1// SPDX-License-Identifier: MIT
2/*
3 * Copyright © 2023 Intel Corporation
4 */
5
6#include <drm/drm_atomic.h>
7#include <drm/drm_atomic_helper.h>
8#include <drm/drm_atomic_uapi.h>
9#include <drm/drm_print.h>
10
11#include "intel_atomic.h"
12#include "intel_crtc.h"
13#include "intel_display_core.h"
14#include "intel_display_types.h"
15#include "intel_load_detect.h"
16
17/* VESA 640x480x72Hz mode to set on the pipe */
18static const struct drm_display_mode load_detect_mode = {
19 DRM_MODE("640x480", DRM_MODE_TYPE_DEFAULT, 31500, 640, 664,
20 704, 832, 0, 480, 489, 491, 520, 0, DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC),
21};
22
23static int intel_modeset_disable_planes(struct drm_atomic_state *state,
24 struct drm_crtc *crtc)
25{
26 struct drm_plane *plane;
27 struct drm_plane_state *plane_state;
28 int ret, i;
29
30 ret = drm_atomic_add_affected_planes(state, crtc);
31 if (ret)
32 return ret;
33
34 for_each_new_plane_in_state(state, plane, plane_state, i) {
35 if (plane_state->crtc != crtc)
36 continue;
37
38 ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
39 if (ret)
40 return ret;
41
42 drm_atomic_set_fb_for_plane(plane_state, NULL);
43 }
44
45 return 0;
46}
47
48struct drm_atomic_state *
49intel_load_detect_get_pipe(struct drm_connector *connector,
50 struct drm_modeset_acquire_ctx *ctx)
51{
52 struct intel_display *display = to_intel_display(connector->dev);
53 struct intel_encoder *encoder =
54 intel_attached_encoder(to_intel_connector(connector));
55 struct intel_crtc *possible_crtc;
56 struct intel_crtc *crtc = NULL;
57 struct drm_mode_config *config = &display->drm->mode_config;
58 struct drm_atomic_state *state = NULL, *restore_state = NULL;
59 struct drm_connector_state *connector_state;
60 struct intel_crtc_state *crtc_state;
61 int ret;
62
63 drm_dbg_kms(display->drm, "[CONNECTOR:%d:%s], [ENCODER:%d:%s]\n",
64 connector->base.id, connector->name,
65 encoder->base.base.id, encoder->base.name);
66
67 drm_WARN_ON(display->drm, !drm_modeset_is_locked(&config->connection_mutex));
68
69 /*
70 * Algorithm gets a little messy:
71 *
72 * - if the connector already has an assigned crtc, use it (but make
73 * sure it's on first)
74 *
75 * - try to find the first unused crtc that can drive this connector,
76 * and use that if we find one
77 */
78
79 /* See if we already have a CRTC for this connector */
80 if (connector->state->crtc) {
81 crtc = to_intel_crtc(connector->state->crtc);
82
83 ret = drm_modeset_lock(lock: &crtc->base.mutex, ctx);
84 if (ret)
85 goto fail;
86
87 /* Make sure the crtc and connector are running */
88 goto found;
89 }
90
91 /* Find an unused one (if possible) */
92 for_each_intel_crtc(display->drm, possible_crtc) {
93 if (!(encoder->base.possible_crtcs &
94 drm_crtc_mask(crtc: &possible_crtc->base)))
95 continue;
96
97 ret = drm_modeset_lock(lock: &possible_crtc->base.mutex, ctx);
98 if (ret)
99 goto fail;
100
101 if (possible_crtc->base.state->enable) {
102 drm_modeset_unlock(lock: &possible_crtc->base.mutex);
103 continue;
104 }
105
106 crtc = possible_crtc;
107 break;
108 }
109
110 /*
111 * If we didn't find an unused CRTC, don't use any.
