drivers/gpu/drm/drm_modes.c - kernel/msm-4.19 - Gitiles

 /*
  * The list_sort function is (presumably) licensed under the GPL (see the
  * top level "COPYING" file for details).
  *
  * The remainder of this file is:
  *
  * Copyright © 1997-2003 by The XFree86 Project, Inc.
  * Copyright © 2007 Dave Airlie
  * Copyright © 2007-2008 Intel Corporation
  *   Jesse Barnes <jesse.barnes@intel.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 "drmP.h"
 #include "drm.h"
 #include "drm_crtc.h"

 #define DRM_MODESET_DEBUG	"drm_mode"
 /**
  * drm_mode_debug_printmodeline - debug print a mode
  * @dev: DRM device
  * @mode: mode to print
  *
  * LOCKING:
  * None.
  *
  * Describe @mode using DRM_DEBUG.
  */
 void drm_mode_debug_printmodeline(struct drm_display_mode *mode)
 {
 	DRM_DEBUG_MODE(DRM_MODESET_DEBUG,
 		"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_set_name - set the name on a mode
  * @mode: name will be set in this mode
  *
  * LOCKING:
  * None.
  *
  * Set the name of @mode to a standard format.
  */
 void drm_mode_set_name(struct drm_display_mode *mode)
 {
 	snprintf(mode->name, DRM_DISPLAY_MODE_LEN, "%dx%d", mode->hdisplay,
 		 mode->vdisplay);
 }
 EXPORT_SYMBOL(drm_mode_set_name);

 /**
  * drm_mode_list_concat - move modes from one list to another
  * @head: source list
  * @new: dst list
  *
  * LOCKING:
  * Caller must ensure both lists are locked.
  *
  * Move all the modes from @head to @new.
  */
 void drm_mode_list_concat(struct list_head *head, struct list_head *new)
 {

 	struct list_head *entry, *tmp;

 	list_for_each_safe(entry, tmp, head) {
 		list_move_tail(entry, new);
 	}
 }
 EXPORT_SYMBOL(drm_mode_list_concat);

 /**
  * drm_mode_width - get the width of a mode
  * @mode: mode
  *
  * LOCKING:
  * None.
  *
  * Return @mode's width (hdisplay) value.
  *
  * FIXME: is this needed?
  *
  * RETURNS:
  * @mode->hdisplay
  */
 int drm_mode_width(struct drm_display_mode *mode)
 {
 	return mode->hdisplay;

 }
 EXPORT_SYMBOL(drm_mode_width);

 /**
  * drm_mode_height - get the height of a mode
  * @mode: mode
  *
  * LOCKING:
  * None.
  *
  * Return @mode's height (vdisplay) value.
  *
  * FIXME: is this needed?
  *
  * RETURNS:
  * @mode->vdisplay
  */
 int drm_mode_height(struct drm_display_mode *mode)
 {
 	return mode->vdisplay;
 }
 EXPORT_SYMBOL(drm_mode_height);

 /**
  * drm_mode_vrefresh - get the vrefresh of a mode
  * @mode: mode
  *
  * LOCKING:
  * None.
  *
  * Return @mode's vrefresh rate or calculate it if necessary.
  *
  * FIXME: why is this needed?  shouldn't vrefresh be set already?
  *
  * RETURNS:
  * Vertical refresh rate of @mode x 1000. For precision reasons.
  */
 int drm_mode_vrefresh(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) {
 		/* work out vrefresh the value will be x1000 */
 		calc_val = (mode->clock * 1000);

 		calc_val /= mode->htotal;
 		calc_val *= 1000;
 		calc_val /= mode->vtotal;

 		refresh = calc_val;
 		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 parameters
  * @p: mode
  * @adjust_flags: unused? (FIXME)
  *
  * LOCKING:
  * None.
  *
  * Setup the CRTC modesetting parameters for @p, adjusting if necessary.
  */
 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_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;
 		}

 		p->crtc_vtotal |= 1;
 	}

 	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 (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;
 	}

 	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);

 	p->crtc_hadjusted = false;
 	p->crtc_vadjusted = false;
 }
 EXPORT_SYMBOL(drm_mode_set_crtcinfo);


