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 .hpd_enable = dp_bridge_hpd_enable,
106 .hpd_disable = dp_bridge_hpd_disable,
107 .hpd_notify = dp_bridge_hpd_notify,
108 };
109
dp_bridge_init(struct msm_dp * dp_display,struct drm_device * dev,struct drm_encoder * encoder)110 struct drm_bridge *dp_bridge_init(struct msm_dp *dp_display, struct drm_device *dev,
111 struct drm_encoder *encoder)
112 {
113 int rc;
114 struct msm_dp_bridge *dp_bridge;
115 struct drm_bridge *bridge;
116
117 dp_bridge = devm_kzalloc(dev->dev, sizeof(*dp_bridge), GFP_KERNEL);
118 if (!dp_bridge)
119 return ERR_PTR(-ENOMEM);
120
121 dp_bridge->dp_display = dp_display;
122
123 bridge = &dp_bridge->bridge;
124 bridge->funcs = &dp_bridge_ops;
125 bridge->type = dp_display->connector_type;
126
127 /*
128 * Many ops only make sense for DP. Why?
129 * - Detect/HPD are used by DRM to know if a display is _physically_
130 * there, not whether the display is powered on / finished initting.
131 * On eDP we assume the display is always there because you can't
132 * know until power is applied. If we don't implement the ops DRM will
133 * assume our display is always there.
134 * - Currently eDP mode reading is driven by the panel driver. This
135 * allows the panel driver to properly power itself on to read the
136 * modes.
137 */
138 if (!dp_display->is_edp) {
139 bridge->ops =
140 DRM_BRIDGE_OP_DETECT |
141 DRM_BRIDGE_OP_HPD |
142 DRM_BRIDGE_OP_MODES;
143 }
144
145 drm_bridge_add(bridge);
146
147 rc = drm_bridge_attach(encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
148 if (rc) {
149 DRM_ERROR("failed to attach bridge, rc=%d\n", rc);
150 drm_bridge_remove(bridge);
151
152 return ERR_PTR(rc);
153 }
154
155 if (dp_display->next_bridge) {
156 rc = drm_bridge_attach(encoder,
157 dp_display->next_bridge, bridge,
158 DRM_BRIDGE_ATTACH_NO_CONNECTOR);
159 if (rc < 0) {
160 DRM_ERROR("failed to attach panel bridge: %d\n", rc);
161 drm_bridge_remove(bridge);
162 return ERR_PTR(rc);
163 }
164 }
165
166 return bridge;
167 }
168
169 /* connector initialization */
dp_drm_connector_init(struct msm_dp * dp_display,struct drm_encoder * encoder)170 struct drm_connector *dp_drm_connector_init(struct msm_dp *dp_display, struct drm_encoder *encoder)
171 {
172 struct drm_connector *connector = NULL;
173
174 connector = drm_bridge_connector_init(dp_display->drm_dev, encoder);
175 if (IS_ERR(connector))
176 return connector;
177
178 drm_connector_attach_encoder(connector, encoder);
179
180 return connector;
181 }
182