112 */
113 if (!crtc) {
114 drm_dbg_kms(display->drm,
115 "no pipe available for load-detect\n");
116 ret = -ENODEV;
117 goto fail;
118 }
119
120found:
121 state = drm_atomic_state_alloc(dev: display->drm);
122 restore_state = drm_atomic_state_alloc(dev: display->drm);
123 if (!state || !restore_state) {
124 ret = -ENOMEM;
125 goto fail;
126 }
127
128 state->acquire_ctx = ctx;
129 to_intel_atomic_state(state)->internal = true;
130
131 restore_state->acquire_ctx = ctx;
132 to_intel_atomic_state(restore_state)->internal = true;
133
134 connector_state = drm_atomic_get_connector_state(state, connector);
135 if (IS_ERR(ptr: connector_state)) {
136 ret = PTR_ERR(ptr: connector_state);
137 goto fail;
138 }
139
140 ret = drm_atomic_set_crtc_for_connector(conn_state: connector_state, crtc: &crtc->base);
141 if (ret)
142 goto fail;
143
144 crtc_state = intel_atomic_get_crtc_state(state, crtc);
145 if (IS_ERR(ptr: crtc_state)) {
146 ret = PTR_ERR(ptr: crtc_state);
147 goto fail;
148 }
149
150 crtc_state->uapi.active = true;
151
152 ret = drm_atomic_set_mode_for_crtc(state: &crtc_state->uapi,
153 mode: &load_detect_mode);
154 if (ret)
155 goto fail;
156
157 ret = intel_modeset_disable_planes(state, crtc: &crtc->base);
158 if (ret)
159 goto fail;
160
161 ret = PTR_ERR_OR_ZERO(ptr: drm_atomic_get_connector_state(state: restore_state, connector));
162 if (!ret)
163 ret = PTR_ERR_OR_ZERO(ptr: drm_atomic_get_crtc_state(state: restore_state, crtc: &crtc->base));
164 if (!ret)
165 ret = drm_atomic_add_affected_planes(state: restore_state, crtc: &crtc->base);
166 if (ret) {
167 drm_dbg_kms(display->drm,
168 "Failed to create a copy of old state to restore: %i\n",
169 ret);
170 goto fail;
171 }
172
173 ret = drm_atomic_commit(state);
174 if (ret) {
175 drm_dbg_kms(display->drm,
176 "failed to set mode on load-detect pipe\n");
177 goto fail;
178 }
179
180 drm_atomic_state_put(state);
181
182 /* let the connector get through one full cycle before testing */
183 intel_crtc_wait_for_next_vblank(crtc);
184
185 return restore_state;
186
187fail:
188 if (state) {
189 drm_atomic_state_put(state);
190 state = NULL;
191 }
192 if (restore_state) {
193 drm_atomic_state_put(state: restore_state);
194 restore_state = NULL;
195 }
196
197 if (ret == -EDEADLK)
198 return ERR_PTR(error: ret);
199
200 return NULL;
201}
202
203void intel_load_detect_release_pipe(struct drm_connector *connector,
204 struct drm_atomic_state *state,
205 struct drm_modeset_acquire_ctx *ctx)
206{
207 struct intel_display *display = to_intel_display(connector->dev);
208 struct intel_encoder *intel_encoder =
209 intel_attached_encoder(to_intel_connector(connector));
210 struct drm_encoder *encoder = &intel_encoder->base;
211 int ret;
212
213 drm_dbg_kms(display->drm, "[CONNECTOR:%d:%s], [ENCODER:%d:%s]\n",
214 connector->base.id, connector->name,
215 encoder->base.id, encoder->name);
216
217 if (IS_ERR_OR_NULL(ptr: state))
218 return;
219
220 ret = drm_atomic_helper_commit_duplicated_state(state, ctx);
221 if (ret)
222 drm_dbg_kms(display->drm,
223 "Couldn't release load detect pipe: %i\n", ret);
224 drm_atomic_state_put(state);
225}
226

source code of linux/drivers/gpu/drm/i915/display/intel_load_detect.c