 /**
  * drm_mode_duplicate - allocate and duplicate an existing mode
  * @m: mode to duplicate
  *
  * LOCKING:
  * None.
  *
  * 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.
  */
 struct drm_display_mode *drm_mode_duplicate(struct drm_device *dev,
 					    struct drm_display_mode *mode)
 {
 	struct drm_display_mode *nmode;
 	int new_id;

 	nmode = drm_mode_create(dev);
 	if (!nmode)
 		return NULL;

 	new_id = nmode->base.id;
 	*nmode = *mode;
 	nmode->base.id = new_id;
 	INIT_LIST_HEAD(&nmode->head);
 	return nmode;
 }
 EXPORT_SYMBOL(drm_mode_duplicate);

 /**
  * drm_mode_equal - test modes for equality
  * @mode1: first mode
  * @mode2: second mode
  *
  * LOCKING:
  * None.
  *
  * Check to see if @mode1 and @mode2 are equivalent.
  *
  * RETURNS:
  * True if the modes are equal, false otherwise.
  */
 bool drm_mode_equal(struct drm_display_mode *mode1, struct drm_display_mode *mode2)
 {
 	/* 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->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 == mode2->flags)
 		return true;

 	return false;
 }
 EXPORT_SYMBOL(drm_mode_equal);

 /**
  * drm_mode_validate_size - make sure modes adhere to size constraints
  * @dev: DRM device
  * @mode_list: list of modes to check
  * @maxX: maximum width
  * @maxY: maximum height
  * @maxPitch: max pitch
  *
  * LOCKING:
  * Caller must hold a lock protecting @mode_list.
  *
  * The DRM device (@dev) has size and pitch limits.  Here we validate the
  * modes we probed for @dev against those limits and set their status as
  * necessary.
  */
 void drm_mode_validate_size(struct drm_device *dev,
 			    struct list_head *mode_list,
 			    int maxX, int maxY, int maxPitch)
 {
 	struct drm_display_mode *mode;

 	list_for_each_entry(mode, mode_list, head) {
 		if (maxPitch > 0 && mode->hdisplay > maxPitch)
 			mode->status = MODE_BAD_WIDTH;

 		if (maxX > 0 && mode->hdisplay > maxX)
 			mode->status = MODE_VIRTUAL_X;

 		if (maxY > 0 && mode->vdisplay > maxY)
 			mode->status = MODE_VIRTUAL_Y;
 	}
 }
 EXPORT_SYMBOL(drm_mode_validate_size);

 /**
  * drm_mode_validate_clocks - validate modes against clock limits
  * @dev: DRM device
  * @mode_list: list of modes to check
  * @min: minimum clock rate array
  * @max: maximum clock rate array
  * @n_ranges: number of clock ranges (size of arrays)
  *
  * LOCKING:
  * Caller must hold a lock protecting @mode_list.
  *
  * Some code may need to check a mode list against the clock limits of the
  * device in question.  This function walks the mode list, testing to make
  * sure each mode falls within a given range (defined by @min and @max
  * arrays) and sets @mode->status as needed.
  */
 void drm_mode_validate_clocks(struct drm_device *dev,
 			      struct list_head *mode_list,
 			      int *min, int *max, int n_ranges)
 {
 	struct drm_display_mode *mode;
 	int i;

 	list_for_each_entry(mode, mode_list, head) {
 		bool good = false;
 		for (i = 0; i < n_ranges; i++) {
 			if (mode->clock >= min[i] && mode->clock <= max[i]) {
 				good = true;
 				break;
 			}
 		}
 		if (!good)
 			mode->status = MODE_CLOCK_RANGE;
 	}
 }
 EXPORT_SYMBOL(drm_mode_validate_clocks);

 /**
  * 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
  *
  * LOCKING:
  * Caller must hold a lock protecting @mode_list.
  *
  * Once mode list generation is complete, a caller can use this routine to
  * remove invalid modes from a mode list.  If any of the modes have a
  * status other than %MODE_OK, they are removed from @mode_list and freed.
  */
 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_MODE(DRM_MODESET_DEBUG,
 					"Not using %s mode %d\n",
 					mode->name, mode->status);
 			}
 			drm_mode_destroy(dev, mode);
 		}
 	}
 }
 EXPORT_SYMBOL(drm_mode_prune_invalid);

 /**
  * drm_mode_compare - compare modes for favorability
  * @lh_a: list_head for first mode
  * @lh_b: list_head for second mode
  *
  * LOCKING:
  * None.
  *
  * 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(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->clock - a->clock;
 	return diff;
 }

