1 /* $NetBSD: drm_modeset_helper.c,v 1.2 2021/12/18 23:44:57 riastradh Exp $ */
2
3 /*
4 * Copyright (c) 2016 Intel Corporation
5 *
6 * Permission to use, copy, modify, distribute, and sell this software and its
7 * documentation for any purpose is hereby granted without fee, provided that
8 * the above copyright notice appear in all copies and that both that copyright
9 * notice and this permission notice appear in supporting documentation, and
10 * that the name of the copyright holders not be used in advertising or
11 * publicity pertaining to distribution of the software without specific,
12 * written prior permission. The copyright holders make no representations
13 * about the suitability of this software for any purpose. It is provided "as
14 * is" without express or implied warranty.
15 *
16 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
17 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
18 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
19 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
20 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
21 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
22 * OF THIS SOFTWARE.
23 */
24
25 #include <sys/cdefs.h>
26 __KERNEL_RCSID(0, "$NetBSD: drm_modeset_helper.c,v 1.2 2021/12/18 23:44:57 riastradh Exp $");
27
28 #include <drm/drm_atomic_helper.h>
29 #include <drm/drm_fb_helper.h>
30 #include <drm/drm_fourcc.h>
31 #include <drm/drm_modeset_helper.h>
32 #include <drm/drm_plane_helper.h>
33 #include <drm/drm_print.h>
34 #include <drm/drm_probe_helper.h>
35
36 /**
37 * DOC: aux kms helpers
38 *
39 * This helper library contains various one-off functions which don't really fit
40 * anywhere else in the DRM modeset helper library.
41 */
42
43 /**
44 * drm_helper_move_panel_connectors_to_head() - move panels to the front in the
45 * connector list
46 * @dev: drm device to operate on
47 *
48 * Some userspace presumes that the first connected connector is the main
49 * display, where it's supposed to display e.g. the login screen. For
50 * laptops, this should be the main panel. Use this function to sort all
51 * (eDP/LVDS/DSI) panels to the front of the connector list, instead of
52 * painstakingly trying to initialize them in the right order.
53 */
drm_helper_move_panel_connectors_to_head(struct drm_device * dev)54 void drm_helper_move_panel_connectors_to_head(struct drm_device *dev)
55 {
56 struct drm_connector *connector, *tmp;
57 struct list_head panel_list;
58
59 INIT_LIST_HEAD(&panel_list);
60
61 spin_lock_irq(&dev->mode_config.connector_list_lock);
62 list_for_each_entry_safe(connector, tmp,
63 &dev->mode_config.connector_list, head) {
64 if (connector->connector_type == DRM_MODE_CONNECTOR_LVDS ||
65 connector->connector_type == DRM_MODE_CONNECTOR_eDP ||
66 connector->connector_type == DRM_MODE_CONNECTOR_DSI)
67 list_move_tail(&connector->head, &panel_list);
68 }
69
70 list_splice(&panel_list, &dev->mode_config.connector_list);
71 spin_unlock_irq(&dev->mode_config.connector_list_lock);
72 }
73 EXPORT_SYMBOL(drm_helper_move_panel_connectors_to_head);
74
75 /**
76 * drm_helper_mode_fill_fb_struct - fill out framebuffer metadata
77 * @dev: DRM device
78 * @fb: drm_framebuffer object to fill out
79 * @mode_cmd: metadata from the userspace fb creation request
80 *
81 * This helper can be used in a drivers fb_create callback to pre-fill the fb's
82 * metadata fields.
83 */
drm_helper_mode_fill_fb_struct(struct drm_device * dev,struct drm_framebuffer * fb,const struct drm_mode_fb_cmd2 * mode_cmd)84 void drm_helper_mode_fill_fb_struct(struct drm_device *dev,
85 struct drm_framebuffer *fb,
86 const struct drm_mode_fb_cmd2 *mode_cmd)
87 {
88 int i;
89
90 fb->dev = dev;
91 fb->format = drm_get_format_info(dev, mode_cmd);
92 fb->width = mode_cmd->width;
93 fb->height = mode_cmd->height;
94 for (i = 0; i < 4; i++) {
95 fb->pitches[i] = mode_cmd->pitches[i];
96 fb->offsets[i] = mode_cmd->offsets[i];
97 }
98 fb->modifier = mode_cmd->modifier[0];
99 fb->flags = mode_cmd->flags;
100 }
101 EXPORT_SYMBOL(drm_helper_mode_fill_fb_struct);
102
103 /*
104 * This is the minimal list of formats that seem to be safe for modeset use
105 * with all current DRM drivers. Most hardware can actually support more
106 * formats than this and drivers may specify a more accurate list when
107 * creating the primary plane. However drivers that still call
108 * drm_plane_init() will use this minimal format list as the default.
