank % (2 * CVT_H_GRANULARITY);
  		/* 14. find the total pixels per line */
  		drm_mode->htotal = drm_mode->hdisplay + hblank;
  		drm_mode->hsync_end = drm_mode->hdisplay + hblank / 2;
  		drm_mode->hsync_start = drm_mode->hsync_end -
  			(drm_mode->htotal * CVT_HSYNC_PERCENTAGE) / 100;
  		drm_mode->hsync_start += CVT_H_GRANULARITY -
  			drm_mode->hsync_start % CVT_H_GRANULARITY;
  		/* fill the Vsync values */
  		drm_mode->vsync_start = drm_mode->vdisplay + CVT_MIN_V_PORCH;
  		drm_mode->vsync_end = drm_mode->vsync_start + vsync;
  	} else {
  		/* Reduced blanking */
  		/* Minimum vertical blanking interval time (µs)- default 460 */
  #define CVT_RB_MIN_VBLANK	460
  		/* Fixed number of clocks for horizontal sync */
  #define CVT_RB_H_SYNC		32
  		/* Fixed number of clocks for horizontal blanking */
  #define CVT_RB_H_BLANK		160
  		/* Fixed number of lines for vertical front porch - default 3*/
  #define CVT_RB_VFPORCH		3
  		int vbilines;
  		int tmp1, tmp2;
  		/* 8. Estimate Horizontal period. */
  		tmp1 = HV_FACTOR * 1000000 -
  			CVT_RB_MIN_VBLANK * HV_FACTOR * vfieldrate;
  		tmp2 = vdisplay_rnd + 2 * vmargin;
  		hperiod = tmp1 / (tmp2 * vfieldrate);
  		/* 9. Find number of lines in vertical blanking */
  		vbilines = CVT_RB_MIN_VBLANK * HV_FACTOR / hperiod + 1;
  		/* 10. Check if vertical blanking is sufficient */
  		if (vbilines < (CVT_RB_VFPORCH + vsync + CVT_MIN_V_BPORCH))
  			vbilines = CVT_RB_VFPORCH + vsync + CVT_MIN_V_BPORCH;
  		/* 11. Find total number of lines in vertical field */
  		drm_mode->vtotal = vdisplay_rnd + 2 * vmargin + vbilines;
  		/* 12. Find total number of pixels in a line */
  		drm_mode->htotal = drm_mode->hdisplay + CVT_RB_H_BLANK;
  		/* Fill in HSync values */
  		drm_mode->hsync_end = drm_mode->hdisplay + CVT_RB_H_BLANK / 2;
  		drm_mode->hsync_start = drm_mode->hsync_end - CVT_RB_H_SYNC;
  		/* Fill in VSync values */
  		drm_mode->vsync_start = drm_mode->vdisplay + CVT_RB_VFPORCH;
  		drm_mode->vsync_end = drm_mode->vsync_start + vsync;
  	}
  	/* 15/13. Find pixel clock frequency (kHz for xf86) */
  	drm_mode->clock = drm_mode->htotal * HV_FACTOR * 1000 / hperiod;
  	drm_mode->clock -= drm_mode->clock % CVT_CLOCK_STEP;
  	/* 18/16. Find actual vertical frame frequency */
  	/* ignore - just set the mode flag for interlaced */
  	if (interlaced) {
  		drm_mode->vtotal *= 2;
  		drm_mode->flags |= DRM_MODE_FLAG_INTERLACE;
  	}
  	/* Fill the mode line name */
  	drm_mode_set_name(drm_mode);
  	if (reduced)
  		drm_mode->flags |= (DRM_MODE_FLAG_PHSYNC |
  					DRM_MODE_FLAG_NVSYNC);
  	else
  		drm_mode->flags |= (DRM_MODE_FLAG_PVSYNC |
  					DRM_MODE_FLAG_NHSYNC);
  
  	return drm_mode;
  }
  EXPORT_SYMBOL(drm_cvt_mode);
  
  /**
   * drm_gtf_mode_complex - create the modeline based on the full GTF algorithm
   * @dev: drm device
   * @hdisplay: hdisplay size
   * @vdisplay: vdisplay size
   * @vrefresh: vrefresh rate.
   * @interlaced: whether to compute an interlaced mode
   * @margins: desired margin (borders) size
   * @GTF_M: extended GTF formula parameters
   * @GTF_2C: extended GTF formula parameters
   * @GTF_K: extended GTF formula parameters
   * @GTF_2J: extended GTF formula parameters
   *
   * GTF feature blocks specify C and J in multiples of 0.5, so we pass them
   * in here multiplied by two.  For a C of 40, pass in 80.
   *
   * Returns:
   * The modeline based on the full GTF algorithm stored in a drm_display_mode object.
   * The display mode object is allocated with drm_mode_create(). Returns NULL
   * when no mode could be allocated.
   */
  struct drm_display_mode *
  drm_gtf_mode_complex(struct drm_device *dev, int hdisplay, int vdisplay,
  		     int vrefresh, bool interlaced, int margins,
  		     int GTF_M, int GTF_2C, int GTF_K, int GTF_2J)
  {	/* 1) top/bottom margin size (% of height) - default: 1.8, */
  #define	GTF_MARGIN_PERCENTAGE		18
  	/* 2) character cell horizontal granularity (pixels) - default 8 */
  #define	GTF_CELL_GRAN			8
  	/* 3) Minimum vertical porch (lines) - default 3 */
  #define	GTF_MIN_V_PORCH			1
  	/* width of vsync in lines */
  #define V_SYNC_RQD			3
  	/* width of hsync as % of total line */
  #define H_SYNC_PERCENT			8
  	/* min time of vsync + back porch (microsec) */
  #define MIN_VSYNC_PLUS_BP		550
  	/* C' and M' are part of the Blanking Duty Cycle computation */
  #define GTF_C_PRIME	((((GTF_2C - GTF_2J) * GTF_K / 256) + GTF_2J) / 2)
  #define GTF_M_PRIME	(GTF_K * GTF_M / 256)
  	struct drm_display_mode *drm_mode;
  	unsigned int hdisplay_rnd, vdisplay_rnd, vfieldrate_rqd;
  	int top_margin, bottom_margin;
  	int interlace;
  	unsigned int hfreq_est;
  	int vsync_plus_bp, vback_porch;
  	unsigned int vtotal_lines, vfieldrate_est, hperiod;
  	unsigned int vfield_rate, vframe_rate;
  	int left_margin, right_margin;
  	unsigned int total_active_pixels, ideal_duty_cycle;
  	unsigned int hblank, total_pixels, pixel_freq;
  	int hsync, hfront_porch, vodd_front_porch_lines;
  	unsigned int tmp1, tmp2;
  
  	drm_mode = drm_mode_create(dev);
  	if (!drm_mode)
  		return NULL;
  