 /* FIXME: what we don't have a list sort function? */
 /* list sort from Mark J Roberts (mjr@znex.org) */
 void list_sort(struct list_head *head,
 	       int (*cmp)(struct list_head *a, struct list_head *b))
 {
 	struct list_head *p, *q, *e, *list, *tail, *oldhead;
 	int insize, nmerges, psize, qsize, i;

 	list = head->next;
 	list_del(head);
 	insize = 1;
 	for (;;) {
 		p = oldhead = list;
 		list = tail = NULL;
 		nmerges = 0;

 		while (p) {
 			nmerges++;
 			q = p;
 			psize = 0;
 			for (i = 0; i < insize; i++) {
 				psize++;
 				q = q->next == oldhead ? NULL : q->next;
 				if (!q)
 					break;
 			}

 			qsize = insize;
 			while (psize > 0 || (qsize > 0 && q)) {
 				if (!psize) {
 					e = q;
 					q = q->next;
 					qsize--;
 					if (q == oldhead)
 						q = NULL;
 				} else if (!qsize || !q) {
 					e = p;
 					p = p->next;
 					psize--;
 					if (p == oldhead)
 						p = NULL;
 				} else if (cmp(p, q) <= 0) {
 					e = p;
 					p = p->next;
 					psize--;
 					if (p == oldhead)
 						p = NULL;
 				} else {
 					e = q;
 					q = q->next;
 					qsize--;
 					if (q == oldhead)
 						q = NULL;
 				}
 				if (tail)
 					tail->next = e;
 				else
 					list = e;
 				e->prev = tail;
 				tail = e;
 			}
 			p = q;
 		}

 		tail->next = list;
 		list->prev = tail;

 		if (nmerges <= 1)
 			break;

 		insize *= 2;
 	}

 	head->next = list;
 	head->prev = list->prev;
 	list->prev->next = head;
 	list->prev = head;
 }

 /**
  * drm_mode_sort - sort mode list
  * @mode_list: list to sort
  *
  * LOCKING:
  * Caller must hold a lock protecting @mode_list.
  *
  * Sort @mode_list by favorability, putting good modes first.
  */
 void drm_mode_sort(struct list_head *mode_list)
 {
 	list_sort(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
  *
  * LOCKING:
  * Caller must hold a lock protecting @mode_list.
  *
  * 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 modes. All modes unverified after this point
  * will be removed by the prune invalid modes.
  */
 void drm_mode_connector_list_update(struct drm_connector *connector)
 {
 	struct drm_display_mode *mode;
 	struct drm_display_mode *pmode, *pt;
 	int found_it;

 	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 */
 				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);
	/*
	* The list_sort function is (presumably) licensed under the GPL (see the
	* top level "COPYING" file for details).
	*
	* The remainder of this file is:
	*
	* Copyright © 1997-2003 by The XFree86 Project, Inc.
	* Copyright © 2007 Dave Airlie
	* Copyright © 2007-2008 Intel Corporation
	* Jesse Barnes <jesse.barnes@intel.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 "drmP.h"
	#include "drm.h"
	#include "drm_crtc.h"

	#define DRM_MODESET_DEBUG "drm_mode"
	/**
	* drm_mode_debug_printmodeline - debug print a mode
	* @dev: DRM device
	* @mode: mode to print
	*
	* LOCKING:
	* None.
	*
	* Describe @mode using DRM_DEBUG.
	*/
	void drm_mode_debug_printmodeline(struct drm_display_mode *mode)
	{
	DRM_DEBUG_MODE(DRM_MODESET_DEBUG,
	"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_set_name - set the name on a mode
	* @mode: name will be set in this mode
	*
	* LOCKING:
	* None.
	*
	* Set the name of @mode to a standard format.
	*/
	void drm_mode_set_name(struct drm_display_mode *mode)
	{
	snprintf(mode->name, DRM_DISPLAY_MODE_LEN, "%dx%d", mode->hdisplay,
	mode->vdisplay);
	}
	EXPORT_SYMBOL(drm_mode_set_name);

	/**
	* drm_mode_list_concat - move modes from one list to another
	* @head: source list
	* @new: dst list
	*
	* LOCKING:
	* Caller must ensure both lists are locked.
	*
	* Move all the modes from @head to @new.
	*/
	void drm_mode_list_concat(struct list_head head, struct list_head new)
	{

	struct list_head entry, tmp;

	list_for_each_safe(entry, tmp, head) {
	list_move_tail(entry, new);
	}
	}
	EXPORT_SYMBOL(drm_mode_list_concat);

