sbin/hammer2/cmd_debug.c: Clear errno

[dragonfly.git] / sys / dev / drm / drm_modes.c

/*
 * 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 " DRM_MODE_FMT "\n", DRM_MODE_ARG(mode));
}
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_add(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_unregister(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;
        u64 tmp;

        /* 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) */
        tmp = drm_mode->htotal; /* perform intermediate calcs in u64 */
        tmp *= HV_FACTOR * 1000;
        do_div(tmp, hperiod);
        tmp -= drm_mode->clock % CVT_CLOCK_STEP;
        drm_mode->clock = tmp;
        /* 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);
}

/**
 * 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;
}

/**
 * drm_bus_flags_from_videomode - extract information about pixelclk and
 * DE polarity from videomode and store it in a separate variable
 * @vm: videomode structure to use
 * @bus_flags: information about pixelclk and DE polarity will be stored here
 *
 * Sets DRM_BUS_FLAG_DE_(LOW|HIGH) and DRM_BUS_FLAG_PIXDATA_(POS|NEG)EDGE
 * in @bus_flags according to DISPLAY_FLAGS found in @vm
 */
void drm_bus_flags_from_videomode(const struct videomode *vm, u32 *bus_flags)
{
        *bus_flags = 0;
        if (vm->flags & DISPLAY_FLAGS_PIXDATA_POSEDGE)
                *bus_flags |= DRM_BUS_FLAG_PIXDATA_POSEDGE;
        if (vm->flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
                *bus_flags |= DRM_BUS_FLAG_PIXDATA_NEGEDGE;

        if (vm->flags & DISPLAY_FLAGS_DE_LOW)
                *bus_flags |= DRM_BUS_FLAG_DE_LOW;
        if (vm->flags & DISPLAY_FLAGS_DE_HIGH)
                *bus_flags |= DRM_BUS_FLAG_DE_HIGH;
}
EXPORT_SYMBOL_GPL(drm_bus_flags_from_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
 * @bus_flags: information about pixelclk and DE polarity
 * @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, u32 *bus_flags,
                            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);
        if (bus_flags)
                drm_bus_flags_from_videomode(&vm, bus_flags);

        pr_debug("%pOF: got %dx%d display mode from %s\n",
                np, vm.hactive, vm.vactive, np->name);
        drm_mode_debug_printmodeline(dmode);

        return 0;
}
#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_get_hv_timing - Fetches hdisplay/vdisplay for given mode
 * @mode: mode to query
 * @hdisplay: hdisplay value to fill in
 * @vdisplay: vdisplay value to fill in
 *
 * The vdisplay value will be doubled if the specified mode is a stereo mode of
 * the appropriate layout.
 */
void drm_mode_get_hv_timing(const struct drm_display_mode *mode,
                            int *hdisplay, int *vdisplay)
{
        struct drm_display_mode adjusted = *mode;

        drm_mode_set_crtcinfo(&adjusted, CRTC_STEREO_DOUBLE_ONLY);
        *hdisplay = adjusted.crtc_hdisplay;
        *vdisplay = adjusted.crtc_vdisplay;
}
EXPORT_SYMBOL(drm_mode_get_hv_timing);

/**
 * 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;

        return drm_mode_equal_no_clocks(mode1, mode2);
}
EXPORT_SYMBOL(drm_mode_equal);

/**
 * drm_mode_equal_no_clocks - 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.
 *
 * Returns:
 * True if the modes are equal, false otherwise.
 */
bool drm_mode_equal_no_clocks(const struct drm_display_mode *mode1, const struct drm_display_mode *mode2)
{
        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_no_clocks);

/**
 * 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);