  	/* 1. In order to give correct results, the number of horizontal
  	 * pixels requested is first processed to ensure that it is divisible
  	 * by the character size, by rounding it to the nearest character
  	 * cell boundary:
  	 */
  	hdisplay_rnd = (hdisplay + GTF_CELL_GRAN / 2) / GTF_CELL_GRAN;
  	hdisplay_rnd = hdisplay_rnd * GTF_CELL_GRAN;
  
  	/* 2. If interlace is requested, the number of vertical lines assumed
  	 * by the calculation must be halved, as the computation calculates
  	 * the number of vertical lines per field.
  	 */
  	if (interlaced)
  		vdisplay_rnd = vdisplay / 2;
  	else
  		vdisplay_rnd = vdisplay;
  
  	/* 3. Find the frame rate required: */
  	if (interlaced)
  		vfieldrate_rqd = vrefresh * 2;
  	else
  		vfieldrate_rqd = vrefresh;
  
  	/* 4. Find number of lines in Top margin: */
  	top_margin = 0;
  	if (margins)
  		top_margin = (vdisplay_rnd * GTF_MARGIN_PERCENTAGE + 500) /
  				1000;
  	/* 5. Find number of lines in bottom margin: */
  	bottom_margin = top_margin;
  
  	/* 6. If interlace is required, then set variable interlace: */
  	if (interlaced)
  		interlace = 1;
  	else
  		interlace = 0;
  
  	/* 7. Estimate the Horizontal frequency */
  	{
  		tmp1 = (1000000  - MIN_VSYNC_PLUS_BP * vfieldrate_rqd) / 500;
  		tmp2 = (vdisplay_rnd + 2 * top_margin + GTF_MIN_V_PORCH) *
  				2 + interlace;
  		hfreq_est = (tmp2 * 1000 * vfieldrate_rqd) / tmp1;
  	}
  
  	/* 8. Find the number of lines in V sync + back porch */
  	/* [V SYNC+BP] = RINT(([MIN VSYNC+BP] * hfreq_est / 1000000)) */
  	vsync_plus_bp = MIN_VSYNC_PLUS_BP * hfreq_est / 1000;
  	vsync_plus_bp = (vsync_plus_bp + 500) / 1000;
  	/*  9. Find the number of lines in V back porch alone: */
  	vback_porch = vsync_plus_bp - V_SYNC_RQD;
  	/*  10. Find the total number of lines in Vertical field period: */
  	vtotal_lines = vdisplay_rnd + top_margin + bottom_margin +
  			vsync_plus_bp + GTF_MIN_V_PORCH;
  	/*  11. Estimate the Vertical field frequency: */
  	vfieldrate_est = hfreq_est / vtotal_lines;
  	/*  12. Find the actual horizontal period: */
  	hperiod = 1000000 / (vfieldrate_rqd * vtotal_lines);
  
  	/*  13. Find the actual Vertical field frequency: */
  	vfield_rate = hfreq_est / vtotal_lines;
  	/*  14. Find the Vertical frame frequency: */
  	if (interlaced)
  		vframe_rate = vfield_rate / 2;
  	else
  		vframe_rate = vfield_rate;
  	/*  15. Find number of pixels in left margin: */
  	if (margins)
  		left_margin = (hdisplay_rnd * GTF_MARGIN_PERCENTAGE + 500) /
  				1000;
  	else
  		left_margin = 0;
  
  	/* 16.Find number of pixels in right margin: */
  	right_margin = left_margin;
  	/* 17.Find total number of active pixels in image and left and right */
  	total_active_pixels = hdisplay_rnd + left_margin + right_margin;
  	/* 18.Find the ideal blanking duty cycle from blanking duty cycle */
  	ideal_duty_cycle = GTF_C_PRIME * 1000 -
  				(GTF_M_PRIME * 1000000 / hfreq_est);
  	/* 19.Find the number of pixels in the blanking time to the nearest
  	 * double character cell: */
  	hblank = total_active_pixels * ideal_duty_cycle /
  			(100000 - ideal_duty_cycle);
  	hblank = (hblank + GTF_CELL_GRAN) / (2 * GTF_CELL_GRAN);
  	hblank = hblank * 2 * GTF_CELL_GRAN;
  	/* 20.Find total number of pixels: */
  	total_pixels = total_active_pixels + hblank;
  	/* 21.Find pixel clock frequency: */
  	pixel_freq = total_pixels * hfreq_est / 1000;
  	/* Stage 1 computations are now complete; I should really pass
  	 * the results to another function and do the Stage 2 computations,
  	 * but I only need a few more values so I'll just append the
  	 * computations here for now */
  	/* 17. Find the number of pixels in the horizontal sync period: */
  	hsync = H_SYNC_PERCENT * total_pixels / 100;
  	hsync = (hsync + GTF_CELL_GRAN / 2) / GTF_CELL_GRAN;
  	hsync = hsync * GTF_CELL_GRAN;
  	/* 18. Find the number of pixels in horizontal front porch period */
  	hfront_porch = hblank / 2 - hsync;
  	/*  36. Find the number of lines in the odd front porch period: */
  	vodd_front_porch_lines = GTF_MIN_V_PORCH ;
  
