OpenCloudOS-Kernel/drivers/gpu/drm/xen/xen_drm_front_cfg.c

78 lines
1.8 KiB
C

// SPDX-License-Identifier: GPL-2.0 OR MIT
/*
* Xen para-virtual DRM device
*
* Copyright (C) 2016-2018 EPAM Systems Inc.
*
* Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
*/
#include <drm/drmP.h>
#include <linux/device.h>
#include <xen/interface/io/displif.h>
#include <xen/xenbus.h>
#include "xen_drm_front.h"
#include "xen_drm_front_cfg.h"
static int cfg_connector(struct xen_drm_front_info *front_info,
struct xen_drm_front_cfg_connector *connector,
const char *path, int index)
{
char *connector_path;
connector_path = devm_kasprintf(&front_info->xb_dev->dev,
GFP_KERNEL, "%s/%d", path, index);
if (!connector_path)
return -ENOMEM;
if (xenbus_scanf(XBT_NIL, connector_path, XENDISPL_FIELD_RESOLUTION,
"%d" XENDISPL_RESOLUTION_SEPARATOR "%d",
&connector->width, &connector->height) < 0) {
/* either no entry configured or wrong resolution set */
connector->width = 0;
connector->height = 0;
return -EINVAL;
}
connector->xenstore_path = connector_path;
DRM_INFO("Connector %s: resolution %dx%d\n",
connector_path, connector->width, connector->height);
return 0;
}
int xen_drm_front_cfg_card(struct xen_drm_front_info *front_info,
struct xen_drm_front_cfg *cfg)
{
struct xenbus_device *xb_dev = front_info->xb_dev;
int ret, i;
if (xenbus_read_unsigned(front_info->xb_dev->nodename,
XENDISPL_FIELD_BE_ALLOC, 0)) {
DRM_INFO("Backend can provide display buffers\n");
cfg->be_alloc = true;
}
cfg->num_connectors = 0;
for (i = 0; i < ARRAY_SIZE(cfg->connectors); i++) {
ret = cfg_connector(front_info, &cfg->connectors[i],
xb_dev->nodename, i);
if (ret < 0)
break;
cfg->num_connectors++;
}
if (!cfg->num_connectors) {
DRM_ERROR("No connector(s) configured at %s\n",
xb_dev->nodename);
return -ENODEV;
}
return 0;
}