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
10#include "i915_drv.h"
11#include "intel_atomic.h"
12#include "intel_crtc.h"
13#include "intel_display_types.h"
14#include "intel_load_detect.h"
15
16/* VESA 640x480x72Hz mode to set on the pipe */
17static const struct drm_display_mode load_detect_mode = {
18	DRM_MODE("640x480", DRM_MODE_TYPE_DEFAULT, 31500, 640, 664,
19		 704, 832, 0, 480, 489, 491, 520, 0, DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC),
20};
21
22static int intel_modeset_disable_planes(struct drm_atomic_state *state,
23					struct drm_crtc *crtc)
24{
25	struct drm_plane *plane;
26	struct drm_plane_state *plane_state;
27	int ret, i;
28
29	ret = drm_atomic_add_affected_planes(state, crtc);
30	if (ret)
31		return ret;
32
33	for_each_new_plane_in_state(state, plane, plane_state, i) {
34		if (plane_state->crtc != crtc)
35			continue;
36
37		ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
38		if (ret)
39			return ret;
40
41		drm_atomic_set_fb_for_plane(plane_state, NULL);
42	}
43
44	return 0;
45}
46
47struct drm_atomic_state *
48intel_load_detect_get_pipe(struct drm_connector *connector,
49			   struct drm_modeset_acquire_ctx *ctx)
50{
51	struct intel_encoder *encoder =
52		intel_attached_encoder(to_intel_connector(connector));
53	struct intel_crtc *possible_crtc;
54	struct intel_crtc *crtc = NULL;
55	struct drm_device *dev = encoder->base.dev;
56	struct drm_i915_private *dev_priv = to_i915(dev);
57	struct drm_mode_config *config = &dev->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(&dev_priv->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(dev, !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(&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(dev, possible_crtc) {
93		if (!(encoder->base.possible_crtcs &
94		      drm_crtc_mask(&possible_crtc->base)))
95			continue;
96
97		ret = drm_modeset_lock(&possible_crtc->base.mutex, ctx);
98		if (ret)
99			goto fail;
100
101		if (possible_crtc->base.state->enable) {
102			drm_modeset_unlock(&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(&dev_priv->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);
122	restore_state = drm_atomic_state_alloc(dev);
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(connector_state)) {
136		ret = PTR_ERR(connector_state);
137		goto fail;
138	}
139
140	ret = drm_atomic_set_crtc_for_connector(connector_state, &crtc->base);
141	if (ret)
142		goto fail;
143
144	crtc_state = intel_atomic_get_crtc_state(state, crtc);
145	if (IS_ERR(crtc_state)) {
146		ret = PTR_ERR(crtc_state);
147		goto fail;
148	}
149
150	crtc_state->uapi.active = true;
151
152	ret = drm_atomic_set_mode_for_crtc(&crtc_state->uapi,
153					   &load_detect_mode);
154	if (ret)
155		goto fail;
156
157	ret = intel_modeset_disable_planes(state, &crtc->base);
158	if (ret)
159		goto fail;
160
161	ret = PTR_ERR_OR_ZERO(drm_atomic_get_connector_state(restore_state, connector));
162	if (!ret)
163		ret = PTR_ERR_OR_ZERO(drm_atomic_get_crtc_state(restore_state, &crtc->base));
164	if (!ret)
165		ret = drm_atomic_add_affected_planes(restore_state, &crtc->base);
166	if (ret) {
167		drm_dbg_kms(&dev_priv->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(&dev_priv->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(restore_state);
194		restore_state = NULL;
195	}
196
197	if (ret == -EDEADLK)
198		return ERR_PTR(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_encoder *intel_encoder =
208		intel_attached_encoder(to_intel_connector(connector));
209	struct drm_i915_private *i915 = to_i915(intel_encoder->base.dev);
210	struct drm_encoder *encoder = &intel_encoder->base;
211	int ret;
212
213	drm_dbg_kms(&i915->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(state))
218		return;
219
220	ret = drm_atomic_helper_commit_duplicated_state(state, ctx);
221	if (ret)
222		drm_dbg_kms(&i915->drm,
223			    "Couldn't release load detect pipe: %i\n", ret);
224	drm_atomic_state_put(state);
225}
226