1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2017-2020, The Linux Foundation. All rights reserved.
4 */
5
6 #include <drm/drm_atomic_helper.h>
7 #include <drm/drm_atomic.h>
8 #include <drm/drm_bridge.h>
9 #include <drm/drm_bridge_connector.h>
10 #include <drm/drm_crtc.h>
11
12 #include "msm_drv.h"
13 #include "msm_kms.h"
14 #include "dp_drm.h"
15
16 /**
17 * dp_bridge_detect - callback to determine if connector is connected
18 * @bridge: Pointer to drm bridge structure
19 * Returns: Bridge's 'is connected' status
20 */
dp_bridge_detect(struct drm_bridge * bridge)21 static enum drm_connector_status dp_bridge_detect(struct drm_bridge *bridge)
22 {
23 struct msm_dp *dp;
24
25 dp = to_dp_bridge(bridge)->dp_display;
26
27 drm_dbg_dp(dp->drm_dev, "is_connected = %s\n",
28 (dp->is_connected) ? "true" : "false");
29
30 return (dp->is_connected) ? connector_status_connected :
31 connector_status_disconnected;
32 }
33
dp_bridge_atomic_check(struct drm_bridge * bridge,struct drm_bridge_state * bridge_state,struct drm_crtc_state * crtc_state,struct drm_connector_state * conn_state)34 static int dp_bridge_atomic_check(struct drm_bridge *bridge,
35 struct drm_bridge_state *bridge_state,
36 struct drm_crtc_state *crtc_state,
37 struct drm_connector_state *conn_state)
38 {
39 struct msm_dp *dp;
40
41 dp = to_dp_bridge(bridge)->dp_display;
42
43 drm_dbg_dp(dp->drm_dev, "is_connected = %s\n",
44 (dp->is_connected) ? "true" : "false");
45
46 /*
47 * There is no protection in the DRM framework to check if the display
48 * pipeline has been already disabled before trying to disable it again.
49 * Hence if the sink is unplugged, the pipeline gets disabled, but the
50 * crtc->active is still true. Any attempt to set the mode or manually
51 * disable this encoder will result in the crash.
52 *
53 * TODO: add support for telling the DRM subsystem that the pipeline is
54 * disabled by the hardware and thus all access to it should be forbidden.
55 * After that this piece of code can be removed.
56 */
57 if (bridge->ops & DRM_BRIDGE_OP_HPD)
58 return (dp->is_connected) ? 0 : -ENOTCONN;
59
60 return 0;
61 }
62
63
64 /**
65 * dp_bridge_get_modes - callback to add drm modes via drm_mode_probed_add()
66 * @bridge: Poiner to drm bridge
67 * @connector: Pointer to drm connector structure
68 * Returns: Number of modes added
69 */
dp_bridge_get_modes(struct drm_bridge * bridge,struct drm_connector * connector)70 static int dp_bridge_get_modes(struct drm_bridge *bridge, struct drm_connector *connector)
71 {
72 int rc = 0;
73 struct msm_dp *dp;
74
75 if (!connector)
76 return 0;
77
78 dp = to_dp_bridge(bridge)->dp_display;
79
80 /* pluggable case assumes EDID is read when HPD */
81 if (dp->is_connected) {
82 rc = dp_display_get_modes(dp);
83 if (rc <= 0) {
84 DRM_ERROR("failed to get DP sink modes, rc=%d\n", rc);
85 return rc;
86 }
87 } else {
88 drm_dbg_dp(connector->dev, "No sink connected\n");
89 }
90 return rc;
91 }
92
93 static const struct drm_bridge_funcs dp_bridge_ops = {
94 .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
95 .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
96 .atomic_reset = drm_atomic_helper_bridge_reset,
97 .enable = dp_bridge_enable,
98 .disable = dp_bridge_disable,
99 .post_disable = dp_bridge_post_disable,
100 .mode_set = dp_bridge_mode_set,
101 .mode_valid = dp_bridge_mode_valid,
102 .get_modes = dp_bridge_get_modes,
103 .detect = dp_bridge_detect,
104 .atomic_check = dp_bridge_atomic_check,
105 };
106
dp_bridge_init(struct msm_dp * dp_display,struct drm_device * dev,struct drm_encoder * encoder)107 struct drm_bridge *dp_bridge_init(struct msm_dp *dp_display, struct drm_device *dev,
108 struct drm_encoder *encoder)
109 {
110 int rc;
111 struct msm_dp_bridge *dp_bridge;
112 struct drm_bridge *bridge;
113
114 dp_bridge = devm_kzalloc(dev->dev, sizeof(*dp_bridge), GFP_KERNEL);
115 if (!dp_bridge)
116 return ERR_PTR(-ENOMEM);
117
118 dp_bridge->dp_display = dp_display;
119
120 bridge = &dp_bridge->bridge;
121 bridge->funcs = &dp_bridge_ops;
122 bridge->type = dp_display->connector_type;
123
124 /*
125 * Many ops only make sense for DP. Why?
126 * - Detect/HPD are used by DRM to know if a display is _physically_
127 * there, not whether the display is powered on / finished initting.
128 * On eDP we assume the display is always there because you can't
129 * know until power is applied. If we don't implement the ops DRM will
130 * assume our display is always there.
131 * - Currently eDP mode reading is driven by the panel driver. This
132 * allows the panel driver to properly power itself on to read the
133 * modes.
134 */
135 if (!dp_display->is_edp) {
136 bridge->ops =
137 DRM_BRIDGE_OP_DETECT |
138 DRM_BRIDGE_OP_HPD |
139 DRM_BRIDGE_OP_MODES;
140 }
141
142 drm_bridge_add(bridge);
143
144 rc = drm_bridge_attach(encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
145 if (rc) {
146 DRM_ERROR("failed to attach bridge, rc=%d\n", rc);
147 drm_bridge_remove(bridge);
148
149 return ERR_PTR(rc);
150 }
151
152 if (dp_display->next_bridge) {
153 rc = drm_bridge_attach(encoder,
154 dp_display->next_bridge, bridge,
155 DRM_BRIDGE_ATTACH_NO_CONNECTOR);
156 if (rc < 0) {
157 DRM_ERROR("failed to attach panel bridge: %d\n", rc);
158 drm_bridge_remove(bridge);
159 return ERR_PTR(rc);
160 }
161 }
162
163 return bridge;
164 }
165
166 /* connector initialization */
dp_drm_connector_init(struct msm_dp * dp_display,struct drm_encoder * encoder)167 struct drm_connector *dp_drm_connector_init(struct msm_dp *dp_display, struct drm_encoder *encoder)
168 {
169 struct drm_connector *connector = NULL;
170
171 connector = drm_bridge_connector_init(dp_display->drm_dev, encoder);
172 if (IS_ERR(connector))
173 return connector;
174
175 drm_connector_attach_encoder(connector, encoder);
176
177 return connector;
178 }
179