  	/* finally, pack the results in the mode struct */
  	drm_mode->hdisplay = hdisplay_rnd;
  	drm_mode->hsync_start = hdisplay_rnd + hfront_porch;
  	drm_mode->hsync_end = drm_mode->hsync_start + hsync;
  	drm_mode->htotal = total_pixels;
  	drm_mode->vdisplay = vdisplay_rnd;
  	drm_mode->vsync_start = vdisplay_rnd + vodd_front_porch_lines;
  	drm_mode->vsync_end = drm_mode->vsync_start + V_SYNC_RQD;
  	drm_mode->vtotal = vtotal_lines;
  
  	drm_mode->clock = pixel_freq;
  
  	if (interlaced) {
  		drm_mode->vtotal *= 2;
  		drm_mode->flags |= DRM_MODE_FLAG_INTERLACE;
  	}
  
  	drm_mode_set_name(drm_mode);
  	if (GTF_M == 600 && GTF_2C == 80 && GTF_K == 128 && GTF_2J == 40)
  		drm_mode->flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_PVSYNC;
  	else
  		drm_mode->flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_NVSYNC;
  
  	return drm_mode;
  }
  EXPORT_SYMBOL(drm_gtf_mode_complex);
  
  /**
   * drm_gtf_mode - create the modeline based on the GTF algorithm
   * @dev: drm device
   * @hdisplay: hdisplay size
   * @vdisplay: vdisplay size
   * @vrefresh: vrefresh rate.
   * @interlaced: whether to compute an interlaced mode
   * @margins: desired margin (borders) size
   *
   * return the modeline based on GTF algorithm
   *
   * This function is to create the modeline based on the GTF algorithm.
   * Generalized Timing Formula is derived from:
   *	GTF Spreadsheet by Andy Morrish (1/5/97)
   *	available at http://www.vesa.org
   *
   * And it is copied from the file of xserver/hw/xfree86/modes/xf86gtf.c.
   * What I have done is to translate it by using integer calculation.
   * I also refer to the function of fb_get_mode in the file of
   * drivers/video/fbmon.c
   *
   * Standard GTF parameters:
   * M = 600
   * C = 40
   * K = 128
   * J = 20
   *
   * Returns:
   * The modeline based on the GTF algorithm stored in a drm_display_mode object.
   * The display mode object is allocated with drm_mode_create(). Returns NULL
   * when no mode could be allocated.
   */
  struct drm_display_mode *
  drm_gtf_mode(struct drm_device *dev, int hdisplay, int vdisplay, int vrefresh,
  	     bool interlaced, int margins)
  {
  	return drm_gtf_mode_complex(dev, hdisplay, vdisplay, vrefresh,
  				    interlaced, margins,
  				    600, 40 * 2, 128, 20 * 2);
  }
  EXPORT_SYMBOL(drm_gtf_mode);
  
  #ifdef CONFIG_VIDEOMODE_HELPERS
  /**
   * drm_display_mode_from_videomode - fill in @dmode using @vm,
   * @vm: videomode structure to use as source
   * @dmode: drm_display_mode structure to use as destination
   *
   * Fills out @dmode using the display mode specified in @vm.
   */
  void drm_display_mode_from_videomode(const struct videomode *vm,
  				     struct drm_display_mode *dmode)
  {
  	dmode->hdisplay = vm->hactive;
  	dmode->hsync_start = dmode->hdisplay + vm->hfront_porch;
  	dmode->hsync_end = dmode->hsync_start + vm->hsync_len;
  	dmode->htotal = dmode->hsync_end + vm->hback_porch;
  
  	dmode->vdisplay = vm->vactive;
  	dmode->vsync_start = dmode->vdisplay + vm->vfront_porch;
  	dmode->vsync_end = dmode->vsync_start + vm->vsync_len;
  	dmode->vtotal = dmode->vsync_end + vm->vback_porch;
  
  	dmode->clock = vm->pixelclock / 1000;
  
  	dmode->flags = 0;
  	if (vm->flags & DISPLAY_FLAGS_HSYNC_HIGH)
  		dmode->flags |= DRM_MODE_FLAG_PHSYNC;
  	else if (vm->flags & DISPLAY_FLAGS_HSYNC_LOW)
  		dmode->flags |= DRM_MODE_FLAG_NHSYNC;
  	if (vm->flags & DISPLAY_FLAGS_VSYNC_HIGH)
  		dmode->flags |= DRM_MODE_FLAG_PVSYNC;
  	else if (vm->flags & DISPLAY_FLAGS_VSYNC_LOW)
  		dmode->flags |= DRM_MODE_FLAG_NVSYNC;
  	if (vm->flags & DISPLAY_FLAGS_INTERLACED)
  		dmode->flags |= DRM_MODE_FLAG_INTERLACE;
  	if (vm->flags & DISPLAY_FLAGS_DOUBLESCAN)
  		dmode->flags |= DRM_MODE_FLAG_DBLSCAN;
  	if (vm->flags & DISPLAY_FLAGS_DOUBLECLK)
  		dmode->flags |= DRM_MODE_FLAG_DBLCLK;
  	drm_mode_set_name(dmode);
  }
  EXPORT_SYMBOL_GPL(drm_display_mode_from_videomode);
  
  /**
   * drm_display_mode_to_videomode - fill in @vm using @dmode,
   * @dmode: drm_display_mode structure to use as source
   * @vm: videomode structure to use as destination
   *
   * Fills out @vm using the display mode specified in @dmode.
   */
  void drm_display_mode_to_videomode(const struct drm_display_mode *dmode,
  				   struct videomode *vm)
  {
  	vm->hactive = dmode->hdisplay;
  	vm->hfront_porch = dmode->hsync_start - dmode->hdisplay;
  	vm->hsync_len = dmode->hsync_end - dmode->hsync_start;
  	vm->hback_porch = dmode->htotal - dmode->hsync_end;
  
  	vm->vactive = dmode->vdisplay;
  	vm->vfront_porch = dmode->vsync_start - dmode->vdisplay;
  	vm->vsync_len = dmode->vsync_end - dmode->vsync_start;
  	vm->vback_porch = dmode->vtotal - dmode->vsync_end;
  
  	vm->pixelclock = dmode->clock * 1000;
  
  	vm->flags = 0;
  	if (dmode->flags & DRM_MODE_FLAG_PHSYNC)
  		vm->flags |= DISPLAY_FLAGS_HSYNC_HIGH;
  	else if (dmode->flags & DRM_MODE_FLAG_NHSYNC)
  		vm->flags |= DISPLAY_FLAGS_HSYNC_LOW;
  	if (dmode->flags & DRM_MODE_FLAG_PVSYNC)
  		vm->flags |= DISPLAY_FLAGS_VSYNC_HIGH;
  	else if (dmode->flags & DRM_MODE_FLAG_NVSYNC)
  		vm->flags |= DISPLAY_FLAGS_VSYNC_LOW;
  	if (dmode->flags & DRM_MODE_FLAG_INTERLACE)
  		vm->flags |= DISPLAY_FLAGS_INTERLACED;
  	if (dmode->flags & DRM_MODE_FLAG_DBLSCAN)
  		vm->flags |= DISPLAY_FLAGS_DOUBLESCAN;
  	if (dmode->flags & DRM_MODE_FLAG_DBLCLK)
  		vm->flags |= DISPLAY_FLAGS_DOUBLECLK;
  }
  EXPORT_SYMBOL_GPL(drm_display_mode_to_videomode);
  
