xref: /linux/drivers/gpu/drm/drm_modeset_helper.c (revision e08a1d97d33e2ac05cd368b955f9fdc2823f15fd)
1 /*
2  * Copyright (c) 2016 Intel Corporation
3  *
4  * Permission to use, copy, modify, distribute, and sell this software and its
5  * documentation for any purpose is hereby granted without fee, provided that
6  * the above copyright notice appear in all copies and that both that copyright
7  * notice and this permission notice appear in supporting documentation, and
8  * that the name of the copyright holders not be used in advertising or
9  * publicity pertaining to distribution of the software without specific,
10  * written prior permission.  The copyright holders make no representations
11  * about the suitability of this software for any purpose.  It is provided "as
12  * is" without express or implied warranty.
13  *
14  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
20  * OF THIS SOFTWARE.
21  */
22 
23 #include <drm/drm_modeset_helper.h>
24 #include <drm/drm_plane_helper.h>
25 
26 /**
27  * DOC: aux kms helpers
28  *
29  * This helper library contains various one-off functions which don't really fit
30  * anywhere else in the DRM modeset helper library.
31  */
32 
33 /**
34  * drm_helper_move_panel_connectors_to_head() - move panels to the front in the
35  * 						connector list
36  * @dev: drm device to operate on
37  *
38  * Some userspace presumes that the first connected connector is the main
39  * display, where it's supposed to display e.g. the login screen. For
40  * laptops, this should be the main panel. Use this function to sort all
41  * (eDP/LVDS) panels to the front of the connector list, instead of
42  * painstakingly trying to initialize them in the right order.
43  */
44 void drm_helper_move_panel_connectors_to_head(struct drm_device *dev)
45 {
46 	struct drm_connector *connector, *tmp;
47 	struct list_head panel_list;
48 
49 	INIT_LIST_HEAD(&panel_list);
50 
51 	list_for_each_entry_safe(connector, tmp,
52 				 &dev->mode_config.connector_list, head) {
53 		if (connector->connector_type == DRM_MODE_CONNECTOR_LVDS ||
54 		    connector->connector_type == DRM_MODE_CONNECTOR_eDP)
55 			list_move_tail(&connector->head, &panel_list);
56 	}
57 
58 	list_splice(&panel_list, &dev->mode_config.connector_list);
59 }
60 EXPORT_SYMBOL(drm_helper_move_panel_connectors_to_head);
61 
62 /**
63  * drm_helper_mode_fill_fb_struct - fill out framebuffer metadata
64  * @fb: drm_framebuffer object to fill out
65  * @mode_cmd: metadata from the userspace fb creation request
66  *
67  * This helper can be used in a drivers fb_create callback to pre-fill the fb's
68  * metadata fields.
69  */
70 void drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,
71 				    const struct drm_mode_fb_cmd2 *mode_cmd)
72 {
73 	const struct drm_format_info *info;
74 	int i;
75 
76 	info = drm_format_info(mode_cmd->pixel_format);
77 	if (!info || !info->depth) {
78 		char *format_name = drm_get_format_name(mode_cmd->pixel_format);
79 
80 		DRM_DEBUG_KMS("non-RGB pixel format %s\n", format_name);
81 		kfree(format_name);
82 
83 		fb->depth = 0;
84 		fb->bits_per_pixel = 0;
85 	} else {
86 		fb->depth = info->depth;
87 		fb->bits_per_pixel = info->cpp[0] * 8;
88 	}
89 
90 	fb->width = mode_cmd->width;
91 	fb->height = mode_cmd->height;
92 	for (i = 0; i < 4; i++) {
93 		fb->pitches[i] = mode_cmd->pitches[i];
94 		fb->offsets[i] = mode_cmd->offsets[i];
95 		fb->modifier[i] = mode_cmd->modifier[i];
96 	}
97 	fb->pixel_format = mode_cmd->pixel_format;
98 	fb->flags = mode_cmd->flags;
99 }
100 EXPORT_SYMBOL(drm_helper_mode_fill_fb_struct);
101 
102 /*
103  * This is the minimal list of formats that seem to be safe for modeset use
104  * with all current DRM drivers.  Most hardware can actually support more
105  * formats than this and drivers may specify a more accurate list when
106  * creating the primary plane.  However drivers that still call
107  * drm_plane_init() will use this minimal format list as the default.
108  */
109 static const uint32_t safe_modeset_formats[] = {
110 	DRM_FORMAT_XRGB8888,
111 	DRM_FORMAT_ARGB8888,
112 };
113 
114 static struct drm_plane *create_primary_plane(struct drm_device *dev)
115 {
116 	struct drm_plane *primary;
117 	int ret;
118 
119 	primary = kzalloc(sizeof(*primary), GFP_KERNEL);
120 	if (primary == NULL) {
121 		DRM_DEBUG_KMS("Failed to allocate primary plane\n");
122 		return NULL;
123 	}
124 
125 	/*
126 	 * Remove the format_default field from drm_plane when dropping
127 	 * this helper.
128 	 */
129 	primary->format_default = true;
130 
131 	/* possible_crtc's will be filled in later by crtc_init */
132 	ret = drm_universal_plane_init(dev, primary, 0,
133 				       &drm_primary_helper_funcs,
134 				       safe_modeset_formats,
135 				       ARRAY_SIZE(safe_modeset_formats),
136 				       DRM_PLANE_TYPE_PRIMARY, NULL);
137 	if (ret) {
138 		kfree(primary);
139 		primary = NULL;
140 	}
141 
142 	return primary;
143 }
144 
145 /**
146  * drm_crtc_init - Legacy CRTC initialization function
147  * @dev: DRM device
148  * @crtc: CRTC object to init
149  * @funcs: callbacks for the new CRTC
150  *
151  * Initialize a CRTC object with a default helper-provided primary plane and no
152  * cursor plane.
153  *
154  * Returns:
155  * Zero on success, error code on failure.
156  */
157 int drm_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
158 		  const struct drm_crtc_funcs *funcs)
159 {
160 	struct drm_plane *primary;
161 
162 	primary = create_primary_plane(dev);
163 	return drm_crtc_init_with_planes(dev, crtc, primary, NULL, funcs,
164 					 NULL);
165 }
166 EXPORT_SYMBOL(drm_crtc_init);
167