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