  #ifdef CONFIG_OF
  /**
   * of_get_drm_display_mode - get a drm_display_mode from devicetree
   * @np: device_node with the timing specification
   * @dmode: will be set to the return value
   * @index: index into the list of display timings in devicetree
   *
   * This function is expensive and should only be used, if only one mode is to be
   * read from DT. To get multiple modes start with of_get_display_timings and
   * work with that instead.
   *
   * Returns:
   * 0 on success, a negative errno code when no of videomode node was found.
   */
  int of_get_drm_display_mode(struct device_node *np,
  			    struct drm_display_mode *dmode, int index)
  {
  	struct videomode vm;
  	int ret;
  
  	ret = of_get_videomode(np, &vm, index);
  	if (ret)
  		return ret;
  
  	drm_display_mode_from_videomode(&vm, dmode);
  
  	pr_debug("%s: got %dx%d display mode from %s\n",
  		of_node_full_name(np), vm.hactive, vm.vactive, np->name);
  	drm_mode_debug_printmodeline(dmode);
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(of_get_drm_display_mode);
  #endif /* CONFIG_OF */
  #endif /* CONFIG_VIDEOMODE_HELPERS */
  
  /**
   * drm_mode_set_name - set the name on a mode
   * @mode: name will be set in this mode
   *
   * Set the name of @mode to a standard format which is <hdisplay>x<vdisplay>
   * with an optional 'i' suffix for interlaced modes.
   */
  void drm_mode_set_name(struct drm_display_mode *mode)
  {
  	bool interlaced = !!(mode->flags & DRM_MODE_FLAG_INTERLACE);
  
  	snprintf(mode->name, DRM_DISPLAY_MODE_LEN, "%dx%d%s",
  		 mode->hdisplay, mode->vdisplay,
  		 interlaced ? "i" : "");
  }
  EXPORT_SYMBOL(drm_mode_set_name);
  
  /** drm_mode_hsync - get the hsync of a mode
   * @mode: mode
   *
   * Returns:
   * @modes's hsync rate in kHz, rounded to the nearest integer. Calculates the
   * value first if it is not yet set.
   */
  int drm_mode_hsync(const struct drm_display_mode *mode)
  {
  	unsigned int calc_val;
  
  	if (mode->hsync)
  		return mode->hsync;
  
  	if (mode->htotal < 0)
  		return 0;
  
  	calc_val = (mode->clock * 1000) / mode->htotal; /* hsync in Hz */
  	calc_val += 500;				/* round to 1000Hz */
  	calc_val /= 1000;				/* truncate to kHz */
  
  	return calc_val;
  }
  EXPORT_SYMBOL(drm_mode_hsync);
  
  /**
   * drm_mode_vrefresh - get the vrefresh of a mode
   * @mode: mode
   *
   * Returns:
   * @modes's vrefresh rate in Hz, rounded to the nearest integer. Calculates the
   * value first if it is not yet set.
   */
  int drm_mode_vrefresh(const struct drm_display_mode *mode)
  {
  	int refresh = 0;
  	unsigned int calc_val;
  
  	if (mode->vrefresh > 0)
  		refresh = mode->vrefresh;
  	else if (mode->htotal > 0 && mode->vtotal > 0) {
  		int vtotal;
  		vtotal = mode->vtotal;
  		/* work out vrefresh the value will be x1000 */
  		calc_val = (mode->clock * 1000);
  		calc_val /= mode->htotal;
  		refresh = (calc_val + vtotal / 2) / vtotal;
  
  		if (mode->flags & DRM_MODE_FLAG_INTERLACE)
  			refresh *= 2;
  		if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
  			refresh /= 2;
  		if (mode->vscan > 1)
  			refresh /= mode->vscan;
  	}
  	return refresh;
  }
  EXPORT_SYMBOL(drm_mode_vrefresh);
  
  /**
   * drm_mode_set_crtcinfo - set CRTC modesetting timing parameters
   * @p: mode
   * @adjust_flags: a combination of adjustment flags
   *
   * Setup the CRTC modesetting timing parameters for @p, adjusting if necessary.
   *
   * - The CRTC_INTERLACE_HALVE_V flag can be used to halve vertical timings of
   *   interlaced modes.
   * - The CRTC_STEREO_DOUBLE flag can be used to compute the timings for
   *   buffers containing two eyes (only adjust the timings when needed, eg. for
   *   "frame packing" or "side by side full").
   * - The CRTC_NO_DBLSCAN and CRTC_NO_VSCAN flags request that adjustment *not*
   *   be performed for doublescan and vscan > 1 modes respectively.
   */
  void drm_mode_set_crtcinfo(struct drm_display_mode *p, int adjust_flags)
  {
  	if ((p == NULL) || ((p->type & DRM_MODE_TYPE_CRTC_C) == DRM_MODE_TYPE_BUILTIN))
  		return;
  
  	p->crtc_clock = p->clock;
  	p->crtc_hdisplay = p->hdisplay;
  	p->crtc_hsync_start = p->hsync_start;
  	p->crtc_hsync_end = p->hsync_end;
  	p->crtc_htotal = p->htotal;
  	p->crtc_hskew = p->hskew;
  	p->crtc_vdisplay = p->vdisplay;
  	p->crtc_vsync_start = p->vsync_start;
  	p->crtc_vsync_end = p->vsync_end;
  	p->crtc_vtotal = p->vtotal;
  
