xref: /linux/drivers/gpu/drm/drm_modeset_helper.c (revision 95298d63c67673c654c08952672d016212b26054)
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_atomic_helper.h>
24 #include <drm/drm_fb_helper.h>
25 #include <drm/drm_fourcc.h>
26 #include <drm/drm_modeset_helper.h>
27 #include <drm/drm_plane_helper.h>
28 #include <drm/drm_print.h>
29 #include <drm/drm_probe_helper.h>
30 
31 /**
32  * DOC: aux kms helpers
33  *
34  * This helper library contains various one-off functions which don't really fit
35  * anywhere else in the DRM modeset helper library.
36  */
37 
38 /**
39  * drm_helper_move_panel_connectors_to_head() - move panels to the front in the
40  * 						connector list
41  * @dev: drm device to operate on
42  *
43  * Some userspace presumes that the first connected connector is the main
44  * display, where it's supposed to display e.g. the login screen. For
45  * laptops, this should be the main panel. Use this function to sort all
46  * (eDP/LVDS/DSI) panels to the front of the connector list, instead of
47  * painstakingly trying to initialize them in the right order.
48  */
49 void drm_helper_move_panel_connectors_to_head(struct drm_device *dev)
50 {
51 	struct drm_connector *connector, *tmp;
52 	struct list_head panel_list;
53 
54 	INIT_LIST_HEAD(&panel_list);
55 
56 	spin_lock_irq(&dev->mode_config.connector_list_lock);
57 	list_for_each_entry_safe(connector, tmp,
58 				 &dev->mode_config.connector_list, head) {
59 		if (connector->connector_type == DRM_MODE_CONNECTOR_LVDS ||
60 		    connector->connector_type == DRM_MODE_CONNECTOR_eDP ||
61 		    connector->connector_type == DRM_MODE_CONNECTOR_DSI)
62 			list_move_tail(&connector->head, &panel_list);
63 	}
64 
65 	list_splice(&panel_list, &dev->mode_config.connector_list);
66 	spin_unlock_irq(&dev->mode_config.connector_list_lock);
67 }
68 EXPORT_SYMBOL(drm_helper_move_panel_connectors_to_head);
69 
70 /**
71  * drm_helper_mode_fill_fb_struct - fill out framebuffer metadata
72  * @dev: DRM device
73  * @fb: drm_framebuffer object to fill out
74  * @mode_cmd: metadata from the userspace fb creation request
75  *
76  * This helper can be used in a drivers fb_create callback to pre-fill the fb's
77  * metadata fields.
78  */
79 void drm_helper_mode_fill_fb_struct(struct drm_device *dev,
80 				    struct drm_framebuffer *fb,
81 				    const struct drm_mode_fb_cmd2 *mode_cmd)
82 {
83 	int i;
84 
85 	fb->dev = dev;
86 	fb->format = drm_get_format_info(dev, mode_cmd);
87 	fb->width = mode_cmd->width;
88 	fb->height = mode_cmd->height;
89 	for (i = 0; i < 4; i++) {
90 		fb->pitches[i] = mode_cmd->pitches[i];
91 		fb->offsets[i] = mode_cmd->offsets[i];
92 	}
93 	fb->modifier = mode_cmd->modifier[0];
94 	fb->flags = mode_cmd->flags;
95 }
96 EXPORT_SYMBOL(drm_helper_mode_fill_fb_struct);
97 
98 /*
99  * This is the minimal list of formats that seem to be safe for modeset use
100  * with all current DRM drivers.  Most hardware can actually support more
101  * formats than this and drivers may specify a more accurate list when
102  * creating the primary plane.  However drivers that still call
103  * drm_plane_init() will use this minimal format list as the default.
104  */
105 static const uint32_t safe_modeset_formats[] = {
106 	DRM_FORMAT_XRGB8888,
107 	DRM_FORMAT_ARGB8888,
108 };
109 
110 static struct drm_plane *create_primary_plane(struct drm_device *dev)
111 {
112 	struct drm_plane *primary;
113 	int ret;
114 
115 	primary = kzalloc(sizeof(*primary), GFP_KERNEL);
116 	if (primary == NULL) {
117 		DRM_DEBUG_KMS("Failed to allocate primary plane\n");
118 		return NULL;
119 	}
120 
121 	/*
122 	 * Remove the format_default field from drm_plane when dropping
123 	 * this helper.
