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/display/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, hpd;
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 	/* Check status of HPD pin before attempting an AUX transaction that
137 	 * would result in a number of (futile) retries on a connector which
138 	 * has no display plugged.
139 	 *
140 	 * TODO: look into checking this before probing I2C to detect DVI/HDMI
141 	 */
142 	hpd = nvif_conn_hpd_status(&nv_connector->conn);
143 	if (hpd == NVIF_CONN_HPD_STATUS_NOT_PRESENT)
144 		goto out;
145 
146 	status = nouveau_dp_probe_dpcd(nv_connector, nv_encoder);
147 	if (status == connector_status_disconnected)
148 		goto out;
149 
150 	/* If we're in MST mode, we're done here */
151 	if (mstm && mstm->can_mst && mstm->is_mst) {
152 		ret = NOUVEAU_DP_MST;
153 		goto out;
154 	}
155 
156 	nv_encoder->dp.link_bw = 27000 * dpcd[DP_MAX_LINK_RATE];
157 	nv_encoder->dp.link_nr =
158 		dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
159 
160 	if (connector->connector_type == DRM_MODE_CONNECTOR_eDP && dpcd[DP_DPCD_REV] >= 0x13) {
161 		struct drm_dp_aux *aux = &nv_connector->aux;
162 		int ret, i;
163 		u8 sink_rates[16];
164 
165 		ret = drm_dp_dpcd_read(aux, DP_SUPPORTED_LINK_RATES, sink_rates, sizeof(sink_rates));
166 		if (ret == sizeof(sink_rates)) {
167 			for (i = 0; i < ARRAY_SIZE(sink_rates); i += 2) {
168 				int val = ((sink_rates[i + 1] << 8) | sink_rates[i]) * 200 / 10;
169 				if (val && (i == 0 || val > nv_encoder->dp.link_bw))
170 					nv_encoder->dp.link_bw = val;
171 			}
172 		}
173 	}
174 
175 	NV_DEBUG(drm, "display: %dx%d dpcd 0x%02x\n",
176 		 nv_encoder->dp.link_nr, nv_encoder->dp.link_bw,
177 		 dpcd[DP_DPCD_REV]);
178 	NV_DEBUG(drm, "encoder: %dx%d\n",
179 		 nv_encoder->dcb->dpconf.link_nr,
180 		 nv_encoder->dcb->dpconf.link_bw);
181 
182 	if (nv_encoder->dcb->dpconf.link_nr < nv_encoder->dp.link_nr)
183 		nv_encoder->dp.link_nr = nv_encoder->dcb->dpconf.link_nr;
184 	if (nv_encoder->dcb->dpconf.link_bw < nv_encoder->dp.link_bw)
185 		nv_encoder->dp.link_bw = nv_encoder->dcb->dpconf.link_bw;
186 
187 	NV_DEBUG(drm, "maximum: %dx%d\n",
188 		 nv_encoder->dp.link_nr, nv_encoder->dp.link_bw);
189 
190 	if (mstm && mstm->can_mst) {
191 		ret = nv50_mstm_detect(nv_encoder);
192 		if (ret == 1) {
193 			ret = NOUVEAU_DP_MST;
194 			goto out;
195 		} else if (ret != 0) {
196 			goto out;
197 		}
198 	}
199 	ret = NOUVEAU_DP_SST;
200 
201 out:
202 	if (mstm && !mstm->suspended && ret != NOUVEAU_DP_MST)
203 		nv50_mstm_remove(mstm);
204 
205 	mutex_unlock(&nv_encoder->dp.hpd_irq_lock);
206 	return ret;
207 }
208 
209 void nouveau_dp_irq(struct nouveau_drm *drm,
210 		    struct nouveau_connector *nv_connector)
211 {
212 	struct drm_connector *connector = &nv_connector->base;
213 	struct nouveau_encoder *outp = find_encoder(connector, DCB_OUTPUT_DP);
214 	struct nv50_mstm *mstm;
215 	int ret;
216 	bool send_hpd = false;
217 
218 	if (!outp)
219 		return;
220 
221 	mstm = outp->dp.mstm;
222 	NV_DEBUG(drm, "service %s\n", connector->name);
223 
224 	mutex_lock(&outp->dp.hpd_irq_lock);
225 
226 	if (mstm && mstm->is_mst) {
227 		if (!nv50_mstm_service(drm, nv_connector, mstm))
228 			send_hpd = true;
229 	} else {
230 		drm_dp_cec_irq(&nv_connector->aux);
231 
232 		if (nouveau_dp_has_sink_count(connector, outp)) {
233 			ret = drm_dp_read_sink_count(&nv_connector->aux);
234 			if (ret != outp->dp.sink_count)
235 				send_hpd = true;
236 			if (ret >= 0)
237 				outp->dp.sink_count = ret;
238 		}
239 	}
240 
241 	mutex_unlock(&outp->dp.hpd_irq_lock);
242 
243 	if (send_hpd)
244 		nouveau_connector_hpd(connector);
245 }
246 
247 /* TODO:
248  * - Use the minimum possible BPC here, once we add support for the max bpc
249  *   property.
250  * - Validate against the DP caps advertised by the GPU (we don't check these
251  *   yet)
252  */
253 enum drm_mode_status
254 nv50_dp_mode_valid(struct drm_connector *connector,
255 		   struct nouveau_encoder *outp,
256 		   const struct drm_display_mode *mode,
257 		   unsigned *out_clock)
258 {
259 	const unsigned int min_clock = 25000;
260 	unsigned int max_rate, mode_rate, ds_max_dotclock, clock = mode->clock;
261 	const u8 bpp = connector->display_info.bpc * 3;
262 
263 	if (mode->flags & DRM_MODE_FLAG_INTERLACE && !outp->caps.dp_interlace)
264 		return MODE_NO_INTERLACE;
265 
266 	if ((mode->flags & DRM_MODE_FLAG_3D_MASK) == DRM_MODE_FLAG_3D_FRAME_PACKING)
267 		clock *= 2;
268 
269 	max_rate = outp->dp.link_nr * outp->dp.link_bw;
270 	mode_rate = DIV_ROUND_UP(clock * bpp, 8);
271 	if (mode_rate > max_rate)
272 		return MODE_CLOCK_HIGH;
273 
274 	ds_max_dotclock = drm_dp_downstream_max_dotclock(outp->dp.dpcd, outp->dp.downstream_ports);
275 	if (ds_max_dotclock && clock > ds_max_dotclock)
276 		return MODE_CLOCK_HIGH;
277 
278 	if (clock < min_clock)
279 		return MODE_CLOCK_LOW;
280 
281 	if (out_clock)
282 		*out_clock = clock;
283 
284 	return MODE_OK;
285 }
286