  	if (p->flags & DRM_MODE_FLAG_INTERLACE) {
  		if (adjust_flags & CRTC_INTERLACE_HALVE_V) {
  			p->crtc_vdisplay /= 2;
  			p->crtc_vsync_start /= 2;
  			p->crtc_vsync_end /= 2;
  			p->crtc_vtotal /= 2;
  		}
  	}
  
  	if (!(adjust_flags & CRTC_NO_DBLSCAN)) {
  		if (p->flags & DRM_MODE_FLAG_DBLSCAN) {
  			p->crtc_vdisplay *= 2;
  			p->crtc_vsync_start *= 2;
  			p->crtc_vsync_end *= 2;
  			p->crtc_vtotal *= 2;
  		}
  	}
  
  	if (!(adjust_flags & CRTC_NO_VSCAN)) {
  		if (p->vscan > 1) {
  			p->crtc_vdisplay *= p->vscan;
  			p->crtc_vsync_start *= p->vscan;
  			p->crtc_vsync_end *= p->vscan;
  			p->crtc_vtotal *= p->vscan;
  		}
  	}
  
  	if (adjust_flags & CRTC_STEREO_DOUBLE) {
  		unsigned int layout = p->flags & DRM_MODE_FLAG_3D_MASK;
  
  		switch (layout) {
  		case DRM_MODE_FLAG_3D_FRAME_PACKING:
  			p->crtc_clock *= 2;
  			p->crtc_vdisplay += p->crtc_vtotal;
  			p->crtc_vsync_start += p->crtc_vtotal;
  			p->crtc_vsync_end += p->crtc_vtotal;
  			p->crtc_vtotal += p->crtc_vtotal;
  			break;
  		}
  	}
  
  	p->crtc_vblank_start = min(p->crtc_vsync_start, p->crtc_vdisplay);
  	p->crtc_vblank_end = max(p->crtc_vsync_end, p->crtc_vtotal);
  	p->crtc_hblank_start = min(p->crtc_hsync_start, p->crtc_hdisplay);
  	p->crtc_hblank_end = max(p->crtc_hsync_end, p->crtc_htotal);
  }
  EXPORT_SYMBOL(drm_mode_set_crtcinfo);
  
  /**
   * drm_mode_copy - copy the mode
   * @dst: mode to overwrite
   * @src: mode to copy
   *
   * Copy an existing mode into another mode, preserving the object id and
   * list head of the destination mode.
   */
  void drm_mode_copy(struct drm_display_mode *dst, const struct drm_display_mode *src)
  {
  	int id = dst->base.id;
  	struct list_head head = dst->head;
  
  	*dst = *src;
  	dst->base.id = id;
  	dst->head = head;
  }
  EXPORT_SYMBOL(drm_mode_copy);
  
  /**
   * drm_mode_duplicate - allocate and duplicate an existing mode
   * @dev: drm_device to allocate the duplicated mode for
   * @mode: mode to duplicate
   *
   * Just allocate a new mode, copy the existing mode into it, and return
   * a pointer to it.  Used to create new instances of established modes.
   *
   * Returns:
   * Pointer to duplicated mode on success, NULL on error.
   */
  struct drm_display_mode *drm_mode_duplicate(struct drm_device *dev,
  					    const struct drm_display_mode *mode)
  {
  	struct drm_display_mode *nmode;
  
  	nmode = drm_mode_create(dev);
  	if (!nmode)
  		return NULL;
  
  	drm_mode_copy(nmode, mode);
  
  	return nmode;
  }
  EXPORT_SYMBOL(drm_mode_duplicate);
  
  /**
   * drm_mode_equal - test modes for equality
   * @mode1: first mode
   * @mode2: second mode
   *
   * Check to see if @mode1 and @mode2 are equivalent.
   *
   * Returns:
   * True if the modes are equal, false otherwise.
   */
  bool drm_mode_equal(const struct drm_display_mode *mode1, const struct drm_display_mode *mode2)
  {
  	if (!mode1 && !mode2)
  		return true;
  
  	if (!mode1 || !mode2)
  		return false;
  
  	/* do clock check convert to PICOS so fb modes get matched
  	 * the same */
  	if (mode1->clock && mode2->clock) {
  		if (KHZ2PICOS(mode1->clock) != KHZ2PICOS(mode2->clock))
  			return false;
  	} else if (mode1->clock != mode2->clock)
  		return false;
  
  	if ((mode1->flags & DRM_MODE_FLAG_3D_MASK) !=
  	    (mode2->flags & DRM_MODE_FLAG_3D_MASK))
  		return false;
  
  	return drm_mode_equal_no_clocks_no_stereo(mode1, mode2);
  }
  EXPORT_SYMBOL(drm_mode_equal);
  
  /**
   * drm_mode_equal_no_clocks_no_stereo - test modes for equality
   * @mode1: first mode
   * @mode2: second mode
   *
   * Check to see if @mode1 and @mode2 are equivalent, but
   * don't check the pixel clocks nor the stereo layout.
   *
   * Returns:
   * True if the modes are equal, false otherwise.
   */
  bool drm_mode_equal_no_clocks_no_stereo(const struct drm_display_mode *mode1,
  					const struct drm_display_mode *mode2)
  {
  	if (mode1->hdisplay == mode2->hdisplay &&
  	    mode1->hsync_start == mode2->hsync_start &&
  	    mode1->hsync_end == mode2->hsync_end &&
  	    mode1->htotal == mode2->htotal &&
  	    mode1->hskew == mode2->hskew &&
  	    mode1->vdisplay == mode2->vdisplay &&
  	    mode1->vsync_start == mode2->vsync_start &&
  	    mode1->vsync_end == mode2->vsync_end &&
  	    mode1->vtotal == mode2->vtotal &&
  	    mode1->vscan == mode2->vscan &&
  	    (mode1->flags & ~DRM_MODE_FLAG_3D_MASK) ==
  	     (mode2->flags & ~DRM_MODE_FLAG_3D_MASK))
  		return true;
  
  	return false;
  }
  EXPORT_SYMBOL(drm_mode_equal_no_clocks_no_stereo);
  