124 	 */
125 	primary->format_default = true;
126 
127 	/* possible_crtc's will be filled in later by crtc_init */
128 	ret = drm_universal_plane_init(dev, primary, 0,
129 				       &drm_primary_helper_funcs,
130 				       safe_modeset_formats,
131 				       ARRAY_SIZE(safe_modeset_formats),
132 				       NULL,
133 				       DRM_PLANE_TYPE_PRIMARY, NULL);
134 	if (ret) {
135 		kfree(primary);
136 		primary = NULL;
137 	}
138 
139 	return primary;
140 }
141 
142 /**
143  * drm_crtc_init - Legacy CRTC initialization function
144  * @dev: DRM device
145  * @crtc: CRTC object to init
146  * @funcs: callbacks for the new CRTC
147  *
148  * Initialize a CRTC object with a default helper-provided primary plane and no
149  * cursor plane.
150  *
151  * Note that we make some assumptions about hardware limitations that may not be
152  * true for all hardware:
153  *
154  * 1. Primary plane cannot be repositioned.
155  * 2. Primary plane cannot be scaled.
156  * 3. Primary plane must cover the entire CRTC.
157  * 4. Subpixel positioning is not supported.
158  * 5. The primary plane must always be on if the CRTC is enabled.
159  *
160  * This is purely a backwards compatibility helper for old drivers. Drivers
161  * should instead implement their own primary plane. Atomic drivers must do so.
162  * Drivers with the above hardware restriction can look into using &struct
163  * drm_simple_display_pipe, which encapsulates the above limitations into a nice
164  * interface.
165  *
166  * Returns:
167  * Zero on success, error code on failure.
168  */
169 int drm_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
170 		  const struct drm_crtc_funcs *funcs)
171 {
172 	struct drm_plane *primary;
173 
174 	primary = create_primary_plane(dev);
175 	return drm_crtc_init_with_planes(dev, crtc, primary, NULL, funcs,
176 					 NULL);
177 }
178 EXPORT_SYMBOL(drm_crtc_init);
179 
180 /**
181  * drm_mode_config_helper_suspend - Modeset suspend helper
182  * @dev: DRM device
183  *
184  * This helper function takes care of suspending the modeset side. It disables
185  * output polling if initialized, suspends fbdev if used and finally calls
186  * drm_atomic_helper_suspend().
187  * If suspending fails, fbdev and polling is re-enabled.
188  *
189  * Returns:
190  * Zero on success, negative error code on error.
191  *
192  * See also:
193  * drm_kms_helper_poll_disable() and drm_fb_helper_set_suspend_unlocked().
194  */
195 int drm_mode_config_helper_suspend(struct drm_device *dev)
196 {
197 	struct drm_atomic_state *state;
198 
199 	if (!dev)
200 		return 0;
201 
202 	drm_kms_helper_poll_disable(dev);
203 	drm_fb_helper_set_suspend_unlocked(dev->fb_helper, 1);
204 	state = drm_atomic_helper_suspend(dev);
205 	if (IS_ERR(state)) {
206 		drm_fb_helper_set_suspend_unlocked(dev->fb_helper, 0);
207 		drm_kms_helper_poll_enable(dev);
208 		return PTR_ERR(state);
209 	}
210 
211 	dev->mode_config.suspend_state = state;
212 
213 	return 0;
214 }
215 EXPORT_SYMBOL(drm_mode_config_helper_suspend);
216 
217 /**
218  * drm_mode_config_helper_resume - Modeset resume helper
219  * @dev: DRM device
220  *
221  * This helper function takes care of resuming the modeset side. It calls
222  * drm_atomic_helper_resume(), resumes fbdev if used and enables output polling
223  * if initiaized.
224  *
225  * Returns:
226  * Zero on success, negative error code on error.
227  *
228  * See also:
229  * drm_fb_helper_set_suspend_unlocked() and drm_kms_helper_poll_enable().
230  */
231 int drm_mode_config_helper_resume(struct drm_device *dev)
232 {
233 	int ret;
234 
235 	if (!dev)
236 		return 0;
237 
238 	if (WARN_ON(!dev->mode_config.suspend_state))
239 		return -EINVAL;
240 
241 	ret = drm_atomic_helper_resume(dev, dev->mode_config.suspend_state);
242 	if (ret)
243 		DRM_ERROR("Failed to resume (%d)\n", ret);
244 	dev->mode_config.suspend_state = NULL;
245 
246 	drm_fb_helper_set_suspend_unlocked(dev->fb_helper, 0);
247 	drm_kms_helper_poll_enable(dev);
248 
249 	return ret;
250 }
251 EXPORT_SYMBOL(drm_mode_config_helper_resume);
252