/**
 * drm_mode_validate_ycbcr420 - add 'ycbcr420-only' modes only when allowed
 * @mode: mode to check
 * @connector: drm connector under action
 *
 * This function is a helper which can be used to filter out any YCBCR420
 * only mode, when the source doesn't support it.
 *
 * Returns:
 * The mode status
 */
enum drm_mode_status
drm_mode_validate_ycbcr420(const struct drm_display_mode *mode,
                           struct drm_connector *connector)
{
        u8 vic = drm_match_cea_mode(mode);
        enum drm_mode_status status = MODE_OK;
        struct drm_hdmi_info *hdmi = &connector->display_info.hdmi;

        if (test_bit(vic, hdmi->y420_vdb_modes)) {
                if (!connector->ycbcr_420_allowed)
                        status = MODE_NO_420;
        }

        return status;
}
EXPORT_SYMBOL(drm_mode_validate_ycbcr420);

#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(NO_420),
        MODE_STATUS(STALE),
        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
 *
 * 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)
{
        struct drm_display_mode *pmode, *pt;

        WARN_ON(!mutex_is_locked(&connector->dev->mode_config.mutex));

        list_for_each_entry_safe(pmode, pt, &connector->probed_modes, head) {
                struct drm_display_mode *mode;
                bool found_it = false;

                /* go through current modes checking for the new probed mode */
                list_for_each_entry(mode, &connector->modes, head) {
                        if (!drm_mode_equal(pmode, mode))
                                continue;

                        found_it = true;

                        /*
                         * If the old matching mode is stale (ie. left over
                         * from a previous probe) just replace it outright.
                         * Otherwise just merge the type bits between all
                         * equal probed modes.
                         *
                         * If two probed modes are considered equal, pick the
                         * actual timings from the one that's marked as
                         * preferred (in case the match isn't 100%). If
                         * multiple or zero preferred modes are present, favor
                         * the mode added to the probed_modes list first.
                         */
                        if (mode->status == MODE_STALE) {
                                drm_mode_copy(mode, pmode);
                        } else if ((mode->type & DRM_MODE_TYPE_PREFERRED) == 0 &&
                                   (pmode->type & DRM_MODE_TYPE_PREFERRED) != 0) {
                                pmode->type |= mode->type;
                                drm_mode_copy(mode, pmode);
                        } 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) {
                pr_warn("[drm] 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;
        /* fix up 1368x768: GFT/CVT can't express 1366 width due to alignment */
        if (cmd->xres == 1366)
                drm_mode_fixup_1366x768(mode);
        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;

        drm_mode_set_crtcinfo(out, CRTC_INTERLACE_HALVE_V);

        ret = 0;

out:
        return ret;
}

/**
 * drm_mode_is_420_only - if a given videomode can be only supported in YCBCR420
 * output format
 *
 * @display: display under action
 * @mode: video mode to be tested.
 *
 * Returns:
 * true if the mode can be supported in YCBCR420 format
 * false if not.
 */
bool drm_mode_is_420_only(const struct drm_display_info *display,
                          const struct drm_display_mode *mode)
{
        u8 vic = drm_match_cea_mode(mode);

        return test_bit(vic, display->hdmi.y420_vdb_modes);
}
EXPORT_SYMBOL(drm_mode_is_420_only);

/**
 * drm_mode_is_420_also - if a given videomode can be supported in YCBCR420
 * output format also (along with RGB/YCBCR444/422)
 *
 * @display: display under action.
 * @mode: video mode to be tested.
 *
 * Returns:
 * true if the mode can be support YCBCR420 format
 * false if not.
 */
bool drm_mode_is_420_also(const struct drm_display_info *display,
                          const struct drm_display_mode *mode)
{
        u8 vic = drm_match_cea_mode(mode);

        return test_bit(vic, display->hdmi.y420_cmdb_modes);
}
EXPORT_SYMBOL(drm_mode_is_420_also);
/**
 * drm_mode_is_420 - if a given videomode can be supported in YCBCR420
 * output format
 *
 * @display: display under action.
 * @mode: video mode to be tested.
 *
 * Returns:
 * true if the mode can be supported in YCBCR420 format
 * false if not.
 */
bool drm_mode_is_420(const struct drm_display_info *display,
                     const struct drm_display_mode *mode)
{
        return drm_mode_is_420_only(display, mode) ||
                drm_mode_is_420_also(display, mode);
}
EXPORT_SYMBOL(drm_mode_is_420);