  /**
   * drm_mode_validate_basic - make sure the mode is somewhat sane
   * @mode: mode to check
   *
   * Check that the mode timings are at least somewhat reasonable.
   * Any hardware specific limits are left up for each driver to check.
   *
   * Returns:
   * The mode status
   */
  enum drm_mode_status
  drm_mode_validate_basic(const struct drm_display_mode *mode)
  {
  	if (mode->clock == 0)
  		return MODE_CLOCK_LOW;
  
  	if (mode->hdisplay == 0 ||
  	    mode->hsync_start < mode->hdisplay ||
  	    mode->hsync_end < mode->hsync_start ||
  	    mode->htotal < mode->hsync_end)
  		return MODE_H_ILLEGAL;
  
  	if (mode->vdisplay == 0 ||
  	    mode->vsync_start < mode->vdisplay ||
  	    mode->vsync_end < mode->vsync_start ||
  	    mode->vtotal < mode->vsync_end)
  		return MODE_V_ILLEGAL;
  
  	return MODE_OK;
  }
  EXPORT_SYMBOL(drm_mode_validate_basic);
  
  /**
   * drm_mode_validate_size - make sure modes adhere to size constraints
   * @mode: mode to check
   * @maxX: maximum width
   * @maxY: maximum height
   *
   * This function is a helper which can be used to validate modes against size
   * limitations of the DRM device/connector. If a mode is too big its status
   * member is updated with the appropriate validation failure code. The list
   * itself is not changed.
   *
   * Returns:
   * The mode status
   */
  enum drm_mode_status
  drm_mode_validate_size(const struct drm_display_mode *mode,
  		       int maxX, int maxY)
  {
  	if (maxX > 0 && mode->hdisplay > maxX)
  		return MODE_VIRTUAL_X;
  
  	if (maxY > 0 && mode->vdisplay > maxY)
  		return MODE_VIRTUAL_Y;
  
  	return MODE_OK;
  }
  EXPORT_SYMBOL(drm_mode_validate_size);
  
  #define MODE_STATUS(status) [MODE_ ## status + 3] = #status
  
  static const char * const drm_mode_status_names[] = {
  	MODE_STATUS(OK),
  	MODE_STATUS(HSYNC),
  	MODE_STATUS(VSYNC),
  	MODE_STATUS(H_ILLEGAL),
  	MODE_STATUS(V_ILLEGAL),
  	MODE_STATUS(BAD_WIDTH),
  	MODE_STATUS(NOMODE),
  	MODE_STATUS(NO_INTERLACE),
  	MODE_STATUS(NO_DBLESCAN),
  	MODE_STATUS(NO_VSCAN),
  	MODE_STATUS(MEM),
  	MODE_STATUS(VIRTUAL_X),
  	MODE_STATUS(VIRTUAL_Y),
  	MODE_STATUS(MEM_VIRT),
  	MODE_STATUS(NOCLOCK),
  	MODE_STATUS(CLOCK_HIGH),
  	MODE_STATUS(CLOCK_LOW),
  	MODE_STATUS(CLOCK_RANGE),
  	MODE_STATUS(BAD_HVALUE),
  	MODE_STATUS(BAD_VVALUE),
  	MODE_STATUS(BAD_VSCAN),
  	MODE_STATUS(HSYNC_NARROW),
  	MODE_STATUS(HSYNC_WIDE),
  	MODE_STATUS(HBLANK_NARROW),
  	MODE_STATUS(HBLANK_WIDE),
  	MODE_STATUS(VSYNC_NARROW),
  	MODE_STATUS(VSYNC_WIDE),
  	MODE_STATUS(VBLANK_NARROW),
  	MODE_STATUS(VBLANK_WIDE),
  	MODE_STATUS(PANEL),
  	MODE_STATUS(INTERLACE_WIDTH),
  	MODE_STATUS(ONE_WIDTH),
  	MODE_STATUS(ONE_HEIGHT),
  	MODE_STATUS(ONE_SIZE),
  	MODE_STATUS(NO_REDUCED),
  	MODE_STATUS(NO_STEREO),
  	MODE_STATUS(UNVERIFIED),
  	MODE_STATUS(BAD),
  	MODE_STATUS(ERROR),
  };
  
  #undef MODE_STATUS
  
  static const char *drm_get_mode_status_name(enum drm_mode_status status)
  {
  	int index = status + 3;
  
  	if (WARN_ON(index < 0 || index >= ARRAY_SIZE(drm_mode_status_names)))
  		return "";
  
  	return drm_mode_status_names[index];
  }
  
  /**
   * drm_mode_prune_invalid - remove invalid modes from mode list
   * @dev: DRM device
   * @mode_list: list of modes to check
   * @verbose: be verbose about it
   *
   * This helper function can be used to prune a display mode list after
   * validation has been completed. All modes who's status is not MODE_OK will be
   * removed from the list, and if @verbose the status code and mode name is also
   * printed to dmesg.
   */
  void drm_mode_prune_invalid(struct drm_device *dev,
  			    struct list_head *mode_list, bool verbose)
  {
  	struct drm_display_mode *mode, *t;
  
  	list_for_each_entry_safe(mode, t, mode_list, head) {
  		if (mode->status != MODE_OK) {
  			list_del(&mode->head);
  			if (verbose) {
  				drm_mode_debug_printmodeline(mode);
  				DRM_DEBUG_KMS("Not using %s mode: %s\n",
  					      mode->name,
  					      drm_get_mode_status_name(mode->status));
  			}
  			drm_mode_destroy(dev, mode);
  		}
  	}
  }
  EXPORT_SYMBOL(drm_mode_prune_invalid);
  
  /**
   * drm_mode_compare - compare modes for favorability
   * @priv: unused
   * @lh_a: list_head for first mode
   * @lh_b: list_head for second mode
   *
   * Compare two modes, given by @lh_a and @lh_b, returning a value indicating
   * which is better.
   *
   * Returns:
   * Negative if @lh_a is better than @lh_b, zero if they're equivalent, or
   * positive if @lh_b is better than @lh_a.
   */
  static int drm_mode_compare(void *priv, struct list_head *lh_a, struct list_head *lh_b)
  {
  	struct drm_display_mode *a = list_entry(lh_a, struct drm_display_mode, head);
  	struct drm_display_mode *b = list_entry(lh_b, struct drm_display_mode, head);
  	int diff;
  
  	diff = ((b->type & DRM_MODE_TYPE_PREFERRED) != 0) -
  		((a->type & DRM_MODE_TYPE_PREFERRED) != 0);
  	if (diff)
  		return diff;
  	diff = b->hdisplay * b->vdisplay - a->hdisplay * a->vdisplay;
  	if (diff)
  		return diff;
  
  	diff = b->vrefresh - a->vrefresh;
  	if (diff)
  		return diff;
  
  	diff = b->clock - a->clock;
  	return diff;
  }
  
  /**
   * drm_mode_sort - sort mode list
   * @mode_list: list of drm_display_mode structures to sort
   *
   * Sort @mode_list by favorability, moving good modes to the head of the list.
   */
  void drm_mode_sort(struct list_head *mode_list)
  {
  	list_sort(NULL, mode_list, drm_mode_compare);
  }
  EXPORT_SYMBOL(drm_mode_sort);
  