	/**
	* drm_mode_width - get the width of a mode
	* @mode: mode
	*
	* LOCKING:
	* None.
	*
	* Return @mode's width (hdisplay) value.
	*
	* FIXME: is this needed?
	*
	* RETURNS:
	* @mode->hdisplay
	*/
	int drm_mode_width(struct drm_display_mode *mode)
	{
	return mode->hdisplay;

	}
	EXPORT_SYMBOL(drm_mode_width);

	/**
	* drm_mode_height - get the height of a mode
	* @mode: mode
	*
	* LOCKING:
	* None.
	*
	* Return @mode's height (vdisplay) value.
	*
	* FIXME: is this needed?
	*
	* RETURNS:
	* @mode->vdisplay
	*/
	int drm_mode_height(struct drm_display_mode *mode)
	{
	return mode->vdisplay;
	}
	EXPORT_SYMBOL(drm_mode_height);

	/**
	* drm_mode_vrefresh - get the vrefresh of a mode
	* @mode: mode
	*
	* LOCKING:
	* None.
	*
	* Return @mode's vrefresh rate or calculate it if necessary.
	*
	* FIXME: why is this needed? shouldn't vrefresh be set already?
	*
	* RETURNS:
	* Vertical refresh rate of @mode x 1000. For precision reasons.
	*/
	int drm_mode_vrefresh(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) {
	/* work out vrefresh the value will be x1000 */
	calc_val = (mode->clock * 1000);

	calc_val /= mode->htotal;
	calc_val *= 1000;
	calc_val /= mode->vtotal;

	refresh = calc_val;
	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 parameters
	* @p: mode
	* @adjust_flags: unused? (FIXME)
	*
	* LOCKING:
	* None.
	*
	* Setup the CRTC modesetting parameters for @p, adjusting if necessary.
	*/
	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_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;
	}

	p->crtc_vtotal \|= 1;
	}

	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 (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;
	}

	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);

	p->crtc_hadjusted = false;
	p->crtc_vadjusted = false;
	}
	EXPORT_SYMBOL(drm_mode_set_crtcinfo);


	/**
	* drm_mode_duplicate - allocate and duplicate an existing mode
	* @m: mode to duplicate
	*
	* LOCKING:
	* None.
	*
	* 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.
	*/
	struct drm_display_mode drm_mode_duplicate(struct drm_device dev,
	struct drm_display_mode *mode)
	{
	struct drm_display_mode *nmode;
	int new_id;

	nmode = drm_mode_create(dev);
	if (!nmode)
	return NULL;

	new_id = nmode->base.id;
	nmode = mode;
	nmode->base.id = new_id;
	INIT_LIST_HEAD(&nmode->head);
	return nmode;
	}
	EXPORT_SYMBOL(drm_mode_duplicate);

	/**
	* drm_mode_equal - test modes for equality
	* @mode1: first mode
	* @mode2: second mode
	*
	* LOCKING:
	* None.
	*
	* Check to see if @mode1 and @mode2 are equivalent.
	*
	* RETURNS:
	* True if the modes are equal, false otherwise.
	*/
	bool drm_mode_equal(struct drm_display_mode mode1, struct drm_display_mode mode2)
	{
	/* 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->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 == mode2->flags)
	return true;

	return false;
	}
	EXPORT_SYMBOL(drm_mode_equal);

	/**
	* drm_mode_validate_size - make sure modes adhere to size constraints
	* @dev: DRM device
	* @mode_list: list of modes to check
	* @maxX: maximum width
	* @maxY: maximum height
	* @maxPitch: max pitch
	*
	* LOCKING:
	* Caller must hold a lock protecting @mode_list.
	*
	* The DRM device (@dev) has size and pitch limits. Here we validate the
	* modes we probed for @dev against those limits and set their status as
	* necessary.
	*/
	void drm_mode_validate_size(struct drm_device *dev,
	struct list_head *mode_list,
	int maxX, int maxY, int maxPitch)
	{
	struct drm_display_mode *mode;

	list_for_each_entry(mode, mode_list, head) {
	if (maxPitch > 0 && mode->hdisplay > maxPitch)
	mode->status = MODE_BAD_WIDTH;

	if (maxX > 0 && mode->hdisplay > maxX)
	mode->status = MODE_VIRTUAL_X;

	if (maxY > 0 && mode->vdisplay > maxY)
	mode->status = MODE_VIRTUAL_Y;
	}
	}
	EXPORT_SYMBOL(drm_mode_validate_size);

