1 /*
2  * Copyright 2009 Red Hat Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  * Authors: Ben Skeggs
23  */
24 
25 #include <drm/drm_dp_helper.h>
26 
27 #include "nouveau_drv.h"
28 #include "nouveau_connector.h"
29 #include "nouveau_encoder.h"
30 #include "nouveau_crtc.h"
31 
32 #include <nvif/class.h>
33 #include <nvif/cl5070.h>
34 
35 MODULE_PARM_DESC(mst, "Enable DisplayPort multi-stream (default: enabled)");
36 static int nouveau_mst = 1;
37 module_param_named(mst, nouveau_mst, int, 0400);
38 
39 static bool
40 nouveau_dp_has_sink_count(struct drm_connector *connector,
41 			  struct nouveau_encoder *outp)
42 {
43 	return drm_dp_read_sink_count_cap(connector, outp->dp.dpcd, &outp->dp.desc);
44 }
45 
46 static enum drm_connector_status
47 nouveau_dp_probe_dpcd(struct nouveau_connector *nv_connector,
48 		      struct nouveau_encoder *outp)
49 {
50 	struct drm_connector *connector = &nv_connector->base;
51 	struct drm_dp_aux *aux = &nv_connector->aux;
52 	struct nv50_mstm *mstm = NULL;
53 	enum drm_connector_status status = connector_status_disconnected;
54 	int ret;
55 	u8 *dpcd = outp->dp.dpcd;
56 
57 	ret = drm_dp_read_dpcd_caps(aux, dpcd);
58 	if (ret < 0)
59 		goto out;
60 
61 	ret = drm_dp_read_desc(aux, &outp->dp.desc, drm_dp_is_branch(dpcd));
62 	if (ret < 0)
63 		goto out;
64 
65 	if (nouveau_mst) {
66 		mstm = outp->dp.mstm;
67 		if (mstm)
68 			mstm->can_mst = drm_dp_read_mst_cap(aux, dpcd);
69 	}
70 
71 	if (nouveau_dp_has_sink_count(connector, outp)) {
72 		ret = drm_dp_read_sink_count(aux);
73 		if (ret < 0)
74 			goto out;
75 
76 		outp->dp.sink_count = ret;
77 
78 		/*
79 		 * Dongle connected, but no display. Don't bother reading
80 		 * downstream port info
81 		 */
82 		if (!outp->dp.sink_count)
83 			return connector_status_disconnected;
84 	}
85 
86 	ret = drm_dp_read_downstream_info(aux, dpcd,
87 					  outp->dp.downstream_ports);
88 	if (ret < 0)
89 		goto out;
90 
91 	status = connector_status_connected;
92 out:
93 	if (status != connector_status_connected) {
94 		/* Clear any cached info */
95 		outp->dp.sink_count = 0;
96 	}
97 	return status;
98 }
99 
100 int
101 nouveau_dp_detect(struct nouveau_connector *nv_connector,
102 		  struct nouveau_encoder *nv_encoder)
103 {
104 	struct drm_device *dev = nv_encoder->base.base.dev;
105 	struct nouveau_drm *drm = nouveau_drm(dev);
106 	struct drm_connector *connector = &nv_connector->base;
107 	struct nv50_mstm *mstm = nv_encoder->dp.mstm;
108 	enum drm_connector_status status;
109 	u8 *dpcd = nv_encoder->dp.dpcd;
110 	int ret = NOUVEAU_DP_NONE;
111 
112 	/* If we've already read the DPCD on an eDP device, we don't need to
113 	 * reread it as it won't change
114 	 */
115 	if (connector->connector_type == DRM_MODE_CONNECTOR_eDP &&
116 	    dpcd[DP_DPCD_REV] != 0)
117 		return NOUVEAU_DP_SST;
118 
119 	mutex_lock(&nv_encoder->dp.hpd_irq_lock);
120 	if (mstm) {
121 		/* If we're not ready to handle MST state changes yet, just
122 		 * report the last status of the connector. We'll reprobe it
123 		 * once we've resumed.