  /**
   * drm_mode_connector_list_update - update the mode list for the connector
   * @connector: the connector to update
   * @merge_type_bits: whether to merge or overwrite type bits
   *
   * This moves the modes from the @connector probed_modes list
   * to the actual mode list. It compares the probed mode against the current
   * list and only adds different/new modes.
   *
   * This is just a helper functions doesn't validate any modes itself and also
   * doesn't prune any invalid modes. Callers need to do that themselves.
   */
  void drm_mode_connector_list_update(struct drm_connector *connector,
  				    bool merge_type_bits)
  {
  	struct drm_display_mode *mode;
  	struct drm_display_mode *pmode, *pt;
  	int found_it;
  
  	WARN_ON(!mutex_is_locked(&connector->dev->mode_config.mutex));
  
  	list_for_each_entry_safe(pmode, pt, &connector->probed_modes,
  				 head) {
  		found_it = 0;
  		/* go through current modes checking for the new probed mode */
  		list_for_each_entry(mode, &connector->modes, head) {
  			if (drm_mode_equal(pmode, mode)) {
  				found_it = 1;
  				/* if equal delete the probed mode */
  				mode->status = pmode->status;
  				/* Merge type bits together */
  				if (merge_type_bits)
  					mode->type |= pmode->type;
  				else
  					mode->type = pmode->type;
  				list_del(&pmode->head);
  				drm_mode_destroy(connector->dev, pmode);
  				break;
  			}
  		}
  
  		if (!found_it) {
  			list_move_tail(&pmode->head, &connector->modes);
  		}
  	}
  }
  EXPORT_SYMBOL(drm_mode_connector_list_update);
  
  /**
   * drm_mode_parse_command_line_for_connector - parse command line modeline for connector
   * @mode_option: optional per connector mode option
   * @connector: connector to parse modeline for
   * @mode: preallocated drm_cmdline_mode structure to fill out
   *
   * This parses @mode_option command line modeline for modes and options to
   * configure the connector. If @mode_option is NULL the default command line
   * modeline in fb_mode_option will be parsed instead.
   *
   * This uses the same parameters as the fb modedb.c, except for an extra
   * force-enable, force-enable-digital and force-disable bit at the end:
   *
   *	<xres>x<yres>[M][R][-<bpp>][@<refresh>][i][m][eDd]
   *
   * The intermediate drm_cmdline_mode structure is required to store additional
   * options from the command line modline like the force-enable/disable flag.
   *
   * Returns:
   * True if a valid modeline has been parsed, false otherwise.
   */
  bool drm_mode_parse_command_line_for_connector(const char *mode_option,
  					       struct drm_connector *connector,
  					       struct drm_cmdline_mode *mode)
  {
  	const char *name;
  	unsigned int namelen;
  	bool res_specified = false, bpp_specified = false, refresh_specified = false;
  	unsigned int xres = 0, yres = 0, bpp = 32, refresh = 0;
  	bool yres_specified = false, cvt = false, rb = false;
  	bool interlace = false, margins = false, was_digit = false;
  	int i;
  	enum drm_connector_force force = DRM_FORCE_UNSPECIFIED;
  
  #ifdef CONFIG_FB
  	if (!mode_option)
  		mode_option = fb_mode_option;
  #endif
  
  	if (!mode_option) {
  		mode->specified = false;
  		return false;
  	}
  
  	name = mode_option;
  	namelen = strlen(name);
  	for (i = namelen-1; i >= 0; i--) {
  		switch (name[i]) {
  		case '@':
  			if (!refresh_specified && !bpp_specified &&
  			    !yres_specified && !cvt && !rb && was_digit) {
  				refresh = simple_strtol(&name[i+1], NULL, 10);
  				refresh_specified = true;
  				was_digit = false;
  			} else
  				goto done;
  			break;
  		case '-':
  			if (!bpp_specified && !yres_specified && !cvt &&
  			    !rb && was_digit) {
  				bpp = simple_strtol(&name[i+1], NULL, 10);
  				bpp_specified = true;
  				was_digit = false;
  			} else
  				goto done;
  			break;
  		case 'x':
  			if (!yres_specified && was_digit) {
  				yres = simple_strtol(&name[i+1], NULL, 10);
  				yres_specified = true;
  				was_digit = false;
  			} else
  				goto done;
  			break;
  		case '0' ... '9':
  			was_digit = true;
  			break;
  		case 'M':
  			if (yres_specified || cvt || was_digit)
  				goto done;
  			cvt = true;
  			break;
  		case 'R':
  			if (yres_specified || cvt || rb || was_digit)
  				goto done;
  			rb = true;
  			break;
  		case 'm':
  			if (cvt || yres_specified || was_digit)
  				goto done;
  			margins = true;
  			break;
  		case 'i':
  			if (cvt || yres_specified || was_digit)
  				goto done;
  			interlace = true;
  			break;
  		case 'e':
  			if (yres_specified || bpp_specified || refresh_specified ||
  			    was_digit || (force != DRM_FORCE_UNSPECIFIED))
  				goto done;
  
  			force = DRM_FORCE_ON;
  			break;
  		case 'D':
  			if (yres_specified || bpp_specified || refresh_specified ||
  			    was_digit || (force != DRM_FORCE_UNSPECIFIED))
  				goto done;
  
  			if ((connector->connector_type != DRM_MODE_CONNECTOR_DVII) &&
  			    (connector->connector_type != DRM_MODE_CONNECTOR_HDMIB))
  				force = DRM_FORCE_ON;
  			else
  				force = DRM_FORCE_ON_DIGITAL;
  			break;
  		case 'd':
  			if (yres_specified || bpp_specified || refresh_specified ||
  			    was_digit || (force != DRM_FORCE_UNSPECIFIED))
  				goto done;
  
