1 | // SPDX-License-Identifier: GPL-2.0 OR MIT |
2 | |
3 | /* |
4 | * Xen para-virtual DRM device |
5 | * |
6 | * Copyright (C) 2016-2018 EPAM Systems Inc. |
7 | * |
8 | * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> |
9 | */ |
10 | |
11 | #include <linux/device.h> |
12 | |
13 | #include <drm/drm_print.h> |
14 | |
15 | #include <xen/interface/io/displif.h> |
16 | #include <xen/xenbus.h> |
17 | |
18 | #include "xen_drm_front.h" |
19 | #include "xen_drm_front_cfg.h" |
20 | |
21 | static int cfg_connector(struct xen_drm_front_info *front_info, |
22 | struct xen_drm_front_cfg_connector *connector, |
23 | const char *path, int index) |
24 | { |
25 | char *connector_path; |
26 | |
27 | connector_path = devm_kasprintf(dev: &front_info->xb_dev->dev, |
28 | GFP_KERNEL, fmt: "%s/%d" , path, index); |
29 | if (!connector_path) |
30 | return -ENOMEM; |
31 | |
32 | if (xenbus_scanf(XBT_NIL, dir: connector_path, XENDISPL_FIELD_RESOLUTION, |
33 | fmt: "%d" XENDISPL_RESOLUTION_SEPARATOR "%d" , |
34 | &connector->width, &connector->height) < 0) { |
35 | /* either no entry configured or wrong resolution set */ |
36 | connector->width = 0; |
37 | connector->height = 0; |
38 | return -EINVAL; |
39 | } |
40 | |
41 | connector->xenstore_path = connector_path; |
42 | |
43 | DRM_INFO("Connector %s: resolution %dx%d\n" , |
44 | connector_path, connector->width, connector->height); |
45 | return 0; |
46 | } |
47 | |
48 | int xen_drm_front_cfg_card(struct xen_drm_front_info *front_info, |
49 | struct xen_drm_front_cfg *cfg) |
50 | { |
51 | struct xenbus_device *xb_dev = front_info->xb_dev; |
52 | int ret, i; |
53 | |
54 | if (xenbus_read_unsigned(dir: front_info->xb_dev->nodename, |
55 | XENDISPL_FIELD_BE_ALLOC, default_val: 0)) { |
56 | DRM_INFO("Backend can provide display buffers\n" ); |
57 | cfg->be_alloc = true; |
58 | } |
59 | |
60 | cfg->num_connectors = 0; |
61 | for (i = 0; i < ARRAY_SIZE(cfg->connectors); i++) { |
62 | ret = cfg_connector(front_info, connector: &cfg->connectors[i], |
63 | path: xb_dev->nodename, index: i); |
64 | if (ret < 0) |
65 | break; |
66 | cfg->num_connectors++; |
67 | } |
68 | |
69 | if (!cfg->num_connectors) { |
70 | DRM_ERROR("No connector(s) configured at %s\n" , |
71 | xb_dev->nodename); |
72 | return -ENODEV; |
73 | } |
74 | |
75 | return 0; |
76 | } |
77 | |
78 | |