124 		 */
125 		if (mstm->suspended) {
126 			if (mstm->is_mst)
127 				ret = NOUVEAU_DP_MST;
128 			else if (connector->status ==
129 				 connector_status_connected)
130 				ret = NOUVEAU_DP_SST;
131 
132 			goto out;
133 		}
134 	}
135 
136 	status = nouveau_dp_probe_dpcd(nv_connector, nv_encoder);
137 	if (status == connector_status_disconnected)
138 		goto out;
139 
140 	/* If we're in MST mode, we're done here */
141 	if (mstm && mstm->can_mst && mstm->is_mst) {
142 		ret = NOUVEAU_DP_MST;
143 		goto out;
144 	}
145 
146 	nv_encoder->dp.link_bw = 27000 * dpcd[DP_MAX_LINK_RATE];
147 	nv_encoder->dp.link_nr =
148 		dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
149 
150 	NV_DEBUG(drm, "display: %dx%d dpcd 0x%02x\n",
151 		 nv_encoder->dp.link_nr, nv_encoder->dp.link_bw,
152 		 dpcd[DP_DPCD_REV]);
153 	NV_DEBUG(drm, "encoder: %dx%d\n",
154 		 nv_encoder->dcb->dpconf.link_nr,
155 		 nv_encoder->dcb->dpconf.link_bw);
156 
157 	if (nv_encoder->dcb->dpconf.link_nr < nv_encoder->dp.link_nr)
158 		nv_encoder->dp.link_nr = nv_encoder->dcb->dpconf.link_nr;
159 	if (nv_encoder->dcb->dpconf.link_bw < nv_encoder->dp.link_bw)
160 		nv_encoder->dp.link_bw = nv_encoder->dcb->dpconf.link_bw;
161 
162 	NV_DEBUG(drm, "maximum: %dx%d\n",
163 		 nv_encoder->dp.link_nr, nv_encoder->dp.link_bw);
164 
165 	if (mstm && mstm->can_mst) {
166 		ret = nv50_mstm_detect(nv_encoder);
167 		if (ret == 1) {
168 			ret = NOUVEAU_DP_MST;
169 			goto out;
170 		} else if (ret != 0) {
171 			goto out;
172 		}
173 	}
174 	ret = NOUVEAU_DP_SST;
175 
176 out:
177 	if (mstm && !mstm->suspended && ret != NOUVEAU_DP_MST)
178 		nv50_mstm_remove(mstm);
179 
180 	mutex_unlock(&nv_encoder->dp.hpd_irq_lock);
181 	return ret;
182 }
183 
184 void nouveau_dp_irq(struct nouveau_drm *drm,
185 		    struct nouveau_connector *nv_connector)
186 {
187 	struct drm_connector *connector = &nv_connector->base;
188 	struct nouveau_encoder *outp = find_encoder(connector, DCB_OUTPUT_DP);
189 	struct nv50_mstm *mstm;
190 	int ret;
191 	bool send_hpd = false;
192 
193 	if (!outp)
194 		return;
195 
196 	mstm = outp->dp.mstm;
197 	NV_DEBUG(drm, "service %s\n", connector->name);
198 
199 	mutex_lock(&outp->dp.hpd_irq_lock);
200 
201 	if (mstm && mstm->is_mst) {
202 		if (!nv50_mstm_service(drm, nv_connector, mstm))
203 			send_hpd = true;
204 	} else {
205 		drm_dp_cec_irq(&nv_connector->aux);
206 
207 		if (nouveau_dp_has_sink_count(connector, outp)) {
208 			ret = drm_dp_read_sink_count(&nv_connector->aux);
209 			if (ret != outp->dp.sink_count)
210 				send_hpd = true;
211 			if (ret >= 0)
212 				outp->dp.sink_count = ret;
213 		}
214 	}
215 
216 	mutex_unlock(&outp->dp.hpd_irq_lock);
217 
218 	if (send_hpd)
219 		nouveau_connector_hpd(connector);
220 }
221 
222 /* TODO:
223  * - Use the minimum possible BPC here, once we add support for the max bpc
224  *   property.
225  * - Validate against the DP caps advertised by the GPU (we don't check these
226  *   yet)
227  */
228 enum drm_mode_status
229 nv50_dp_mode_valid(struct drm_connector *connector,
230 		   struct nouveau_encoder *outp,
231 		   const struct drm_display_mode *mode,
232 		   unsigned *out_clock)
233 {
234 	const unsigned min_clock = 25000;
235 	unsigned max_clock, ds_clock, clock;
236 	enum drm_mode_status ret;
237 
238 	if (mode->flags & DRM_MODE_FLAG_INTERLACE && !outp->caps.dp_interlace)
239 		return MODE_NO_INTERLACE;
240 
241 	max_clock = outp->dp.link_nr * outp->dp.link_bw;
242 	ds_clock = drm_dp_downstream_max_dotclock(outp->dp.dpcd,
243 						  outp->dp.downstream_ports);
244 	if (ds_clock)
245 		max_clock = min(max_clock, ds_clock);
246 
247 	clock = mode->clock * (connector->display_info.bpc * 3) / 10;
248 	ret = nouveau_conn_mode_clock_valid(mode, min_clock, max_clock,
249 					    &clock);
250 	if (out_clock)
251 		*out_clock = clock;
252 	return ret;
253 }
254