  			force = DRM_FORCE_OFF;
  			break;
  		default:
  			goto done;
  		}
  	}
  
  	if (i < 0 && yres_specified) {
  		char *ch;
  		xres = simple_strtol(name, &ch, 10);
  		if ((ch != NULL) && (*ch == 'x'))
  			res_specified = true;
  		else
  			i = ch - name;
  	} else if (!yres_specified && was_digit) {
  		/* catch mode that begins with digits but has no 'x' */
  		i = 0;
  	}
  done:
  	if (i >= 0) {
  		printk(KERN_WARNING
  			"parse error at position %i in video mode '%s'\n",
  			i, name);
  		mode->specified = false;
  		return false;
  	}
  
  	if (res_specified) {
  		mode->specified = true;
  		mode->xres = xres;
  		mode->yres = yres;
  	}
  
  	if (refresh_specified) {
  		mode->refresh_specified = true;
  		mode->refresh = refresh;
  	}
  
  	if (bpp_specified) {
  		mode->bpp_specified = true;
  		mode->bpp = bpp;
  	}
  	mode->rb = rb;
  	mode->cvt = cvt;
  	mode->interlace = interlace;
  	mode->margins = margins;
  	mode->force = force;
  
  	return true;
  }
  EXPORT_SYMBOL(drm_mode_parse_command_line_for_connector);
  
  /**
   * drm_mode_create_from_cmdline_mode - convert a command line modeline into a DRM display mode
   * @dev: DRM device to create the new mode for
   * @cmd: input command line modeline
   *
   * Returns:
   * Pointer to converted mode on success, NULL on error.
   */
  struct drm_display_mode *
  drm_mode_create_from_cmdline_mode(struct drm_device *dev,
  				  struct drm_cmdline_mode *cmd)
  {
  	struct drm_display_mode *mode;
  
  	if (cmd->cvt)
  		mode = drm_cvt_mode(dev,
  				    cmd->xres, cmd->yres,
  				    cmd->refresh_specified ? cmd->refresh : 60,
  				    cmd->rb, cmd->interlace,
  				    cmd->margins);
  	else
  		mode = drm_gtf_mode(dev,
  				    cmd->xres, cmd->yres,
  				    cmd->refresh_specified ? cmd->refresh : 60,
  				    cmd->interlace,
  				    cmd->margins);
  	if (!mode)
  		return NULL;
  
  	mode->type |= DRM_MODE_TYPE_USERDEF;
  	drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
  	return mode;
  }
  EXPORT_SYMBOL(drm_mode_create_from_cmdline_mode);
  
  /**
   * drm_crtc_convert_to_umode - convert a drm_display_mode into a modeinfo
   * @out: drm_mode_modeinfo struct to return to the user
   * @in: drm_display_mode to use
   *
   * Convert a drm_display_mode into a drm_mode_modeinfo structure to return to
   * the user.
   */
  void drm_mode_convert_to_umode(struct drm_mode_modeinfo *out,
  			       const struct drm_display_mode *in)
  {
  	WARN(in->hdisplay > USHRT_MAX || in->hsync_start > USHRT_MAX ||
  	     in->hsync_end > USHRT_MAX || in->htotal > USHRT_MAX ||
  	     in->hskew > USHRT_MAX || in->vdisplay > USHRT_MAX ||
  	     in->vsync_start > USHRT_MAX || in->vsync_end > USHRT_MAX ||
  	     in->vtotal > USHRT_MAX || in->vscan > USHRT_MAX,
  	     "timing values too large for mode info\n");
  
  	out->clock = in->clock;
  	out->hdisplay = in->hdisplay;
  	out->hsync_start = in->hsync_start;
  	out->hsync_end = in->hsync_end;
  	out->htotal = in->htotal;
  	out->hskew = in->hskew;
  	out->vdisplay = in->vdisplay;
  	out->vsync_start = in->vsync_start;
  	out->vsync_end = in->vsync_end;
  	out->vtotal = in->vtotal;
  	out->vscan = in->vscan;
  	out->vrefresh = in->vrefresh;
  	out->flags = in->flags;
  	out->type = in->type;
  	strncpy(out->name, in->name, DRM_DISPLAY_MODE_LEN);
  	out->name[DRM_DISPLAY_MODE_LEN-1] = 0;
  }
  
  /**
   * drm_crtc_convert_umode - convert a modeinfo into a drm_display_mode
   * @out: drm_display_mode to return to the user
   * @in: drm_mode_modeinfo to use
   *
   * Convert a drm_mode_modeinfo into a drm_display_mode structure to return to
   * the caller.
   *
   * Returns:
   * Zero on success, negative errno on failure.
   */
  int drm_mode_convert_umode(struct drm_display_mode *out,
  			   const struct drm_mode_modeinfo *in)
  {
  	int ret = -EINVAL;
  
  	if (in->clock > INT_MAX || in->vrefresh > INT_MAX) {
  		ret = -ERANGE;
  		goto out;
  	}
  
  	if ((in->flags & DRM_MODE_FLAG_3D_MASK) > DRM_MODE_FLAG_3D_MAX)
  		goto out;
  
  	out->clock = in->clock;
  	out->hdisplay = in->hdisplay;
  	out->hsync_start = in->hsync_start;
  	out->hsync_end = in->hsync_end;
  	out->htotal = in->htotal;
  	out->hskew = in->hskew;
  	out->vdisplay = in->vdisplay;
  	out->vsync_start = in->vsync_start;
  	out->vsync_end = in->vsync_end;
  	out->vtotal = in->vtotal;
  	out->vscan = in->vscan;
  	out->vrefresh = in->vrefresh;
  	out->flags = in->flags;
  	out->type = in->type;
  	strncpy(out->name, in->name, DRM_DISPLAY_MODE_LEN);
  	out->name[DRM_DISPLAY_MODE_LEN-1] = 0;
  
  	out->status = drm_mode_validate_basic(out);
  	if (out->status != MODE_OK)
  		goto out;
  
  	ret = 0;
  
  out:
  	return ret;
  }