	/**
	* drm_mode_validate_clocks - validate modes against clock limits
	* @dev: DRM device
	* @mode_list: list of modes to check
	* @min: minimum clock rate array
	* @max: maximum clock rate array
	* @n_ranges: number of clock ranges (size of arrays)
	*
	* LOCKING:
	* Caller must hold a lock protecting @mode_list.
	*
	* Some code may need to check a mode list against the clock limits of the
	* device in question. This function walks the mode list, testing to make
	* sure each mode falls within a given range (defined by @min and @max
	* arrays) and sets @mode->status as needed.
	*/
	void drm_mode_validate_clocks(struct drm_device *dev,
	struct list_head *mode_list,
	int min, int max, int n_ranges)
	{
	struct drm_display_mode *mode;
	int i;

	list_for_each_entry(mode, mode_list, head) {
	bool good = false;
	for (i = 0; i < n_ranges; i++) {
	if (mode->clock >= min[i] && mode->clock <= max[i]) {
	good = true;
	break;
	}
	}
	if (!good)
	mode->status = MODE_CLOCK_RANGE;
	}
	}
	EXPORT_SYMBOL(drm_mode_validate_clocks);

	/**
	* 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
	*
	* LOCKING:
	* Caller must hold a lock protecting @mode_list.
	*
	* Once mode list generation is complete, a caller can use this routine to
	* remove invalid modes from a mode list. If any of the modes have a
	* status other than %MODE_OK, they are removed from @mode_list and freed.
	*/
	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_MODE(DRM_MODESET_DEBUG,
	"Not using %s mode %d\n",
	mode->name, mode->status);
	}
	drm_mode_destroy(dev, mode);
	}
	}
	}
	EXPORT_SYMBOL(drm_mode_prune_invalid);

	/**
	* drm_mode_compare - compare modes for favorability
	* @lh_a: list_head for first mode
	* @lh_b: list_head for second mode
	*
	* LOCKING:
	* None.
	*
	* 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(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->clock - a->clock;
	return diff;
	}

	/* FIXME: what we don't have a list sort function? */
	/* list sort from Mark J Roberts (mjr@znex.org) */
	void list_sort(struct list_head *head,
	int (cmp)(struct list_head a, struct list_head *b))
	{
	struct list_head p, q, e, list, tail, oldhead;
	int insize, nmerges, psize, qsize, i;

	list = head->next;
	list_del(head);
	insize = 1;
	for (;;) {
	p = oldhead = list;
	list = tail = NULL;
	nmerges = 0;

	while (p) {
	nmerges++;
	q = p;
	psize = 0;
	for (i = 0; i < insize; i++) {
	psize++;
	q = q->next == oldhead ? NULL : q->next;
	if (!q)
	break;
	}

	qsize = insize;
	while (psize > 0 \|\| (qsize > 0 && q)) {
	if (!psize) {
	e = q;
	q = q->next;
	qsize--;
	if (q == oldhead)
	q = NULL;
	} else if (!qsize \|\| !q) {
	e = p;
	p = p->next;
	psize--;
	if (p == oldhead)
	p = NULL;
	} else if (cmp(p, q) <= 0) {
	e = p;
	p = p->next;
	psize--;
	if (p == oldhead)
	p = NULL;
	} else {
	e = q;
	q = q->next;
	qsize--;
	if (q == oldhead)
	q = NULL;
	}
	if (tail)
	tail->next = e;
	else
	list = e;
	e->prev = tail;
	tail = e;
	}
	p = q;
	}

	tail->next = list;
	list->prev = tail;

	if (nmerges <= 1)
	break;

	insize *= 2;
	}

	head->next = list;
	head->prev = list->prev;
	list->prev->next = head;
	list->prev = head;
	}

	/**
	* drm_mode_sort - sort mode list
	* @mode_list: list to sort
	*
	* LOCKING:
	* Caller must hold a lock protecting @mode_list.
	*
	* Sort @mode_list by favorability, putting good modes first.
	*/
	void drm_mode_sort(struct list_head *mode_list)
	{
	list_sort(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
	*
	* LOCKING:
	* Caller must hold a lock protecting @mode_list.
	*
	* 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 modes. All modes unverified after this point
	* will be removed by the prune invalid modes.
	*/
	void drm_mode_connector_list_update(struct drm_connector *connector)
	{
	struct drm_display_mode *mode;
	struct drm_display_mode pmode, pt;
	int found_it;

	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 */
	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);