drm_modes.c

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/*
 * Copyright © 1997-2003 by The XFree86 Project, Inc.
 * Copyright © 2007 Dave Airlie
 * Copyright © 2007-2008 Intel Corporation
 *   Jesse Barnes <[email protected]>
 * Copyright 2005-2006 Luc Verhaegen
 * Copyright (c) 2001, Andy Ritger  [email protected]
 *
 * 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>

void drm_mode_debug_printmodeline(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);

#define HV_FACTOR           1000
struct drm_display_mode *drm_cvt_mode(struct drm_device *dev, int hdisplay,
                      int vdisplay, int vrefresh,
                      bool reduced, bool interlaced, bool margins)
{
    /* 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 pixes 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);

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);

struct drm_display_mode *
drm_gtf_mode(struct drm_device *dev, int hdisplay, int vdisplay, int vrefresh,
         bool lace, int margins)
{
    return drm_gtf_mode_complex(dev, hdisplay, vdisplay, vrefresh, lace,
                    margins, 600, 40 * 2, 128, 20 * 2);
}
EXPORT_SYMBOL(drm_gtf_mode);

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);

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);

int drm_mode_width(struct drm_display_mode *mode)
{
    return mode->hdisplay;

}
EXPORT_SYMBOL(drm_mode_width);

int drm_mode_height(struct drm_display_mode *mode)
{
    return mode->vdisplay;
}
EXPORT_SYMBOL(drm_mode_height);

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);

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);

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;
        }
    }

    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);
}
EXPORT_SYMBOL(drm_mode_set_crtcinfo);


void drm_mode_copy(struct drm_display_mode *dst, const struct drm_display_mode *src)
{
    int id = dst->base.id;

    *dst = *src;
    dst->base.id = id;
    INIT_LIST_HEAD(&dst->head);
}
EXPORT_SYMBOL(drm_mode_copy);

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);

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);

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);

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);

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 %d\n",
                    mode->name, mode->status);
            }
            drm_mode_destroy(dev, mode);
        }
    }
}
EXPORT_SYMBOL(drm_mode_prune_invalid);

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->clock - a->clock;
    return diff;
}

void drm_mode_sort(struct list_head *mode_list)
{
    list_sort(NULL, mode_list, drm_mode_compare);
}
EXPORT_SYMBOL(drm_mode_sort);

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);

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;
        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);

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;

    drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
    return mode;
}
EXPORT_SYMBOL(drm_mode_create_from_cmdline_mode);