109 */
110 static const uint32_t safe_modeset_formats[] = {
111 DRM_FORMAT_XRGB8888,
112 DRM_FORMAT_ARGB8888,
113 };
114
create_primary_plane(struct drm_device * dev)115 static struct drm_plane *create_primary_plane(struct drm_device *dev)
116 {
117 struct drm_plane *primary;
118 int ret;
119
120 primary = kzalloc(sizeof(*primary), GFP_KERNEL);
121 if (primary == NULL) {
122 DRM_DEBUG_KMS("Failed to allocate primary plane\n");
123 return NULL;
124 }
125
126 /*
127 * Remove the format_default field from drm_plane when dropping
128 * this helper.
129 */
130 primary->format_default = true;
131
132 /* possible_crtc's will be filled in later by crtc_init */
133 ret = drm_universal_plane_init(dev, primary, 0,
134 &drm_primary_helper_funcs,
135 safe_modeset_formats,
136 ARRAY_SIZE(safe_modeset_formats),
137 NULL,
138 DRM_PLANE_TYPE_PRIMARY, NULL);
139 if (ret) {
140 kfree(primary);
141 primary = NULL;
142 }
143
144 return primary;
145 }
146
147 /**
148 * drm_crtc_init - Legacy CRTC initialization function
149 * @dev: DRM device
150 * @crtc: CRTC object to init
151 * @funcs: callbacks for the new CRTC
152 *
153 * Initialize a CRTC object with a default helper-provided primary plane and no
154 * cursor plane.
155 *
156 * Note that we make some assumptions about hardware limitations that may not be
157 * true for all hardware:
158 *
159 * 1. Primary plane cannot be repositioned.
160 * 2. Primary plane cannot be scaled.
161 * 3. Primary plane must cover the entire CRTC.
162 * 4. Subpixel positioning is not supported.
163 * 5. The primary plane must always be on if the CRTC is enabled.
164 *
165 * This is purely a backwards compatibility helper for old drivers. Drivers
166 * should instead implement their own primary plane. Atomic drivers must do so.
167 * Drivers with the above hardware restriction can look into using &struct
168 * drm_simple_display_pipe, which encapsulates the above limitations into a nice
169 * interface.
170 *
171 * Returns:
172 * Zero on success, error code on failure.
173 */
drm_crtc_init(struct drm_device * dev,struct drm_crtc * crtc,const struct drm_crtc_funcs * funcs)174 int drm_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
175 const struct drm_crtc_funcs *funcs)
176 {
177 struct drm_plane *primary;
178
179 primary = create_primary_plane(dev);
180 return drm_crtc_init_with_planes(dev, crtc, primary, NULL, funcs,
181 NULL);
182 }
183 EXPORT_SYMBOL(drm_crtc_init);
184
185 /**
186 * drm_mode_config_helper_suspend - Modeset suspend helper
187 * @dev: DRM device
188 *
189 * This helper function takes care of suspending the modeset side. It disables
190 * output polling if initialized, suspends fbdev if used and finally calls
191 * drm_atomic_helper_suspend().
192 * If suspending fails, fbdev and polling is re-enabled.
193 *
194 * Returns:
195 * Zero on success, negative error code on error.
196 *
197 * See also:
198 * drm_kms_helper_poll_disable() and drm_fb_helper_set_suspend_unlocked().
199 */
drm_mode_config_helper_suspend(struct drm_device * dev)200 int drm_mode_config_helper_suspend(struct drm_device *dev)
201 {
202 struct drm_atomic_state *state;
203
204 if (!dev)
205 return 0;
206
207 drm_kms_helper_poll_disable(dev);
208 drm_fb_helper_set_suspend_unlocked(dev->fb_helper, 1);
209 state = drm_atomic_helper_suspend(dev);
210 if (IS_ERR(state)) {
211 drm_fb_helper_set_suspend_unlocked(dev->fb_helper, 0);
212 drm_kms_helper_poll_enable(dev);
213 return PTR_ERR(state);
214 }
215
216 dev->mode_config.suspend_state = state;
217
218 return 0;
219 }
220 EXPORT_SYMBOL(drm_mode_config_helper_suspend);
221
222 /**
223 * drm_mode_config_helper_resume - Modeset resume helper
224 * @dev: DRM device
225 *
226 * This helper function takes care of resuming the modeset side. It calls
227 * drm_atomic_helper_resume(), resumes fbdev if used and enables output polling
228 * if initiaized.
229 *
230 * Returns:
231 * Zero on success, negative error code on error.
232 *
233 * See also:
234 * drm_fb_helper_set_suspend_unlocked() and drm_kms_helper_poll_enable().
235 */
drm_mode_config_helper_resume(struct drm_device * dev)236 int drm_mode_config_helper_resume(struct drm_device *dev)
237 {
238 int ret;
239
240 if (!dev)
241 return 0;
242
243 if (WARN_ON(!dev->mode_config.suspend_state))
244 return -EINVAL;
245
246 ret = drm_atomic_helper_resume(dev, dev->mode_config.suspend_state);
247 if (ret)
248 DRM_ERROR("Failed to resume (%d)\n", ret);
249 dev->mode_config.suspend_state = NULL;
250
251 drm_fb_helper_set_suspend_unlocked(dev->fb_helper, 0);
252 drm_kms_helper_poll_enable(dev);
253
254 return ret;
255 }
256 EXPORT_SYMBOL(drm_mode_config_helper_resume);
257