78 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			78 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
| // SPDX-License-Identifier: GPL-2.0 OR MIT
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| 
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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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| 
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| #include <drm/drmP.h>
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| 
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| #include <linux/device.h>
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| 
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| #include <xen/interface/io/displif.h>
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| #include <xen/xenbus.h>
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| 
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| #include "xen_drm_front.h"
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| #include "xen_drm_front_cfg.h"
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| 
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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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| 
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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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| 
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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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| 
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| 	connector->xenstore_path = connector_path;
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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| 	return 0;
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| }
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| 
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