mutter/src/backends/native/meta-kms-utils.c
Jonas Ådahl 8932388dda backend/native: Move some KMS utilities to its own file
They are not strictly related to any of the KMS objects, and should be
reusable without adding a dependency on the non-meta-kms-* files in
meta-kms-*.

https://gitlab.gnome.org/GNOME/mutter/issues/548
https://gitlab.gnome.org/GNOME/mutter/merge_requests/525
2019-06-20 13:31:56 +00:00

84 lines
2.2 KiB
C

/*
* Copyright (C) 2013-2019 Red Hat
* Copyright (c) 2018 DisplayLink (UK) Ltd.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*/
#include "config.h"
#include "backends/native/meta-kms-utils.h"
#include <drm_fourcc.h>
#include <glib.h>
/* added in libdrm 2.4.95 */
#ifndef DRM_FORMAT_INVALID
#define DRM_FORMAT_INVALID 0
#endif
float
meta_calculate_drm_mode_refresh_rate (const drmModeModeInfo *drm_mode)
{
float refresh = 0.0;
if (drm_mode->htotal > 0 && drm_mode->vtotal > 0)
{
/* Calculate refresh rate in milliHz first for extra precision. */
refresh = (drm_mode->clock * 1000000LL) / drm_mode->htotal;
refresh += (drm_mode->vtotal / 2);
refresh /= drm_mode->vtotal;
if (drm_mode->vscan > 1)
refresh /= drm_mode->vscan;
refresh /= 1000.0;
}
return refresh;
}
/**
* meta_drm_format_to_string:
* @tmp: temporary buffer
* @drm_format: DRM fourcc pixel format
*
* Returns a pointer to a string naming the given pixel format,
* usually a pointer to the temporary buffer but not always.
* Invalid formats may return nonsense names.
*
* When calling this, allocate one MetaDrmFormatBuf on the stack to
* be used as the temporary buffer.
*/
const char *
meta_drm_format_to_string (MetaDrmFormatBuf *tmp,
uint32_t drm_format)
{
int i;
if (drm_format == DRM_FORMAT_INVALID)
return "INVALID";
G_STATIC_ASSERT (sizeof (tmp->s) == 5);
for (i = 0; i < 4; i++)
{
char c = (drm_format >> (i * 8)) & 0xff;
tmp->s[i] = g_ascii_isgraph (c) ? c : '.';
}
tmp->s[i] = 0;
return tmp->s;
}